(window.webpackJsonp=window.webpackJsonp||[]).push([[11],{196:function(t,s){t.exports="data:image/png;base64,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"},197:function(t,s,a){t.exports=a.p+"assets/img/no-clear.753f913f.png"},255:function(t,s,a){"use strict";a.r(s);var n=a(10),e=Object(n.a)({},(function(){var t=this,s=t.$createElement,n=t._self._c||s;return n("ContentSlotsDistributor",{attrs:{"slot-key":t.$parent.slotKey}},[n("h1",{attrs:{id:"the-swapchain"}},[n("a",{staticClass:"header-anchor",attrs:{href:"#the-swapchain"}},[t._v("#")]),t._v(" The Swapchain")]),t._v(" "),n("h2",{attrs:{id:"first-some-house-keeping-state"}},[n("a",{staticClass:"header-anchor",attrs:{href:"#first-some-house-keeping-state"}},[t._v("#")]),t._v(" First, some house keeping: State")]),t._v(" "),n("p",[t._v("For convenience we're going to pack all the fields into a struct, and create some methods on that.")]),t._v(" "),n("div",{staticClass:"language-rust extra-class"},[n("pre",{pre:!0,attrs:{class:"language-rust"}},[n("code",[n("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// main.rs")]),t._v("\n"),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("struct")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token type-definition class-name"}},[t._v("State")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n    surface"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("wgpu"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Surface")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n    device"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("wgpu"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Device")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n    queue"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("wgpu"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Queue")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n    sc_desc"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("wgpu"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("SwapChainDescriptor")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n    swap_chain"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("wgpu"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("SwapChain")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n    size"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("winit"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")]),t._v("dpi"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("PhysicalSize")]),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("<")]),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("u32")]),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v(">")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n\n"),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("impl")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("State")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n    "),n("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// Creating some of the wgpu types requires async code")]),t._v("\n    "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("async")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("fn")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token function-definition function"}},[t._v("new")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),t._v("window"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("&")]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Window")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("->")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("Self")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n        "),n("span",{pre:!0,attrs:{class:"token macro property"}},[t._v("todo!")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),t._v("\n    "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n\n    "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("fn")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token function-definition function"}},[t._v("resize")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("&")]),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("mut")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("self")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v(" new_size"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("winit"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")]),t._v("dpi"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("PhysicalSize")]),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("<")]),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("u32")]),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v(">")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n        "),n("span",{pre:!0,attrs:{class:"token macro property"}},[t._v("todo!")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),t._v("\n    "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n\n    "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("fn")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token function-definition function"}},[t._v("input")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("&")]),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("mut")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("self")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v(" event"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("&")]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("WindowEvent")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("->")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("bool")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n        "),n("span",{pre:!0,attrs:{class:"token macro property"}},[t._v("todo!")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),t._v("\n    "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n\n    "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("fn")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token function-definition function"}},[t._v("update")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("&")]),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("mut")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("self")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n        "),n("span",{pre:!0,attrs:{class:"token macro property"}},[t._v("todo!")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),t._v("\n    "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n\n    "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("fn")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token function-definition function"}},[t._v("render")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("&")]),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("mut")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("self")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("->")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Result")]),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("<")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("wgpu"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("SwapChainError")]),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v(">")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n        "),n("span",{pre:!0,attrs:{class:"token macro property"}},[t._v("todo!")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),t._v("\n    "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n")])])]),n("p",[t._v("I'm glossing over "),n("code",[t._v("State")]),t._v("s fields, but they'll make more sense as I explain the code behind the methods.")]),t._v(" "),n("h2",{attrs:{id:"state-new"}},[n("a",{staticClass:"header-anchor",attrs:{href:"#state-new"}},[t._v("#")]),t._v(" State::new()")]),t._v(" "),n("p",[t._v("The code for this is pretty straight forward, but let's break this down a bit.")]),t._v(" "),n("div",{staticClass:"language-rust extra-class"},[n("pre",{pre:!0,attrs:{class:"language-rust"}},[n("code",[n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("impl")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("State")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n    "),n("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// ...")]),t._v("\n    "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("async")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("fn")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token function-definition function"}},[t._v("new")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),t._v("window"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("&")]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Window")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("->")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("Self")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n        "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("let")]),t._v(" size "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" window"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("inner_size")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\n\n        "),n("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// The instance is a handle to our GPU")]),t._v("\n        "),n("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// BackendBit::PRIMARY => Vulkan + Metal + DX12 + Browser WebGPU")]),t._v("\n        "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("let")]),t._v(" instance "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("wgpu"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Instance")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("new")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("wgpu"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("BackendBit")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")]),n("span",{pre:!0,attrs:{class:"token constant"}},[t._v("PRIMARY")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\n        "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("let")]),t._v(" surface "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("unsafe")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v(" instance"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("create_surface")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),t._v("window"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\n        "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("let")]),t._v(" adapter "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" instance"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("request_adapter")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),t._v("\n            "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("&")]),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("wgpu"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("RequestAdapterOptions")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n                power_preference"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("wgpu"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("PowerPreference")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("default")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n                compatible_surface"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Some")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("&")]),t._v("surface"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n            "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n        "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("await")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("unwrap")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\n")])])]),n("p",[t._v("The "),n("code",[t._v("surface")]),t._v(" is used to create the "),n("code",[t._v("swap_chain")]),t._v(". Our "),n("code",[t._v("window")]),t._v(" needs to implement "),n("a",{attrs:{href:"https://crates.io/crates/raw-window-handle",target:"_blank",rel:"noopener noreferrer"}},[t._v("raw-window-handle"),n("OutboundLink")],1),t._v("'s "),n("code",[t._v("HasRawWindowHandle")]),t._v(" trait to access the native window implementation for "),n("code",[t._v("wgpu")]),t._v(" to properly create the graphics backend. Fortunately, winit's "),n("code",[t._v("Window")]),t._v(" fits the bill. We also need it to request our "),n("code",[t._v("adapter")]),t._v(".")]),t._v(" "),n("p",[t._v("We need the "),n("code",[t._v("adapter")]),t._v(" to create the device and queue.")]),t._v(" "),n("div",{staticClass:"language-rust extra-class"},[n("pre",{pre:!0,attrs:{class:"language-rust"}},[n("code",[t._v("        "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("let")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),t._v("device"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v(" queue"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" adapter"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("request_device")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),t._v("\n            "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("&")]),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("wgpu"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("DeviceDescriptor")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n                features"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("wgpu"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Features")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("empty")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n                limits"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("wgpu"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Limits")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("default")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n                label"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("None")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n            "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n            "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("None")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// Trace path")]),t._v("\n        "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("await")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("unwrap")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\n")])])]),n("p",[t._v("The "),n("code",[t._v("features")]),t._v(" field on "),n("code",[t._v("DeviceDescriptor")]),t._v(", allows us to specify what extra features we want. For this simple example, I've deviced to not use any extra features.")]),t._v(" "),n("div",{staticClass:"note"},[n("p",[t._v("The device you have limits the features you can use. If you want to use certain features you may need to limit what devices you support, or provide work arounds.")]),t._v(" "),n("p",[t._v("You can get a list of features supported by your device using "),n("code",[t._v("adapter.features()")]),t._v(", or "),n("code",[t._v("device.features()")]),t._v(".")]),t._v(" "),n("p",[t._v("You can view a full list of features "),n("a",{attrs:{href:"https://docs.rs/wgpu/0.7.0/wgpu/struct.Features.html",target:"_blank",rel:"noopener noreferrer"}},[t._v("here"),n("OutboundLink")],1),t._v(".")])]),t._v(" "),n("p",[t._v("The "),n("code",[t._v("limits")]),t._v(" field describes the limit of certain types of resource we can create. We'll use the defaults for this tutorial, so we can support most devices. You can view a list of limits "),n("a",{attrs:{href:"https://docs.rs/wgpu/0.7.0/wgpu/struct.Limits.html",target:"_blank",rel:"noopener noreferrer"}},[t._v("here"),n("OutboundLink")],1),t._v(".")]),t._v(" "),n("div",{staticClass:"language-rust extra-class"},[n("pre",{pre:!0,attrs:{class:"language-rust"}},[n("code",[t._v("        "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("let")]),t._v(" sc_desc "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("wgpu"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("SwapChainDescriptor")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n            usage"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("wgpu"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("TextureUsage")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")]),n("span",{pre:!0,attrs:{class:"token constant"}},[t._v("RENDER_ATTACHMENT")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n            format"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" adapter"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("get_swap_chain_preferred_format")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("&")]),t._v("surface"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n            width"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" size"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),t._v("width"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n            height"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" size"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),t._v("height"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n            present_mode"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("wgpu"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("PresentMode")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Fifo")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n        "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\n        "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("let")]),t._v(" swap_chain "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" device"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("create_swap_chain")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("&")]),t._v("surface"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("&")]),t._v("sc_desc"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\n")])])]),n("p",[t._v("Here we are defining and creating the "),n("code",[t._v("swap_chain")]),t._v(". The "),n("code",[t._v("usage")]),t._v(" field describes how the "),n("code",[t._v("swap_chain")]),t._v("'s underlying textures will be used. "),n("code",[t._v("RENDER_ATTACHMENT")]),t._v(" specifies that the textures will be used to write to the screen (we'll talk about more "),n("code",[t._v("TextureUsage")]),t._v("s later).")]),t._v(" "),n("p",[t._v("The "),n("code",[t._v("format")]),t._v(" defines how the "),n("code",[t._v("swap_chain")]),t._v("s textures will be stored on the gpu. Different displays prefer different formats. We use "),n("code",[t._v("adapter.get_swap_chain_preferred_format()")]),t._v(" to figure out the best format to use.")]),t._v(" "),n("p",[n("code",[t._v("width")]),t._v(" and "),n("code",[t._v("height")]),t._v(", are the width and height in pixels of the swap chain. This should usually be the width and height of the window.")]),t._v(" "),n("p",[t._v("The "),n("code",[t._v("present_mode")]),t._v(" uses the "),n("code",[t._v("wgpu::PresentMode")]),t._v(" enum which determines how to sync the swap chain with the display. You can see all the options "),n("a",{attrs:{href:"https://docs.rs/wgpu/0.7.0/wgpu/enum.PresentMode.html",target:"_blank",rel:"noopener noreferrer"}},[t._v("in the docs"),n("OutboundLink")],1)]),t._v(" "),n("p",[t._v("At the end of the method, we simply return the resulting struct.")]),t._v(" "),n("div",{staticClass:"language-rust extra-class"},[n("pre",{pre:!0,attrs:{class:"language-rust"}},[n("code",[t._v("        "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("Self")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n            surface"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n            device"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n            queue"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n            sc_desc"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n            swap_chain"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n            size"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n        "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n    "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n    "),n("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// ...")]),t._v("\n"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n")])])]),n("p",[t._v("We'll want to call this in our main method before we enter the event loop.")]),t._v(" "),n("div",{staticClass:"language-rust extra-class"},[n("pre",{pre:!0,attrs:{class:"language-rust"}},[n("code",[n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("use")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("futures"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")]),t._v("executor"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),t._v("block_on"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\n\n"),n("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// Since main can't be async, we're going to need to block")]),t._v("\n"),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("let")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("mut")]),t._v(" state "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("block_on")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("State")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("new")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("&")]),t._v("window"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\n")])])]),n("h2",{attrs:{id:"resize"}},[n("a",{staticClass:"header-anchor",attrs:{href:"#resize"}},[t._v("#")]),t._v(" resize()")]),t._v(" "),n("p",[t._v("If we want to support resizing in our application, we're going to need to recreate the "),n("code",[t._v("swap_chain")]),t._v(" everytime the window's size changes. That's the reason we stored the physical "),n("code",[t._v("size")]),t._v(" and the "),n("code",[t._v("sc_desc")]),t._v(" used to create the swapchain. With all of these, the resize method is very simple.")]),t._v(" "),n("div",{staticClass:"language-rust extra-class"},[n("pre",{pre:!0,attrs:{class:"language-rust"}},[n("code",[n("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// impl State")]),t._v("\n"),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("fn")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token function-definition function"}},[t._v("resize")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("&")]),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("mut")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("self")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v(" new_size"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("winit"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")]),t._v("dpi"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("PhysicalSize")]),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("<")]),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("u32")]),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v(">")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n    "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("self")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),t._v("size "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" new_size"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\n    "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("self")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),t._v("sc_desc"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),t._v("width "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" new_size"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),t._v("width"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\n    "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("self")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),t._v("sc_desc"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),t._v("height "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" new_size"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),t._v("height"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\n    "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("self")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),t._v("swap_chain "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("self")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),t._v("device"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("create_swap_chain")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("&")]),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("self")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),t._v("surface"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("&")]),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("self")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),t._v("sc_desc"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\n"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n")])])]),n("p",[t._v("There's nothing really different here from creating the "),n("code",[t._v("swap_chain")]),t._v(" initially, so I won't get into it.")]),t._v(" "),n("p",[t._v("We call this method in "),n("code",[t._v("main()")]),t._v(" in the event loop for the following events.")]),t._v(" "),n("div",{staticClass:"language-rust extra-class"},[n("pre",{pre:!0,attrs:{class:"language-rust"}},[n("code",[n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("match")]),t._v(" event "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n    "),n("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// ...")]),t._v("\n\n    "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("if")]),t._v(" window_id "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("==")]),t._v(" window"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("id")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=>")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("if")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("!")]),t._v("state"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("input")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),t._v("event"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n        "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("match")]),t._v(" event "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n            "),n("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// ...")]),t._v("\n\n            "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("WindowEvent")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Resized")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),t._v("physical_size"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=>")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n                state"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("resize")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("*")]),t._v("physical_size"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\n            "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n            "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("WindowEvent")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("ScaleFactorChanged")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v(" new_inner_size"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("..")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=>")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n                "),n("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// new_inner_size is &&mut so we have to dereference it twice")]),t._v("\n                state"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("resize")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("*")]),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("*")]),t._v("new_inner_size"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\n            "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n            "),n("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// ...")]),t._v("\n"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n")])])]),n("h2",{attrs:{id:"input"}},[n("a",{staticClass:"header-anchor",attrs:{href:"#input"}},[t._v("#")]),t._v(" input()")]),t._v(" "),n("p",[n("code",[t._v("input()")]),t._v(" returns a "),n("code",[t._v("bool")]),t._v(" to indicate whether an event has been fully processed. If the method returns "),n("code",[t._v("true")]),t._v(", the main loop won't process the event any further.")]),t._v(" "),n("p",[t._v("We're just going to return false for now because we don't have any events we want to capture.")]),t._v(" "),n("div",{staticClass:"language-rust extra-class"},[n("pre",{pre:!0,attrs:{class:"language-rust"}},[n("code",[n("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// impl State")]),t._v("\n"),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("fn")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token function-definition function"}},[t._v("input")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("&")]),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("mut")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("self")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v(" event"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("&")]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("WindowEvent")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("->")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("bool")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n    "),n("span",{pre:!0,attrs:{class:"token boolean"}},[t._v("false")]),t._v("\n"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n")])])]),n("p",[t._v("We need to do a little more work in the event loop. We want "),n("code",[t._v("State")]),t._v(" to have priority over "),n("code",[t._v("main()")]),t._v(". Doing that (and previous changes) should have your loop looking like this.")]),t._v(" "),n("div",{staticClass:"language-rust extra-class"},[n("pre",{pre:!0,attrs:{class:"language-rust"}},[n("code",[n("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// main()")]),t._v("\nevent_loop"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("run")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("move")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token closure-params"}},[n("span",{pre:!0,attrs:{class:"token closure-punctuation punctuation"}},[t._v("|")]),t._v("event"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v(" _"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v(" control_flow"),n("span",{pre:!0,attrs:{class:"token closure-punctuation punctuation"}},[t._v("|")])]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n    "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("match")]),t._v(" event "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n        "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Event")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("WindowEvent")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n            "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("ref")]),t._v(" event"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n            window_id"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n        "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("if")]),t._v(" window_id "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("==")]),t._v(" window"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("id")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=>")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("if")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("!")]),t._v("state"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("input")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),t._v("event"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// UPDATED!")]),t._v("\n            "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("match")]),t._v(" event "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n                "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("WindowEvent")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("CloseRequested")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=>")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("*")]),t._v("control_flow "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("ControlFlow")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Exit")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n                "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("WindowEvent")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("KeyboardInput")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n                    input"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n                    "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("..")]),t._v("\n                "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=>")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n                    "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("match")]),t._v(" input "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n                        "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("KeyboardInput")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n                            state"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("ElementState")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Pressed")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n                            virtual_keycode"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Some")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("VirtualKeyCode")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Escape")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n                            "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("..")]),t._v("\n                        "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=>")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("*")]),t._v("control_flow "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("ControlFlow")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Exit")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n                        _ "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=>")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n                    "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n                "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n                "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("WindowEvent")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Resized")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),t._v("physical_size"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=>")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n                    state"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("resize")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("*")]),t._v("physical_size"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\n                "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n                "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("WindowEvent")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("ScaleFactorChanged")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v(" new_inner_size"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("..")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=>")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n                    state"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("resize")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("*")]),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("*")]),t._v("new_inner_size"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\n                "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n                _ "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=>")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n            "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n        "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n        _ "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=>")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n    "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\n")])])]),n("h2",{attrs:{id:"update"}},[n("a",{staticClass:"header-anchor",attrs:{href:"#update"}},[t._v("#")]),t._v(" update()")]),t._v(" "),n("p",[t._v("We don't have anything to update yet, so leave the method empty.")]),t._v(" "),n("div",{staticClass:"language-rust extra-class"},[n("pre",{pre:!0,attrs:{class:"language-rust"}},[n("code",[n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("fn")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token function-definition function"}},[t._v("update")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("&")]),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("mut")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("self")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n    "),n("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// remove `todo!()`")]),t._v("\n"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n")])])]),n("h2",{attrs:{id:"render"}},[n("a",{staticClass:"header-anchor",attrs:{href:"#render"}},[t._v("#")]),t._v(" render()")]),t._v(" "),n("p",[t._v("Here's where the magic happens. First we need to get a frame to render to. This will include a "),n("code",[t._v("wgpu::Texture")]),t._v(" and "),n("code",[t._v("wgpu::TextureView")]),t._v(" that will hold the actual image we're drawing to (we'll cover this more when we talk about textures).")]),t._v(" "),n("div",{staticClass:"language-rust extra-class"},[n("pre",{pre:!0,attrs:{class:"language-rust"}},[n("code",[n("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// impl State")]),t._v("\n\n"),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("fn")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token function-definition function"}},[t._v("render")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("&")]),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("mut")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("self")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("->")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Result")]),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("<")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("wgpu"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("SwapChainError")]),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v(">")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n    "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("let")]),t._v(" frame "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("self")]),t._v("\n        "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),t._v("swap_chain\n        "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("get_current_frame")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("?")]),t._v("\n        "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),t._v("output"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\n")])])]),n("p",[t._v("We also need to create a "),n("code",[t._v("CommandEncoder")]),t._v(" to create the actual commands to send to the gpu. Most modern graphics frameworks expect commands to be stored in a command buffer before being sent to the gpu. The "),n("code",[t._v("encoder")]),t._v(" builds a command buffer that we can then send to the gpu.")]),t._v(" "),n("div",{staticClass:"language-rust extra-class"},[n("pre",{pre:!0,attrs:{class:"language-rust"}},[n("code",[t._v("    "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("let")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("mut")]),t._v(" encoder "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("self")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),t._v("device"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("create_command_encoder")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("&")]),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("wgpu"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("CommandEncoderDescriptor")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n        label"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Some")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token string"}},[t._v('"Render Encoder"')]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n    "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\n")])])]),n("p",[t._v("Now we can actually get to clearing the screen (long time coming). We need to use the "),n("code",[t._v("encoder")]),t._v(" to create a "),n("code",[t._v("RenderPass")]),t._v(". The "),n("code",[t._v("RenderPass")]),t._v(" has all the methods to do the actual drawing. The code for creating a "),n("code",[t._v("RenderPass")]),t._v(" is a bit nested, so I'll copy it all here, and talk about the pieces.")]),t._v(" "),n("div",{staticClass:"language-rust extra-class"},[n("pre",{pre:!0,attrs:{class:"language-rust"}},[n("code",[t._v("    "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n        "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("let")]),t._v(" _render_pass "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" encoder"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("begin_render_pass")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("&")]),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("wgpu"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("RenderPassDescriptor")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n            label"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Some")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token string"}},[t._v('"Render Pass"')]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n            color_attachments"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("&")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("[")]),t._v("\n                "),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("wgpu"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("RenderPassColorAttachmentDescriptor")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n                    attachment"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("&")]),t._v("frame"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),t._v("view"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n                    resolve_target"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("None")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n                    ops"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("wgpu"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Operations")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n                        load"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("wgpu"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("LoadOp")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Clear")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("wgpu"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Color")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n                            r"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token number"}},[t._v("0.1")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n                            g"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token number"}},[t._v("0.2")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n                            b"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token number"}},[t._v("0.3")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n                            a"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token number"}},[t._v("1.0")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n                        "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n                        store"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token boolean"}},[t._v("true")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n                    "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n                "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n            "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("]")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n            depth_stencil_attachment"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("None")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n        "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\n    "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n\n    "),n("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// submit will accept anything that implements IntoIter")]),t._v("\n    "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("self")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),t._v("queue"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("submit")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("std"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")]),t._v("iter"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("once")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),t._v("encoder"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("finish")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\n\n    "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Ok")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),t._v("\n"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n")])])]),n("p",[t._v("First things first, let's talk about the "),n("code",[t._v("{}")]),t._v(". "),n("code",[t._v("encoder.begin_render_pass(...)")]),t._v(" borrows "),n("code",[t._v("encoder")]),t._v(" mutably (aka "),n("code",[t._v("&mut self")]),t._v("). We can't call "),n("code",[t._v("encoder.finish()")]),t._v(" until we release that mutable borrow. The "),n("code",[t._v("{}")]),t._v(" around "),n("code",[t._v("encoder.begin_render_pass(...)")]),t._v(" tells rust to drop any variables within them when the code leaves that scope thus releasing the mutable borrow on "),n("code",[t._v("encoder")]),t._v(" and allowing us to "),n("code",[t._v("finish()")]),t._v(" it. If you don't like the "),n("code",[t._v("{}")]),t._v(", you can also use "),n("code",[t._v("drop(render_pass)")]),t._v(" to achieve the same effect.")]),t._v(" "),n("p",[t._v("We can get the same results by removing the "),n("code",[t._v("{}")]),t._v(", and the "),n("code",[t._v("let _render_pass =")]),t._v(" line, but we need access to the "),n("code",[t._v("_render_pass")]),t._v(" in the next tutorial, so we'll leave it as is.")]),t._v(" "),n("p",[t._v("The last lines of the code tell "),n("code",[t._v("wgpu")]),t._v(" to finish the command buffer, and to submit it to the gpu's render queue.")]),t._v(" "),n("p",[t._v("We need to update the event loop again to call this method. We'll also call update before it too.")]),t._v(" "),n("div",{staticClass:"language-rust extra-class"},[n("pre",{pre:!0,attrs:{class:"language-rust"}},[n("code",[n("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// main()")]),t._v("\nevent_loop"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("run")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("move")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token closure-params"}},[n("span",{pre:!0,attrs:{class:"token closure-punctuation punctuation"}},[t._v("|")]),t._v("event"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v(" _"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v(" control_flow"),n("span",{pre:!0,attrs:{class:"token closure-punctuation punctuation"}},[t._v("|")])]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n    "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("match")]),t._v(" event "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n        "),n("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// ...")]),t._v("\n        "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Event")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("RedrawRequested")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),t._v("_"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=>")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n            state"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("update")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\n            "),n("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("match")]),t._v(" state"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("render")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n                "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Ok")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),t._v("_"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=>")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n                "),n("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// Recreate the swap_chain if lost")]),t._v("\n                "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Err")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("wgpu"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("SwapChainError")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Lost")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=>")]),t._v(" state"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("resize")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),t._v("state"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),t._v("size"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n                "),n("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// The system is out of memory, we should probably quit")]),t._v("\n                "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Err")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("wgpu"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("SwapChainError")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("OutOfMemory")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=>")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("*")]),t._v("control_flow "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("ControlFlow")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Exit")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n                "),n("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// All other errors (Outdated, Timeout) should be resolved by the next frame")]),t._v("\n                "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Err")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),t._v("e"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=>")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token macro property"}},[t._v("eprintln!")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token string"}},[t._v('"{:?}"')]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v(" e"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n            "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n        "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n        "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Event")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("MainEventsCleared")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=>")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n            "),n("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// RedrawRequested will only trigger once, unless we manually")]),t._v("\n            "),n("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// request it.")]),t._v("\n            window"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),n("span",{pre:!0,attrs:{class:"token function"}},[t._v("request_redraw")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\n        "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n        "),n("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// ...")]),t._v("\n    "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\n")])])]),n("p",[t._v("With all that, you should be getting something that looks like this.")]),t._v(" "),n("p",[n("img",{attrs:{src:a(196),alt:"Window with a blue background"}})]),t._v(" "),n("h2",{attrs:{id:"wait-what-s-going-on-with-renderpassdescriptor"}},[n("a",{staticClass:"header-anchor",attrs:{href:"#wait-what-s-going-on-with-renderpassdescriptor"}},[t._v("#")]),t._v(" Wait, what's going on with RenderPassDescriptor?")]),t._v(" "),n("p",[t._v("Some of you may be able to tell what's going on just by looking at it, but I'd be remiss if I didn't go over it. Let's take a look at the code again.")]),t._v(" "),n("div",{staticClass:"language-rust extra-class"},[n("pre",{pre:!0,attrs:{class:"language-rust"}},[n("code",[n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("&")]),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("wgpu"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("RenderPassDescriptor")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n    label"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Some")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token string"}},[t._v('"Render Pass"')]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n    color_attachments"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("&")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("[")]),t._v("\n        "),n("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// ...")]),t._v("\n    "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("]")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n    depth_stencil_attachment"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("None")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n")])])]),n("p",[t._v("A "),n("code",[t._v("RenderPassDescriptor")]),t._v(" only has three fields: "),n("code",[t._v("label")]),t._v(", "),n("code",[t._v("color_attachments")]),t._v(" and "),n("code",[t._v("depth_stencil_attachment")]),t._v(". The "),n("code",[t._v("color_attachements")]),t._v(" describe where we are going to draw our color to. We'll use "),n("code",[t._v("depth_stencil_attachment")]),t._v(" later, but we'll set it to "),n("code",[t._v("None")]),t._v(" for now.")]),t._v(" "),n("div",{staticClass:"language-rust extra-class"},[n("pre",{pre:!0,attrs:{class:"language-rust"}},[n("code",[n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("wgpu"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("RenderPassColorAttachmentDescriptor")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n    attachment"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token operator"}},[t._v("&")]),t._v("frame"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),t._v("view"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n    resolve_target"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("None")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n    ops"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("wgpu"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Operations")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n        load"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("wgpu"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("LoadOp")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Clear")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),n("span",{pre:!0,attrs:{class:"token namespace"}},[t._v("wgpu"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("::")])]),n("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Color")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n            r"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token number"}},[t._v("0.1")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n            g"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token number"}},[t._v("0.2")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n            b"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token number"}},[t._v("0.3")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n            a"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token number"}},[t._v("1.0")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n        "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n        store"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(":")]),t._v(" "),n("span",{pre:!0,attrs:{class:"token boolean"}},[t._v("true")]),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v("\n    "),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n"),n("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n")])])]),n("p",[t._v("The "),n("code",[t._v("RenderPassColorAttachmentDescriptor")]),t._v(" has the "),n("code",[t._v("attachment")]),t._v(" field which informs "),n("code",[t._v("wgpu")]),t._v(" what texture to save the colors to. In this case we specify "),n("code",[t._v("frame.view")]),t._v(" that we created using "),n("code",[t._v("swap_chain.get_current_frame()")]),t._v(". This means that any colors we draw to this attachment will get drawn to the screen.")]),t._v(" "),n("p",[t._v("The "),n("code",[t._v("resolve_target")]),t._v(" is the texture that will receive the resolved output. This will be the same as "),n("code",[t._v("attachment")]),t._v(" unless multisampling is enabled. We don't need to specify this, so we leave it as "),n("code",[t._v("None")]),t._v(".")]),t._v(" "),n("p",[t._v("The "),n("code",[t._v("ops")]),t._v(" field takes a "),n("code",[t._v("wpgu::Operations")]),t._v(" object. This tells wgpu what to do with the colors on the screen (specified by "),n("code",[t._v("frame.view")]),t._v("). The "),n("code",[t._v("load")]),t._v(" field tells wgpu how to handle colors stored from the previous frame. Currently we are clearing the screen with a bluish color.")]),t._v(" "),n("div",{staticClass:"note"},[n("p",[t._v("It's not uncommon to not clear the screen if the screen is going to be completely covered up with objects. If your scene doesn't cover the entire screen however you can end up with something like this.")]),t._v(" "),n("p",[n("img",{attrs:{src:a(197),alt:"./no-clear.png"}})])]),t._v(" "),n("h2",{attrs:{id:"challenge"}},[n("a",{staticClass:"header-anchor",attrs:{href:"#challenge"}},[t._v("#")]),t._v(" Challenge")]),t._v(" "),n("p",[t._v("Modify the "),n("code",[t._v("input()")]),t._v(" method to capture mouse events, and update the clear color using that. "),n("em",[t._v("Hint: you'll probably need to use "),n("code",[t._v("WindowEvent::CursorMoved")])]),t._v(".")]),t._v(" "),n("AutoGithubLink")],1)}),[],!1,null,null,null);s.default=e.exports}}]);