mirror of
https://github.com/koreader/koreader
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55c0fc6190
It is used by CoverBrowser, in a subprocess, when extracting metadata from PicDocuments, and crash on Android as calling android methods is only allowed from the main thread.
94 lines
2.6 KiB
Lua
94 lines
2.6 KiB
Lua
--[[
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CanvasContext is introduced to abstract out screen hardware code from document
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render module. This abstraction makes it possible to use core document module
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in headless mode.
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You can think of canvas as a virtual screen. It provides render related
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settings like canvas dimension and DPI. User of document module need to
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initialize CanvasContext with settings from the actual hardware screen before
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calling renderPage/drawPage.
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Note: CanvasContext is a singleton and it is not thread safe.
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]]--
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local Mupdf = require("ffi/mupdf")
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local CanvasContext = {
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should_restrict_JIT = false,
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is_color_rendering_enabled = false,
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is_bgr = false,
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}
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--[[
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Initialize CanvasContext with settings from device.
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The following key is required for a device object:
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* should_restrict_JIT: bool
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* hasBGRFrameBuffer: function() -> boolean
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* screen: object with following methods:
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* getWidth() -> int
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* getHeight() -> int
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* getDPI() -> int
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* getSize() -> Rect
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* scaleBySize(int) -> int
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* isColorEnabled() -> boolean
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]]--
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function CanvasContext:init(device)
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self.device = device
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self.screen = device.screen
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self.isAndroid = device.isAndroid
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self.isDesktop = device.isDesktop
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self.isEmulator = device.isEmulator
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self.isKindle = device.isKindle
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self.isPocketBook = device.isPocketBook
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self.should_restrict_JIT = device.should_restrict_JIT
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self.hasSystemFonts = device.hasSystemFonts
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self:setColorRenderingEnabled(device.screen.isColorEnabled())
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-- NOTE: At 32bpp, Kobo's fb is BGR, not RGB. Handle the conversion in MuPDF if needed.
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if device:hasBGRFrameBuffer() then
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self.is_bgr = true
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Mupdf.bgr = true
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end
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-- This one may be called by a subprocess, and would crash on Android when
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-- calling android.isEink() which is only allowed from the main thread.
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local hasEinkScreen = device.hasEinkScreen()
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self.hasEinkScreen = function() return hasEinkScreen end
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self.canHWDither = device.canHWDither
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self.fb_bpp = device.screen.fb_bpp
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end
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function CanvasContext:setColorRenderingEnabled(val)
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self.is_color_rendering_enabled = val
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end
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function CanvasContext:getWidth()
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return self.screen:getWidth()
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end
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function CanvasContext:getHeight()
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return self.screen:getHeight()
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end
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function CanvasContext:getDPI()
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return self.screen:getDPI()
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end
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function CanvasContext:getSize()
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return self.screen:getSize()
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end
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function CanvasContext:scaleBySize(px)
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return self.screen:scaleBySize(px)
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end
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function CanvasContext:enableCPUCores(amount)
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return self.device:enableCPUCores(amount)
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end
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return CanvasContext
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