From b3de9fc9d4458a15f72ffe7d9f9e1278e072bf5b Mon Sep 17 00:00:00 2001
From: matthiascy <matthiasychen@gmail.com>
Date: Thu, 26 Jan 2023 12:02:45 +0100
Subject: [PATCH] fix tutorial8 challenge depth map sampling

---
 .../beginner/tutorial8-depth/src/challenge.rs |  9 ++--
 .../tutorial8-depth/src/challenge.wgsl        |  8 ++--
 code/beginner/tutorial8-depth/src/texture.rs  | 41 +++++++++++++++++++
 3 files changed, 50 insertions(+), 8 deletions(-)

diff --git a/code/beginner/tutorial8-depth/src/challenge.rs b/code/beginner/tutorial8-depth/src/challenge.rs
index 2a61d7b9..ad21cf55 100644
--- a/code/beginner/tutorial8-depth/src/challenge.rs
+++ b/code/beginner/tutorial8-depth/src/challenge.rs
@@ -1,6 +1,7 @@
 use std::iter;
 
 use cgmath::prelude::*;
+use wgpu::{include_spirv_raw};
 use wgpu::util::DeviceExt;
 use winit::{
     event::*,
@@ -295,7 +296,7 @@ struct DepthPass {
 
 impl DepthPass {
     fn new(device: &wgpu::Device, config: &wgpu::SurfaceConfiguration) -> Self {
-        let texture = texture::Texture::create_depth_texture(device, config, "depth_texture");
+        let texture = texture::Texture::create_depth_texture_non_comparison_sampler(device, config, "depth_texture");
 
         let layout = device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
             label: Some("Depth Pass Layout"),
@@ -304,7 +305,7 @@ impl DepthPass {
                     binding: 0,
                     count: None,
                     ty: wgpu::BindingType::Texture {
-                        sample_type: wgpu::TextureSampleType::Depth,
+                        sample_type: wgpu::TextureSampleType::Float { filterable: false },
                         multisampled: false,
                         view_dimension: wgpu::TextureViewDimension::D2,
                     },
@@ -313,7 +314,7 @@ impl DepthPass {
                 wgpu::BindGroupLayoutEntry {
                     binding: 1,
                     count: None,
-                    ty: wgpu::BindingType::Sampler(wgpu::SamplerBindingType::Comparison),
+                    ty: wgpu::BindingType::Sampler(wgpu::SamplerBindingType::NonFiltering),
                     visibility: wgpu::ShaderStages::FRAGMENT,
                 },
             ],
@@ -412,7 +413,7 @@ impl DepthPass {
     }
 
     fn resize(&mut self, device: &wgpu::Device, config: &wgpu::SurfaceConfiguration) {
-        self.texture = texture::Texture::create_depth_texture(device, config, "depth_texture");
+        self.texture = texture::Texture::create_depth_texture_non_comparison_sampler(device, config, "depth_texture");
         self.bind_group = device.create_bind_group(&wgpu::BindGroupDescriptor {
             layout: &self.layout,
             entries: &[
diff --git a/code/beginner/tutorial8-depth/src/challenge.wgsl b/code/beginner/tutorial8-depth/src/challenge.wgsl
index 00860329..62d8655f 100644
--- a/code/beginner/tutorial8-depth/src/challenge.wgsl
+++ b/code/beginner/tutorial8-depth/src/challenge.wgsl
@@ -23,15 +23,15 @@ fn vs_main(
 // Fragment shader
 
 @group(0) @binding(0)
-var t_shadow: texture_depth_2d;
-@group(0)@binding(1)
-var s_shadow: sampler_comparison;
+var t_shadow: texture_2d<f32>;
+@group(0) @binding(1)
+var s_shadow: sampler;
 
 @fragment
 fn fs_main(in: VertexOutput) -> @location(0) vec4<f32> {
     let near = 0.1;
     let far = 100.0;
-    let depth = textureSampleCompare(t_shadow, s_shadow, in.tex_coords, in.clip_position.w);
+    let depth = textureSample(t_shadow, s_shadow, in.tex_coords).x;
     let r = (2.0 * near) / (far + near - depth * (far - near));
     return vec4<f32>(vec3<f32>(r), 1.0);
 }
\ No newline at end of file
diff --git a/code/beginner/tutorial8-depth/src/texture.rs b/code/beginner/tutorial8-depth/src/texture.rs
index e33b4a9a..7e681e42 100644
--- a/code/beginner/tutorial8-depth/src/texture.rs
+++ b/code/beginner/tutorial8-depth/src/texture.rs
@@ -53,6 +53,47 @@ impl Texture {
         }
     }
 
+    pub fn create_depth_texture_non_comparison_sampler(
+        device: &wgpu::Device,
+        config: &wgpu::SurfaceConfiguration,
+        label: &str,
+    ) -> Self {
+        let size = wgpu::Extent3d {
+            width: config.width,
+            height: config.height,
+            depth_or_array_layers: 1,
+        };
+        let desc = wgpu::TextureDescriptor {
+            label: Some(label),
+            size,
+            mip_level_count: 1,
+            sample_count: 1,
+            dimension: wgpu::TextureDimension::D2,
+            format: Self::DEPTH_FORMAT,
+            usage: wgpu::TextureUsages::RENDER_ATTACHMENT | wgpu::TextureUsages::TEXTURE_BINDING,
+        };
+        let texture = device.create_texture(&desc);
+        let view = texture.create_view(&wgpu::TextureViewDescriptor::default());
+        let sampler = device.create_sampler(&wgpu::SamplerDescriptor {
+            address_mode_u: wgpu::AddressMode::ClampToEdge,
+            address_mode_v: wgpu::AddressMode::ClampToEdge,
+            address_mode_w: wgpu::AddressMode::ClampToEdge,
+            mag_filter: wgpu::FilterMode::Nearest,
+            min_filter: wgpu::FilterMode::Nearest,
+            mipmap_filter: wgpu::FilterMode::Nearest,
+            compare: None,
+            lod_min_clamp: 0.0,
+            lod_max_clamp: 100.0,
+            ..Default::default()
+        });
+
+        Self {
+            texture,
+            view,
+            sampler,
+        }
+    }
+
     pub fn from_bytes(
         device: &wgpu::Device,
         queue: &wgpu::Queue,