Rewrite shaders in WGSL (#172)

- Fixes #141

examples/custom-shader/shaders/README.md

@@ -1,13 +0,0 @@
-# Shaders
-
-The GLSL shader source is not compiled as part of the normal cargo build process. This was a conscious decision sparked by the current state of the ecosystem; compiling GLSL-to-SPIR-V requires a C++ toolchain including CMake, which is an unacceptable constraint for a simple crate providing a pixel buffer.
-
-If you need to modify the GLSL sources, you must also recompile the SPIR-V as well. This can be done with `glslang`, `glslc`, etc.
-
-Compile shaders with `glslangValidator`:
-
-```bash
-glslangValidator -V shader.frag && glslangValidator -V shader.vert
-```
-
-For more information, see https://github.com/parasyte/pixels/issues/9

examples/custom-shader/shaders/noise.wgsl

@@ -0,0 +1,73 @@
+// Vertex shader bindings
+
+struct VertexOutput {
+    [[location(0)]] tex_coord: vec2<f32>;
+    [[builtin(position)]] position: vec4<f32>;
+};
+
+let positions: array<vec2<f32>, 6> = array<vec2<f32>, 6>(
+    // Upper left triangle
+    vec2<f32>(-1.0, -1.0),
+    vec2<f32>(1.0, -1.0),
+    vec2<f32>(-1.0, 1.0),
+
+    // Lower right triangle
+    vec2<f32>(-1.0, 1.0),
+    vec2<f32>(1.0, -1.0),
+    vec2<f32>(1.0, 1.0),
+);
+
+let uv: array<vec2<f32>, 6> = array<vec2<f32>, 6>(
+    // Upper left triangle
+    vec2<f32>(0.0, 0.0),
+    vec2<f32>(1.0, 0.0),
+    vec2<f32>(0.0, 1.0),
+
+    // Lower right triangle
+    vec2<f32>(0.0, 1.0),
+    vec2<f32>(1.0, 0.0),
+    vec2<f32>(1.0, 1.0),
+);
+
+[[stage(vertex)]]
+fn vs_main([[builtin(vertex_index)]] vertex_index: u32) -> VertexOutput {
+    var out: VertexOutput;
+    out.tex_coord = uv[vertex_index];
+    out.position = vec4<f32>(positions[vertex_index], 0.0, 1.0);
+    return out;
+}
+
+// Fragment shader bindings
+
+[[group(0), binding(0)]] var r_tex_color: texture_2d<f32>;
+[[group(0), binding(1)]] var r_tex_sampler: sampler;
+[[block]] struct Locals {
+    time: f32;
+};
+[[group(0), binding(2)]] var r_locals: Locals;
+
+let tau: f32 = 6.283185307179586476925286766559;
+let bias: f32 = 0.2376; // Offset the circular time input so it is never 0
+
+// Random functions based on https://thebookofshaders.com/10/
+let random_scale: f32 = 43758.5453123;
+let random_x: f32 = 12.9898;
+let random_y: f32 = 78.233;
+
+fn random(x: f32) -> f32 {
+    return fract(sin(x) * random_scale);
+}
+
+fn random_vec2(st: vec2<f32>) -> f32 {
+    return random(dot(st, vec2<f32>(random_x, random_y)));
+}
+
+[[stage(fragment)]]
+fn fs_main([[location(0)]] tex_coord: vec2<f32>) -> [[location(0)]] vec4<f32> {
+    let sampled_color: vec4<f32> = textureSample(r_tex_color, r_tex_sampler, tex_coord);
+    let noise_color: vec3<f32> = vec3<f32>(random_vec2(
+        tex_coord.xy * vec2<f32>(r_locals.time % tau + bias)
+    ));
+
+    return vec4<f32>(sampled_color.rgb * noise_color, sampled_color.a);
+}

examples/custom-shader/shaders/shader.frag

@@ -1,38 +0,0 @@
-// IMPORTANT: This shader needs to be compiled out-of-band to SPIR-V
-// See: https://github.com/parasyte/pixels/issues/9
-
-#version 450
-
-layout(location = 0) in vec2 v_TexCoord;
-layout(location = 0) out vec4 outColor;
-layout(set = 0, binding = 0) uniform texture2D t_Color;
-layout(set = 0, binding = 1) uniform sampler s_Color;
-layout(set = 0, binding = 2) uniform Locals {
-    float u_Time;
-};
-
-#define PI 3.1415926535897932384626433832795
-#define TAU PI * 2.0
-
-// Offset the circular time input so it is never 0
-#define BIAS 0.2376
-
-// Random functions based on https://thebookofshaders.com/10/
-#define RANDOM_SCALE 43758.5453123
-#define RANDOM_X 12.9898
-#define RANDOM_Y 78.233
-
-float random(float x) {
-    return fract(sin(x) * RANDOM_SCALE);
-}
-
-float random_vec2(vec2 st) {
-    return random(dot(st.xy, vec2(RANDOM_X, RANDOM_Y)));
-}
-
-void main() {
-    vec4 sampledColor = texture(sampler2D(t_Color, s_Color), v_TexCoord.xy);
-    vec3 noiseColor = vec3(random_vec2(v_TexCoord.xy * vec2(mod(u_Time, TAU) + BIAS)));
-
-    outColor = vec4(sampledColor.rgb * noiseColor, sampledColor.a);
-}

examples/custom-shader/shaders/shader.vert

@@ -1,39 +0,0 @@
-// IMPORTANT: This shader needs to be compiled out-of-band to SPIR-V
-// See: https://github.com/parasyte/pixels/issues/9
-
-#version 450
-
-out gl_PerVertex {
-    vec4 gl_Position;
-};
-
-layout(location = 0) out vec2 v_TexCoord;
-
-const vec2 positions[6] = vec2[6](
-    // Upper left triangle
-    vec2(-1.0, -1.0),
-    vec2(1.0, -1.0),
-    vec2(-1.0, 1.0),
-
-    // Lower right triangle
-    vec2(-1.0, 1.0),
-    vec2(1.0, -1.0),
-    vec2(1.0, 1.0)
-);
-
-const vec2 uv[6] = vec2[6](
-    // Upper left triangle
-    vec2(0.0, 0.0),
-    vec2(1.0, 0.0),
-    vec2(0.0, 1.0),
-
-    // Lower right triangle
-    vec2(0.0, 1.0),
-    vec2(1.0, 0.0),
-    vec2(1.0, 1.0)
-);
-
-void main() {
-    v_TexCoord = uv[gl_VertexIndex];
-    gl_Position = vec4(positions[gl_VertexIndex], 0.0, 1.0);
-}

examples/custom-shader/src/renderers.rs

@@ -1,4 +1,5 @@
 use pixels::wgpu::{self, util::DeviceExt};
+use std::borrow::Cow;
 
 pub(crate) struct NoiseRenderer {
     bind_group: wgpu::BindGroup,
@@ -8,8 +9,13 @@ pub(crate) struct NoiseRenderer {
 
 impl NoiseRenderer {
     pub(crate) fn new(device: &wgpu::Device, texture_view: &wgpu::TextureView) -> Self {
-        let vs_module = device.create_shader_module(&wgpu::include_spirv!("../shaders/vert.spv"));
-        let fs_module = device.create_shader_module(&wgpu::include_spirv!("../shaders/frag.spv"));
+        let shader = wgpu::ShaderModuleDescriptor {
+            label: Some("custom_noise_shader"),
+            source: wgpu::ShaderSource::Wgsl(Cow::Borrowed(include_str!("../shaders/noise.wgsl"))),
+            flags: wgpu::ShaderFlags::VALIDATION,
+        };
+        let vs_module = device.create_shader_module(&shader);
+        let fs_module = device.create_shader_module(&shader);
 
         // Create a texture sampler with nearest neighbor
         let sampler = device.create_sampler(&wgpu::SamplerDescriptor {
@@ -103,7 +109,7 @@ impl NoiseRenderer {
             layout: Some(&pipeline_layout),
             vertex: wgpu::VertexState {
                 module: &vs_module,
-                entry_point: "main",
+                entry_point: "vs_main",
                 buffers: &[],
             },
             primitive: wgpu::PrimitiveState::default(),
@@ -111,7 +117,7 @@ impl NoiseRenderer {
             multisample: wgpu::MultisampleState::default(),
             fragment: Some(wgpu::FragmentState {
                 module: &fs_module,
-                entry_point: "main",
+                entry_point: "fs_main",
                 targets: &[wgpu::ColorTargetState {
                     format: wgpu::TextureFormat::Bgra8UnormSrgb,
                     blend: Some(wgpu::BlendState {

shaders/README.md

@@ -1,13 +0,0 @@
-# Shaders
-
-The GLSL shader source is not compiled as part of the normal cargo build process. This was a conscious decision sparked by the current state of the ecosystem; compiling GLSL-to-SPIR-V requires a C++ toolchain including CMake, which is an unacceptable constraint for a simple crate providing a pixel buffer.
-
-If you need to modify the GLSL sources, you must also recompile the SPIR-V as well. This can be done with `glslang`, `glslc`, etc.
-
-Compile shaders with `glslangValidator`:
-
-```bash
-glslangValidator -V shader.frag && glslangValidator -V shader.vert
-```
-
-For more information, see https://github.com/parasyte/pixels/issues/9

shaders/scale.wgsl

@@ -0,0 +1,53 @@
+// Vertex shader bindings
+
+struct VertexOutput {
+    [[location(0)]] tex_coord: vec2<f32>;
+    [[builtin(position)]] position: vec4<f32>;
+};
+
+[[block]] struct Locals {
+    transform: mat4x4<f32>;
+};
+[[group(0), binding(2)]] var r_locals: Locals;
+
+let positions: array<vec2<f32>, 6> = array<vec2<f32>, 6>(
+    // Upper left triangle
+    vec2<f32>(-1.0, -1.0),
+    vec2<f32>(1.0, -1.0),
+    vec2<f32>(-1.0, 1.0),
+
+    // Lower right triangle
+    vec2<f32>(-1.0, 1.0),
+    vec2<f32>(1.0, -1.0),
+    vec2<f32>(1.0, 1.0),
+);
+
+let uv: array<vec2<f32>, 6> = array<vec2<f32>, 6>(
+    // Upper left triangle
+    vec2<f32>(0.0, 0.0),
+    vec2<f32>(1.0, 0.0),
+    vec2<f32>(0.0, 1.0),
+
+    // Lower right triangle
+    vec2<f32>(0.0, 1.0),
+    vec2<f32>(1.0, 0.0),
+    vec2<f32>(1.0, 1.0),
+);
+
+[[stage(vertex)]]
+fn vs_main([[builtin(vertex_index)]] vertex_index: u32) -> VertexOutput {
+    var out: VertexOutput;
+    out.tex_coord = uv[vertex_index];
+    out.position = r_locals.transform * vec4<f32>(positions[vertex_index], 0.0, 1.0);
+    return out;
+}
+
+// Fragment shader bindings
+
+[[group(0), binding(0)]] var r_tex_color: texture_2d<f32>;
+[[group(0), binding(1)]] var r_tex_sampler: sampler;
+
+[[stage(fragment)]]
+fn fs_main([[location(0)]] tex_coord: vec2<f32>) -> [[location(0)]] vec4<f32> {
+    return textureSample(r_tex_color, r_tex_sampler, tex_coord);
+}

shaders/shader.frag

@@ -1,13 +0,0 @@
-// IMPORTANT: This shader needs to be compiled out-of-band to SPIR-V
-// See: https://github.com/parasyte/pixels/issues/9
-
-#version 450
-
-layout(location = 0) in vec2 v_TexCoord;
-layout(location = 0) out vec4 outColor;
-layout(set = 0, binding = 0) uniform texture2D t_Color;
-layout(set = 0, binding = 1) uniform sampler s_Color;
-
-void main() {
-    outColor = texture(sampler2D(t_Color, s_Color), v_TexCoord);
-}

shaders/shader.vert

@@ -1,43 +0,0 @@
-// IMPORTANT: This shader needs to be compiled out-of-band to SPIR-V
-// See: https://github.com/parasyte/pixels/issues/9
-
-#version 450
-
-out gl_PerVertex {
-    vec4 gl_Position;
-};
-
-layout(location = 0) out vec2 v_TexCoord;
-
-layout(set = 0, binding = 2) uniform Locals {
-    mat4 u_Transform;
-};
-
-const vec2 positions[6] = vec2[6](
-    // Upper left triangle
-    vec2(-1.0, -1.0),
-    vec2(1.0, -1.0),
-    vec2(-1.0, 1.0),
-
-    // Lower right triangle
-    vec2(-1.0, 1.0),
-    vec2(1.0, -1.0),
-    vec2(1.0, 1.0)
-);
-
-const vec2 uv[6] = vec2[6](
-    // Upper left triangle
-    vec2(0.0, 0.0),
-    vec2(1.0, 0.0),
-    vec2(0.0, 1.0),
-
-    // Lower right triangle
-    vec2(0.0, 1.0),
-    vec2(1.0, 0.0),
-    vec2(1.0, 1.0)
-);
-
-void main() {
-    v_TexCoord = uv[gl_VertexIndex];
-    gl_Position = u_Transform * vec4(positions[gl_VertexIndex], 0.0, 1.0);
-}

src/renderers.rs

@@ -1,4 +1,5 @@
 use crate::SurfaceSize;
+use std::borrow::Cow;
 use ultraviolet::Mat4;
 use wgpu::util::DeviceExt;
 
@@ -21,8 +22,13 @@ impl ScalingRenderer {
         surface_size: &SurfaceSize,
         render_texture_format: wgpu::TextureFormat,
     ) -> Self {
-        let vs_module = device.create_shader_module(&wgpu::include_spirv!("../shaders/vert.spv"));
-        let fs_module = device.create_shader_module(&wgpu::include_spirv!("../shaders/frag.spv"));
+        let shader = wgpu::ShaderModuleDescriptor {
+            label: Some("pixels_scaling_renderer_shader"),
+            source: wgpu::ShaderSource::Wgsl(Cow::Borrowed(include_str!("../shaders/scale.wgsl"))),
+            flags: wgpu::ShaderFlags::VALIDATION,
+        };
+        let vs_module = device.create_shader_module(&shader);
+        let fs_module = device.create_shader_module(&shader);
 
         // Create a texture sampler with nearest neighbor
         let sampler = device.create_sampler(&wgpu::SamplerDescriptor {
@@ -121,7 +127,7 @@ impl ScalingRenderer {
             layout: Some(&pipeline_layout),
             vertex: wgpu::VertexState {
                 module: &vs_module,
-                entry_point: "main",
+                entry_point: "vs_main",
                 buffers: &[],
             },
             primitive: wgpu::PrimitiveState::default(),
@@ -129,7 +135,7 @@ impl ScalingRenderer {
             multisample: wgpu::MultisampleState::default(),
             fragment: Some(wgpu::FragmentState {
                 module: &fs_module,
-                entry_point: "main",
+                entry_point: "fs_main",
                 targets: &[wgpu::ColorTargetState {
                     format: render_texture_format,
                     blend: Some(wgpu::BlendState {