wip

- everything is flickering wildly. lighting pass probably needs the
  jitter matrix as well. consider rolling it into the viewproj matrix
  for those two steps.

src/common/r_sequence.hpp

@@ -0,0 +1,23 @@
+#pragma once
+
+#include "math.hpp"
+
+#include <glm/glm.hpp>
+
+#include <cmath>
+
+namespace nlrs
+{
+inline glm::vec2 r2Sequence(const std::uint32_t n, const std::uint32_t sequenceLength)
+{
+    // https://extremelearning.com.au/unreasonable-effectiveness-of-quasirandom-sequences/
+    constexpr float G = 1.32471795f;
+    constexpr float A1 = 1.0f / G;
+    constexpr float A2 = 1.0f / (G * G);
+
+    const float i = static_cast<float>(n % sequenceLength);
+    const float x = fract(0.5f + A1 * i);
+    const float y = fract(0.5f + A2 * i);
+    return glm::vec2(x, y);
+}
+} // namespace nlrs

src/pt/deferred_renderer.cpp

@@ -8,6 +8,7 @@
 #include "window.hpp"
 
 #include <common/assert.hpp>
+#include <common/r_sequence.hpp>
 
 #include <algorithm>
 #include <array>
@@ -296,6 +297,7 @@ void DeferredRenderer::render(
         return wgpuDeviceCreateCommandEncoder(gpuContext.device, &cmdEncoderDesc);
     }();
 
+    const Extent2f      framebufferSize = Extent2f(renderDesc.framebufferSize);
     const std::uint32_t frameCount = mFrameCount++;
 
     // GBuffer pass
@@ -311,6 +313,7 @@ void DeferredRenderer::render(
         mDepthTextureView,
         mAlbedoTextureView,
         mNormalTextureView,
+        framebufferSize,
         frameCount);
     wgpuCommandEncoderWriteTimestamp(
         encoder,
@@ -323,7 +326,6 @@ void DeferredRenderer::render(
         encoder,
         mQuerySet,
         offsetof(TimestampsLayout, lightingPassStart) / TimestampsLayout::MEMBER_SIZE);
-    const Extent2f framebufferSize = Extent2f(renderDesc.framebufferSize);
     {
         const glm::mat4 inverseViewProjectionMat =
             glm::inverse(renderDesc.viewReverseZProjectionMatrix);
@@ -456,6 +458,7 @@ void DeferredRenderer::renderDebug(
         mDepthTextureView,
         mAlbedoTextureView,
         mNormalTextureView,
+        framebufferSize,
         mFrameCount++);
 
     mDebugPass.render(gpuContext, encoder, textureView, framebufferSize, gui);
@@ -1005,9 +1008,15 @@ void DeferredRenderer::GbufferPass::render(
     const WGPUTextureView    depthTextureView,
     const WGPUTextureView    albedoTextureView,
     const WGPUTextureView    normalTextureView,
-    const std::uint32_t /*frameCount*/)
+    const Extent2f&          framebufferSize,
+    const std::uint32_t      frameCount)
 {
-    const Uniforms uniforms{viewReverseZProjectionMatrix};
+    Uniforms uniforms{viewReverseZProjectionMatrix, glm::mat4(1.0f)};
+    {
+        const glm::vec2 j = r2Sequence(frameCount, 1 << 20);
+        uniforms.jitterMat[3][0] = (j.x - 0.5f) / framebufferSize.x;
+        uniforms.jitterMat[3][1] = (j.y - 0.5f) / framebufferSize.y;
+    }
     wgpuQueueWriteBuffer(gpuContext.queue, mUniformBuffer.ptr(), 0, &uniforms, sizeof(Uniforms));
 
     const WGPURenderPassEncoder renderPassEncoder = [cmdEncoder,

src/pt/deferred_renderer.hpp

@@ -109,6 +109,7 @@ class DeferredRenderer
         struct Uniforms
         {
             glm::mat4 viewProjectionMat;
+            glm::mat4 jitterMat;
         };
 
     public:
@@ -129,6 +130,7 @@ class DeferredRenderer
             WGPUTextureView    depthTextureView,
             WGPUTextureView    albedoTextureView,
             WGPUTextureView    normalTextureView,
+            const Extent2f&    framebufferSize,
             std::uint32_t      frameCount);
     };
 

src/pt/deferred_renderer_gbuffer_pass.wgsl

@@ -1,4 +1,9 @@
-@group(0) @binding(0) var<uniform> viewReverseZProjectionMat: mat4x4f;
+struct Uniforms {
+    viewReverseZProjectionMat: mat4x4f,
+    jitterMat: mat4x4f
+}
+
+@group(0) @binding(0) var<uniform> uniforms: Uniforms;
 
 struct VertexInput {
     @location(0) position: vec4f,
@@ -15,7 +20,7 @@ struct VertexOutput {
 @vertex
 fn vsMain(in: VertexInput) -> VertexOutput {
     var out: VertexOutput;
-    out.position = viewReverseZProjectionMat * in.position;
+    out.position = uniforms.jitterMat * uniforms.viewReverseZProjectionMat * in.position;
     out.normal = in.normal;
     out.texCoord = in.texCoord;
     return out;

src/pt/shader_source.hpp

@@ -623,7 +623,12 @@ fn animatedBlueNoise(coord: vec2u, frameIdx: u32, totalSampleCount: u32) -> vec2
 }
 )";
 
-const char* const DEFERRED_RENDERER_GBUFFER_PASS_SOURCE = R"(@group(0) @binding(0) var<uniform> viewReverseZProjectionMat: mat4x4f;
+const char* const DEFERRED_RENDERER_GBUFFER_PASS_SOURCE = R"(struct Uniforms {
+    viewReverseZProjectionMat: mat4x4f,
+    jitterMat: mat4x4f
+}
+
+@group(0) @binding(0) var<uniform> uniforms: Uniforms;
 
 struct VertexInput {
     @location(0) position: vec4f,
@@ -640,7 +645,7 @@ struct VertexOutput {
 @vertex
 fn vsMain(in: VertexInput) -> VertexOutput {
     var out: VertexOutput;
-    out.position = viewReverseZProjectionMat * in.position;
+    out.position = uniforms.jitterMat * uniforms.viewReverseZProjectionMat * in.position;
     out.normal = in.normal;
     out.texCoord = in.texCoord;
     return out;