Using uniform buffer for bloom threshold

libraries/render-utils/src/BloomEffect.cpp

@@ -21,13 +21,15 @@
 
 #define BLOOM_BLUR_LEVEL_COUNT  3
 
-BloomThreshold::BloomThreshold(unsigned int downsamplingFactor) :
+BloomThreshold::BloomThreshold(unsigned int downsamplingFactor) {
-    _downsamplingFactor(downsamplingFactor) {
     assert(downsamplingFactor > 0);
+    _parameters.edit()._sampleCount = downsamplingFactor;
 }
 
 void BloomThreshold::configure(const Config& config) {
-    _threshold = config.threshold;
+    if (_parameters.get()._threshold != config.threshold) {
+        _parameters.edit()._threshold = config.threshold;
+    }
 }
 
 void BloomThreshold::run(const render::RenderContextPointer& renderContext, const Inputs& inputs, Outputs& outputs) {
@@ -43,10 +45,11 @@ void BloomThreshold::run(const render::RenderContextPointer& renderContext, cons
 
     auto inputBuffer = inputFrameBuffer->getRenderBuffer(0);
     auto bufferSize = gpu::Vec2u(inputBuffer->getDimensions());
+    const auto downSamplingFactor = _parameters.get()._sampleCount;
 
     // Downsample resolution
-    bufferSize.x /= _downsamplingFactor;
+    bufferSize.x /= downSamplingFactor;
-    bufferSize.y /= _downsamplingFactor;
+    bufferSize.y /= downSamplingFactor;
 
     if (!_outputBuffer || _outputBuffer->getSize() != bufferSize) {
         auto colorTexture = gpu::TexturePointer(gpu::Texture::createRenderBuffer(inputBuffer->getTexelFormat(), bufferSize.x, bufferSize.y,
@@ -54,10 +57,12 @@ void BloomThreshold::run(const render::RenderContextPointer& renderContext, cons
 
         _outputBuffer = gpu::FramebufferPointer(gpu::Framebuffer::create("BloomThreshold"));
         _outputBuffer->setRenderBuffer(0, colorTexture);
+
+        _parameters.edit()._deltaUV = { 1.0f / bufferSize.x, 1.0f / bufferSize.y };
     }
 
     static const int COLOR_MAP_SLOT = 0;
-    static const int THRESHOLD_SLOT = 1;
+    static const int PARAMETERS_SLOT = 1;
 
     if (!_pipeline) {
         auto vs = gpu::StandardShaderLib::getDrawTransformUnitQuadVS();
@@ -66,7 +71,7 @@ void BloomThreshold::run(const render::RenderContextPointer& renderContext, cons
 
         gpu::Shader::BindingSet slotBindings;
         slotBindings.insert(gpu::Shader::Binding("colorMap", COLOR_MAP_SLOT));
-        slotBindings.insert(gpu::Shader::Binding("threshold", THRESHOLD_SLOT));
+        slotBindings.insert(gpu::Shader::Binding("parametersBuffer", PARAMETERS_SLOT));
         gpu::Shader::makeProgram(*program, slotBindings);
 
         gpu::StatePointer state = gpu::StatePointer(new gpu::State());
@@ -86,7 +91,7 @@ void BloomThreshold::run(const render::RenderContextPointer& renderContext, cons
 
         batch.setFramebuffer(_outputBuffer);
         batch.setResourceTexture(COLOR_MAP_SLOT, inputBuffer);
-        batch._glUniform1f(THRESHOLD_SLOT, _threshold);
+        batch.setUniformBuffer(PARAMETERS_SLOT, _parameters);
         batch.draw(gpu::TRIANGLE_STRIP, 4);
     });
 

libraries/render-utils/src/BloomEffect.h

@@ -61,10 +61,11 @@ public:
 
 private:
 
+#include "BloomThreshold.shared.slh"
+
     gpu::FramebufferPointer _outputBuffer;
     gpu::PipelinePointer _pipeline;
-    float _threshold;
+    gpu::StructBuffer<Parameters> _parameters;
-    unsigned int _downsamplingFactor;
 };
 
 

libraries/render-utils/src/BloomThreshold.shared.slh

@@ -0,0 +1,18 @@
+// glsl / C++ compatible source as interface for FadeEffect
+#ifdef __cplusplus
+#   define BT_VEC2 glm::vec2
+#else
+#   define BT_VEC2 vec2
+#endif
+
+struct Parameters
+{
+    BT_VEC2 _deltaUV;
+	float _threshold;
+    int _sampleCount;
+};
+
+    // <@if 1@>
+    // Trigger Scribe include 
+    // <@endif@> <!def that !> 
+//

libraries/render-utils/src/BloomThreshold.slf

@@ -9,37 +9,35 @@
 //  Distributed under the Apache License, Version 2.0.
 //  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
 //
+<@include BloomThreshold.shared.slh@>
 
 uniform sampler2D colorMap;
-uniform float threshold;
+layout(std140) uniform parametersBuffer {
+    Parameters parameters;
+};
 
 in vec2 varTexCoord0;
 out vec4 outFragColor;
 
-#define DOWNSAMPLING_FACTOR     4
-#define SAMPLE_COUNT            (DOWNSAMPLING_FACTOR/2)
-
 void main(void) {
-    vec2 deltaX = dFdx(varTexCoord0) / SAMPLE_COUNT;
-    vec2 deltaY = dFdy(varTexCoord0) / SAMPLE_COUNT;
     vec2 startUv = varTexCoord0;
     vec4 maskedColor = vec4(0,0,0,0);
 
-    for (int y=0 ; y<SAMPLE_COUNT ; y++) {
+    for (int y=0 ; y<parameters._sampleCount ; y++) {
         vec2 uv = startUv;
 
-        for (int x=0 ; x<SAMPLE_COUNT ; x++) {
+        for (int x=0 ; x<parameters._sampleCount ; x++) {
             vec4 color = texture(colorMap, uv);
             float luminance = (color.r+color.g+color.b) / 3.0;
-            float mask = clamp((luminance-threshold)*0.25, 0, 1);
+            float mask = clamp((luminance-parameters._threshold)*0.25, 0, 1);
 
             color *= mask;
             maskedColor += color;
-            uv += deltaX;
+            uv.x += parameters._deltaUV.x;
         }
 
-        startUv += deltaY;
+        startUv.y += parameters._deltaUV.y;
     }
-    maskedColor /= SAMPLE_COUNT*SAMPLE_COUNT;
+    maskedColor /= parameters._sampleCount * parameters._sampleCount;
     outFragColor = vec4(maskedColor.rgb, 1.0);
 }