- create bloom pass in declarative postprocess form

src/hwrenderer/postprocessing/hw_postprocess.cpp

@@ -0,0 +1,191 @@
+
+#include "v_video.h"
+#include "hw_postprocess.h"
+#include "hwrenderer/utility/hw_cvars.h"
+#include "gl_load/gl_load.h" // for GL_RGBA16F - should we create our own enum instead?
+
+Postprocess hw_postprocess;
+
+void PPBloom::DeclareShaders()
+{
+	PPShader shader;
+	shader.VertexShader = "shaders/glsl/screenquad.vp";
+	shader.FragmentShader = "shaders/glsl/bloomcombine.fp";
+	hw_postprocess.Shaders["BloomCombine"] = shader;
+
+	shader.Uniforms = ExtractUniforms::Desc();
+	shader.FragmentShader = "shaders/glsl/bloomextract.fp";
+	hw_postprocess.Shaders["BloomExtract"] = shader;
+
+	shader.Uniforms = BlurUniforms::Desc();
+	shader.FragmentShader = "shaders/glsl/blur.fp";
+	shader.Defines = "#define BLUR_VERTICAL\n";
+	hw_postprocess.Shaders["BlurVertical"] = shader;
+
+	shader.Defines = "#define BLUR_HORIZONTAL\n";
+	hw_postprocess.Shaders["BlurHorizontal"] = shader;
+}
+
+void PPBloom::UpdateTextures(int width, int height)
+{
+	// No scene, no bloom!
+	if (width <= 0 || height <= 0)
+		return;
+
+	int bloomWidth = (width + 1) / 2;
+	int bloomHeight = (height + 1) / 2;
+
+	for (int i = 0; i < NumBloomLevels; i++)
+	{
+		FString vtexture, htexture;
+		vtexture.Format("Bloom.VTexture.%d", i);
+		htexture.Format("Bloom.HTexture.%d", i);
+
+		auto &level = levels[i];
+		level.Viewport.left = 0;
+		level.Viewport.top = 0;
+		level.Viewport.width = (bloomWidth + 1) / 2;
+		level.Viewport.height = (bloomHeight + 1) / 2;
+
+		PPTextureDesc texture;
+		texture.Width = level.Viewport.width;
+		texture.Height = level.Viewport.height;
+		texture.Format = GL_RGBA16F;
+
+		hw_postprocess.Textures[vtexture] = texture;
+		hw_postprocess.Textures[htexture] = texture;
+
+		bloomWidth = level.Viewport.width;
+		bloomHeight = level.Viewport.height;
+	}
+}
+
+void PPBloom::UpdateSteps(int fixedcm)
+{
+	TArray<PPStep> steps;
+
+	// Only bloom things if enabled and no special fixed light mode is active
+	if (!gl_bloom || fixedcm != CM_DEFAULT || gl_ssao_debug)
+	{
+		hw_postprocess.Effects["BloomScene"] = steps;
+		return;
+	}
+
+	PPStep step;
+	step.Textures.Resize(1);
+
+	ExtractUniforms extractUniforms;
+	extractUniforms.Scale = screen->SceneScale();
+	extractUniforms.Offset = screen->SceneOffset();
+
+	auto &level0 = levels[0];
+
+	// Extract blooming pixels from scene texture:
+	step.Viewport = level0.Viewport;
+	step.Textures[0].Type = PPTextureType::CurrentPipelineTexture;
+	step.Textures[0].Filter = PPFilterMode::Linear;
+	step.ShaderName = "BloomExtract";
+	step.Uniforms.Set(extractUniforms);
+	step.Output.Type = PPTextureType::PPTexture;
+	step.Output.Texture = level0.VTexture;
+	step.BlendMode.BlendOp = STYLEOP_Add;
+	step.BlendMode.SrcAlpha = STYLEALPHA_One;
+	step.BlendMode.DestAlpha = STYLEALPHA_Zero;
+	steps.Push(step);
+
+	const float blurAmount = gl_bloom_amount;
+	BlurUniforms blurUniforms;
+	ComputeBlurSamples(7, blurAmount, blurUniforms.SampleWeights);
+
+	// Blur and downscale:
+	for (int i = 0; i < NumBloomLevels - 1; i++)
+	{
+		auto &level = levels[i];
+		auto &next = levels[i + 1];
+		steps.Push(BlurStep(blurUniforms, level.VTexture, level.HTexture, level.Viewport, false));
+		steps.Push(BlurStep(blurUniforms, level.HTexture, next.VTexture, next.Viewport, true));
+	}
+
+	// Blur and upscale:
+	for (int i = NumBloomLevels - 1; i > 0; i--)
+	{
+		auto &level = levels[i];
+		auto &next = levels[i - 1];
+
+		steps.Push(BlurStep(blurUniforms, level.VTexture, level.HTexture, level.Viewport, false));
+		steps.Push(BlurStep(blurUniforms, level.HTexture, level.VTexture, level.Viewport, true));
+
+		// Linear upscale:
+		step.Textures[0].Type = PPTextureType::PPTexture;
+		step.Textures[0].Filter = PPFilterMode::Linear;
+		step.Textures[0].Texture = next.VTexture;
+		step.Output.Texture = next.HTexture;
+		step.Viewport = next.Viewport;
+		step.ShaderName = "BloomCombine";
+		steps.Push(step);
+	}
+
+	steps.Push(BlurStep(blurUniforms, level0.VTexture, level0.HTexture, level0.Viewport, false));
+	steps.Push(BlurStep(blurUniforms, level0.HTexture, level0.VTexture, level0.Viewport, true));
+
+	// Add bloom back to scene texture:
+	step.Textures[0].Type = PPTextureType::PPTexture;
+	step.Textures[0].Filter = PPFilterMode::Linear;
+	step.Textures[0].Texture = level0.VTexture;
+	step.Output.Type = PPTextureType::CurrentPipelineTexture;
+	step.Viewport = screen->mSceneViewport;
+	step.ShaderName = "BloomCombine";
+	step.BlendMode.BlendOp = STYLEOP_Add;
+	step.BlendMode.SrcAlpha = STYLEALPHA_One;
+	step.BlendMode.DestAlpha = STYLEALPHA_One;
+	step.BlendMode.Flags = 0;
+	steps.Push(step);
+
+	hw_postprocess.Effects["BloomScene"] = steps;
+}
+
+PPStep PPBloom::BlurStep(const BlurUniforms &blurUniforms, PPTextureName input, PPTextureName output, PPViewport viewport, bool vertical)
+{
+	PPStep step;
+	step.Textures.Resize(1);
+	step.Viewport = viewport;
+	step.Textures[0].Type = PPTextureType::PPTexture;
+	step.Textures[0].Filter = PPFilterMode::Nearest;
+	step.Textures[0].Texture = input;
+	step.ShaderName = vertical ? "BlurVertical" : "BlurHorizontal";
+	step.Uniforms.Set(blurUniforms);
+	step.Output.Type = PPTextureType::PPTexture;
+	step.Output.Texture = output;
+	step.BlendMode.BlendOp = STYLEOP_Add;
+	step.BlendMode.SrcAlpha = STYLEALPHA_One;
+	step.BlendMode.DestAlpha = STYLEALPHA_Zero;
+	step.BlendMode.Flags = 0;
+	return step;
+}
+
+float PPBloom::ComputeBlurGaussian(float n, float theta) // theta = Blur Amount
+{
+	return (float)((1.0f / sqrtf(2 * (float)M_PI * theta)) * expf(-(n * n) / (2.0f * theta * theta)));
+}
+
+void PPBloom::ComputeBlurSamples(int sampleCount, float blurAmount, float *sampleWeights)
+{
+	sampleWeights[0] = ComputeBlurGaussian(0, blurAmount);
+
+	float totalWeights = sampleWeights[0];
+
+	for (int i = 0; i < sampleCount / 2; i++)
+	{
+		float weight = ComputeBlurGaussian(i + 1.0f, blurAmount);
+
+		sampleWeights[i * 2 + 1] = weight;
+		sampleWeights[i * 2 + 2] = weight;
+
+		totalWeights += weight * 2;
+	}
+
+	for (int i = 0; i < sampleCount; i++)
+	{
+		sampleWeights[i] /= totalWeights;
+	}
+}