From 03d0b09f293b20d454dd5a7357096a2aae557746 Mon Sep 17 00:00:00 2001
From: Magnus Norddahl <dpjudas@users.noreply.github.com>
Date: Sat, 10 Sep 2016 22:39:09 +0200
Subject: [PATCH] Fix depth blur

---
 src/gl/renderer/gl_postprocess.cpp      | 12 ++++------
 wadsrc/static/shaders/glsl/depthblur.fp | 32 ++++++++-----------------
 2 files changed, 14 insertions(+), 30 deletions(-)

diff --git a/src/gl/renderer/gl_postprocess.cpp b/src/gl/renderer/gl_postprocess.cpp
index e00ca7305..9b791a3f1 100644
--- a/src/gl/renderer/gl_postprocess.cpp
+++ b/src/gl/renderer/gl_postprocess.cpp
@@ -118,11 +118,6 @@ CUSTOM_CVAR(Float, gl_ssao_blur_amount, 4.0f, 0)
 {
 	if (self < 0.1f) self = 0.1f;
 }
-CUSTOM_CVAR(Int, gl_ssao_blur_samples, 5, 0)
-{
-	if (self < 3 || self > 15 || self % 2 == 0)
-		self = 9;
-}
 
 EXTERN_CVAR(Float, vid_brightness)
 EXTERN_CVAR(Float, vid_contrast)
@@ -163,7 +158,6 @@ void FGLRenderer::AmbientOccludeScene()
 	float bias = gl_ssao_bias;
 	float aoRadius = gl_ssao_radius;
 	const float blurAmount = gl_ssao_blur_amount;
-	int blurSampleCount = gl_ssao_blur_samples;
 	float aoStrength = gl_ssao_strength;
 	bool multisample = gl_multisample > 1;
 
@@ -174,6 +168,8 @@ void FGLRenderer::AmbientOccludeScene()
 	float nDotVBias = clamp(bias, 0.0f, 1.0f);
 	float r2 = aoRadius * aoRadius;
 
+	float blurSharpness = 1.0f / blurAmount;
+
 	// Calculate linear depth values
 	glBindFramebuffer(GL_FRAMEBUFFER, mBuffers->AmbientFB0);
 	glViewport(0, 0, mBuffers->AmbientWidth, mBuffers->AmbientHeight);
@@ -225,14 +221,14 @@ void FGLRenderer::AmbientOccludeScene()
 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 	mDepthBlurShader->Bind(false);
-	mDepthBlurShader->BlurSharpness[false].Set(blurAmount);
+	mDepthBlurShader->BlurSharpness[false].Set(blurSharpness);
 	mDepthBlurShader->InvFullResolution[false].Set(1.0f / mBuffers->AmbientWidth, 1.0f / mBuffers->AmbientHeight);
 	RenderScreenQuad();
 
 	glBindFramebuffer(GL_FRAMEBUFFER, mBuffers->AmbientFB1);
 	glBindTexture(GL_TEXTURE_2D, mBuffers->AmbientTexture0);
 	mDepthBlurShader->Bind(true);
-	mDepthBlurShader->BlurSharpness[true].Set(blurAmount);
+	mDepthBlurShader->BlurSharpness[true].Set(blurSharpness);
 	mDepthBlurShader->InvFullResolution[true].Set(1.0f / mBuffers->AmbientWidth, 1.0f / mBuffers->AmbientHeight);
 	mDepthBlurShader->PowExponent[true].Set(1.8f);
 	RenderScreenQuad();
diff --git a/wadsrc/static/shaders/glsl/depthblur.fp b/wadsrc/static/shaders/glsl/depthblur.fp
index bd464d03d..c4f4438d3 100644
--- a/wadsrc/static/shaders/glsl/depthblur.fp
+++ b/wadsrc/static/shaders/glsl/depthblur.fp
@@ -7,39 +7,32 @@ uniform float BlurSharpness;
 uniform vec2 InvFullResolution;
 uniform float PowExponent;
 
-#define KERNEL_RADIUS 3.0
+#define KERNEL_RADIUS 7.0
 
-struct CenterPixelData
-{
-	vec2 UV;
-	float Depth;
-	float Sharpness;
-};
-
-float CrossBilateralWeight(float r, float sampleDepth, CenterPixelData center)
+float CrossBilateralWeight(float r, float sampleDepth, float centerDepth)
 {
 	const float blurSigma = KERNEL_RADIUS * 0.5;
 	const float blurFalloff = 1.0 / (2.0 * blurSigma * blurSigma);
 
-	float deltaZ = (sampleDepth - center.Depth) * center.Sharpness;
+	float deltaZ = (sampleDepth - centerDepth) * BlurSharpness;
 
 	return exp2(-r * r * blurFalloff - deltaZ * deltaZ);
 }
 
-void ProcessSample(float ao, float z, float r, CenterPixelData center, inout float totalAO, inout float totalW)
+void ProcessSample(float ao, float z, float r, float centerDepth, inout float totalAO, inout float totalW)
 {
-	float w = CrossBilateralWeight(r, z, center);
+	float w = CrossBilateralWeight(r, z, centerDepth);
 	totalAO += w * ao;
 	totalW += w;
 }
 
-void ProcessRadius(vec2 deltaUV, CenterPixelData center, inout float totalAO, inout float totalW)
+void ProcessRadius(vec2 deltaUV, float centerDepth, inout float totalAO, inout float totalW)
 {
 	for (float r = 1; r <= KERNEL_RADIUS; r += 1.0)
 	{
-		vec2 uv = r * deltaUV + center.UV;
+		vec2 uv = r * deltaUV + TexCoord;
 		vec2 aoZ = texture(AODepthTexture, uv).xy;
-		ProcessSample(aoZ.x, aoZ.y, r, center, totalAO, totalW);
+		ProcessSample(aoZ.x, aoZ.y, r, centerDepth, totalAO, totalW);
 	}
 }
 
@@ -47,16 +40,11 @@ vec2 ComputeBlur(vec2 deltaUV)
 {
 	vec2 aoZ = texture(AODepthTexture, TexCoord).xy;
 
-	CenterPixelData center;
-	center.UV = TexCoord;
-	center.Depth = aoZ.y;
-	center.Sharpness = BlurSharpness;
-
 	float totalAO = aoZ.x;
 	float totalW = 1.0;
 
-	ProcessRadius(deltaUV, center, totalAO, totalW);
-	ProcessRadius(-deltaUV, center, totalAO, totalW);
+	ProcessRadius(deltaUV, aoZ.y, totalAO, totalW);
+	ProcessRadius(-deltaUV, aoZ.y, totalAO, totalW);
 
 	return vec2(totalAO / totalW, aoZ.y);
 }