1 files changed, 27 insertions, 27 deletions

diff --git a/src/renderergl2/glsl/ssao_fp.glsl b/src/renderergl2/glsl/ssao_fp.glsl
index 6263284c..93f61859 100644
--- a/src/renderergl2/glsl/ssao_fp.glsl
+++ b/src/renderergl2/glsl/ssao_fp.glsl
@@ -1,6 +1,6 @@
 uniform sampler2D u_ScreenDepthMap;
 
-uniform vec4   u_ViewInfo; // zfar / znear, zfar
+uniform vec4   u_ViewInfo; // zfar / znear, zfar, 1/width, 1/height
 
 varying vec2   var_ScreenTex;
 
@@ -11,6 +11,7 @@ vec2(0.5784913, -0.002528916), vec2(0.192888, 0.4064181),
 vec2(-0.6335801, -0.5247476),  vec2(-0.5579782, 0.7491854),
 vec2(0.7320465, 0.6317794)
 );
+#define NUM_SAMPLES 3
 
 // Input: It uses texture coords as the random number seed.
 // Output: Random number: [0,1), that is between 0.0 and 0.999999... inclusive.
@@ -39,48 +40,47 @@ mat2 randomRotation( const vec2 p )
 
 float getLinearDepth(sampler2D depthMap, const vec2 tex, const float zFarDivZNear)
 {
-		float sampleZDivW = texture2D(depthMap, tex).r;
-		return 1.0 / mix(zFarDivZNear, 1.0, sampleZDivW);
+	float sampleZDivW = texture2D(depthMap, tex).r;
+	return 1.0 / mix(zFarDivZNear, 1.0, sampleZDivW);
 }
 
-float ambientOcclusion(sampler2D depthMap, const vec2 tex, const float zFarDivZNear, const float zFar)
+float ambientOcclusion(sampler2D depthMap, const vec2 tex, const float zFarDivZNear, const float zFar, const vec2 scale)
 {
 	float result = 0;
 
-	float sampleZ = zFar * getLinearDepth(depthMap, tex, zFarDivZNear);
+	float sampleZ = getLinearDepth(depthMap, tex, zFarDivZNear);
+	float scaleZ = zFarDivZNear * sampleZ;
 
-	vec2 expectedSlope = vec2(dFdx(sampleZ), dFdy(sampleZ)) / vec2(dFdx(tex.x), dFdy(tex.y));
-	
-	if (length(expectedSlope) > 5000.0)
+	vec2 slope = vec2(dFdx(sampleZ), dFdy(sampleZ)) / vec2(dFdx(tex.x), dFdy(tex.y));
+
+	if (length(slope) * zFar > 5000.0)
 		return 1.0;
-	
-	vec2 offsetScale = vec2(3.0 / sampleZ);
-	
+
+	vec2 offsetScale = vec2(scale * 1024.0 / scaleZ);
+
 	mat2 rmat = randomRotation(tex);
-		
+
+	float invZFar = 1.0 / zFar;
+	float zLimit = 20.0 * invZFar;
 	int i;
-	for (i = 0; i < 3; i++)
+	for (i = 0; i < NUM_SAMPLES; i++)
 	{
 		vec2 offset = rmat * poissonDisc[i] * offsetScale;
-		float sampleZ2 = zFar * getLinearDepth(depthMap, tex + offset, zFarDivZNear);
-
-		if (abs(sampleZ - sampleZ2) > 20.0)
-			result += 1.0;
-		else
-		{
-			float expectedZ = sampleZ + dot(expectedSlope, offset);
-			result += step(expectedZ - 1.0, sampleZ2);
-		}
+		float sampleDiff = getLinearDepth(depthMap, tex + offset, zFarDivZNear) - sampleZ;
+
+		bool s1 = abs(sampleDiff) > zLimit;
+		bool s2 = sampleDiff + invZFar > dot(slope, offset);
+		result += float(s1 || s2);
 	}
-	
-	result *= 0.33333;
-	
+
+	result *= 1.0 / float(NUM_SAMPLES);
+
 	return result;
 }
 
 void main()
 {
-	float result = ambientOcclusion(u_ScreenDepthMap, var_ScreenTex, u_ViewInfo.x, u_ViewInfo.y);
-			
+	float result = ambientOcclusion(u_ScreenDepthMap, var_ScreenTex, u_ViewInfo.x, u_ViewInfo.y, u_ViewInfo.wz);
+
 	gl_FragColor = vec4(vec3(result), 1.0);
 }