SSAO version of sunLight shaders.

1 files changed, 123 insertions, 0 deletions

diff --git a/indra/newview/app_settings/shaders/class1/deferred/sunLightSSAOF.glsl b/indra/newview/app_settings/shaders/class1/deferred/sunLightSSAOF.glsl
new file mode 100644
index 0000000000..7450817ea7
--- /dev/null
+++ b/indra/newview/app_settings/shaders/class1/deferred/sunLightSSAOF.glsl
@@ -0,0 +1,123 @@
+/** 
+ * @file sunLightSSAOF.glsl
+ *
+ * Copyright (c) 2007-$CurrentYear$, Linden Research, Inc.
+ * $License$
+ */
+
+#extension GL_ARB_texture_rectangle : enable
+
+//class 1 -- no shadow, SSAO only
+
+uniform sampler2DRect depthMap;
+uniform sampler2DRect normalMap;
+uniform sampler2D noiseMap;
+
+uniform sampler2D		lightFunc;
+
+
+// Inputs
+uniform mat4 shadow_matrix[6];
+uniform vec4 shadow_clip;
+uniform float ssao_radius;
+uniform float ssao_max_radius;
+uniform float ssao_factor;
+uniform float ssao_factor_inv;
+
+varying vec2 vary_fragcoord;
+varying vec4 vary_light;
+
+uniform mat4 inv_proj;
+uniform vec2 screen_res;
+
+uniform float shadow_bias;
+uniform float shadow_offset;
+
+vec4 getPosition(vec2 pos_screen)
+{
+	float depth = texture2DRect(depthMap, pos_screen.xy).a;
+	vec2 sc = pos_screen.xy*2.0;
+	sc /= screen_res;
+	sc -= vec2(1.0,1.0);
+	vec4 ndc = vec4(sc.x, sc.y, 2.0*depth-1.0, 1.0);
+	vec4 pos = inv_proj * ndc;
+	pos /= pos.w;
+	pos.w = 1.0;
+	return pos;
+}
+
+//calculate decreases in ambient lighting when crowded out (SSAO)
+float calcAmbientOcclusion(vec4 pos, vec3 norm)
+{
+	float ret = 1.0;
+	
+	float dist = dot(pos.xyz,pos.xyz);
+	
+	if (dist < 64.0*64.0)
+	{
+		vec2 kern[8];
+		// exponentially (^2) distant occlusion samples spread around origin
+		kern[0] = vec2(-1.0, 0.0) * 0.125*0.125;
+		kern[1] = vec2(1.0, 0.0) * 0.250*0.250;
+		kern[2] = vec2(0.0, 1.0) * 0.375*0.375;
+		kern[3] = vec2(0.0, -1.0) * 0.500*0.500;
+		kern[4] = vec2(0.7071, 0.7071) * 0.625*0.625;
+		kern[5] = vec2(-0.7071, -0.7071) * 0.750*0.750;
+		kern[6] = vec2(-0.7071, 0.7071) * 0.875*0.875;
+		kern[7] = vec2(0.7071, -0.7071) * 1.000*1.000;
+
+		vec2 pos_screen = vary_fragcoord.xy;
+		vec3 pos_world = pos.xyz;
+		vec2 noise_reflect = texture2D(noiseMap, vary_fragcoord.xy/128.0).xy;
+		
+		float angle_hidden = 0.0;
+		int points = 0;
+		
+		float scale = min(ssao_radius / -pos_world.z, ssao_max_radius);
+		
+		// it was found that keeping # of samples a constant was the fastest, probably due to compiler optimizations (unrolling?)
+		for (int i = 0; i < 8; i++)
+		{
+			vec2 samppos_screen = pos_screen + scale * reflect(kern[i], noise_reflect);
+			vec3 samppos_world = getPosition(samppos_screen).xyz; 
+			
+			vec3 diff = pos_world - samppos_world;
+			float dist2 = dot(diff, diff);
+			
+			// assume each sample corresponds to an occluding sphere with constant radius, constant x-sectional area
+			// --> solid angle shrinking by the square of distance
+			//radius is somewhat arbitrary, can approx with just some constant k * 1 / dist^2
+			//(k should vary inversely with # of samples, but this is taken care of later)
+			
+			//if (dot((samppos_world - 0.05*norm - pos_world), norm) > 0.0)  // -0.05*norm to shift sample point back slightly for flat surfaces
+			//	angle_hidden += min(1.0/dist2, ssao_factor_inv); // dist != 0 follows from conditional.  max of 1.0 (= ssao_factor_inv * ssao_factor)
+			angle_hidden = angle_hidden + float(dot((samppos_world - 0.05*norm - pos_world), norm) > 0.0) * min(1.0/dist2, ssao_factor_inv);
+			
+			// 'blocked' samples (significantly closer to camera relative to pos_world) are "no data", not "no occlusion" 
+			points = points + int(diff.z > -1.0);
+		}
+		
+		angle_hidden = min(ssao_factor*angle_hidden/float(points), 1.0);
+		
+		ret = (1.0 - (float(points != 0) * angle_hidden));
+		ret += max((dist-32.0*32.0)/(32.0*32.0), 0.0);
+	}
+	
+	return min(ret, 1.0);
+}
+
+void main() 
+{
+	vec2 pos_screen = vary_fragcoord.xy;
+	
+	//try doing an unproject here
+	
+	vec4 pos = getPosition(pos_screen);
+	
+    vec3 norm = texture2DRect(normalMap, pos_screen).xyz*2.0-1.0;
+		
+	gl_FragColor[0] = 1.0;
+	gl_FragColor[1] = calcAmbientOcclusion(pos, norm);
+	gl_FragColor[2] = 1.0; 
+	gl_FragColor[3] = 1.0;
+}