787866909d
Normals RTT is not mipmapped and thus bad things happened above a certain value in the depth buffer because of trilinear filtering.
67 lines
2.2 KiB
GLSL
67 lines
2.2 KiB
GLSL
#version 130
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uniform sampler2D normals_and_depth;
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uniform mat4 invprojm;
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uniform mat4 projm;
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uniform vec4 samplePoints[16];
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in vec2 uv;
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const float strengh = 4.;
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const float radius = .4f;
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#define SAMPLES 16
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const float invSamples = strengh / SAMPLES;
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// Found here : http://byteblacksmith.com/improvements-to-the-canonical-one-liner-glsl-rand-for-opengl-es-2-0/
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float rand(vec2 co)
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{
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return fract(sin(dot(co.xy,vec2(12.9898,78.233))) * 43758.5453);
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}
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void main(void)
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{
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vec4 cur = texture2D(normals_and_depth, uv);
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float curdepth = texture2D(normals_and_depth, uv).a;
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vec4 FragPos = invprojm * (2.0f * vec4(uv, curdepth, 1.0f) - 1.0f);
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FragPos /= FragPos.w;
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// get the normal of current fragment
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vec3 norm = normalize(cur.xyz * vec3(2.0) - vec3(1.0));
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// Workaround for nvidia and skyboxes
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float len = dot(vec3(1.0), abs(cur.xyz));
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if (len < 0.2 || curdepth > 0.999) discard;
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// Make a tangent as random as possible
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vec3 randvect;
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randvect.x = rand(uv);
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randvect.y = rand(vec2(randvect.x, FragPos.z));
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randvect.z = rand(randvect.xy);
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vec3 tangent = normalize(cross(norm, randvect));
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vec3 bitangent = cross(norm, tangent);
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float bl = 0.0;
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for(int i = 0; i < SAMPLES; ++i) {
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vec3 sampleDir = samplePoints[i].x * tangent + samplePoints[i].y * bitangent + samplePoints[i].z * norm;
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sampleDir *= samplePoints[i].w;
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vec4 samplePos = FragPos + radius * vec4(sampleDir, 0.0);
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vec4 sampleProj = projm * samplePos;
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sampleProj /= sampleProj.w;
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bool isInsideTexture = (sampleProj.x > -1.) && (sampleProj.x < 1.) && (sampleProj.y > -1.) && (sampleProj.y < 1.);
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// get the depth of the occluder fragment
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float occluderFragmentDepth = texture2D(normals_and_depth, (sampleProj.xy * 0.5) + 0.5).a;
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// Position of the occluder fragment in worldSpace
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vec4 occluderPos = invprojm * vec4(sampleProj.xy, 2.0 * occluderFragmentDepth - 1.0, 1.0f);
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occluderPos /= occluderPos.w;
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bool isOccluded = isInsideTexture && (sampleProj.z > (2. * occluderFragmentDepth - 1.0)) && (distance(FragPos, occluderPos) < radius);
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bl += isOccluded ? smoothstep(radius, 0, distance(samplePos, FragPos)) : 0.;
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}
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// output the result
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float ao = 1.0 - bl * invSamples;
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gl_FragColor = vec4(ao);
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}
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