72 lines
2 KiB
GLSL
72 lines
2 KiB
GLSL
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#version 330 core
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#pragma optionNV (unroll all)
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out float fragColor;
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in vec2 texCoord;
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uniform sampler2D depth_tex;
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uniform sampler2D normal_tex;
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uniform mat4 fg_ProjectionMatrix;
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const float RADIUS = 0.04;
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const float BIAS = 0.05;
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const float SCALE = 3.0;
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const float MAX_DISTANCE = 0.08;
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const float INTENSITY = 1.5;
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const vec2 kernel[4] = vec2[](
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vec2( 0.0, 1.0), // top
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vec2( 1.0, 0.0), // right
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vec2( 0.0, -1.0), // bottom
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vec2(-1.0, 0.0)); // left
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vec3 positionFromDepth(vec2 pos, float depth);
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vec3 decodeNormal(vec2 enc);
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float rand(vec2 co) {
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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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float sampleAO(vec3 fragPos, vec3 normal, vec2 coords)
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{
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float sampleDepth = texture(depth_tex, coords).r * 2.0 - 1.0;
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vec3 samplePoint = positionFromDepth(coords * 2.0 - 1.0, sampleDepth);
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vec3 diff = samplePoint - fragPos;
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float l = length(diff);
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vec3 v = diff / l;
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float d = l * SCALE;
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float ao = max(0.0, dot(normal, v) - BIAS) * (1.0 / (1.0 + d));
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ao *= smoothstep(MAX_DISTANCE, MAX_DISTANCE * 0.5, l);
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return ao;
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}
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void main()
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{
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float fragDepth = texture(depth_tex, texCoord).r;
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vec3 fragPos = positionFromDepth(texCoord * 2.0 - 1.0, fragDepth * 2.0 - 1.0);
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vec3 normal = normalize(decodeNormal(texture(normal_tex, texCoord).rg));
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vec2 randomVec = normalize(vec2(rand(texCoord) * 2.0 - 1.0,
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rand(texCoord+1.0) * 2.0 - 1.0));
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const float sin45 = 0.707107;
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float occlusion = 0.0;
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for (int i = 0; i < 4; ++i) {
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vec2 k1 = reflect(kernel[i], randomVec) * RADIUS;
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vec2 k2 = vec2(k1.x * sin45 - k1.y * sin45, k1.x * sin45 + k1.y * sin45);
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occlusion += sampleAO(fragPos, normal, texCoord + k1);
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occlusion += sampleAO(fragPos, normal, texCoord + k2 * 0.75);
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occlusion += sampleAO(fragPos, normal, texCoord + k1 * 0.5);
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occlusion += sampleAO(fragPos, normal, texCoord + k2 * 0.25);
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}
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occlusion /= 16.0;
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fragColor = clamp(1.0 - occlusion * INTENSITY, 0.0, 1.0);
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}
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