133 lines
3.6 KiB
GLSL
133 lines
3.6 KiB
GLSL
// based on code by arkano22. See: http://www.gamedev.net/forums/topic/550699-ssao-no-halo-artifacts/
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// - rlyeh, public domain
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uniform vec2 camerarange = vec2(1.0, 1024.0);
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// uniform sampler2D som; // Depth texture (iChannel1)
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#if 0
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uniform sampler2D rand; // Random texture (iChannel2)
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vec2 getRandom(vec2 uv) {
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vec3 random = texture2D(rand, uv.st);
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return random*2.0-vec3(1.0);
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}
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#else
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#define MOD3 vec3(.1031,.11369,.13787)
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float hash12(vec2 p) {
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vec3 p3 = fract(vec3(p.xyx) * MOD3);
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p3 += dot(p3, p3.yzx + 19.19);
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return fract((p3.x + p3.y) * p3.z);
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}
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vec2 hash22(vec2 p) {
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vec3 p3 = fract(vec3(p.xyx) * MOD3);
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p3 += dot(p3, p3.yzx+19.19);
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return fract(vec2((p3.x + p3.y)*p3.z, (p3.x+p3.z)*p3.y));
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}
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vec3 getPosition(vec2 uv) {
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float fl = textureLod(iChannel0, vec2(0.), 0.).x;
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float d = textureLod(iChannel0, uv, 0.).w;
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vec2 p = uv*2.-1.;
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mat3 ca = mat3(1.,0.,0.,0.,1.,0.,0.,0.,-1./1.5);
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vec3 rd = normalize( ca * vec3(p,fl) );
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vec3 pos = rd * d;
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return pos;
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}
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vec2 getRandom(vec2 uv) {
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return normalize(hash22(uv*126.1231) * 2. - 1.);
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}
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#endif
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float pw = 1.0/iResolution.x*0.5;
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float ph = 1.0/iResolution.y*0.5;
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float readDepth(in vec2 coord) {
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if (coord.x<0||coord.y<0) return 1.0;
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float nearZ = camerarange.x;
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float farZ =camerarange.y;
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float posZ = texture(iChannel1, coord).x;
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return (2.0 * nearZ) / (nearZ + farZ - posZ * (farZ - nearZ));
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}
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float compareDepths(in float depth1, in float depth2,inout int far) {
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float diff = (depth1 - depth2)*100; //depth difference (0-100)
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float gdisplace = 0.2; //gauss bell center
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float garea = 2.0; //gauss bell width 2
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//reduce left bell width to avoid self-shadowing
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if (diff<gdisplace){
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garea = 0.1;
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}else{
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far = 1;
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}
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float gauss = pow(2.7182,-2*(diff-gdisplace)*(diff-gdisplace)/(garea*garea));
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return gauss;
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}
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float calcAO(float depth, vec2 uv, float dw, float dh) {
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float temp = 0;
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float temp2 = 0;
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float coordw = uv.x + dw/depth;
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float coordh = uv.y + dh/depth;
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float coordw2 = uv.x - dw/depth;
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float coordh2 = uv.y - dh/depth;
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if (coordw < 1.0 && coordw > 0.0 && coordh < 1.0 && coordh > 0.0){
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vec2 coord = vec2(coordw , coordh);
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vec2 coord2 = vec2(coordw2, coordh2);
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int far = 0;
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temp = compareDepths(depth, readDepth(coord),far);
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//DEPTH EXTRAPOLATION:
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if (far > 0){
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temp2 = compareDepths(readDepth(coord2),depth,far);
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temp += (1.0-temp)*temp2;
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}
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}
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return temp;
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}
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void mainImage( out vec4 fragColor, in vec2 fragCoord )
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{
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//randomization texture:
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vec2 uv = fragCoord.xy / iResolution.xy;
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vec2 random = getRandom( uv + vec2(iTime) );
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//initialize stuff:
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float depth = readDepth(uv);
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float ao = 0.0;
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for(int i=0; i<4;++i) {
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//calculate color bleeding and ao:
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ao+=calcAO(depth, uv, pw, ph);
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ao+=calcAO(depth, uv, pw, -ph);
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ao+=calcAO(depth, uv, -pw, ph);
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ao+=calcAO(depth, uv, -pw, -ph);
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ao+=calcAO(depth, uv, pw*1.2, 0);
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ao+=calcAO(depth, uv, -pw*1.2, 0);
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ao+=calcAO(depth, uv, 0, ph*1.2);
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ao+=calcAO(depth, uv, 0, -ph*1.2);
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//sample jittering:
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pw += random.x*0.0007;
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ph += random.y*0.0007;
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//increase sampling area:
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pw *= 1.7;
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ph *= 1.7;
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}
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//final values, some adjusting:
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vec4 texel = texture(iChannel0, uv);
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float finalAO = 1.0-(ao/32.0); finalAO = 0.5+finalAO*0.5;
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fragColor = vec4(texel.rgb * vec3(finalAO), texel.a);
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//fragColor = vec4(vec3(finalAO), texel.a); // << debug
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}
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