Solara-Shaders/shaders/lib/reflections/raytrace.glsl
2024-06-22 15:15:55 -04:00

89 lines
2.4 KiB
GLSL

vec3 nvec3(vec4 pos) {
return pos.xyz/pos.w;
}
vec4 nvec4(vec3 pos) {
return vec4(pos.xyz, 1.0);
}
float cdist(vec2 coord) {
return max(abs(coord.x - 0.5), abs(coord.y - 0.5)) * 1.85;
}
#if REFLECTION_MODE == 0
float errMult = 1.0;
#elif REFLECTION_MODE == 1
float errMult = 1.3;
#else
float errMult = 1.6;
#endif
vec4 Raytrace(sampler2D depthtex, vec3 viewPos, vec3 normal, float dither, out float border,
int maxf, float stp, float ref, float inc) {
vec3 pos = vec3(0.0);
float dist = 0.0;
#ifdef TAA
#if TAA_MODE == 0
dither = fract(dither + frameCounter * 0.618);
#else
dither = fract(dither + frameCounter * 0.5);
#endif
#endif
vec3 start = viewPos + normal * 0.075;
vec3 vector = stp * reflect(normalize(viewPos), normalize(normal));
viewPos += vector;
vec3 tvector = vector;
int sr = 0;
for(int i = 0; i < 30; i++) {
pos = nvec3(gbufferProjection * nvec4(viewPos)) * 0.5 + 0.5;
if (pos.x < -0.05 || pos.x > 1.05 || pos.y < -0.05 || pos.y > 1.05) break;
vec3 rfragpos = vec3(pos.xy, texture2D(depthtex,pos.xy).r);
rfragpos = nvec3(gbufferProjectionInverse * nvec4(rfragpos * 2.0 - 1.0));
dist = abs(dot(normalize(start - rfragpos), normal));
float err = length(viewPos - rfragpos);
float lVector = length(vector) * pow(length(tvector), 0.1) * errMult;
if (err < lVector) {
sr++;
if (sr >= maxf) break;
tvector -= vector;
vector *= ref;
}
vector *= inc;
tvector += vector;
viewPos = start + tvector * (0.025 * dither + 0.975);
}
border = cdist(pos.st);
#ifdef REFLECTION_PREVIOUS
//Previous frame reprojection from Chocapic13
vec4 viewPosPrev = gbufferProjectionInverse * vec4(pos * 2.0 - 1.0, 1.0);
viewPosPrev /= viewPosPrev.w;
viewPosPrev = gbufferModelViewInverse * viewPosPrev;
vec4 previousPosition = viewPosPrev + vec4(cameraPosition - previousCameraPosition, 0.0);
previousPosition = gbufferPreviousModelView * previousPosition;
previousPosition = gbufferPreviousProjection * previousPosition;
pos.xy = previousPosition.xy / previousPosition.w * 0.5 + 0.5;
#endif
return vec4(pos, dist);
}
vec4 BasicReflect(vec3 viewPos, vec3 normal, out float border) {
vec3 reflectedViewPos = reflect(viewPos, normal) + normal * dot(viewPos, normal) * 0.5;
vec3 pos = nvec3(gbufferProjection * nvec4(reflectedViewPos)) * 0.5 + 0.5;
border = cdist(pos.st);
return vec4(pos, 0.0);
}