cOMS/shaders/liquids/water/water_caustics_fragment.hlsl
2024-07-12 15:26:57 +02:00

32 lines
1.3 KiB
HLSL

// if has derivative
#extension GL_OES_standard_derivatives : enablen
varying vec3 oldPos;
varying vec3 newPos;
varying vec3 ray;
void main() {
/* if the triangle gets smaller, it gets brighter, and vice versa */
// if has derivative
float oldArea = length(dFdx(oldPos)) * length(dFdy(oldPos));
float newArea = length(dFdx(newPos)) * length(dFdy(newPos));
gl_FragColor = vec4(oldArea / newArea * 0.2, 1.0, 0.0, 0.0);
// gl_FragColor = vec4(0.2, 0.2, 0.0, 0.0);
vec3 refractedLight = refract(-light, vec3(0.0, 1.0, 0.0), IOR_AIR / IOR_WATER);
/* compute a blob shadow and make sure we only draw a shadow if the player is blocking the light */
vec3 dir = (sphereCenter - newPos) / sphereRadius;
vec3 area = cross(dir, refractedLight);
float shadow = dot(area, area);
float dist = dot(dir, -refractedLight);
shadow = 1.0 + (shadow - 1.0) / (0.05 + dist * 0.025);
shadow = clamp(1.0 / (1.0 + exp(-shadow)), 0.0, 1.0);
shadow = mix(1.0, shadow, clamp(dist * 2.0, 0.0, 1.0));
gl_FragColor.g = shadow;
/* shadow for the rim of the pool */
vec2 t = intersectCube(newPos, -refractedLight, vec3(-1.0, -poolHeight, -1.0), vec3(1.0, 2.0, 1.0));
gl_FragColor.r *= 1.0 / (1.0 + exp(-200.0 / (1.0 + 10.0 * (t.y - t.x)) * (newPos.y - refractedLight.y * t.y - 2.0 / 12.0)));
}