VoxelEngine/res/shaders/lib/shadows.glsl
2025-09-23 00:51:21 +03:00

61 lines
1.7 KiB
GLSL

#ifndef SHADOWS_GLSL_
#define SHADOWS_GLSL_
#include <constants>
uniform sampler2DShadow u_shadows[2];
uniform mat4 u_shadowsMatrix[2];
uniform float u_dayTime;
uniform int u_shadowsRes;
uniform float u_shadowsOpacity;
uniform float u_shadowsSoftness;
float calc_shadow(
sampler2DShadow shadowsMap,
mat4 shadowMatrix,
vec4 modelPos,
vec3 realnormal,
vec3 normalOffset,
float bias
) {
float step = 1.0 / float(u_shadowsRes);
vec4 mpos = shadowMatrix * vec4(modelPos.xyz + normalOffset, 1.0);
vec3 projCoords = mpos.xyz / mpos.w;
projCoords = projCoords * 0.5 + 0.5;
projCoords.z -= 0.00001 / u_shadowsRes + bias;
float shadow = 0.0;
if (dot(realnormal, u_sunDir) < 0.0) {
// 3x3 kernel
for (int y = -1; y <= 1; y++) {
for (int x = -1; x <= 1; x++) {
vec3 offset = vec3(x, y, -(abs(x) + abs(y)) * 0.8) * step * 1.0 * u_shadowsSoftness;
shadow += texture(shadowsMap, projCoords + offset);
}
}
shadow /= 9.0;
} else {
shadow = 0.0;
}
return shadow;
}
// TODO: add array textures support
float calc_shadow(vec4 modelPos, vec3 realnormal, float distance) {
#ifdef ENABLE_SHADOWS
float s = u_shadowsOpacity;
vec3 normalOffset = realnormal * (distance > 64.0 ? 0.2 : 0.04);
// as slow as mix(...)
float shadow = (distance < 80.0)
? calc_shadow(u_shadows[0], u_shadowsMatrix[0], modelPos, realnormal, normalOffset, 0.0)
: calc_shadow(u_shadows[1], u_shadowsMatrix[1], modelPos, realnormal, normalOffset, 0.001);
return 0.5 * (1.0 + s * shadow);
#else
return 1.0;
#endif
}
#endif // SHADOWS_GLSL_