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out vec4 fragColor;
#ifndef UTIL_TEX
# define UTIL_TEX
uniform sampler2DArray utilTex;
# define texelfetch_noise_tex(coord) texelFetch(utilTex, ivec3(ivec2(coord) % LUT_SIZE, 2.0), 0)
#endif /* UTIL_TEX */
void main()
{
if (laNumLight == 0) {
/* Early exit: No lights in scene */
fragColor.r = 1.0;
return;
}
ivec2 texel = ivec2(gl_FragCoord.xy);
float depth = texelFetch(depthBuffer, texel, 0).r;
if (depth == 1.0f) {
/* Early exit background does not receive shadows */
fragColor.r = 1.0;
return;
}
vec2 texel_size = 1.0 / vec2(textureSize(depthBuffer, 0)).xy;
vec2 uvs = saturate(gl_FragCoord.xy * texel_size);
vec4 rand = texelfetch_noise_tex(texel);
float accum_light = 0.0;
float tracing_depth = depth;
/* Constant bias (due to depth buffer precision) */
/* Magic numbers for 24bits of precision.
* From http://terathon.com/gdc07_lengyel.pdf (slide 26) */
tracing_depth -= mix(2.4e-7, 4.8e-7, depth);
/* Convert to view Z. */
tracing_depth = get_view_z_from_depth(tracing_depth);
vec3 viewPosition = get_view_space_from_depth(uvs, depth);
vec3 worldPosition = transform_point(ViewMatrixInverse, viewPosition);
vec3 true_normal = normalize(cross(dFdx(viewPosition), dFdy(viewPosition)));
for (int i = 0; i < MAX_LIGHT && i < laNumLight; i++) {
LightData ld = lights_data[i];
vec4 l_vector; /* Non-Normalized Light Vector with length in last component. */
l_vector.xyz = ld.l_position - worldPosition;
l_vector.w = length(l_vector.xyz);
float l_vis = light_shadowing(
ld, worldPosition, viewPosition, tracing_depth, true_normal, rand.x, true, 1.0);
accum_light += l_vis;
}
fragColor.r = accum_light / float(laNumLight);
}
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