quakeforge/libs/video/renderer/glsl/iqm.frag

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struct light {
vec4 position; // xyz = pos, w = strength
vec4 color; // rgb. a = ?
};
uniform sampler2D texture;
uniform sampler2D normalmap;
uniform vec3 ambient;
uniform light lights[8];
uniform vec4 fog;
varying vec3 position;
varying vec3 bitangent;
varying vec3 tangent;
varying vec3 normal;
varying vec2 st;
varying vec4 color;
float
sqr (float x)
{
return x * x;
}
vec4
fogBlend (vec4 color)
{
float f;
vec4 fog_color = vec4 (fog.rgb, 1.0);
f = exp (-sqr (fog.a / gl_FragCoord.w));
return mix (fog_color, color, f);
}
vec3
calc_light (vec3 n, int ind)
{
vec3 d;
light l = lights[ind];
float mag;
d = l.position.xyz - position;
mag = dot (d, n);
mag = max (0.0, mag);
return l.color.rgb * (l.position.w * mag / dot (d, d));
}
void
main (void)
{
mat3 tbn = mat3 (tangent, bitangent, normal);
vec3 norm, l;
vec4 col;
norm = (texture2D (normalmap, st).xyz - vec3(0.5)) * 2.0;
norm = tbn * norm;
l = ambient;
l += calc_light (norm, 0);
l += calc_light (norm, 1);
l += calc_light (norm, 2);
l += calc_light (norm, 3);
l += calc_light (norm, 4);
l += calc_light (norm, 5);
l += calc_light (norm, 6);
l += calc_light (norm, 7);
col = texture2D (texture, st) * color * vec4 (l, 1.0);
gl_FragColor = fogBlend (col);
}