32 lines
832 B
GLSL
32 lines
832 B
GLSL
uniform sampler2D ove_maintex;
|
|
uniform vec2 viewport;
|
|
|
|
uniform float histogram_scale;
|
|
uniform float histogram_power;
|
|
|
|
in vec2 ove_texcoord;
|
|
out vec4 frag_color;
|
|
|
|
void main(void) {
|
|
vec3 col = vec3(0.0);
|
|
float histogram_height = ceil(viewport.y * histogram_scale);
|
|
vec3 histogram_ratio = vec3(0.0);
|
|
vec3 sum = vec3(0.0);
|
|
float ratio = 0.0;
|
|
vec3 total_pixels = vec3(ceil(viewport.x * viewport.y *
|
|
histogram_scale));
|
|
|
|
for (int i = 0; float(i) < histogram_height; i++) {
|
|
ratio = float(i) / float(histogram_height - 1.0);
|
|
sum += texture(
|
|
ove_maintex,
|
|
vec2(ove_texcoord.x, ratio)
|
|
).rgb;
|
|
}
|
|
|
|
histogram_ratio = pow(sum / total_pixels, vec3(histogram_power));
|
|
col = step(vec3(ove_texcoord.y), histogram_ratio);
|
|
|
|
frag_color = vec4(col, 1.0);
|
|
}
|