Troy James Sobotka
6ebe0084a3
Basic pass at histogram. Uses a power based scale compared against the total pixel count. Probably needs a UI toggle to flip lines on and off as the text and lines in OpenGL are a large cycles sucker. Could be likely much faster when migrated to a geometry shader approach. Uses the scaled viewport resolution to increase performance as much as possible.
36 lines
885 B
GLSL
36 lines
885 B
GLSL
#version 150
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uniform sampler2D ove_maintex;
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uniform vec2 ove_resolution;
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uniform vec2 ove_viewport;
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uniform float histogram_scale;
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uniform float histogram_power;
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in vec2 ove_texcoord;
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out vec4 fragColor;
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void main(void) {
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vec3 col = vec3(0.0);
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float histogram_height = ceil(ove_viewport.y * histogram_scale);
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vec3 histogram_ratio = vec3(0.0);
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vec3 sum = vec3(0.0);
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float ratio = 0.0;
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vec3 total_pixels = vec3(ceil(ove_viewport.x * ove_resolution.y *
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histogram_scale));
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for (int i = 0; i < histogram_height; i++) {
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ratio = float(i) / float(histogram_height - 1.0);
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sum += texture(
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ove_maintex,
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vec2(ove_texcoord.x, ratio)
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).rgb;
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}
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histogram_ratio = pow(sum / total_pixels, vec3(histogram_power));
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col = step(vec3(ove_texcoord.y), histogram_ratio);
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fragColor = vec4(col, 1.0);
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}
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