85 lines
2.2 KiB
GLSL
85 lines
2.2 KiB
GLSL
// credit: https://www.shadertoy.com/view/4tGXzt
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#define BEATMOVE 1
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const float FREQ_RANGE = 64.0;
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const float PI = 3.1415;
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const float RADIUS = 0.6;
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const float BRIGHTNESS = 0.2;
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const float SPEED = 0.5;
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//convert HSV to RGB
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vec3 hsv2rgb(vec3 c){
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vec4 K = vec4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
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vec3 p = abs(fract(c.xxx + K.xyz) * 6.0 - K.www);
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return c.z * mix(K.xxx, clamp(p - K.xxx, 0.0, 1.0), c.y);
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}
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float luma(vec3 color) {
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return dot(color, vec3(0.299, 0.587, 0.114));
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}
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float getfrequency(float x) {
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return texture(iChannel0, vec2(floor(x * FREQ_RANGE + 1.0) / FREQ_RANGE, 0.25)).x + 0.06;
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}
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float getfrequency_smooth(float x) {
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float index = floor(x * FREQ_RANGE) / FREQ_RANGE;
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float next = floor(x * FREQ_RANGE + 1.0) / FREQ_RANGE;
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return mix(getfrequency(index), getfrequency(next), smoothstep(0.0, 1.0, fract(x * FREQ_RANGE)));
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}
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float getfrequency_blend(float x) {
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return mix(getfrequency(x), getfrequency_smooth(x), 0.5);
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}
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vec3 doHalo(vec2 fragment, float radius) {
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float dist = length(fragment);
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float ring = 1.0 / abs(dist - radius);
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float b = dist < radius ? BRIGHTNESS * 0.3 : BRIGHTNESS;
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vec3 col = vec3(0.0);
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float angle = atan(fragment.x, fragment.y);
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col += hsv2rgb( vec3( ( angle + iTime * 0.25 ) / (PI * 2.0), 1.0, 1.0 ) ) * ring * b;
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float frequency = max(getfrequency_blend(abs(angle / PI)) - 0.02, 0.0);
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col *= frequency;
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// Black halo
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col *= smoothstep(radius * 0.5, radius, dist);
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return col;
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}
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vec3 doLine(vec2 fragment, float radius, float x) {
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vec3 col = hsv2rgb(vec3(x * 0.23 + iTime * 0.12, 1.0, 1.0));
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float freq = abs(fragment.x * 0.5);
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col *= (1.0 / abs(fragment.y)) * BRIGHTNESS * getfrequency(freq);
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col = col * smoothstep(radius, radius * 1.8, abs(fragment.x));
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return col;
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}
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void mainImage( out vec4 fragColor, in vec2 fragCoord ) {
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vec2 fragPos = fragCoord / iResolution.xy;
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fragPos = (fragPos - 0.5) * 2.0;
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fragPos.x *= iResolution.x / iResolution.y;
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vec3 color = vec3(0.0134, 0.052, 0.1);
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color += doHalo(fragPos, RADIUS);
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float c = cos(iTime * SPEED);
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float s = sin(iTime * SPEED);
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vec2 rot = mat2(c,s,-s,c) * fragPos;
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color += doLine(rot, RADIUS, rot.x);
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color += max(luma(color) - 1.0, 0.0);
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fragColor = vec4(color, 1.0);
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}
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