75 lines
1.7 KiB
GLSL
75 lines
1.7 KiB
GLSL
#version 120
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#ifdef GL_ES
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precision mediump float;
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#endif
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#define PI 3.14159265359
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uniform vec2 u_resolution;
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uniform vec2 u_mouse;
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uniform float u_time;
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uniform vec2 u_translation;
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uniform float u_zoom;
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#define N 48.
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#define B 4.
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vec3 pal(in float t, in vec3 a, in vec3 b, in vec3 c, in vec3 d) {
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return a + b*cos(6.28318*(c*t+d));
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}
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float iterate(vec2 p) {
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vec2 z = vec2(0), c = p;
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float i;
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for (i=0.; i < N; i++ ) {
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z = mat2(z, -z.y, z.x) * z + c;
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if (dot(z, z) > B*B) break;
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}
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//return i;
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// Compute the iteration smoothly, instead of in integers.
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if (p.y < 0.f) return i;
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return i - log(log(dot(z, z)) / log(B)) / log(2.);;
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}
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void main() {
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vec2 R = u_resolution.xy;
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vec2 uv = 1.2 * (2. * gl_FragCoord.xy - R - 1.) / R.y - vec2(.4, 0.);
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//vec2 z = vec2(0), c = uv;
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//float i;
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//for (i = 0.; i < N; i++) {
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// z = mat2(z, -z.y, z.x) * z + c;
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// if (dot(z, z) > B*B) break;
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//}
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float n = iterate(uv) / N;
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vec3 col = pal(fract(n + 0.5), vec3(.5), vec3(.5), vec3(1), vec3(.0, .1, .2));
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//if (n == 1.) {n = 0; }
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gl_FragColor = vec4(n == 1. ? vec3(0) : col, 1.);
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//vec2 st = gl_FragCoord.xy/u_resolution.xy;
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//vec3 color = vec3(0.0);
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//vec3 pct = vec3(st.x);
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// pct.r = smoothstep(0.0,1.0, st.x);
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// pct.g = sin(st.x*PI);
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// pct.b = pow(st.x,0.5);
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//color = mix(colorA, colorB, pct);
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// Plot transition lines for each channel
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// color = mix(color,vec3(1.0,0.0,0.0),plot(st,pct.r));
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// color = mix(color,vec3(0.0,1.0,0.0),plot(st,pct.g));
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// color = mix(color,vec3(0.0,0.0,1.0),plot(st,pct.b));
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// gl_FragColor = vec4(color,1.0);
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}
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