initial commit

1 files changed, 45 insertions, 0 deletions

diff --git a/mandelbrot.glsl b/mandelbrot.glsl
new file mode 100644
index 0000000..d3d0ee2
--- /dev/null
+++ b/mandelbrot.glsl
@@ -0,0 +1,45 @@
+#version 100
+precision highp float;
+
+uniform vec2 resolution;
+uniform vec2 location;
+uniform double zoom;
+
+uniform int max;
+
+vec2 compsquare(vec2 z) {
+    float temp = z.x;
+    z.x = z.x * z.x - z.y * z.y;
+    z.y = 2.0 * temp * z.y;
+    return z;
+}
+
+vec3 hsv2rgb(vec3 hue){
+    vec4 K = vec4(1.0, 2.0/3.0, 1.0/3.0, 3.0);
+    vec3 p = abs(fract(hue.xxx + K.xyz) * 6.0 - K.www);
+    return hue.z * mix(K.xxx, clamp(p - K.xxx, 0.0, 1.0), hue.y);
+}
+
+vec3 mandelbort(vec2 point){
+    vec2 z = vec2(0.0);
+    float iters = 0.0;
+    for (iters = 0.0;   iters < float(max); ++iters)
+    {
+        z = compsquare(z) + point;
+        if(dot(z, z) > 4.0) break;
+    }
+    float hue = iters / float(max);
+    if(hue > 0.98) return vec3(0.0);
+    return hsv2rgb(vec3(hue, 1.0, 1.0));
+}
+
+void main()
+{
+    vec2 uv = gl_FragCoord.xy / resolution;
+    uv.x *= resolution.x / resolution.y;
+    uv -= vec2(0.7, 0.5);
+    uv *= zoom;
+    uv -= location;
+
+    gl_FragColor = vec4(mandelbort(uv), 1.0);
+}