56 lines
1.3 KiB
GLSL
56 lines
1.3 KiB
GLSL
//
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// Fragment shader for drawing the Mandelbrot set
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//
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// Authors: Dave Baldwin, Steve Koren, Randi Rost
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// based on a shader by Michael Rivero
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//
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// Copyright (c) 2002-2005: 3Dlabs, Inc.
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//
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// See 3Dlabs-License.txt for license information
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//
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varying vec3 Position;
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varying float LightIntensity;
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uniform float MaxIterations;
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uniform float Zoom;
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uniform float Xcenter;
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uniform float Ycenter;
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uniform vec3 InnerColor;
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uniform vec3 OuterColor1;
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uniform vec3 OuterColor2;
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void main()
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{
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float real = Position.x * Zoom + Xcenter;
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float imag = Position.y * Zoom + Ycenter;
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float Creal = real; // Change this line...
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float Cimag = imag; // ...and this one to get a Julia set
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float r2 = 0.0;
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float iter;
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// for (iter = 0.0; iter < MaxIterations && r2 < 4.0; ++iter)
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for (iter = 0.0; iter < 12 && r2 < 4.0; ++iter)
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{
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float tempreal = real;
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real = (tempreal * tempreal) - (imag * imag) + Creal;
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imag = 2.0 * tempreal * imag + Cimag;
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r2 = (real * real) + (imag * imag);
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}
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// Base the color on the number of iterations
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vec3 color;
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if (r2 < 4.0)
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color = InnerColor;
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else
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color = mix(OuterColor1, OuterColor2, fract(iter * 0.05));
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color *= LightIntensity;
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gl_FragColor = vec4(color, 1.0);
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}
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