61 lines
1.6 KiB
GLSL
Executable file
61 lines
1.6 KiB
GLSL
Executable file
// Based on work by David Li(http://david.li/waves)
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#version 450
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#ifdef GL_ES
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precision mediump float;
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#endif
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const float PI = 3.14159265359;
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const float G = 9.81;
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const float KM = 370.0;
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const float size = 250.0;
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const float resolution = 512.0;
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const float choppiness = 1.5;
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uniform sampler2D texPhases;
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uniform sampler2D texInitialSpectrum;
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in vec2 texCoord;
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out vec4 fragColor;
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vec2 multiplyComplex(vec2 a, vec2 b) {
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return vec2(a[0] * b[0] - a[1] * b[1], a[1] * b[0] + a[0] * b[1]);
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}
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vec2 multiplyByI(vec2 z) {
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return vec2(-z[1], z[0]);
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}
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float omega(float k) {
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return sqrt(G * k * (1.0 + k * k / KM * KM));
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}
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void main() {
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vec2 coordinates = texCoord * resolution;// gl_FragCoord.xy - 0.5;
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float n = (coordinates.x < resolution * 0.5) ? coordinates.x : coordinates.x - resolution;
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float m = (coordinates.y < resolution * 0.5) ? coordinates.y : coordinates.y - resolution;
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vec2 waveVector = (2.0 * PI * vec2(n, m)) / size;
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float phase = texture2D(texPhases, texCoord).r;
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vec2 phaseVector = vec2(cos(phase), sin(phase));
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vec2 h0 = texture2D(texInitialSpectrum, texCoord).rg;
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vec2 h0Star = texture2D(texInitialSpectrum, vec2(1.0 - texCoord + 1.0 / resolution)).rg;
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h0Star.y *= -1.0;
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vec2 h = multiplyComplex(h0, phaseVector) + multiplyComplex(h0Star, vec2(phaseVector.x, -phaseVector.y));
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vec2 hX = -multiplyByI(h * (waveVector.x / length(waveVector))) * choppiness;
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vec2 hZ = -multiplyByI(h * (waveVector.y / length(waveVector))) * choppiness;
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// No DC term
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if (waveVector.x == 0.0 && waveVector.y == 0.0) {
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h = vec2(0.0);
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hX = vec2(0.0);
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hZ = vec2(0.0);
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}
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fragColor = vec4(hX + multiplyByI(h), hZ);
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}
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