51 lines
1.4 KiB
GLSL
51 lines
1.4 KiB
GLSL
uniform sampler2D sceneTex;
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uniform float textureWidth;
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uniform float textureHeight;
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uniform float time;
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varying vec2 pos;
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#define DEG2RAD (6.2832/360.0)
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// Converts pixel coordinates to texture coordinates
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vec2 pix2tex(vec2 pix)
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{
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return vec2(pix.x / textureWidth, 1.0 - pix.y / textureHeight);
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}
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float wave(vec2 pos, vec2 wave_dir, float wave_length, float wave_speed)
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{
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return sin(((pos.x * wave_dir.x) + (pos.y * wave_dir.y)) * 6.2832 / wave_length +
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time * wave_speed * 6.2832 / wave_length);
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}
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vec2 displacement(float wave_angle, float wave_length, float wave_speed, float wave_height)
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{
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vec2 wave_dir = vec2(cos(wave_angle * DEG2RAD), sin(wave_angle * DEG2RAD));
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return wave_dir * (wave(pos, wave_dir, wave_length, wave_speed) * wave_height);
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}
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// Only for debugging
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float wave_color(float wave_angle, float wave_length, float wave_speed, float wave_height)
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{
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vec2 wave_dir = vec2(cos(wave_angle * DEG2RAD), sin(wave_angle * DEG2RAD));
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return wave(pos, wave_dir, wave_length, wave_speed) * 0.5 + 0.5;
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}
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void main()
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{
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vec2 texpos = pos;
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texpos += displacement( 20.0, 250.0, 120.0, 4.0);
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texpos += displacement(-40.0, 350.0, 100.0, 4.0);
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texpos += displacement(240.0, 1000.0, 100.0, 12.0);
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texpos += displacement(160.0, 50.0, 30.0, 2.0);
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vec3 tex = texture2D(sceneTex, pix2tex(texpos)).rgb;
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//tex.r = wave_color( 20, 250, 150, 4); // debug
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gl_FragColor = vec4(tex, 1.0);
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}
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