mirror of https://github.com/axmolengine/axmol.git
41 lines
887 B
GLSL
41 lines
887 B
GLSL
// Shader from http://www.iquilezles.org/apps/shadertoy/
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#ifdef GL_ES
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precision highp float;
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#endif
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uniform vec2 center;
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uniform vec2 resolution;
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uniform vec2 u_screenSize;
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uniform vec4 u_Time;
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void main(void)
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{
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float time = u_Time[1];
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#ifdef METAL
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vec2 fragCoord = vec2(gl_FragCoord.x, u_screenSize.y - gl_FragCoord.y);
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#else
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vec2 fragCoord = gl_FragCoord.xy;
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#endif
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vec2 p = 2.0 * (fragCoord - center.xy) / resolution.xy;
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// animate
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float tt = mod(time,2.0)/2.0;
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float ss = pow(tt,.2)*0.5 + 0.5;
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ss -= ss*0.2*sin(tt*6.2831*5.0)*exp(-tt*6.0);
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p *= vec2(0.5,1.5) + ss*vec2(0.5,-0.5);
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float a = atan(p.x,p.y)/3.141593;
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float r = length(p);
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// shape
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float h = abs(a);
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float d = (13.0*h - 22.0*h*h + 10.0*h*h*h)/(6.0-5.0*h);
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// color
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float f = step(r,d) * pow(1.0-r/d,0.25);
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gl_FragColor = vec4(f,0.0,0.0,1.0);
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}
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