mirror of https://github.com/axmolengine/axmol.git
116 lines
4.4 KiB
GLSL
116 lines
4.4 KiB
GLSL
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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 float iChannelTime[4]; // channel playback time (in seconds)
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//uniform vec3 iChannelResolution[4]; // channel resolution (in pixels)
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vec4 iMouse = vec4(0,0,0,0); // mouse pixel coords. xy: current (if MLB down), zw: click
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//uniform sampler2D iChannel0; // input channel. XX = 2D/Cube
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uniform vec4 u_Time;
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void main(void)
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{
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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 iResolution = resolution; // viewport resolution (in pixels)
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float iGlobalTime = u_Time[1]; // shader playback time (in seconds)
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float pointRadius = 0.06;
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float linkSize = 0.04;
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float noiseStrength = 0.08; // range: 0-1
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float minDimension = min(iResolution.x, iResolution.y);
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vec2 bounds = vec2(iResolution.x / minDimension, iResolution.y / minDimension);
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//vec2 uv = fragCoord.xy / minDimension;
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vec2 uv = (2. * fragCoord.xy - center.xy) / iResolution.xy;
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vec3 pointR = vec3(0.0, 0.0, 1.0);
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vec3 pointG = vec3(0.0, 0.0, 1.0);
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vec3 pointB = vec3(0.0, 0.0, 1.0);
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// Make the points orbit round the origin in 3 dimensions.
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// Coefficients are arbitrary to give different behaviours.
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// The Z coordinate should always be >0.0, as it's used directly to
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// multiply the radius to give the impression of depth.
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pointR.x += 0.32 * sin(1.32 * iGlobalTime);
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pointR.y += 0.3 * sin(1.03 * iGlobalTime);
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pointR.z += 0.4 * sin(1.32 * iGlobalTime);
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pointG.x += 0.31 * sin(0.92 * iGlobalTime);
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pointG.y += 0.29 * sin(0.99 * iGlobalTime);
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pointG.z += 0.38 * sin(1.24 * iGlobalTime);
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pointB.x += 0.33 * sin(1.245 * iGlobalTime);
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pointB.y += 0.3 * sin(1.41 * iGlobalTime);
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pointB.z += 0.41 * sin(1.11 * iGlobalTime);
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// Centre the points in the display
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vec2 midUV = vec2(bounds.x * 0.5, bounds.y * 0.5);
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pointR.xy += midUV;
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pointG.xy += midUV;
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pointB.xy += midUV;
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// Calculate the vectors from the current fragment to the coloured points
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vec2 vecToR = pointR.xy - uv;
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vec2 vecToG = pointG.xy - uv;
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vec2 vecToB = pointB.xy - uv;
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vec2 dirToR = normalize(vecToR.xy);
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vec2 dirToG = normalize(vecToG.xy);
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vec2 dirToB = normalize(vecToB.xy);
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float distToR = length(vecToR);
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float distToG = length(vecToG);
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float distToB = length(vecToB);
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// Calculate the dot product between vectors from the current fragment to each pair
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// of adjacent coloured points. This helps us determine how close the current fragment
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// is to a link between points.
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float dotRG = dot(dirToR, dirToG);
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float dotGB = dot(dirToG, dirToB);
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float dotBR = dot(dirToB, dirToR);
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// Start with a bright coloured dot around each point
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gl_FragColor.x = 1.0 - smoothstep(distToR, 0.0, pointRadius * pointR.z);
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gl_FragColor.y = 1.0 - smoothstep(distToG, 0.0, pointRadius * pointG.z);
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gl_FragColor.z = 1.0 - smoothstep(distToB, 0.0, pointRadius * pointB.z);
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gl_FragColor.w = 1.0;
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// We want to show a coloured link between adjacent points.
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// Determine the strength of each link at the current fragment.
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// This tends towards 1.0 as the vectors to each point tend towards opposite directions.
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float linkStrengthRG = 1.0 - smoothstep(dotRG, -1.01, -1.0 + (linkSize * pointR.z * pointG.z));
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float linkStrengthGB = 1.0 - smoothstep(dotGB, -1.01, -1.0 + (linkSize * pointG.z * pointB.z));
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float linkStrengthBR = 1.0 - smoothstep(dotBR, -1.01, -1.0 + (linkSize * pointB.z * pointR.z));
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// If the current fragment is in a link, we need to know how much the
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// linked points contribute of their colour.
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float sumDistRG = distToR + distToG;
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float sumDistGB = distToG + distToB;
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float sumDistBR = distToB + distToR;
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float contribRonRG = 1.0 - (distToR / sumDistRG);
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float contribRonBR = 1.0 - (distToR / sumDistBR);
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float contribGonRG = 1.0 - (distToG / sumDistRG);
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float contribGonGB = 1.0 - (distToG / sumDistGB);
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float contribBonGB = 1.0 - (distToB / sumDistGB);
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float contribBonBR = 1.0 - (distToB / sumDistBR);
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// Additively blend the link colours into the fragment.
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gl_FragColor.x += (linkStrengthRG * contribRonRG) + (linkStrengthBR * contribRonBR);
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gl_FragColor.y += (linkStrengthGB * contribGonGB) + (linkStrengthRG * contribGonRG);
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gl_FragColor.z += (linkStrengthBR * contribBonBR) + (linkStrengthGB * contribBonGB);
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// Use an underlying texture to provide some noise
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float noiseMin = 1.0 - noiseStrength;
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gl_FragColor.xyz *= (1.0 - noiseStrength) + (noiseStrength * 0.);
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}
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