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# CharStiles/learnWithJason.glsl

Created January 21, 2022 03:07
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 #ifdef GL_ES precision mediump float; #endif uniform vec2 u_resolution; uniform float u_time; uniform float u_vol; #define PI 3.14 float getBPMVis(float bpm){ // this function can be found graphed out here :https://www.desmos.com/calculator/rx86e6ymw7 float bps = 60./bpm; // beats per second float bpmVis = tan((u_time*PI)/bps); // multiply it by PI so that tan has a regular spike every 1 instead of PI // divide by the beat per second so there are that many spikes per second bpmVis = clamp(bpmVis,0.,10.); // tan goes to infinity so lets clamp it at 10 bpmVis = abs(bpmVis)/20.; // tan goes up and down but we only want it to go up // (so it looks like a spike) so we take the absolute value // dividing by 20 makes the tan function more spiking than smoothly going // up and down, check out the desmos link to see what i mean return bpmVis; } // https://math.stackexchange.com/questions/2491494/does-there-exist-a-smooth-approximation-of-x-bmod-y // found this equation and converted it to GLSL, usually e is supposed to be squared but in this case I like the way it looks as 0 //idk float smoothMod(float x, float y, float e){ float top = cos(PI * (x/y)) * sin(PI * (x/y)); float bot = pow(sin(PI * (x/y)),2.); float at = atan(top/bot); return y * (1./2.) - (1./PI) * at ; } // Repeat around the origin by a fixed angle. // For easier use, num of repetitions is use to specify the angle. vec2 modPolar(vec2 p, float repetitions) { float angle = 2.*3.14/repetitions; float a = atan(p.y, p.x) + angle/2.; float r = length(p); //float c = floor(a/angle); a = smoothMod(a,angle,033323231231561.9) - angle/2.; //a = mix(a,) vec2 p2 = vec2(cos(a), sin(a))*r; //p = mix(p,p2, pow(angle - abs(angle-(angle/2.) ) /angle , 2.) ); return p2; } // http://www.iquilezles.org/www/articles/palettes/palettes.htm // to see this function graphed out go to: https://www.desmos.com/calculator/rz7abjujdj vec3 cosPalette( float t , vec3 brightness, vec3 contrast, vec3 osc, vec3 phase) { return brightness + contrast*cos( 6.28318*(osc*t+phase) ); } void pR(inout vec2 p, float a) { p = cos(a)*p + sin(a)*vec2(p.y, -p.x); } // main is a reserved function that is going to be called first void main(void) { vec2 normCoord = gl_FragCoord.xy/u_resolution; float time = u_time/5.0; //slow down time vec2 uv = -1. + 2. * normCoord; uv.x *= u_resolution.x/u_resolution.y; pR(uv, time); uv = modPolar(uv,20. + (10. * abs(sin(time)))); uv.x += sin(time); pR(uv, -time); float radius = length(uv * 10.); float rings = sin(u_vol * 0.1 - radius) ; float angle = sin(atan(uv.x,uv.y)+time); float swirly = sin(rings + cos(angle) + time); float beat = getBPMVis(30.); vec3 brightness = vec3(mix(0.7, 0.1, (sin(time + length(uv*20.) +beat )+1.)/2.) ); vec3 contrast = vec3(0.15); vec3 osc = vec3(0.5,1.0,0); vec3 phase = vec3(0.4,0.9,0.2); vec3 palette = cosPalette(angle + swirly + rings, brightness, contrast, osc, phase); vec4 color = vec4(palette, 1); gl_FragColor = color; }
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