#define SHOW_SEGMENTS 1 // segment.x is distance to closest point // segment.y is barycentric coefficient for closest point // segment.z is length of closest point on curve, on the curve, starting from A // segment.a is approximate length of curve vec4 segment( vec2 p, vec2 a, vec2 b ) { a -= p; b -= p; vec3 k = vec3( dot(a,a) , dot(b,b) , dot(a,b) ); float t = (k.x - k.z)/( k.x + k.y - 2.*k.z ); float len = length(b-a); if( t < 0. ){ return vec4( sqrt(k.x) , 0. , 0. , len ); } else if( t > 1. ){ return vec4( sqrt(k.y) , 1. , len , len ); } else { return vec4( length(a*(1.-t) + b*t) , t , t*len , len ); } } // https://www.shadertoy.com/view/4djSRW #define ITERATIONS 4 // *** Change these to suit your range of random numbers.. // *** Use this for integer stepped ranges, ie Value-Noise/Perlin noise functions. #define HASHSCALE1 .1031 #define HASHSCALE3 vec3(.1031, .1030, .0973) #define HASHSCALE4 vec4(1031, .1030, .0973, .1099) //---------------------------------------------------------------------------------------- /// 3 out, 2 in... vec3 hash32(vec2 p) { vec3 p3 = fract(vec3(p.xyx) * HASHSCALE3); p3 += dot(p3, p3.yxz+19.19); return fract((p3.xxy+p3.yzz)*p3.zyx); } vec3 hash3point(vec2 p) { //vec3 col = hash32(p); vec3 col = hash32(p*1.25672+vec2(.2,.8)) * hash32(vec2(p.y,p.x)/3.42464-vec2(.5,.0)) - hash32(vec2(3.0+p.y,1.2)) ; return pow( (abs(col)+max(col,0.0))/2.0 , vec3(.6,.5,.4) ); } float smoothFunction(float k) { return 1.0 / ( 1.0 + k*k ); } vec3 smoothFunction(vec3 k) { return 1.0 / ( 1.0 + k*k ); } float coeffDistPoint(vec2 uv,vec2 colPoint,float scale) { //float dist = length(uv - colPoint) * scale; //dist = pow(dist,0.25); //dist = 1.0 - smoothstep(0.0,1.0,dist); vec2 uv_ = (uv - colPoint)*scale*24.0; float dist = dot(uv_,uv_); return 1.0 / ( 1.0 + dist ); } vec3 mixColorLine(vec2 uv,vec3 currentCol,vec3 colLine,vec2 lineA,vec2 lineB,float scale) { return mix( currentCol , colLine , 1.0 - smoothstep(0.0,1.0,(( segment(uv,lineA,lineB).x * scale ))) ); } // pointA and pointB are on the same side of the half plane delimited by line (lineA,lineB) bool pointsOnSameSideOfLine(vec2 pointA,vec2 pointB,vec2 lineA, vec2 lineB) { vec2 n = lineB - lineA; n = vec2(n.y,-n.x); return dot(pointA-lineA,n) * dot(pointB-lineA,n) > 0.0; } float viewportMagnify = 1.0; vec2 screenToViewport(vec2 uv) { return (uv - iResolution.xy/2.0 ) / min(iResolution.x,iResolution.y) * viewportMagnify; } vec2 viewportToScreen(vec2 uv,vec2 base) { return (uv - base/4.0) / viewportMagnify * min(iResolution.x,iResolution.y) + iResolution.xy/2.0; //return (uv - iResolution.xy/2.0 ) / min(iResolution.x,iResolution.y) * viewportMagnify; } float det22(vec2 a,vec2 b) { return a.x*b.y - a.y*b.x; } struct Pinwheel { vec2 A; // Right angle, divided into 1 acute and 1 obtuse vec2 B; // Acute angle, stays acute vec2 C; // Obtuse angle, stays obtuse vec2 D; // on GA vec2 E; // on AB vec2 F; // on BC, close to B vec2 G; // on BC, close to C }; vec3 barycentricCoordinate(vec2 P,Pinwheel T) { vec2 PA = P - T.A; vec2 PB = P - T.B; vec2 PC = P - T.C; vec3 r = vec3( det22(PB,PC), det22(PC,PA), det22(PA,PB) ); return r / (r.x + r.y + r.z); } #define EQUERRE_COPY(T,Q) \ T.A = Q.A; \ T.B = Q.B; \ T.C = Q.C; #define EQUERRE_COMPUTE_DEFG(T) \ T.E = (T.A + T.B)/2.0; \ T.F = (3.0 * T.B + 2.0 * T.C)/5.0; \ T.G = (T.B + 4.0 * T.C)/5.0; \ T.D = (T.G + T.A)/2.0; #define EQUERRE_GET1(T,Q) \ T.A = Q.F; \ T.B = Q.B; \ T.C = Q.E; #define EQUERRE_GET2(T,Q) \ T.A = Q.F; \ T.B = Q.G; \ T.C = Q.E; #define EQUERRE_GET3(T,Q) \ T.A = Q.D; \ T.B = Q.E; \ T.C = Q.G; #define EQUERRE_GET4(T,Q) \ T.A = Q.D; \ T.B = Q.E; \ T.C = Q.A; #define EQUERRE_GET5(T,Q) \ T.A = Q.G; \ T.B = Q.A; \ T.C = Q.C; #define EQUERRE_COND_12_345(X,T) \ pointsOnSameSideOfLine(uv,T.F,T.E,T.G) #define EQUERRE_COND_1_2(X,T) \ pointsOnSameSideOfLine(uv,T.B,T.E,T.F) #define EQUERRE_COND_34_5(X,T) \ pointsOnSameSideOfLine(uv,T.E,T.A,T.G) #define EQUERRE_COND_3_4(X,T) \ pointsOnSameSideOfLine(uv,T.G,T.E,T.D) #define EQUERRE_CENTER(T) ((T.A+T.B+T.C)/3.0) void mainImage( out vec4 fragColor, in vec2 fragCoord ) { int nbIterations = iMouse.z > .5 ? 5 : 4; vec2 base = vec2(2.0,1.0); vec2 uv = screenToViewport(fragCoord.xy ); viewportMagnify = 1./1.; uv *= viewportMagnify; //uv *= mat2(cos(iTime/48.+vec4(0.,1.6,-1.6,0.))); uv += base/2.3; // Base Triangle Pinwheel Tri; Pinwheel Tri_TMP; Tri.A = Tri.B = Tri.C = vec2(0.0); Tri.B.x += base.x; Tri.C.y += base.y; fragColor = vec4(1.); vec3 coeffs = barycentricCoordinate(uv,Tri); float e = -1e-2; if( coeffs.x < e || coeffs.y < e || coeffs.z < e ) return; int PinwheelID = 0; int Mode = int(floor(mod(iTime/1.5,8.))); for(int i = 0 ; i < nbIterations ; i++) { PinwheelID *= 5; EQUERRE_COMPUTE_DEFG(Tri); if( EQUERRE_COND_12_345(uv,Tri) ) { if( EQUERRE_COND_1_2(uv,Tri) ) { EQUERRE_GET1(Tri_TMP,Tri); } else { EQUERRE_GET2(Tri_TMP,Tri); PinwheelID += 1; } } else if( EQUERRE_COND_34_5(uv,Tri) ) { if( EQUERRE_COND_3_4(uv,Tri) ) { EQUERRE_GET3(Tri_TMP,Tri); PinwheelID += 2; } else { EQUERRE_GET4(Tri_TMP,Tri); PinwheelID += 3; } } else { EQUERRE_GET5(Tri_TMP,Tri); PinwheelID += 4; } EQUERRE_COPY(Tri,Tri_TMP); } //fragColor.rgb = hash3point(EQUERRE_CENTER(Tri)); float k = float(PinwheelID)/pow(5.,float(nbIterations)); k = ( k - mod(iTime*.05,1.) )/.2/(iMouse.z > .5 ? .2 : 1.); fragColor.rgb -= step( abs(k) , 1. ) * (cos(k*vec3(7.,5.,3.)*3.)*.5+.5)*(1. - k*k); // interesting variation // but needs tuning in color //fragColor = sqrt( cos(fragColor*3.14*vec4(1.,2.,3.,1.))*.5+.5 ); float scale = float(nbIterations); scale = pow(2.0,scale)/viewportMagnify/scale*16.; vec3 EquerreColor = vec3(.0);//1. - fragColor.rgb; #if SHOW_SEGMENTS==1 #define OPERATION1(x,y) fragColor.rgb = mixColorLine(uv,fragColor.rgb,EquerreColor,x,y,scale); OPERATION1(Tri.A,Tri.B); OPERATION1(Tri.B,Tri.C); OPERATION1(Tri.C,Tri.A); #endif fragColor.rgb = tanh(fragColor.rgb*6.); }