precision highp float; uniform vec2 resolution; uniform float time; uniform vec2 mouse; uniform sampler2D backbuffer; const float pi = acos(-1.); const float pi2 = pi*2.; float hash(float x) { return fract(sin(x) * 43758.5453); } mat2 rotate(float a) { return mat2(cos(a), -sin(a), sin(a), cos(a)); } float atan2(float y, float x){ return x == 0.0 ? sign(y)*pi/2. : atan(y, x); } vec2 pmod(vec2 p, float r) { float a = atan2(p.y, p.x) + 2.0 * pi / r * 0.5; float n = 2.0 * pi / r; a = floor(a / n) * n; return p * rotate(-a); } float sdLine(vec2 p, vec2 normal, float l) { vec2 n = normalize(normal); return dot(p, n) - l; } float smoothMax(float d1, float d2, float k) { float h = exp(k*d1) + exp(k*d2); return log(h)/k; } const float rDango = 0.5; const float rStick = 0.05; const float dishPos = 5.; float dist(vec3 p) { float dDish = smoothMax(length(p-vec3(0,0,dishPos))-6., 9.-length(p-vec3(0,0,dishPos+3.5)), 5.); p.x = abs(p.x); if(p.x>rDango*1.1) { p.x -= rDango*2.2; } float dStick = max(length(p.zx)-rStick, max(p.y-1.4,-p.y-2.7)); vec3 z = p; z.y = abs(z.y); if(z.y>rDango) { z.y -= rDango*2.; } //float dPink = length(p-vec3(0,rDango*2.,0))-rDango; //float dWhite = length(p)-rDango; //float dGreen = length(p-vec3(0,-rDango*2.,0))-rDango; float dDango = length(z)-rDango; //return min(dDish, min(min(dPink, dWhite), min(dGreen, dStick))); return min(dDish, min(dDango, dStick)); } vec3 calcNormal(vec3 p) { vec2 e = vec2(0.0001, 0); return normalize(vec3(dist(p+e.xyy)-dist(p-e.xyy), dist(p+e.yxy)-dist(p-e.yxy), dist(p+e.yyx)-dist(p-e.yyx) )); } vec3 objColor(vec3 p) { vec3 col = vec3(0); float th = 0.001; if(smoothMax(length(p-vec3(0,0,dishPos))-6., 9.-length(p-vec3(0,0,dishPos+3.5)), 5.) < th) { col = vec3(1, 1, 1); } p.x = abs(p.x); if(p.x>rDango*1.1) { p.x -= rDango*2.2; } if(max(length(p.zx)-rStick, p.y-1.4) < th) { col = vec3(0.9, 0.7, 0.6); } else if(length(p-vec3(0,rDango*2.,0))-rDango < th) { col = vec3(0.8, 0.5, 0.6); } else if(length(p)-rDango < th) { col = vec3(1, 1, 0.95); } else if(length(p-vec3(0,-rDango*2.,0))-rDango < th) { col = vec3(0.5, 0.9, 0.3); } return col; } // https://wgld.org/d/glsl/g020.html float genShadow(vec3 ro, vec3 rd) { float h = 0.; float c = 0.001; float r = 1.0; float shadowCoef = 0.5; for(float t = 0.; t< 50.; t++) { h = dist(ro+rd*c); if(h < 0.001) { return shadowCoef; } r = min(r, h*16.0/c); c += h; } return 1.0 - shadowCoef + r*shadowCoef; } void main(void) { vec2 p = (gl_FragCoord.xy * 2.0 - resolution.xy) / min(resolution.x, resolution.y); vec3 col = vec3(0); vec2 q = resolution / min(resolution.x, resolution.y); vec3 background = vec3(0.5, 0.6, 0.95)*0.4; col += mix(background, vec3(1), smoothstep(0., 1.5, p.y)); // dango & stick & dish vec3 cPos = vec3(-6,0,2)*0.8; cPos.xy *= rotate(time*0.5); vec3 cDir = normalize(vec3(-cPos.x, -cPos.y, -2.)); vec3 up = normalize(vec3(0,0,1)); vec3 cSide = normalize(cross(cDir, up)); vec3 cUp = normalize(cross(cSide, cDir)); vec3 ray = normalize(p.x*cSide + p.y*cUp + cDir*2.5); vec3 lightDir = normalize(vec3(-1., -0.5, 0.8)); lightDir.xy *= rotate(time*0.5); vec3 rayPos = cPos; float d = 0.; for(int i=0; i<100; i++) { d = dist(rayPos); if(d < 0.001 || length(rayPos-cPos) > 20.) { break; } rayPos += ray*d; } if(d < 0.001) { vec3 normal = calcNormal(rayPos); float s = dot(normal, lightDir); float diff = max(s, 0.5); float spec = pow(max(s,0.), 60.); float shadow = genShadow(rayPos + normal*0.001, lightDir); col = (objColor(rayPos)*diff + spec) * shadow; } // snow const float N1 = 5.; for(float i=0.; i