78 lines
1.9 KiB
JavaScript
78 lines
1.9 KiB
JavaScript
export default `#define MAX_STEPS 1280
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#define MAX_DIST 1280.
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#define E 0.00001
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#define PI 3.141592
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vec3 rotX(vec3 v, float a) {
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return vec3(v.x, v.y * cos(a) - v.z * sin(a), v.y * sin(a) + v.z * cos(a));
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}
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vec3 rotY(vec3 v, float a) {
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return vec3(v.x * cos(a) + v.z * sin(a), v.y, v.z * cos(a) - v.x * sin(a));
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}
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vec3 rotZ(vec3 v, float a) {
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return vec3(v.x * cos(a) - v.y * sin(a), v.x * sin(a) + v.y * cos(a), v.z);
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}
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float sdfSphere(vec3 p, float r) {
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return length(p) - r;
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}
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float scene(vec3 p) {
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int index = -1;
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float d = 10000.;
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float sd1 = sdfSphere(p, 1.);
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d = min(sd1, d);
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return d;
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}
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vec2 march(vec3 ro, vec3 rd) {
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float dO = 0.;
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float mind = 10000.;
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float index;
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for (int steps = 0; steps < MAX_STEPS; steps++) {
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vec3 p = ro + rd * dO;
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float dS = scene(p);
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if (dS < mind)
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mind = dS;
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dO += dS;
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if (dS < E || dO > MAX_DIST)
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break;
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}
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return vec2(dO, mind);
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}
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vec3 normal(vec3 p) {
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float d = scene(p);
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vec2 e = vec2(0.001, 0);
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vec3 n = d - vec3(
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scene(p - e.xyy),
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scene(p - e.yxy),
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scene(p - e.yyx));
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return (normalize(n));
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}
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float light(vec3 p, vec3 n) {
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vec3 lightPos = vec3(-5. * sin(iTime * 4.), -5. * sin(iTime * 3.), -5. * cos(iTime * 2.));
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vec3 l = normalize(lightPos - p);
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float dif = clamp(dot(l, n), 0., 1.);
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vec2 d = march(p+n*E * 30., l);
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if (d.x < length(lightPos - p))
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dif *= 0.1;
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return (dif);
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}
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void mainImage( out vec4 fragColor, in vec2 fragCoord ) {
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vec2 uv = ((fragCoord - .5 * iResolution.xy) / iResolution.y);
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vec3 ro = vec3(0., 0., -4.);
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vec3 rd = normalize(vec3(uv.x, uv.y, 1.));
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vec3 col = vec3(0);
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vec2 d = march(ro, rd);
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vec3 p = ro + rd * d.x;
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vec3 n = normal(p);
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p += n * E * 10.;
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float dif = light(p, n);
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col += vec3(dif);
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fragColor = vec4(col, 1.0);
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}`;
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