diff --git a/experiments/cubes/main.frag b/experiments/cubes/main.frag new file mode 100644 index 0000000..ad27a30 --- /dev/null +++ b/experiments/cubes/main.frag @@ -0,0 +1,122 @@ +#ifdef GL_ES +precision mediump float; +#endif + +uniform vec2 u_resolution; +uniform vec2 u_mouse; +uniform float u_time; + +#define PI 3.14159265359 + +float rhombSDF(vec2 st) { + vec2 st1 = (st)*2.; + vec2 st2 = (vec2(st.x,0.-st.y)*2.-1.)*2.; + float triangle1 = max(abs(st1.x)*.866025+st1.y*.5,-st1.y*.5); + float triangle2 = max(abs(st2.x)*.866025+st2.y*.5,-st2.y*.5); + return max(triangle1, triangle2); +} + +float rectSDF(vec2 st, vec2 s) { + return max(abs(st.x/s.x),abs(st.y/s.y)); +} + +float random (vec2 st) { + return fract(sin(dot(st.xy, + vec2(12.9898,78.233)))* + 43758.5453123); +} + +float stroke(in float x_coor, float s, float width){ + float d = step(s,x_coor+width*.5)-step(s,x_coor-width*.5); + return clamp(d, 0.,1.); +} + +float triSDF(vec2 st) { + st = st*2.; + return max(abs(st.x)*.866025+st.y*.5,-st.y*.5); +} + +vec2 rotate(vec2 st, float a) { + return mat2(cos(a),-sin(a),sin(a),cos(a))*(st); +} + + +float sphereSDF(vec3 p, float r) { + return length(p) - r; +} + +float sceneSDF(vec3 ray) { + return sphereSDF(ray, .0001); +} + +float boxSDF(vec3 p, vec3 b) +{ + vec3 q = abs(p) - b; + return length(max(q,0.0)) + min(max(q.x,max(q.y,q.z)),0.0); +} + +mat4 rotateY(float theta) { + float c = cos(theta); + float s = sin(theta); + + return mat4( + vec4(c,0,s,0), + vec4(0,1,0,0), + vec4(-s,0,c,0), + vec4(0,0,0,1) + ); + +} +mat4 rotation3d(vec3 axis, float angle) { + axis = normalize(axis); + float s = sin(angle); + float c = cos(angle); + float oc = 1.0 - c; + + return mat4( + oc * axis.x * axis.x + c, oc * axis.x * axis.y - axis.z * s, oc * axis.z * axis.x + axis.y * s, 0.0, + oc * axis.x * axis.y + axis.z * s, oc * axis.y * axis.y + c, oc * axis.y * axis.z - axis.x * s, 0.0, + oc * axis.z * axis.x - axis.y * s, oc * axis.y * axis.z + axis.x * s, oc * axis.z * axis.z + c, 0.0, + 0.0, 0.0, 0.0, 1.0 + ); +} + + +float rayMarch(vec3 ro, vec3 rd, float start, float end, vec4 rot) { + + float MAX_MARCHING_STEPS = 250.; + float EPSILON = 0.1; + float depth = start; + for (float i = 0.; i < MAX_MARCHING_STEPS; i++) { + vec3 p = ro + depth * rd; + p = (rotation3d(rot.xyz, rot.w) * vec4(p, 1.0)).xyz; + float d = boxSDF(p , vec3(.5,.5,.5)); + depth += d; + if (d < EPSILON || depth > end) break; + } + return depth; +} + + + +void main() { + vec2 st = (gl_FragCoord.xy-.5*u_resolution) / u_resolution.y; + float temp = 0.; + vec3 ro = vec3(0, 0, 5); //ray origin + vec3 rd = normalize(vec3(st, -1)); //ray direction + float d = rayMarch(ro+vec3(0,.2,.0), rd, 0.,100.,vec4(.4,.8,-.9,.4)); + d = min(d,rayMarch(ro+vec3(-.2,.0,.0), rd, 0.,100.,vec4(.2,.1,.3,.9))); + d = min(d,rayMarch(ro+vec3(-.2,-.8,.0), rd, 0.,100.,vec4(.2,.1,.3,.9))); + d = min(d,rayMarch(ro+vec3(-.2,.3,.0), rd, 0.,100.,vec4(.2,.1,.3,.9))); + d = min(d,rayMarch(ro+vec3(-.2,.0,-.8), rd, 0.,100.,vec4(.2,.1,.3,.9))); + d = 1.-d/7.; + vec3 col = vec3(d); + if (d > 100.0) { + //col = vec3(0.1); + } else { + //col = vec3(0.,0.,1.); + } + + + gl_FragColor = vec4(col, 1.0); +}