fractorb
annotate mbrot.glsl @ 0:6e849d7377ff
initial commit
| author | John Tsiombikas <nuclear@member.fsf.org> |
|---|---|
| date | Sat, 18 Nov 2017 20:04:16 +0200 |
| parents | |
| children | 436f82447c44 |
| rev | line source |
|---|---|
| nuclear@0 | 1 // vi:ft=glsl: |
| nuclear@0 | 2 #define ITER 96 |
| nuclear@0 | 3 |
| nuclear@0 | 4 uniform float view_scale; |
| nuclear@0 | 5 uniform vec2 view_center; |
| nuclear@0 | 6 |
| nuclear@0 | 7 float mbrot_dist_point(in vec2 c, in vec2 p) |
| nuclear@0 | 8 { |
| nuclear@0 | 9 vec2 z = c; |
| nuclear@0 | 10 float mindist_sq = 8192.0; |
| nuclear@0 | 11 |
| nuclear@0 | 12 for(int i=0; i<ITER; i++) { |
| nuclear@0 | 13 float x = (z.x * z.x - z.y * z.y) + c.x; |
| nuclear@0 | 14 float y = (z.x * z.y + z.x * z.y) + c.y; |
| nuclear@0 | 15 |
| nuclear@0 | 16 z = vec2(x, y); |
| nuclear@0 | 17 mindist_sq = min(mindist_sq, dot(z, z)); |
| nuclear@0 | 18 } |
| nuclear@0 | 19 |
| nuclear@0 | 20 return sqrt(mindist_sq); |
| nuclear@0 | 21 } |
| nuclear@0 | 22 |
| nuclear@0 | 23 void main() |
| nuclear@0 | 24 { |
| nuclear@0 | 25 vec2 c = gl_TexCoord[0].xy * view_scale - view_center; |
| nuclear@0 | 26 float m = 1.0 - mbrot_dist_point(c, vec2(0.0, 0.0)); |
| nuclear@0 | 27 |
| nuclear@0 | 28 gl_FragColor.rgb = vec3(m, m, m); |
| nuclear@0 | 29 gl_FragColor.a = 1.0; |
| nuclear@0 | 30 } |