#define r 300.0
uniform int _t;
vec2 center = vec2(1366.0 / 2.0, 768.0 / 2.0);
void main()
{
vec2 c = vec2((gl_FragCoord.x - center.x) / r, (gl_FragCoord.y - center.y) / r);
vec3 color;
vec2 z = c;
float a = 0;
for(int i = 0;i < 64;i++)
{
a = float(i);
z = vec2(z.x * z.x - z.y * z.y, 2 * z.x * z.y) + c;
if(length(z) > 32)
break;
}
gl_FragColor = vec4(vec3(a / float(20)), 1.0);
}
[GLSL]着色器周记03
原文：http://www.cnblogs.com/tkgamegroup/p/4228255.html
