axmol/tests/cpp-tests/Resources/Shaders/example_Mandelbrot.fsh

48 lines
1.1 KiB
GLSL

// Shader from http://www.iquilezles.org/apps/shadertoy/
#ifdef GL_ES
precision highp float;
#endif
uniform vec2 center;
uniform vec2 resolution;
uniform vec2 u_screenSize;
uniform vec4 u_Time;
void main(void)
{
#ifdef METAL
vec2 fragCoord = vec2(gl_FragCoord.x, u_screenSize.y - gl_FragCoord.y);
#else
vec2 fragCoord = gl_FragCoord.xy;
#endif
vec2 p = 2.0 * (fragCoord - center.xy) / resolution.xy;
p.x *= resolution.x/resolution.y;
float zoo = .62+.38*sin(.1*u_Time[1]);
float coa = cos( 0.1*(1.0-zoo)*u_Time[1] );
float sia = sin( 0.1*(1.0-zoo)*u_Time[1] );
zoo = pow( zoo,8.0);
vec2 xy = vec2( p.x*coa-p.y*sia, p.x*sia+p.y*coa);
vec2 cc = vec2(-.745,.186) + xy*zoo;
vec2 z = vec2(0.0);
vec2 z2 = z*z;
float m2;
float co = 0.0;
for( int i=0; i<256; i++ )
{
z = cc + vec2( z.x*z.x - z.y*z.y, 2.0*z.x*z.y );
m2 = dot(z,z);
if( m2>1024.0 ) break;
co += 1.0;
}
co = co + 1.0 - log2(.5*log2(m2));
co = sqrt(co/256.0);
gl_FragColor = vec4( .5+.5*cos(6.2831*co+0.0),
.5+.5*cos(6.2831*co+0.4),
.5+.5*cos(6.2831*co+0.7),
1.0 );
}