thebookofshaders/examples/07/distanceFieldAnimate.frag
Patricio Gonzalez Vivo dfae205172 adding examples
2015-10-09 17:43:53 -04:00

40 lines
1.2 KiB
GLSL
Executable File

#ifdef GL_ES
precision mediump float;
#endif
#define TWO_PI 6.28318530718
uniform vec2 u_resolution;
uniform vec2 u_mouse;
uniform float u_time;
// rotation transformation matrix
mat2 rotationMatrix( float angle)
{
return mat2( cos( angle ), -sin( angle ),
sin( angle ), cos( angle ));
}
void main(){
vec2 st = gl_FragCoord.xy/u_resolution.xy;
vec3 color = vec3(0.0);
float d = 1.0;
// Remap the space to -1. to 1.
st = (st *2.-1. );
// Remap the coordinates with rotation using transformation matrix
st = st * rotationMatrix(u_time/1.5);
// Create secondary set of coordinates rotated in opposing direction
vec2 st2 = st * rotationMatrix(u_time * -2.);
// Make the distance field - composite the different formulars together
d = length( abs(st2)- sin(u_time+ 0.5) +0.9 );
d *= 1. - length( 1. - max(abs(st)-sin(u_time/1.),0.) ) ;
d *= length( min(abs(st2)- sin((u_time/ 4.)), sin(u_time / 10. + 0.1)) );
// Visualize the distance field
gl_FragColor = vec4( clamp (fract(d* abs(sin(u_time/ 4.)) ), 0.6, 0.1) , clamp(fract(d* abs(log(u_time/10.)) ), 0.9, 1.), clamp ( 1. -abs(cos(u_time)), 0.5, 1. ), fract(d* abs(sin(u_time/ 4.)) ));
}