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

39 lines
829 B
GLSL

// Author @patriciogv - 2015
// http://patriciogonzalezvivo.com
#ifdef GL_ES
precision mediump float;
#endif
#define PI 3.14159265359
#define TWO_PI 6.28318530718
uniform vec2 u_resolution;
uniform vec2 u_mouse;
uniform float u_time;
float shape(vec2 st, float N){
st = st *2.-1.;
float a = atan(st.x,st.y)+PI;
float r = TWO_PI/floor(N);
return cos(floor(.5+a/r)*r-a)*length(st);
}
void main(){
vec2 st = gl_FragCoord.xy/u_resolution.xy;
st.x *= u_resolution.x/u_resolution.y;
vec3 color = vec3(0.0);
float sides = u_time*.5;
float minSides = 3.;
float maxSides = 6.;
float d = mix(shape(st,minSides+mod(sides,maxSides)),
shape(st,minSides+mod(sides+1.,maxSides)),
pow(fract(sides),20.));
// Size
d = step(.4,d);
gl_FragColor = vec4(vec3(1.0-d),1.0);
}