thebookofshaders/09/zigzag.frag
Patricio Gonzalez Vivo 23aa64f115 adding patterns
2015-03-31 16:03:11 -04:00

38 lines
789 B
GLSL

// Author @patriciogv - 2015
// http://patriciogonzalezvivo.com
#ifdef GL_ES
precision mediump float;
#endif
uniform vec2 u_resolution;
uniform vec2 u_mouse;
uniform float u_time;
vec2 mirrorTile(vec2 _st, float _zoom){
_st *= _zoom;
if (fract(_st.y * 0.5) > 0.5){
_st.x = _st.x+0.5;
_st.y = 1.0-_st.y;
}
return fract(_st);
}
float fillY(vec2 _st, float _pct,float _antia){
return smoothstep( _pct-_antia, _pct, _st.y);
}
void main(){
vec2 st = gl_FragCoord.xy/u_resolution.xy;
vec3 color = vec3(0.0);
st = mirrorTile(st*vec2(1.,2.),5.);
float x = st.x*2.;
float a = floor(1.+sin(x*3.14));
float b = floor(1.+sin((x+1.)*3.14));
float f = fract(x);
color = vec3( fillY(st,mix(a,b,f),0.01) );
gl_FragColor = vec4( color, 1.0 );
}