You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
59 lines
1.1 KiB
GLSL
59 lines
1.1 KiB
GLSL
// Author @patriciogv - 2015
|
|
// http://patriciogonzalezvivo.com
|
|
|
|
#ifdef GL_ES
|
|
precision mediump float;
|
|
#endif
|
|
|
|
#define PI 3.14159265358979323846
|
|
|
|
uniform vec2 u_resolution;
|
|
uniform float u_time;
|
|
|
|
vec2 rotate2D (vec2 _st, float _angle) {
|
|
_st -= 0.5;
|
|
_st = mat2(cos(_angle),-sin(_angle),
|
|
sin(_angle),cos(_angle)) * _st;
|
|
_st += 0.5;
|
|
return _st;
|
|
}
|
|
|
|
vec2 tile (vec2 _st, float _zoom) {
|
|
_st *= _zoom;
|
|
return fract(_st);
|
|
}
|
|
|
|
vec2 rotateTilePattern(vec2 _st){
|
|
_st *= 2.0;
|
|
|
|
float index = 0.0;
|
|
if (fract(_st.x * 0.5) > 0.5){
|
|
index += 1.0;
|
|
}
|
|
if (fract(_st.y * 0.5) > 0.5){
|
|
index += 2.0;
|
|
}
|
|
|
|
_st = fract(_st);
|
|
|
|
if(index == 1.0){
|
|
_st = rotate2D(_st,PI*0.5);
|
|
} else if(index == 2.0){
|
|
_st = rotate2D(_st,PI*-0.5);
|
|
} else if(index == 3.0){
|
|
_st = rotate2D(_st,PI);
|
|
}
|
|
|
|
return _st;
|
|
}
|
|
|
|
void main (void) {
|
|
vec2 st = gl_FragCoord.xy/u_resolution.xy;
|
|
|
|
st = tile(st,3.0);
|
|
st = rotateTilePattern(st);
|
|
// st = tile(st,3.0);
|
|
// st = rotate2D(st,-PI*u_time*0.25);
|
|
|
|
gl_FragColor = vec4(vec3(step(st.x,st.y)),1.0);
|
|
} |