thebookofshaders/07/cross.frag
Patricio Gonzalez Vivo 0160b2c15c finishing shapes
2015-04-02 13:43:22 -04:00

32 lines
738 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;
float box(in vec2 _st, in vec2 _size){
_size = vec2(0.5) - _size*0.5;
vec2 uv = smoothstep(_size,
_size+vec2(0.001),
_st);
uv *= smoothstep(_size,
_size+vec2(0.001),
vec2(1.0)-_st);
return uv.x*uv.y;
}
float cross(in vec2 _st, float _size){
return box(_st, vec2(_size,_size/4.)) +
box(_st, vec2(_size/4.,_size));
}
void main(){
vec2 st = gl_FragCoord.xy/u_resolution.xy;
gl_FragColor = vec4( vec3( cross(st,0.4) ) ,1.0);
}