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.
51 lines
1.2 KiB
GLSL
51 lines
1.2 KiB
GLSL
// Author @patriciogv ( patriciogonzalezvivo.com ) - 2015
|
|
|
|
#ifdef GL_ES
|
|
precision mediump float;
|
|
#endif
|
|
|
|
#define PI 3.14159265359
|
|
|
|
uniform vec2 u_resolution;
|
|
uniform float u_time;
|
|
|
|
mat2 rotate2d(float angle){
|
|
return mat2(cos(angle),-sin(angle),
|
|
sin(angle),cos(angle));
|
|
}
|
|
|
|
float boxDF(vec2 st, float size) {
|
|
st = st*2.-1.;
|
|
return length(max(abs(st)-size,.0));
|
|
}
|
|
|
|
float box(vec2 st, float size, float radio) {
|
|
radio = max(radio,.000001);
|
|
return 1.-step(radio,boxDF(st,size-radio));
|
|
}
|
|
|
|
float cross(vec2 st, float radio) {
|
|
float size = .25;
|
|
size *= (1.0-radio*2.);
|
|
return box(st,size,radio) +
|
|
box(st+vec2(.0,size*(1.0-radio*2.)),size,min(radio,size)) +
|
|
box(st+vec2(.0,-size*(1.0-radio*2.)),size,min(radio,size)) +
|
|
box(st+vec2(size*(1.0-radio*2.),.0),size,min(radio,size)) +
|
|
box(st+vec2(-size*(1.0-radio*2.),.0),size,min(radio,size));
|
|
}
|
|
|
|
void main(){
|
|
vec2 st = gl_FragCoord.xy/u_resolution.xy;
|
|
st.x *= u_resolution.x/u_resolution.y;
|
|
vec3 color = vec3(0.0);
|
|
|
|
st -= vec2(0.5);
|
|
st = rotate2d( sin(u_time)*PI ) * st;
|
|
st += vec2(0.5);
|
|
|
|
// Add the shape on the foreground
|
|
color += cross(st,(1.0-abs(sin(u_time)))*.5);
|
|
|
|
gl_FragColor = vec4(color,1.0);
|
|
}
|