Files
glsl_playground/utilities/shapes.glsl

31 lines
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GLSL

vec3 circle(in vec2 _st, in float _radius, vec3 color){
vec2 dist = _st-vec2(0.5);
return color-smoothstep(_radius-(_radius*0.02),
_radius+(_radius*0.02),
dot(dist,dist)*4.0);
}
vec3 box(vec2 width, vec2 height) {
height = vec2(0.5) - height*0.5;
vec2 he = height+0.001;
vec2 uv = smoothstep(height, he, width);
uv *= smoothstep(height, he, vec2(1.0)-width);
return vec3(uv.x*uv.y);
}
// Inspired by (but modified)
// http://thndl.com/square-shaped-shaders.html
#define TAU 6.28318530718
vec3 polygon(int n, float size, vec2 pos, vec3 color, float rot) {
float e = 0.01;
vec2 st = gl_FragCoord.xy/u_resolution.xy;
st.x *= u_resolution.x/u_resolution.y;
st = (st-pos)*2.;
float a = atan(st.x,st.y)+rot;
float r = TAU/float(n);
float d = cos(floor(.5+a/r)*r-a)*length(st);
return color-smoothstep(size-e,size+e,d);
}