thebookofshaders/07/rect-df.frag
2015-05-10 18:19:50 -04:00

30 lines
763 B
GLSL

#ifdef GL_ES
precision mediump float;
#endif
uniform vec2 u_resolution;
uniform vec2 u_mouse;
uniform float u_time;
void main(){
vec2 st = gl_FragCoord.xy/u_resolution.xy;
st.x *= u_resolution.x/u_resolution.y;
vec3 color = vec3(0.0);
float d = 0.0;
// Remap the space to -1. to 1.
st = st *2.-1.;
// Make the distance field
d = length( abs(st)-.3 );
// d = length( min(abs(st)-.3,0.) );
// d = length( max(abs(st)-.3,0.) );
// Visualize the distance field
gl_FragColor = vec4(vec3(fract(d*10.0)),1.0);
// Drawing with the distance field
// gl_FragColor = vec4(vec3( step(.3,d) ),1.0);
// gl_FragColor = vec4(vec3( step(.3,d) * step(d,.4)),1.0);
// gl_FragColor = vec4(vec3( smoothstep(.3,.4,d)* smoothstep(.6,.5,d)) ,1.0);
}