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.
thebookofshaders/08/cross-translate.frag

42 lines
1013 B
GLSL

// Author @patriciogv ( patriciogonzalezvivo.com ) - 2015
#ifdef GL_ES
precision mediump float;
#endif
uniform vec2 u_resolution;
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;
vec3 color = vec3(0.0);
// To move the cross we move the space
vec2 translate = vec2(cos(u_time),sin(u_time));
st += translate*0.35;
// Show the coordinates of the space on the background
// color = vec3(st.x,st.y,0.0);
// Add the shape on the foreground
color += vec3(cross(st,0.25));
gl_FragColor = vec4(color,1.0);
}