v4k-git-backup/demos/html5/art/fx/fxOutline.fs

19 lines
582 B
GLSL

uniform int thickness = 2;
uniform vec4 border_color = vec4(1,1,0,1);
void main() {
vec4 texel = texture(iChannel0, uv);
float outline = 0.0;
if( texel.a == 0.0 ) {
for( int x = -thickness; x <= thickness; x++ ) {
for( int y = -thickness;y <= thickness; y++ ) {
float sample = texture(iChannel0, uv+vec2(float(x)/iWidth, float(y)/iHeight)).a;
if( sample > 0.0 ) {
outline = 1.0;
}
}
}
}
FRAGCOLOR = mix(texel, border_color, outline * border_color.a);
}