31 lines
764 B
GLSL
31 lines
764 B
GLSL
|
|
#include "/var/signal.glsl"
|
|
|
|
#define signal 0 // [0 1]
|
|
|
|
vec3 ntsc(vec3 color) {
|
|
// convert to YIQ
|
|
float y = dot(color, vec3(0.299, 0.587, 0.114));
|
|
float i = dot(color, vec3(0.596, -.274, -.322));
|
|
float q = dot(color, vec3(0.211, -.523, 0.312));
|
|
|
|
// faux ntsc signal
|
|
float carrier = 6.283 * 3.570 * gl_FragCoord.x;
|
|
float phase = sin(carrier) * i + cos(carrier) * q;
|
|
float quad = cos(carrier) * i - sin(carrier) * q;
|
|
|
|
// decode faux signal
|
|
i = quad * cos(carrier);
|
|
q = phase * sin(carrier);
|
|
|
|
// convert back to RGB
|
|
vec3 yiqColor = vec3(y, i, q);
|
|
|
|
vec3 outColor = vec3(0);
|
|
outColor.r = dot(yiqColor, vec3(1, 0.956, 0.619));
|
|
outColor.g = dot(yiqColor, vec3(1, -.272, -.674));
|
|
outColor.b = dot(yiqColor, vec3(1, -1.106, 1.703));
|
|
|
|
return outColor;
|
|
}
|
|
|