v4k-git-backup/demos/art/shadertoys/MdfGD2.fs

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2023-08-10 14:30:56 +00:00
// bwvideo.mp4
float sat( float t ) {
return clamp( t, 0.0, 1.0 );
}
vec2 sat( vec2 t ) {
return clamp( t, 0.0, 1.0 );
}
// vec3 sat( vec3 v ) {
// return clamp( v, 0.0f, 1.0f );
// }
//remaps inteval [a;b] to [0;1]
float remap( float t, float a, float b ) {
return sat( (t - a) / (b - a) );
}
//note: /\ t=[0;0.5;1], y=[0;1;0]
float linterp( float t ) {
return sat( 1.0 - abs( 2.0*t - 1.0 ) );
}
//note: [0;1]
float rand( vec2 n ) {
return fract(sin(dot(n.xy, vec2(12.9898, 78.233)))* 43758.5453);
}
//note: [-1;1]
float srand( vec2 n ) {
return rand(n) * 2.0 - 1.0;
}
float mytrunc( float x, float num_levels )
{
return floor(x*num_levels) / num_levels;
}
vec2 mytrunc( vec2 x, vec2 num_levels )
{
return floor(x*num_levels) / num_levels;
}
vec3 rgb2yuv( vec3 rgb )
{
vec3 yuv;
yuv.x = dot( rgb, vec3(0.299,0.587,0.114) );
yuv.y = dot( rgb, vec3(-0.14713, -0.28886, 0.436) );
yuv.z = dot( rgb, vec3(0.615, -0.51499, -0.10001) );
return yuv;
}
vec3 yuv2rgb( vec3 yuv )
{
vec3 rgb;
rgb.r = yuv.x + yuv.z * 1.13983;
rgb.g = yuv.x + dot( vec2(-0.39465, -0.58060), yuv.yz );
rgb.b = yuv.x + yuv.y * 2.03211;
return rgb;
}
void mainImage( out vec4 fragColor, in vec2 fragCoord )
{
float THRESHOLD = 0.1 + iMouse.x / iResolution.x;
float time_s = mod( iGlobalTime, 32.0 );
float glitch_threshold = 1.0 - THRESHOLD;
const float max_ofs_siz = 0.1; //TOOD: input
const float yuv_threshold = 0.5; //TODO: input, >1.0f == no distort
const float time_frq = 16.0;
vec2 uv = fragCoord.xy / iResolution.xy;
uv.y = 1.0 - uv.y;
const float min_change_frq = 4.0;
float ct = mytrunc( time_s, min_change_frq );
float change_rnd = rand( mytrunc(uv.yy,vec2(16)) + 150.0 * ct );
float tf = time_frq*change_rnd;
float t = 5.0 * mytrunc( time_s, tf );
float vt_rnd = 0.5*rand( mytrunc(uv.yy + t, vec2(11)) );
vt_rnd += 0.5 * rand(mytrunc(uv.yy + t, vec2(7)));
vt_rnd = vt_rnd*2.0 - 1.0;
vt_rnd = sign(vt_rnd) * sat( ( abs(vt_rnd) - glitch_threshold) / (1.0-glitch_threshold) );
vec2 uv_nm = uv;
uv_nm = sat( uv_nm + vec2(max_ofs_siz*vt_rnd, 0) );
float rnd = rand( vec2( mytrunc( time_s, 8.0 )) );
uv_nm.y = (rnd>mix(1.0, 0.975, sat(THRESHOLD))) ? 1.0-uv_nm.y : uv_nm.y;
vec4 smpl = texture( iChannel0, uv_nm, -10.0 );
vec3 smpl_yuv = rgb2yuv( smpl.rgb );
smpl_yuv.y /= 1.0-3.0*abs(vt_rnd) * sat( yuv_threshold - vt_rnd );
smpl_yuv.z += 0.125 * vt_rnd * sat( vt_rnd - yuv_threshold );
fragColor = vec4( yuv2rgb(smpl_yuv), smpl.a );
}