Pixel-Composer/shaders/sh_curve/sh_curve.fsh
2024-09-10 10:40:05 +07:00

130 lines
3.2 KiB
GLSL

#ifdef _YY_HLSL11_
#define CURVE_MAX 1024
#else
#define CURVE_MAX 256
#endif
varying vec2 v_vTexcoord;
varying vec4 v_vColour;
uniform float w_curve[CURVE_MAX];
uniform int w_amount;
uniform float r_curve[CURVE_MAX];
uniform int r_amount;
uniform float g_curve[CURVE_MAX];
uniform int g_amount;
uniform float b_curve[CURVE_MAX];
uniform int b_amount;
uniform float a_curve[CURVE_MAX];
uniform int a_amount;
float eval_curve_segment_t(in float _y0, in float ax0, in float ay0, in float bx1, in float by1, in float _y1, in float prog) {
return _y0 * pow(1. - prog, 3.) +
ay0 * 3. * pow(1. - prog, 2.) * prog +
by1 * 3. * (1. - prog) * pow(prog, 2.) +
_y1 * pow(prog, 3.);
}
float eval_curve_segment_x(in float _y0, in float ax0, in float ay0, in float bx1, in float by1, in float _y1, in float _x) {
float st = 0.;
float ed = 1.;
float _prec = 0.0001;
float _xt = _x;
int _binRep = 8;
if(_x <= 0.) return _y0;
if(_x >= 1.) return _y1;
if(_y0 == ay0 && _y0 == by1 && _y0 == _y1) return _y0;
for(int i = 0; i < _binRep; i++) {
float _ftx = 3. * pow(1. - _xt, 2.) * _xt * ax0
+ 3. * (1. - _xt) * pow(_xt, 2.) * bx1
+ pow(_xt, 3.);
if(abs(_ftx - _x) < _prec)
return eval_curve_segment_t(_y0, ax0, ay0, bx1, by1, _y1, _xt);
if(_xt < _x) st = _xt;
else ed = _xt;
_xt = (st + ed) / 2.;
}
int _newRep = 16;
for(int i = 0; i < _newRep; i++) {
float slope = ( 9. * ax0 - 9. * bx1 + 3.) * _xt * _xt
+ (-12. * ax0 + 6. * bx1) * _xt
+ 3. * ax0;
float _ftx = 3. * pow(1. - _xt, 2.) * _xt * ax0
+ 3. * (1. - _xt) * pow(_xt, 2.) * bx1
+ pow(_xt, 3.)
- _x;
_xt -= _ftx / slope;
if(abs(_ftx) < _prec)
break;
}
_xt = clamp(_xt, 0., 1.);
return eval_curve_segment_t(_y0, ax0, ay0, bx1, by1, _y1, _xt);
}
float curveEval(in float[CURVE_MAX] curve, in int amo, in float _x) {
int _shf = amo - int(floor(float(amo) / 6.) * 6.);
int _segs = (amo - _shf) / 6 - 1;
float _shift = _shf > 0? curve[0] : 0.;
float _scale = _shf > 1? curve[1] : 1.;
_x = _x / _scale - _shift;
_x = clamp(_x, 0., 1.);
for( int i = 0; i < _segs; i++ ) {
int ind = _shf + i * 6;
float _x0 = curve[ind + 2];
float _y0 = curve[ind + 3];
//float bx0 = _x0 + curve[ind + 0];
//float by0 = _y0 + curve[ind + 1];
float ax0 = _x0 + curve[ind + 4];
float ay0 = _y0 + curve[ind + 5];
float _x1 = curve[ind + 6 + 2];
float _y1 = curve[ind + 6 + 3];
float bx1 = _x1 + curve[ind + 6 + 0];
float by1 = _y1 + curve[ind + 6 + 1];
//float ax1 = _x1 + curve[ind + 6 + 4];
//float ay1 = _y1 + curve[ind + 6 + 5];
if(_x < _x0) continue;
if(_x > _x1) continue;
return eval_curve_segment_x(_y0, ax0, ay0, bx1, by1, _y1, (_x - _x0) / (_x1 - _x0));
}
return curve[0];
}
void main() {
vec4 col = texture2D( gm_BaseTexture, v_vTexcoord );
col.r = curveEval(r_curve, r_amount, col.r);
col.g = curveEval(g_curve, g_amount, col.g);
col.b = curveEval(b_curve, b_amount, col.b);
col.a = curveEval(a_curve, b_amount, col.a);
float w = (col.r + col.g + col.b) / 3.;
float wtarget = curveEval(w_curve, w_amount, w);
col.rgb *= wtarget / w;
gl_FragColor = col;
}