| #define MIN(x, y) ((x)<(y)?(x):(y))
|
| #define MAX(z, a) ((z)>(a)?(z):(a))
|
|
|
| typedef struct _HSL {
|
| float h;
|
| float s;
|
| float l;
|
| } HSL, *PHSL, *LPHSL;
|
|
|
| HSL rgbQuadRGB(RGBQUAD rgbQuad) {
|
| HSL hsl;
|
|
|
| BYTE r = rgbQuad.rgbRed, g = rgbQuad.rgbGreen, b = rgbQuad.rgbBlue;
|
| float fr = (float)r/255.f;
|
| float fg = (float)g/255.f;
|
| float fb = (float)b/255.f;
|
|
|
| float minr = MIN(MIN(fr, fg), fb), maxr = MAX(MAX(fr, fg), fb);
|
| float delta = maxr-minr;
|
| float delr, delg, delb;
|
|
|
| float h = 0.f, s = 0.f, l = (float)((maxr+minr)/2.f);
|
|
|
| if (delta != 0.f) {
|
| s = l < 0.5f ? (float)(delta / (maxr + minr)) : (float)(delta / (2.f - maxr - minr));
|
| delr = (float)(((maxr - fr) / 6.f + (delta / 2.f)) / delta);
|
| delg = (float)(((maxr - fg) / 6.f + (delta / 2.f)) / delta);
|
| delb = (float)(((maxr - fb) / 6.f + (delta / 2.f)) / delta);
|
|
|
| if (fr == maxr) h = delb-delg;
|
| else if (fg == maxr) h = (1.f / 3.f) + delr - delb;
|
| else if (fb == maxr) h = (2.f / 3.f) + delg - delr;
|
| if (h < 0.f) h += 1.f;
|
| if (h > 1.f) h -= 1.f;
|
| }
|
|
|
| hsl.h = h;
|
| hsl.s = s;
|
| hsl.l = l;
|
| return hsl;
|
| }
|
|
|
| RGBQUAD hslRGB(HSL hsl) {
|
| RGBQUAD rgbq;
|
| float r = hsl.l, g = hsl.l, b = hsl.l;
|
| float h = hsl.h, s2 = hsl.s, l = hsl.l;
|
| float vh = (l <= 0.5f) ? (l*(1.f + s2)) : (l+s2-l*s2);
|
|
|
| float m, sv, frac, vsf, mid, mid2;
|
| int st;
|
|
|
| if (vh > 0.f) {
|
| m = l + l - vh;
|
| sv = (vh - m) / vh;
|
| h *= 6.f;
|
| st = (int)h;
|
| frac = h-st;
|
| vsf = vh*sv*frac;
|
| mid = m+vsf;
|
| mid2 = vh-vsf;
|
| switch(st) {
|
| case 0:
|
| r = vh;
|
| g = mid;
|
| b = m;
|
| break;
|
| case 1:
|
| r = mid2;
|
| g = vh;
|
| b = m;
|
| break;
|
| case 2:
|
| r = m;
|
| g = vh;
|
| b = mid;
|
| break;
|
| case 3:
|
| r = m;
|
| g = mid2;
|
| b = vh;
|
| break;
|
| case 4:
|
| r = mid;
|
| g = m;
|
| b = vh;
|
| break;
|
| case 5:
|
| r = vh;
|
| g = m;
|
| b = mid2;
|
| break;
|
| }
|
| }
|
|
|
| rgbq.rgbRed = (BYTE)(r*255.f);
|
| rgbq.rgbGreen = (BYTE)(g*255.f);
|
| rgbq.rgbBlue = (BYTE)(b*255.f);
|
| return rgbq;
|
| }
|
|
|
