COLORREF AdjustLightness(COLORREF c, float factor)
{
BYTE R = GetRValueSafe(c), G = GetGValueSafe(c), B = GetBValueSafe(c);
// cf. http://en.wikipedia.org/wiki/HSV_color_space#Hue_and_chroma
BYTE M = max(max(R, G), B), m = min(min(R, G), B);
if (M == m) {
// for grayscale values, lightness is proportional to the color value
BYTE X = (BYTE)limitValue((int)floorf(M * factor + 0.5f), 0, 255);
return RGB(X, X, X);
}
BYTE C = M - m;
BYTE Ha = (BYTE)abs(M == R ? G - B : M == G ? B - R : R - G);
// cf. http://en.wikipedia.org/wiki/HSV_color_space#Lightness
float L2 = (float)(M + m);
// cf. http://en.wikipedia.org/wiki/HSV_color_space#Saturation
float S = C / (L2 > 255.0f ? 510.0f - L2 : L2);
L2 = limitValue(L2 * factor, 0.0f, 510.0f);
// cf. http://en.wikipedia.org/wiki/HSV_color_space#From_HSL
float C1 = (L2 > 255.0f ? 510.0f - L2 : L2) * S;
float X1 = C1 * Ha / C;
float m1 = (L2 - C1) / 2;
R = (BYTE)floorf((M == R ? C1 : m != R ? X1 : 0) + m1 + 0.5f);
G = (BYTE)floorf((M == G ? C1 : m != G ? X1 : 0) + m1 + 0.5f);
B = (BYTE)floorf((M == B ? C1 : m != B ? X1 : 0) + m1 + 0.5f);
return RGB(R, G, B);
}
void SetMainWndBgCol(EbookControls *ctrls)
{
COLORREF bgColor = gGlobalPrefs->ebookUI.backgroundColor;
if (gGlobalPrefs->useSysColors)
bgColor = GetSysColor(COLOR_WINDOW);
Style *styleMainWnd = StyleByName("styleMainWnd");
CrashIf(!styleMainWnd);
styleMainWnd->Set(Prop::AllocColorSolid(PropBgColor, GetRValueSafe(bgColor), GetGValueSafe(bgColor), GetBValueSafe(bgColor)));
ctrls->mainWnd->SetStyle(styleMainWnd);
Style *styleStatus = StyleByName("styleStatus");
styleStatus->Set(Prop::AllocColorSolid(PropBgColor, GetRValueSafe(bgColor), GetGValueSafe(bgColor), GetBValueSafe(bgColor)));
ctrls->status->SetStyle(styleStatus);
// TODO: should also allow to change text color
// TODO: also match the colors of progress bar to be based on background color
// note: callers are expected to update the background of tree control and
// other colors that are supposed to match background color
}
void UpdateBitmapColors(HBITMAP hbmp, COLORREF textColor, COLORREF bgColor)
{
if ((textColor & 0xFFFFFF) == WIN_COL_BLACK &&
(bgColor & 0xFFFFFF) == WIN_COL_WHITE)
return;
// color order in DIB is blue-green-red-alpha
int base[4] = { GetBValueSafe(textColor), GetGValueSafe(textColor), GetRValueSafe(textColor), 0 };
int diff[4] = {
GetBValueSafe(bgColor) - base[0],
GetGValueSafe(bgColor) - base[1],
GetRValueSafe(bgColor) - base[2],
255
};
HDC hDC = GetDC(NULL);
BITMAPINFO bmi = { 0 };
SizeI size = GetBitmapSize(hbmp);
bmi.bmiHeader.biSize = sizeof(bmi.bmiHeader);
bmi.bmiHeader.biWidth = size.dx;
bmi.bmiHeader.biHeight = size.dy;
bmi.bmiHeader.biPlanes = 1;
bmi.bmiHeader.biBitCount = 32;
bmi.bmiHeader.biCompression = BI_RGB;
int bmpBytes = size.dx * size.dy * 4;
ScopedMem<unsigned char> bmpData((unsigned char *)malloc(bmpBytes));
CrashIf(!bmpData);
if (GetDIBits(hDC, hbmp, 0, size.dy, bmpData, &bmi, DIB_RGB_COLORS)) {
for (int i = 0; i < bmpBytes; i++) {
int k = i % 4;
bmpData[i] = (uint8_t)(base[k] + mul255(bmpData[i], diff[k]));
}
SetDIBits(hDC, hbmp, 0, size.dy, bmpData, &bmi, DIB_RGB_COLORS);
}
ReleaseDC(NULL, hDC);
}
static inline Color ToColor(COLORREF c)
{
return Color(GetRValueSafe(c), GetGValueSafe(c), GetBValueSafe(c));
}
Pen *LoadPen(Pen &p, COLORREF c, REAL width) {
p.SetColor(Color(GetRValueSafe(c), GetGValueSafe(c), GetBValueSafe(c)));
p.SetWidth(width);
return &p;
}
Brush *LoadBrush(SolidBrush &b, COLORREF c) {
b.SetColor(Color(GetRValueSafe(c), GetGValueSafe(c), GetBValueSafe(c)));
return &b;
}