+wxImage::HSVValue wxImage::RGBtoHSV(const RGBValue& rgb)
+{
+ const double red = rgb.red / 255.0,
+ green = rgb.green / 255.0,
+ blue = rgb.blue / 255.0;
+
+ // find the min and max intensity (and remember which one was it for the
+ // latter)
+ double minimumRGB = red;
+ if ( green < minimumRGB )
+ minimumRGB = green;
+ if ( blue < minimumRGB )
+ minimumRGB = blue;
+
+ enum { RED, GREEN, BLUE } chMax = RED;
+ double maximumRGB = red;
+ if ( green > maximumRGB )
+ {
+ chMax = GREEN;
+ maximumRGB = green;
+ }
+ if ( blue > maximumRGB )
+ {
+ chMax = BLUE;
+ maximumRGB = blue;
+ }
+
+ const double value = maximumRGB;
+
+ double hue = 0.0, saturation;
+ const double deltaRGB = maximumRGB - minimumRGB;
+ if ( wxIsNullDouble(deltaRGB) )
+ {
+ // Gray has no color
+ hue = 0.0;
+ saturation = 0.0;
+ }
+ else
+ {
+ switch ( chMax )
+ {
+ case RED:
+ hue = (green - blue) / deltaRGB;
+ break;
+
+ case GREEN:
+ hue = 2.0 + (blue - red) / deltaRGB;
+ break;
+
+ case BLUE:
+ hue = 4.0 + (red - green) / deltaRGB;
+ break;
+
+ default:
+ wxFAIL_MSG(wxT("hue not specified"));
+ break;
+ }
+
+ hue /= 6.0;
+
+ if ( hue < 0.0 )
+ hue += 1.0;
+
+ saturation = deltaRGB / maximumRGB;
+ }
+
+ return HSVValue(hue, saturation, value);
+}
+
+wxImage::RGBValue wxImage::HSVtoRGB(const HSVValue& hsv)
+{
+ double red, green, blue;
+
+ if ( wxIsNullDouble(hsv.saturation) )
+ {
+ // Grey
+ red = hsv.value;
+ green = hsv.value;
+ blue = hsv.value;
+ }
+ else // not grey
+ {
+ double hue = hsv.hue * 6.0; // sector 0 to 5
+ int i = (int)floor(hue);
+ double f = hue - i; // fractional part of h
+ double p = hsv.value * (1.0 - hsv.saturation);
+
+ switch (i)
+ {
+ case 0:
+ red = hsv.value;
+ green = hsv.value * (1.0 - hsv.saturation * (1.0 - f));
+ blue = p;
+ break;
+
+ case 1:
+ red = hsv.value * (1.0 - hsv.saturation * f);
+ green = hsv.value;
+ blue = p;
+ break;
+
+ case 2:
+ red = p;
+ green = hsv.value;
+ blue = hsv.value * (1.0 - hsv.saturation * (1.0 - f));
+ break;
+
+ case 3:
+ red = p;
+ green = hsv.value * (1.0 - hsv.saturation * f);
+ blue = hsv.value;
+ break;
+
+ case 4:
+ red = hsv.value * (1.0 - hsv.saturation * (1.0 - f));
+ green = p;
+ blue = hsv.value;
+ break;
+
+ default: // case 5:
+ red = hsv.value;
+ green = p;
+ blue = hsv.value * (1.0 - hsv.saturation * f);
+ break;
+ }
+ }
+
+ return RGBValue((unsigned char)(red * 255.0),
+ (unsigned char)(green * 255.0),
+ (unsigned char)(blue * 255.0));
+}
+
+/*
+ * Rotates the hue of each pixel of the image. angle is a double in the range
+ * -1.0..1.0 where -1.0 is -360 degrees and 1.0 is 360 degrees
+ */
+void wxImage::RotateHue(double angle)
+{
+ AllocExclusive();
+
+ unsigned char *srcBytePtr;
+ unsigned char *dstBytePtr;
+ unsigned long count;
+ wxImage::HSVValue hsv;
+ wxImage::RGBValue rgb;
+
+ wxASSERT (angle >= -1.0 && angle <= 1.0);
+ count = M_IMGDATA->m_width * M_IMGDATA->m_height;
+ if ( count > 0 && !wxIsNullDouble(angle) )
+ {
+ srcBytePtr = M_IMGDATA->m_data;
+ dstBytePtr = srcBytePtr;
+ do
+ {
+ rgb.red = *srcBytePtr++;
+ rgb.green = *srcBytePtr++;
+ rgb.blue = *srcBytePtr++;
+ hsv = RGBtoHSV(rgb);
+
+ hsv.hue = hsv.hue + angle;
+ if (hsv.hue > 1.0)
+ hsv.hue = hsv.hue - 1.0;
+ else if (hsv.hue < 0.0)
+ hsv.hue = hsv.hue + 1.0;
+
+ rgb = HSVtoRGB(hsv);
+ *dstBytePtr++ = rgb.red;
+ *dstBytePtr++ = rgb.green;
+ *dstBytePtr++ = rgb.blue;
+ } while (--count != 0);
+ }
+}
+
projects / wxWidgets.git / blobdiff