Pinta.ImageManipulation.HistogramRgb.AddSurfaceRectangleToHistogram C# (CSharp) Method

		protected override unsafe void AddSurfaceRectangleToHistogram (ISurface surface, Rectangle rect)
		{
			long[] histogramB = histogram[0];
			long[] histogramG = histogram[1];
			long[] histogramR = histogram[2];

			int rect_right = rect.Right;

			for (int y = rect.Y; y <= rect.Bottom; ++y) {
				ColorBgra* ptr = surface.GetPointAddress (rect.X, y);
				for (int x = rect.X; x <= rect_right; ++x) {
					++histogramB[ptr->B];
					++histogramG[ptr->G];
					++histogramR[ptr->R];
					++ptr;
				}
			}
		}