下面阴影处理中// GetRValue(oldcolor) * alpha / 1;改成/255,怎么与/1没什么变化?????

mirroatl199 2013-01-29 09:03:01





/*========================================================================

	说明:	在指定的矩形区域内绘制阴影.	

==========================================================================*/

void DrawShadow(CDC *pDC, CRect rect)

{

	COLORREF oldcolor = RGB(255, 255, 255);

	BYTE newValR, newValG, newValB;

	BYTE AlphaArray[] = {140, 170, 212, 240};

	BYTE AlphaArray2[] = {170, 205, 220, 240, 240, 250, 255};

	

	// 底部的阴影 -----------------------------------------

	int i, j;

	for (j = 0; j < 4; j++)

	{

		for (i = 6; i <= rect.right - 5; i++)

		{

			oldcolor = pDC->GetPixel(i, rect.bottom - (4 - j));

			newValR = GetRValue(oldcolor) * AlphaArray[j] / 255;  

			newValG = GetGValue(oldcolor) * AlphaArray[j] / 255;  

			newValB = GetBValue(oldcolor) * AlphaArray[j] / 255;  

			pDC->SetPixel(i, rect.bottom - (4 - j), RGB(newValR, newValG, newValB));

		}

	}

	

	// 右边的阴影 -----------------------------------------

	for (i = 0; i < 4; i++)

	{

		for (j = 6; j <= rect.bottom - 5; j++)

		{

			oldcolor = pDC->GetPixel(rect.right - (4 - i), j);

			newValR = GetRValue(oldcolor) * AlphaArray[i] / 255;  

			newValG = GetGValue(oldcolor) * AlphaArray[i] / 255;  

			newValB = GetBValue(oldcolor) * AlphaArray[i] / 255;  

			pDC->SetPixel(rect.right - (4 - i), j, RGB(newValR, newValG, newValB));

		}

	}

	

	// 其他部位的阴影 --------------------------------------

	for (i = 0; i < 4; i++)

	{

		for (j = 0; j < 4; j++)

		{

			if ((i + j) > 6) break;

			BYTE alpha = AlphaArray2[i + j];

			oldcolor = pDC->GetPixel(rect.right - 4 + i, rect.bottom - 4 + j);

			newValR = GetRValue(oldcolor) * alpha / 1;  //改成/255,怎么与/1没什么变化?????

			newValG = GetGValue(oldcolor) * alpha / 1;  

			newValB = GetBValue(oldcolor) * alpha / 1;  

			pDC->SetPixel(rect.right - 4 + i, rect.bottom - 4 + j, RGB(newValR, newValG, newValB));

			

			oldcolor = pDC->GetPixel(rect.right - 4 + i, rect.top + 5 - j);

			newValR = GetRValue(oldcolor) * alpha / 1;  

			newValG = GetGValue(oldcolor) * alpha / 1;  

			newValB = GetBValue(oldcolor) * alpha / 1;  

			pDC->SetPixel(rect.right - 4 + i, rect.top + 5 - j, RGB(newValR, newValG, newValB));

			

			oldcolor = pDC->GetPixel(rect.left - i + 5, rect.bottom - 4 + j);

			newValR = GetRValue(oldcolor) * alpha / 1;  

			newValG = GetGValue(oldcolor) * alpha / 1;  

			newValB = GetBValue(oldcolor) * alpha / 1;  

			pDC->SetPixel(rect.left - i + 5, rect.bottom - 4 + j, RGB(newValR, newValG, newValB));

		}

	}

}