Gradient fill

Carrying out a gradient fill is something very simple to do. The following code carries this out (whether you require a palette or not).

Aside from this function, you need to either have a CRect attribute in the class (m_rcClient), or set the width and height of the fill in the function itself. Also, a bool which indicates whether we need to use a palette or not.

This example carries out a blue gradient fill. If you want to use other colours, then you can do so easily for Red and Green (place the calculation in the Red or Green component of the RGB call!).

It really depends how sophisticated you want to get, you typically need to balance flexibility with speed when it comes to drawing.

void CImageWnd::DoGradientFill(CDC *pDC) const
{
	int nWidth = m_rcClient.Width(); 
	int nHeight = m_rcClient.Height();
	CRect rectangle;

	if(m_bUsePalette)
	{
		for(int i = 0; i < nHeight; ++i) // Fill in strip
		{
			rectangle.SetRect(0, i, nWidth, i + 1);
			
			CBrush brush;
			brush.CreateSolidBrush(RGB(0, 0, 255 - MulDiv(i,>252, nHeight)));
			pDC->FillRect(&rectangle, &brush);
		}
	}
	else
	{
		for(int i = 0; i < nHeight; ++i) // Fill in strip
		{
			rectangle.SetRect(0, i, nWidth, i + 1);
			pDC->FillSolidRect(&rectangle, RGB(0, 0, 255 ->MulDiv(i, 252, nHeight)));
		}
	}
}