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)));
		}
	}
}




Comments

  • There are no comments yet. Be the first to comment!

Leave a Comment
  • Your email address will not be published. All fields are required.

Top White Papers and Webcasts

  • IBM Worklight is a mobile application development platform that lets you extend your business to mobile devices. It is designed to provide an open, comprehensive platform to build, run and manage HTML5, hybrid and native mobile apps.

  • Businesses are moving more and more of their customer transactions to the web. Security is understandably a top concern as online transactions increase, so it is important to make sure your electronic signature provider meets the highest security standards. That means more than simply passing a security audit or obtaining a certification. This white paper provides recommendations for taking a broader view of e-signature security, and answers key questions that help identify the security requirements against …

Most Popular Programming Stories

More for Developers

Latest Developer Headlines

RSS Feeds