Interactive PowerBasic Forum

The following example creates a solid brush based on a color that has an alpha component of 128. The code uses that brush to paint two rectangles. The first rectangle is painted with the compositing mode set to CompositingQualityHighSpeed, and the second rectangle is painted with the compositing mode set to CompositingQualityHighQuality.

C++


VOID Example_SetCompositingQuality(HDC hdc)
{
   Graphics graphics(hdc);

   // Create a SolidBrush object with an alpha-blended color.
   SolidBrush alphaBrush(Color(180, 255, 0, 0));

   // Set the compositing mode to CompositingQualityHighSpeed,
   // and fill a rectangle.
   graphics.SetCompositingQuality(CompositingQualityHighSpeed);
   graphics.FillRectangle(&alphaBrush, 0, 0, 100, 100);

   // Set the compositing mode to CompositingQualityHighQuality,
   // and fill a rectangle.
   graphics.SetCompositingQuality(CompositingQualityHighQuality);
   graphics.FillRectangle(&alphaBrush, 100, 0, 100, 100);
}


PowerBASIC


SUB GDIP_SetCompositingQuality (BYVAL hdc AS DWORD)

   LOCAL hStatus AS LONG
   LOCAL pGraphics AS DWORD
   LOCAL pAlphaBrush AS DWORD

   hStatus = GdipCreateFromHDC(hdc, pGraphics)

   ' // Create a SolidBrush object with an alpha-blended color.
   hStatus = GdipCreateSolidFill(GDIP_ARGB(180, 255, 0, 0), pAlphaBrush)

   ' // Set the compositing mode to CompositingQualityHighSpeed, and fill a rectangle.
   hStatus = GdipSetCompositingQuality(pGraphics, %CompositingQualityHighSpeed)
   hStatus = GdipFillRectangle(pGraphics, pAlphaBrush, 0, 0, 100, 100)

   ' // Set the compositing mode to CompositingQualityHighQuality, and fill a rectangle.
   hStatus = GdipSetCompositingMode(pGraphics, %CompositingQualityHighQuality)
   hStatus = GdipFillRectangle(pGraphics, pAlphaBrush, 100, 0, 100, 100)

   ' // Cleanup
   IF pAlphaBrush THEN GdipDeleteBrush(pAlphaBrush)
   IF pGraphics THEN GdipDeleteGraphics(pGraphics)

END SUB


(http://www.jose.it-berater.org/captures/GdipSetCompositingQuality.png)