Dst... example for C++ Builder
Calculate the values to zoom in by 10 percent and center the image.
Lead1->AutoScroll = False;
Lead1->DstWidth = (Lead1->DstWidth * 110) / 100;
Lead1->DstHeight = (Lead1->DstHeight * 110) / 100;
Lead1->DstTop = (Lead1->Height - Lead1->DstHeight) / 2;
Lead1->DstLeft = (Lead1->Width - Lead1->DstWidth) / 2;
//Set the clipping area to the same as the destination rectangle
Lead1->DstClipWidth = Lead1->DstWidth;
Lead1->DstClipHeight = Lead1->DstHeight;
Lead1->DstClipTop = Lead1->DstTop;
Lead1->DstClipLeft = Lead1->DstLeft;
//Redisplay the image
Lead1->ForceRepaint();