This topic pertains only to application development in C and C++. See DirectDraw Visual Basic Samples.

Description

The Stretch sample application program illustrates stretching and clipping while blitting a bitmap image.

Path

Source: (SDK root)\Samples\Multimedia\DDraw\Src\Stretch

Executable: (SDK root)\Samples\Multimedia\DDraw\Bin\Stretch.exe

User's Guide

Stretch must be run in a video mode that uses 8 bits per pixel. It will not work properly in other video modes.

The program displays a red torus moving in its client window. Control the rotational speed with the Stop, Slow, and Fast options in the Rotation menu. Alter the size of the window by selecting items from the Size menu, or by resizing the window with the mouse.

Programming Notes

Any time you resize the Stretch program window to a size other than 1x1, you are using the image stretching capabilities of the DirectDraw blitting methods.

The clipper for the primary surface is set to the client window. To demonstrate clipping, partially overlap another window over the Stretch program's window. When Stretch blits the bitmap, the portion of the bitmap that would fall within the other window is clipped.