Many external events such as resizing a window or scrolling a window can affect paint output. This may require changing the transformation information, setting a clipping region or changing the device context boundaries.
When a painting canvas (bitmap) is scrolled or zoomed, the input coordinates and painting output must be transformed. The L_PntSetTransformation function sets the necessary information. This function uses a PAINTXFORM structure to set the transformation information.
The Related Topics provide examples for handling certain Windows messages that can affect paint output.
|Processing the WM_PAINT Message|
|Processing the WM_SIZE Message|
|Processing the Window Activation Messages|
|Processing Window Scrolling Messages|