PAINTCALLBACK_STRETCHDIBITS Function

#include "l_bitmap.h"

L_BOOL pEXT_CALLBACK YourFunction(pDisplay, nXDest, nYDest, nDestWidth, nDestHeight, nXSrc, nYSrc, nSrcWidth, nSrcHeight, lpvBits, lpbmi, fuColorUse, ulROP3Code, pUserData)

This is the callback that replaces the StretchDIBits GDI function.

Parameters

L_VOID *pDisplay

Handle of the device context passed to the paint function.

L_INT nXDest

Specifies the x-coordinate, in logical units, of the upper-left corner of the destination rectangle.

L_INT nYDest

Specifies the y-coordinate, in logical units, of the upper-left corner of the destination rectangle.

L_INT nDestWidth

Specifies the width, in logical units, of the destination rectangle.

L_INT nDestHeight

Specifies the height, in logical units, of the destination rectangle.

L_INT nXSrc

Specifies the x-coordinate, in pixels, of the source rectangle in the DIB.

L_INT nYSrc

Specifies the y-coordinate, in pixels, of the source rectangle in the DIB.

L_INT nSrcWidth

Specifies the width, in pixels, of the source rectangle in the DIB.

L_INT nSrcHeight

Specifies the height, in pixels, of the source rectangle in the DIB.

L_VOID lpvBits

Pointer to the DIB bits, which are stored as an array of bytes.

BITMAPINFO lpbmi

Pointer to a BITMAPINFO structure that contains information about the DIB.

L_UINT fuColorUse

Specifies whether the bmiColors member of the BITMAPINFO structure was provided and, if so, whether bmiColors contains explicit red, green, blue (RGB) values or indexes.

L_UINT32 ulROP3Code

Specifies how the source pixels, the destination device context's current brush, and the destination pixels are to be combined to form the new image.

L_VOID pUserData

Void pointer that you can use to access a variable or structure containing data that your callback function needs. This gives you a way to receive data indirectly from the function that uses this callback function. (This is the same pointer that you pass in the pUserData parameter of the PAINTCALLBACKDATA structure.)

Returns

The return values are the same as the return values for the corresponding GDI function.

Comments

The internal display engine calls your callback function if you override the corresponding GDI function in the PAINTCALLBACKDATA structure.

pDisplay is the pDisplay member from the PAINTCALLBACKDATA structure that you passed to the paint function. The default callbacks expect it to be a HDC handle. But, if you override all the paint callbacks, it can be a pointer of any type you want.

Please see the Microsoft documentation for the values you are expected to return and for the meaning of the parameters before pUserData.

Required DLLs and Libraries

Example

For an example, refer to L_PaintDCCallback.

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