L_GetBitmapAlpha

#include "l_bitmap.h"

L_LTKRN_API L_INT L_GetBitmapAlpha(pBitmap, pAlpha, uStructSize)

pBITMAPHANDLE pBitmap;

points to the source bitmap handle

pBITMAPHANDLE pAlpha;

points to the destination bitmap handle

L_UINT uStructSize;

size in bytes, of the structure pointed to by pAlpha

Creates a grayscale bitmap from the source bitmap's alpha channel data.

Parameter

Description

pBitmap

Points to the source bitmap handle.

pAlpha

Points to the destination bitmap handle to hold the alpha channel data.

uStructSize

Size in bytes, of the structure pointed to by pAlpha, for versioning. Use sizeof(BITMAPHANDLE).

Returns

SUCCESS

The function was successful.

< 1

An error occurred. Refer to Return Codes.

Comments

This function does not support signed data images. It returns the error code ERROR_SIGNED_DATA_NOT_SUPPORTED if a signed data image is passed to this function.

Only 16-, 32-, and 64-bit images can have an alpha channel. If the source bitmap has another color resolution, the result is an image filled with zeros.

Typically, the alpha channel contains a mask that is used for transparency, as shown in the example for L_SetBitmapAlpha.

Required DLLs and Libraries

LTKRN

For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application.

Platforms

Win32, x64, Linux.

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