L_GetTag
#include "l_bitmap.h"
L_LTFIL_API L_INT L_GetTag(uTag, pType, pCount, pData)
L_UINT16 uTag; |
/* tag to identify the data in the TIFF file */ |
L_UINT16* pType; |
/* address of the variable for the data type */ |
L_UINT* pCount; |
/* address of the variable for the count */ |
L_VOID* pData; |
/* pointer to the buffer for the data */ |
Gets the data that is ready to be saved as tagged data in a TIFF file. This lets you see the data that was specified with the L_SetTag function.
Parameter |
Description |
|
uTag |
Tag to identify the data in the TIFF file. Use the same tag that you specified in the L_SetTag function. |
|
pType |
Address of the variable to be updated with the tagged data type. The following are possible values: |
|
|
Value |
Meaning |
|
TAG_BYTE |
[1] Byte. |
|
TAG_ASCII |
[2] Byte in the range of 0 to 255. |
|
TAG_SBYTE |
[6] Byte used as signed number in the range of -128 to +127. |
|
TAG_UNDEFINED |
[7] Byte, with application-defined usage. |
|
TAG_SHORT |
[3] Two bytes, unsigned. |
|
TAG_SSHORT |
[8] Two bytes, signed. |
|
TAG_LONG |
[4] Four bytes, unsigned. |
|
TAG_SLONG |
[9] Four bytes, signed. |
|
TAG_RATIONAL |
[5] Eight bytes, used as a pair of unsigned long integers, where the first number is the numerator and the second is the denominator of a fraction. |
|
TAG_SRATIONAL |
[10] Eight bytes, used as a pair of signed long integers, where the first number is the numerator and the second is the denominator of a fraction. |
|
TAG_FLOAT |
[11] Four bytes used as a floating point number. |
|
TAG_DOUBLE |
[12] Eight bytes used as a double-precision floating point number. |
pCount |
Address of the variable to be updated with the count of data items. The count is based on the tagged data type. For example, if the count is 2 and the data type is TAG_DOUBLE, the required buffer size is 16. |
|
pData |
Pointer to the buffer to be updated with the data. You can pass NULL if you want to use this function's return value to determine the required buffer size. |
Returns
>0 |
Length of the tagged data, in bytes. |
<= 0 |
An error occurred. Refer to Return Codes. |
Comments
It is often convenient to call this function twice, as follows:
1. |
Call the function the first time, specifying NULL in the pData parameter, and using the return value to determine the required size of the buffer. |
2. |
Allocate the buffer. |
3. |
Call the function the second time, passing a pointer to your buffer in the pData parameter. |
For general information about TIFF tags, refer to Implementing TIFF Comments and Tags.
To detect whether a file has annotation information, you should call L_GetTag and see if ANNTAG_TYPE is present.
Required DLLs and Libraries
LTFIL 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
Windows 2000 / XP/Vista, Windows CE.
See Also
Functions: |
|
Topics: |
Example
Refer to L_SetTag.