#ifdef __cplusplus

[0] Fix | Delete

extern "C" {

[1] Fix | Delete

#endif

[2] Fix | Delete

[3] Fix | Delete

#ifndef GD_IO_H

[4] Fix | Delete

#define GD_IO_H 1

[5] Fix | Delete

[6] Fix | Delete

#include <stdio.h>

[7] Fix | Delete

[8] Fix | Delete

#ifdef VMS

[9] Fix | Delete

# define Putchar gdPutchar

[10] Fix | Delete

#endif

[11] Fix | Delete

[12] Fix | Delete

/*

[13] Fix | Delete

Group: Types

[14] Fix | Delete

[15] Fix | Delete

typedef: gdIOCtx

[16] Fix | Delete

[17] Fix | Delete

gdIOCtx structures hold function pointers for doing image IO.

[18] Fix | Delete

[19] Fix | Delete

Most of the gd functions that read and write files, such as

[20] Fix | Delete

<gdImagePng> also have variants that accept a <gdIOCtx> structure;

[21] Fix | Delete

see <gdImagePngCtx> and <gdImageCreateFromJpegCtx>.

[22] Fix | Delete

[23] Fix | Delete

Those who wish to provide their own custom routines to read and

[24] Fix | Delete

write images can populate a gdIOCtx structure with functions of

[25] Fix | Delete

their own devising to to read and write data. For image reading, the

[26] Fix | Delete

only mandatory functions are getC and getBuf, which must return the

[27] Fix | Delete

number of characters actually read, or a negative value on error or

[28] Fix | Delete

EOF. These functions must read the number of characters requested

[29] Fix | Delete

unless at the end of the file.

[30] Fix | Delete

[31] Fix | Delete

For image writing, the only mandatory functions are putC and putBuf,

[32] Fix | Delete

which return the number of characters written; these functions must

[33] Fix | Delete

write the number of characters requested except in the event of an

[34] Fix | Delete

error. The seek and tell functions are only required in conjunction

[35] Fix | Delete

with the gd2 file format, which supports quick loading of partial

[36] Fix | Delete

images. The gd_free function will not be invoked when calling the

[37] Fix | Delete

standard Ctx functions; it is an implementation convenience when

[38] Fix | Delete

adding new data types to gd. For examples, see gd_png.c, gd_gd2.c,

[39] Fix | Delete

gd_jpeg.c, etc., all of which rely on gdIOCtx to implement the

[40] Fix | Delete

standard image read and write functions.

[41] Fix | Delete

[42] Fix | Delete

> typedef struct gdIOCtx

[43] Fix | Delete

> {

[44] Fix | Delete

> int (*getC) (struct gdIOCtx *);

[45] Fix | Delete

> int (*getBuf) (struct gdIOCtx *, void *, int wanted);

[46] Fix | Delete

>

[47] Fix | Delete

> void (*putC) (struct gdIOCtx *, int);

[48] Fix | Delete

> int (*putBuf) (struct gdIOCtx *, const void *, int wanted);

[49] Fix | Delete

>

[50] Fix | Delete

> // seek must return 1 on SUCCESS, 0 on FAILURE. Unlike fseek!

[51] Fix | Delete

> int (*seek) (struct gdIOCtx *, const int);

[52] Fix | Delete

> long (*tell) (struct gdIOCtx *);

[53] Fix | Delete

>

[54] Fix | Delete

> void (*gd_free) (struct gdIOCtx *);

[55] Fix | Delete

> } gdIOCtx;

[56] Fix | Delete

[57] Fix | Delete

[58] Fix | Delete

[59] Fix | Delete

[60] Fix | Delete

*/

[61] Fix | Delete

typedef struct gdIOCtx {

[62] Fix | Delete

int (*getC)(struct gdIOCtx *);

[63] Fix | Delete

int (*getBuf)(struct gdIOCtx *, void *, int);

[64] Fix | Delete

void (*putC)(struct gdIOCtx *, int);

[65] Fix | Delete

int (*putBuf)(struct gdIOCtx *, const void *, int);

[66] Fix | Delete

/* seek must return 1 on SUCCESS, 0 on FAILURE. Unlike fseek! */

[67] Fix | Delete

int (*seek)(struct gdIOCtx *, const int);

[68] Fix | Delete

long (*tell)(struct gdIOCtx *);

[69] Fix | Delete

void (*gd_free)(struct gdIOCtx *);

[70] Fix | Delete

void *data;

[71] Fix | Delete

} gdIOCtx;

[72] Fix | Delete

[73] Fix | Delete

typedef struct gdIOCtx *gdIOCtxPtr;

[74] Fix | Delete

[75] Fix | Delete

void Putword(int w, gdIOCtx *ctx);

[76] Fix | Delete

void Putchar(int c, gdIOCtx *ctx);

[77] Fix | Delete

[78] Fix | Delete

void gdPutC(const unsigned char c, gdIOCtx *ctx);

[79] Fix | Delete

int gdPutBuf(const void *, int, gdIOCtx *);

[80] Fix | Delete

void gdPutWord(int w, gdIOCtx *ctx);

[81] Fix | Delete

void gdPutInt(int w, gdIOCtx *ctx);

[82] Fix | Delete

[83] Fix | Delete

int gdGetC(gdIOCtx *ctx);

[84] Fix | Delete

int gdGetBuf(void *, int, gdIOCtx *);

[85] Fix | Delete

int gdGetByte(int *result, gdIOCtx *ctx);

[86] Fix | Delete

int gdGetWord(int *result, gdIOCtx *ctx);

[87] Fix | Delete

int gdGetWordLSB(signed short int *result, gdIOCtx *ctx);

[88] Fix | Delete

int gdGetInt(int *result, gdIOCtx *ctx);

[89] Fix | Delete

int gdGetIntLSB(signed int *result, gdIOCtx *ctx);

[90] Fix | Delete

[91] Fix | Delete

int gdSeek(gdIOCtx *ctx, const int offset);

[92] Fix | Delete

long gdTell(gdIOCtx *ctx);

[93] Fix | Delete

[94] Fix | Delete

#endif

[95] Fix | Delete

[96] Fix | Delete

#ifdef __cplusplus

[97] Fix | Delete

}

[98] Fix | Delete

#endif

[99] Fix | Delete

[100] Fix | Delete