pngz.h File Reference

#include <png.h>

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Data Structures
struct	pixel
	pixel in RGBA8 format. More...
struct	pngz
	easy png structure. More...

Typedefs
typedef struct pixel	pixel
	pixel in RGBA8 format.
typedef struct pngz	pngz
	easy png structure.

Functions
pixel **	pngz_alloc_pixels (unsigned rows, unsigned cols)
	allocate a pixel buffer.
unsigned char **	pngz_alloc_bytes (unsigned rows, unsigned cols)
	allocate raw pixel byte buffer.
int	pngz_free_pixels (pixel **pixels, unsigned rows)
	safely free pixel buffer.
int	pngz_free_bytes (unsigned char **bytes, unsigned rows)
	safely free pixel buffer.
int	pngz_free (pngz *z)
	free a pngz structs pixels.
int	pngz_pack_pixels (unsigned char **bytes_src, pixel **pixels_dest, unsigned rows, unsigned cols)
	pack pixels with bytes.
int	pngz_unpack_pixels (pixel **pixels_src, unsigned char **bytes_dest, unsigned rows, unsigned cols)
	unpack pixels into raw byte ptrs.
int	pngz_load (pngz *z)
	load a pngz object into memory
int	pngz_load_from (pngz *z, char *path)
	load a pngz from a path directly passed into the call, just indirectly calls the standard pngz_load()
int	pngz_save (pngz z)
	write a png back out to file
int	pngz_save_as (pngz z, char *path)
	write a png back out to file with a new name
void	pngz_print (pngz z)
	print a pngz ztruct contents.
void	pngz_print_pixel (pixel p)
	print out a single pixels rgba values in hex.
void	pngz_print_indent (pngz z, int indent)
	print a pngz ztruct contents.
void	pngz_print_pixel_indent (pixel p, int indent)
	print out a single pixels rgba values.

Typedef Documentation

pixel

typedef struct pixel pixel

pixel in RGBA8 format.

pngz

typedef struct pngz pngz

easy png structure.

always contains RGBA8 color (0x0 - 0xFFFFFF). pixel buffer is [height][width] pixels ([rows][cols])

Function Documentation

pngz_alloc_bytes()

unsigned char ** pngz_alloc_bytes	(	unsigned	rows,
		unsigned	cols
	)

allocate raw pixel byte buffer.

Parameters

rows	number of rows to allocate
cols	number bytes per row to allocate

Returns

a ptr to buffer, returns null and sets errno on failure

Definition at line 66 of file pngz.c.

pngz_alloc_pixels()

pixel ** pngz_alloc_pixels	(	unsigned	rows,
		unsigned	cols
	)

allocate a pixel buffer.

every pixel will be represented as a struct

Parameters

rows	number of rows to allocate
cols	number pixels per col to allocate

Returns

exit code, setting errno on failure

Definition at line 37 of file pngz.c.

pngz_free()

int pngz_free

(

pngz *

z

)

free a pngz structs pixels.

Parameters

z	pngz* with pixels loaded into memory

Returns

exit code, error if you try to free a NULL ptr

Definition at line 155 of file pngz.c.

References pngz::height, pngz::pixels, and pngz_free_pixels().

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pngz_free_bytes()

int pngz_free_bytes	(	unsigned char **	bytes,
		unsigned	rows
	)

safely free pixel buffer.

Parameters

bytes	2D pixel bytes of size [rows][cols * 4]
rows	number of rows to free

Returns

exit code

Definition at line 124 of file pngz.c.

pngz_free_pixels()

int pngz_free_pixels	(	pixel **	pixels,
		unsigned	rows
	)

safely free pixel buffer.

Parameters

pixels	2D pixel ptr of size [rows][cols]
rows	number of rows to free

Returns

exit code

Definition at line 93 of file pngz.c.

pngz_load()

int pngz_load

(

pngz *

z

)

load a pngz object into memory

Parameters

z	pngz* easy png ptr to load into

Returns

exit code

Definition at line 231 of file pngz.c.

References pngz::height, pngz::path, pngz::pixels, pngz_alloc_bytes(), pngz_alloc_pixels(), pngz_free_bytes(), pngz_pack_pixels(), and pngz::width.

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pngz_load_from()

int pngz_load_from	(	pngz *	z,
		char *	path
	)

load a pngz from a path directly passed into the call, just indirectly calls the standard pngz_load()

Parameters

z	pngz* easy png ptr to load into
path	char* path to read from

Returns

exit code

Definition at line 219 of file pngz.c.

References pngz::path, and pngz_load().

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pngz_pack_pixels()

int pngz_pack_pixels	(	unsigned char **	bytes_src,
		pixel **	pixels_dest,
		unsigned	rows,
		unsigned	cols
	)

pack pixels with bytes.

Parameters

bytes_src	unpacked pixel byte source
pixels_dest	packed pixel destination
rows	rows of pixels
cols	cols of pixels (IN PIXELS NOT BYTES)

Returns

exit code

Definition at line 170 of file pngz.c.

References pixel::r.

pngz_print()

void pngz_print

(

pngz

z

)

print a pngz ztruct contents.

Parameters

z	pngz to print

Returns

void

Definition at line 403 of file pngz.c.

References pngz::cols, pngz::pixels, and pngz::rows.

pngz_print_indent()

void pngz_print_indent	(	pngz	z,
		int	indent
	)

print a pngz ztruct contents.

Parameters

z	pngz to print
indent	int for how much to indent this print

Returns

void

Definition at line 445 of file pngz.c.

References pngz::height, pngz::pixels, print_indent(), and pngz::width.

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pngz_print_pixel()

void pngz_print_pixel

(

pixel

p

)

print out a single pixels rgba values in hex.

Parameters

p	unsigned char* to the pixel to print

Returns

void

Definition at line 422 of file pngz.c.

References pixel::a, pixel::g, and pixel::r.

pngz_print_pixel_indent()

void pngz_print_pixel_indent	(	pixel	p,
		int	indent
	)

print out a single pixels rgba values.

Parameters

p	unsigned char* to the pixel to print
indent	int for how much to indent this print

Returns

void

Definition at line 469 of file pngz.c.

References pixel::a, pixel::g, print_indent(), and pixel::r.

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pngz_save()

int pngz_save

(

pngz

z

)

write a png back out to file

Parameters

z	pngz* easy png ptr to write to file

Returns

exit code

Definition at line 328 of file pngz.c.

References pngz::path, and pngz_save_as().

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pngz_save_as()

int pngz_save_as	(	pngz	z,
		char *	path
	)

write a png back out to file with a new name

Parameters

path	char* file path to save to
z	pngz* easy png ptr to write to file

Returns

exit code

Definition at line 339 of file pngz.c.

References pngz::height, pngz::pixels, pngz_alloc_bytes(), pngz_free_bytes(), pngz_unpack_pixels(), and pngz::width.

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pngz_unpack_pixels()

int pngz_unpack_pixels	(	pixel **	pixels_src,
		unsigned char **	bytes_dest,
		unsigned	rows,
		unsigned	cols
	)

unpack pixels into raw byte ptrs.

Parameters

pixels_src	packed pixel source
bytes_dest	unpacked byte destination
rows	rows of pixels
cols	cols of pixels (IN PIXELS NOT BYTES)

Returns

exit code

Definition at line 197 of file pngz.c.

References pixel::r.