libpngloader

PNG Loader

PNGLoader library is used to load PNG images from file into buffer with PNG file header. It is lite and OpenGL friendly rather than libPNG.

Here the main features of the PNGLoader:

• Small size of memory usage (about 35kB),
• Simple functioning. Except some functions like saving image to the PNG file (rather than libPNG),
• Possible to load PNG image from last row (useful for texture loading),
• Simple programming interface (only one function to call)
• Open permissive license, that accept usage in the commercial projects (LGPLv2).

Common restrictions:

• Current version (0.2.0) works only with 8 bits per channel,
• Can not load palette PNG images,
• Skip auxiliary chunks
• Depend on side library (zlib)

Usage of the PNGLoader library

Include

into source code to use PNGLoader library functions.

Add to linker flags

for static linking or

-lpngloader.dll

for dynamic linking. If dynamic linked version is used,

-lz

must be added to the linker flags.

Functions and types

describes PNGLoader error type.

describes PNG file header.

function load PNG from

file_name

file into memory pointed by

data

.

header

variable holds content of IHDR chunk with PNG data. Image is loaded from bottom to top if

flip

is set to

true

.

LoadPNGFromFile

return error code with

png_error_t

type.

variable is a pointer to the pointer. Memory is allocated automatically on success. Use

FreePNG

to safely release memory.

The

must point to the

png_header_t

allocated variable. It's content will be overwritten on function

LoadPNGFromFile

call. An undefined content will be in

header

on error.

This function is the same as

except the source of the PNG. The source for this function is plain array of bytes.

raw_data

is a pointer to PNG data in memory.

length

represent size of the memory image of the PNG.

function safely free memory after

LoadPNG

was completed. This function must be called with

data

argument after successful complete of

LoadPNG

function if data not needed anymore.

function extract module version in "N.N.N.N" form, where N is a number of version component. Version string will be copied into

str

with null symbol at the end. To prevent buffer overflow

n

argument must contain length of the buffer. Most of version strings does not exceed 11 chars length in the buffer.