资源简介
Linux操作系统配置nginx+php+mysql工具,libpng-1.6.25.tar.gz
代码片段和文件信息
#if 0 /* in case someone actually tries to compile this */
/* example.c - an example of using libpng
* Last changed in libpng 1.6.24 [August 4 2016]
* Maintained 1998-2016 Glenn Randers-Pehrson
* Maintained 1996 1997 Andreas Dilger)
* Written 1995 1996 Guy Eric Schalnat Group 42 Inc.)
* To the extent possible under law the authors have waived
* all copyright and related or neighboring rights to this file.
* This work is published from: United States.
*/
/* This is an example of how to use libpng to read and write PNG files.
* The file libpng-manual.txt is much more verbose then this. If you have not
* read it do so first. This was designed to be a starting point of an
* implementation. This is not officially part of libpng is hereby placed
* in the public domain and therefore does not require a copyright notice.
*
* This file does not currently compile because it is missing certain
* parts like allocating memory to hold an image. You will have to
* supply these parts to get it to compile. For an example of a minimal
* working PNG reader/writer see pngtest.c included in this distribution;
* see also the programs in the contrib directory.
*/
/* The simple but restricted approach to reading a PNG file or data stream
* just requires two function calls as in the following complete program.
* Writing a file just needs one function call so long as the data has an
* appropriate layout.
*
* The following code reads PNG image data from a file and writes it in a
* potentially new format to a new file. While this code will compile there is
* minimal (insufficient) error checking; for a more realistic version look at
* contrib/examples/pngtopng.c
*/
#include
#include
#include
#include
#include
#include
int main(int argc const char **argv)
{
if (argc == 3)
{
png_image image; /* The control structure used by libpng */
/* Initialize the ‘png_image‘ structure. */
memset(&image 0 (sizeof image));
image.version = PNG_IMAGE_VERSION;
/* The first argument is the file to read: */
if (png_image_begin_read_from_file(&image argv[1]) != 0)
{
png_bytep buffer;
/* Set the format in which to read the PNG file; this code chooses a
* simple sRGB format with a non-associated alpha channel adequate to
* store most images.
*/
image.format = PNG_FORMAT_RGBA;
/* Now allocate enough memory to hold the image in this format; the
* PNG_IMAGE_SIZE macro uses the information about the image (width
* height and format) stored in ‘image‘.
*/
buffer = malloc(PNG_IMAGE_SIZE(image));
/* If enough memory was available read the image in the desired format
* then write the result out to the new file. ‘background‘ is not
* necessary when reading the image because the alpha channel is
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