#define?_CRT_SECURE_NO_DEPRECATE
#include?

#include?
#include?
#include?
#include?

/*?A?coloured?pixel.?*/

typedef?struct?{
????uint8_t?red;
????uint8_t?green;
????uint8_t?blue;
????uint8_t?alpha;
}?pixel_t;

/*?A?picture.?*/

typedef?struct?{
????pixel_t?*pixels;
????size_t?width;
????size_t?height;
}?bitmap_t;

/*?Given?“bitmap“?this?returns?the?pixel?of?bitmap?at?the?point
（“x“?“y“）.?*/

static?pixel_t?*?pixel_at（bitmap_t?*?bitmap?int?x?int?y）
{
????return?bitmap->pixels?+?bitmap->width?*?y?+?x;
}

/*?Write?“bitmap“?to?a?PNG?file?specified?by?“path“;?returns?0?on
success?non-zero?on?error.?*/

static?int?save_png_to_file（bitmap_t?*bitmap?const?char?*path）
{
????FILE?*?fp;
????png_structp?png_ptr?=?NULL;
????png_infop?info_ptr?=?NULL;
????size_t?x?y;
????png_byte?**?row_pointers?=?NULL;
????/*?“status“?contains?the?return?value?of?this?function.?At?first
????it?is?set?to?a?value?which?means?‘failure‘.?When?the?routine
????has?finished?its?work?it?is?set?to?a?value?which?means
????‘success‘.?*/
????int?status?=?-1;
????/*?The?following?number?is?set?by?trial?and?error?only.?I?cannot
????see?where?it?it?is?documented?in?the?libpng?manual.
????*/
????int?pixel_size?=?4;
????int?depth?=?8;

????fp?=?fopen（path?“wb“）;
????if?（!fp）?{
????????goto?fopen_failed;
????}

????png_ptr?=?png_create_write_struct（PNG_LIBPNG_VER_STRING?NULL?NULL?NULL）;
????if?（png_ptr?==?NULL）?{
????????goto?png_create_write_struct_failed;
????}

????info_ptr?=?png_create_info_struct（png_ptr）;
????if?（info_ptr?==?NULL）?{
????????goto?png_create_info_struct_failed;
????}

????/*?Set?up?error?handling.?*/

????if?（setjmp（png_jmpbuf（png_ptr）））?{
????????goto?png_failure;
????}

????/*?Set?image?attributes.?*/

????png_set_IHDR（png_ptr
????????info_ptr
????????bitmap->width
????????bitmap->height
????????depth
????????PNG_COLOR_TYPE_RGBA
????????PNG_INTERLACE_NONE
????????PNG_COMPRESSION_TYPE_DEFAULT
????????PNG_FILTER_TYPE_DEFAULT）;

????/*?Initialize?rows?of?PNG.?*/

????row_pointers?=?png_malloc（png_ptr?bitmap->height?*?sizeof（png_byte?*））;
????for?（y?=?0;?y?height;?++y）?{
????????png_byte?*row?=
????????????png_malloc（png_ptr?sizeof（uint8_t）?*?bitmap->width?*?pixel_size）;
????????row_pointers[y]?=?row;
????????for?（x?=?0;?x?width;?++x）?{
????????????pixel_t?*?pixel?=?pixel_at（bitmap?x?y）;
????????????*row++?=?pixel->red;
????????????*row++?=?pixel->green;
????????????*row++?=?pixel->blue;
????????????*row++?=?pixel->alpha;
????????}
????}

????/*?Write?the?image?data?to?“fp“.?*/

????png_init_io（png_ptr?fp）;
????png_set_rows（png_ptr?info_ptr?row_pointers）;
????png_write_png（png_ptr?info_ptr?PNG_TRANSFORM_IDENTITY?NULL）;

????/*?The?routine?has?successfully?written?the?file?so?we?set
????“status“?to?a?value?which?indicates?success.?*/

????status?=?0;

????for?（y?=?0;?

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??2017-01-04?13:43??libpngcsdn\
?????文件?????1308812??2017-01-04?10:08??libpngcsdn\lpng1627.zip
?????文件????????4245??2017-01-04?13:43??libpngcsdn\sourc.c
?????文件??????694552??2017-01-04?10:15??libpngcsdn\zlib128.zip