m/grafX2
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

move Load_PNG/Save_PNG/etc to pngformat.c

Browse Source
This commit is contained in:
Thomas Bernard 2019-12-07 15:10:43 +01:00
parent bbeba1acf8
commit 7ae15c6e37
No known key found for this signature in database
GPG Key ID: 0FF11B67A5C0863C
3 changed files with 809 additions and 765 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
src/Makefile
View File

@ -809,6 +809,7 @@ OBJS = main.o init.o graph.o $(APIOBJ) misc.o special.o \
windows.o brush.o realpath.o mountlist.o input.o hotkeys.o \
transform.o pversion.o factory.o $(PLATFORMOBJ) \
loadsave.o loadsavefuncs.o \
pngformat.o \
fileformats.o miscfileformats.o libraw2crtc.o \
brush_ops.o buttons_effects.o layers.o \
oldies.o tiles.o colorred.o unicode.o gfx2surface.o \
@ -820,6 +821,7 @@ endif
TESTSOBJS = $(patsubst %.c,%.o,$(wildcard tests/*.c)) \
miscfileformats.o fileformats.o oldies.o libraw2crtc.o \
loadsavefuncs.o packbits.o tifformat.o c64load.o 6502.o \
pngformat.o \
op_c.o colorred.o \
unicode.o \
io.o realpath.o version.o pversion.o \

766
src/fileformats.c
View File

@ -32,32 +32,11 @@
#endif
#include <string.h>
#ifndef __no_pnglib__
// just for png_sig_cmp()
#include <png.h>
#if !defined(PNG_HAVE_PLTE)
#define PNG_HAVE_PLTE 0x02
#endif
#if (PNG_LIBPNG_VER_MAJOR <= 1) && (PNG_LIBPNG_VER_MINOR < 4)
// Compatibility layer to allow us to use libng 1.4 or any older one.
// This function is renamed in 1.4
#define png_set_expand_gray_1_2_4_to_8(x) png_set_gray_1_2_4_to_8(x)
// Wrappers that are mandatory in 1.4. Older version allowed direct access.
#define png_get_rowbytes(png_ptr,info_ptr) ((info_ptr)->rowbytes)
#define png_get_image_width(png_ptr,info_ptr) ((info_ptr)->width)
#define png_get_image_height(png_ptr,info_ptr) ((info_ptr)->height)
#define png_get_bit_depth(png_ptr,info_ptr) ((info_ptr)->bit_depth)
#define png_get_color_type(png_ptr,info_ptr) ((info_ptr)->color_type)
#endif
#endif
#ifndef png_jmpbuf
# define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
#endif
#include <stdlib.h>
#include <assert.h>
#if defined(WIN32)
#if defined(_MSC_VER)
#include <stdio.h>
@ -6360,746 +6339,3 @@ void Save_XPM(T_IO_Context* context)
fclose(file);
}
//////////////////////////////////// PNG ////////////////////////////////////
/**
* @defgroup PNG PNG format
* @ingroup loadsaveformats
* Portable Network Graphics
*
* We make use of libpng : http://www.libpng.org/pub/png/libpng.html
* @{
*/
#ifndef __no_pnglib__
/// Test for PNG format
///
/// The 8 byte signature at the start of file is tested
void Test_PNG(T_IO_Context * context, FILE * file)
{
byte png_header[8];
(void)context;
File_error=1;
// Lecture du header du fichier
if (Read_bytes(file,png_header,8))
{
if ( !png_sig_cmp(png_header, 0, 8))
File_error=0;
}
}
/// Callback to handle our private chunks
///
/// We have one private chunk at the moment :
/// - "crNg" which is similar to a CRNG chunk in an IFF file
static int PNG_read_unknown_chunk(png_structp ptr, png_unknown_chunkp chunk)
{
T_IO_Context * context;
// png_unknown_chunkp members:
// png_byte name[5];
// png_byte *data;
// png_size_t size;
context = (T_IO_Context *)png_get_user_chunk_ptr(ptr);
GFX2_Log(GFX2_DEBUG, "PNG private chunk '%s' :\n", chunk->name);
GFX2_LogHexDump(GFX2_DEBUG, "", chunk->data, 0, chunk->size);
if (!strcmp((const char *)chunk->name, "crNg"))
{
unsigned int i;
const byte *chunk_ptr = chunk->data;
// Should be a multiple of 6
if (chunk->size % 6)
return (-1);
for(i=0;i<chunk->size/6 && i<16; i++)
{
word rate;
word flags;
byte min_col;
byte max_col;
// Rate (big-endian word)
rate = *(chunk_ptr++) << 8;
rate |= *(chunk_ptr++);
// Flags (big-endian)
flags = *(chunk_ptr++) << 8;
flags |= *(chunk_ptr++);
// Min color
min_col = *(chunk_ptr++);
// Max color
max_col = *(chunk_ptr++);
// Check validity
if (min_col != max_col)
{
// Valid cycling range
if (max_col<min_col)
SWAP_BYTES(min_col,max_col)
context->Cycle_range[i].Start=min_col;
context->Cycle_range[i].End=max_col;
context->Cycle_range[i].Inverse=(flags&2)?1:0;
context->Cycle_range[i].Speed=(flags&1) ? rate/78 : 0;
context->Color_cycles=i+1;
}
}
return (1); // >0 = success
}
return (0); /* did not recognize */
}
/// Private structure used in PNG_memory_read() and PNG_memory_write()
struct PNG_memory_buffer {
char * buffer;
unsigned long offset;
unsigned long size;
};
/// read from memory buffer
static void PNG_memory_read(png_structp png_ptr, png_bytep p, png_size_t count)
{
struct PNG_memory_buffer * buffer = (struct PNG_memory_buffer *)png_get_io_ptr(png_ptr);
GFX2_Log(GFX2_DEBUG, "PNG_memory_read(%p, %p, %u) (io_ptr=%p)\n", png_ptr, p, count, buffer);
if (buffer == NULL || p == NULL)
return;
if (buffer->offset + count <= buffer->size)
{
memcpy(p, buffer->buffer + buffer->offset, count);
buffer->offset += count;
}
else
{
unsigned long available_count = buffer->size - buffer->offset;
GFX2_Log(GFX2_DEBUG, "PNG_memory_read(): only %lu bytes available\n", available_count);
if (available_count > 0)
{
memcpy(p, buffer->buffer + buffer->offset, available_count);
buffer->offset += available_count;
}
}
}
/// Read PNG format file
void Load_PNG_Sub(T_IO_Context * context, FILE * file, const char * memory_buffer, unsigned long memory_buffer_size)
{
png_structp png_ptr;
png_infop info_ptr = NULL;
// Prepare internal PNG loader
png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (png_ptr)
{
// Prepare internal PNG loader
info_ptr = png_create_info_struct(png_ptr);
if (info_ptr)
{
png_byte color_type;
png_byte bit_depth;
byte bpp;
struct PNG_memory_buffer buffer;
// Setup a return point. If a pnglib loading error occurs
// in this if(), the else will be executed.
if (!setjmp(png_jmpbuf(png_ptr)))
{
// to read from memory, I need to use png_set_read_fn() instead of calling png_init_io()
if (file != NULL)
png_init_io(png_ptr, file);
else
{
buffer.buffer = (char *)memory_buffer;
buffer.offset = 8; // skip header
buffer.size = memory_buffer_size;
png_set_read_fn(png_ptr, &buffer, PNG_memory_read);
}
// Inform pnglib we already loaded the header.
png_set_sig_bytes(png_ptr, 8);
// Hook the handler for unknown chunks
png_set_read_user_chunk_fn(png_ptr, (png_voidp)context, &PNG_read_unknown_chunk);
// Load file information
png_read_info(png_ptr, info_ptr);
color_type = png_get_color_type(png_ptr,info_ptr);
bit_depth = png_get_bit_depth(png_ptr,info_ptr);
switch (color_type)
{
case PNG_COLOR_TYPE_GRAY_ALPHA:
// no more than 8bpp or else we enable true color picture loading
bpp = MIN(8, bit_depth * 2);
break;
case PNG_COLOR_TYPE_RGB:
bpp = bit_depth * 3;
break;
case PNG_COLOR_TYPE_RGB_ALPHA:
bpp = bit_depth * 4;
break;
case PNG_COLOR_TYPE_PALETTE:
case PNG_COLOR_TYPE_GRAY:
default:
// no more than 8bpp or else we enable true color picture loading
bpp = MIN(8, bit_depth);
}
GFX2_Log(GFX2_DEBUG, "PNG type=%u bit_depth=%u : %ubpp\n", color_type, bit_depth, bpp);
// If it's any supported file
// (Note: As of writing this, this test covers every possible
// image format of libpng)
if (color_type == PNG_COLOR_TYPE_PALETTE
|| color_type == PNG_COLOR_TYPE_GRAY
|| color_type == PNG_COLOR_TYPE_GRAY_ALPHA
|| color_type == PNG_COLOR_TYPE_RGB
|| color_type == PNG_COLOR_TYPE_RGB_ALPHA
)
{
enum PIXEL_RATIO ratio = PIXEL_SIMPLE;
int num_text;
png_text *text_ptr;
int unit_type;
png_uint_32 res_x;
png_uint_32 res_y;
// Comment (tEXt)
context->Comment[0]='\0'; // Clear the previous comment
if ((num_text=png_get_text(png_ptr, info_ptr, &text_ptr, NULL)))
{
while (num_text--)
{
int size = COMMENT_SIZE;
#ifdef PNG_iTXt_SUPPORTED
size_t length = (text_ptr[num_text].compression >= 1) ? text_ptr[num_text].itxt_length : text_ptr[num_text].text_length;
#else
size_t length = text_ptr[num_text].text_length;
if (text_ptr[num_text].compression >= 1)
continue; // skip iTXt
#endif
if (length > 0 && length < COMMENT_SIZE)
size = (int)length;
GFX2_Log(GFX2_DEBUG, "PNG Text %d \"%s\" (%lu bytes): %.*s\n",
text_ptr[num_text].compression, text_ptr[num_text].key,
(unsigned long)length,
(int)MIN(length, 160), text_ptr[num_text].text);
if (strcmp(text_ptr[num_text].key,"Title") == 0)
{
strncpy(context->Comment, text_ptr[num_text].text, size);
context->Comment[size]='\0';
break; // Skip all others tEXt chunks
}
else if(strcmp(text_ptr[num_text].key, "Comment") == 0)
{
strncpy(context->Comment, text_ptr[num_text].text, size);
context->Comment[size]='\0';
break; // Skip all others tEXt chunks
}
}
}
// Pixel Ratio (pHYs)
if (png_get_pHYs(png_ptr, info_ptr, &res_x, &res_y, &unit_type))
{
// Ignore unit, and use the X/Y ratio as a hint for
// WIDE or TALL pixels
if (res_x>0 && res_y>0)
{
GFX2_Log(GFX2_DEBUG, "PNG pHYs unit %d %dx%d\n", unit_type, res_x, res_y);
if (unit_type == 1)
GFX2_Log(GFX2_DEBUG, " %dx%d DPI\n", (res_x * 254 + 5000) / 10000, (res_y * 254 + 5000) / 10000);
if (res_y * 10 > res_x * 12) // X/Y < 1/1.2
ratio = PIXEL_WIDE;
else if (res_x * 10 > res_y * 12) // X/Y > 1.2
ratio = PIXEL_TALL;
}
}
Pre_load(context,
png_get_image_width(png_ptr, info_ptr),
png_get_image_height(png_ptr, info_ptr),
file != NULL ? File_length_file(file) : memory_buffer_size,
FORMAT_PNG, ratio, bpp);
if (File_error==0)
{
int x,y;
png_colorp palette;
int num_palette;
png_bytep * Row_pointers = NULL;
byte row_pointers_allocated = 0;
int num_trans;
png_bytep trans;
png_color_16p trans_values;
// 16-bit images
if (bit_depth == 16)
{
// Reduce to 8-bit
png_set_strip_16(png_ptr);
}
else if (bit_depth < 8)
{
// Inform libpng we want one byte per pixel,
// even though the file was less than 8bpp
png_set_packing(png_ptr);
}
// Images with alpha channel
if (color_type & PNG_COLOR_MASK_ALPHA)
{
// Tell libpng to ignore it
png_set_strip_alpha(png_ptr);
}
// Greyscale images :
if (color_type == PNG_COLOR_TYPE_GRAY || color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
{
// Map low bpp greyscales to full 8bit (0-255 range)
if (bit_depth < 8)
{
#if (PNG_LIBPNG_VER_MAJOR <= 1) && (PNG_LIBPNG_VER_MINOR < 4)
// Works well with png 1.2.8, but deprecated in 1.4 ...
png_set_gray_1_2_4_to_8(png_ptr);
#else
// ...where this seems to replace it:
png_set_expand_gray_1_2_4_to_8(png_ptr);
#endif
}
// Create greyscale palette
for (x=0;x<256;x++)
{
context->Palette[x].R=x;
context->Palette[x].G=x;
context->Palette[x].B=x;
}
}
else if (color_type == PNG_COLOR_TYPE_PALETTE) // Palette images
{
if (bit_depth < 8)
{
// Clear unused colors
if (Config.Clear_palette)
memset(context->Palette,0,sizeof(T_Palette));
}
// Get a pointer to the PNG palette
png_get_PLTE(png_ptr, info_ptr, &palette,
&num_palette);
// Copy all colors to the context
for (x=0;x<num_palette;x++)
{
context->Palette[x].R=palette[x].red;
context->Palette[x].G=palette[x].green;
context->Palette[x].B=palette[x].blue;
}
// The palette must not be freed: it is owned by libpng.
palette = NULL;
}
// Transparency (tRNS)
if (png_get_tRNS(png_ptr, info_ptr, &trans, &num_trans, &trans_values))
{
GFX2_Log(GFX2_DEBUG, "PNG transparency %d %p %p\n", num_trans, trans, trans_values);
if (color_type == PNG_COLOR_TYPE_PALETTE && trans!=NULL)
{
int i;
for (i=0; i<num_trans; i++)
{
// Look for the first color with alpha = 0 (full transparency)
if (trans[i]==0)
{
context->Transparent_color = i;
context->Background_transparent = 1;
break;
}
}
}
else if ((color_type == PNG_COLOR_TYPE_GRAY
|| color_type == PNG_COLOR_TYPE_RGB) && trans_values!=NULL)
{
// In this case, num_trans is supposed to be "1",
// and trans_values[0] contains the reference color
// (RGB triplet) that counts as transparent.
// Ideally, we should reserve this color in the palette,
// (so it's not merged and averaged with a neighbor one)
// and after creating the optimized palette, find its
// index and mark it transparent.
// Current implementation: ignore.
}
}
png_set_interlace_handling(png_ptr); // return number of image passes (7 for interlaced images)
png_read_update_info(png_ptr, info_ptr);
// Allocate row pointers
Row_pointers = (png_bytep*) malloc(sizeof(png_bytep) * context->Height);
row_pointers_allocated = 0;
/* read file */
if (!setjmp(png_jmpbuf(png_ptr)))
{
if (color_type == PNG_COLOR_TYPE_GRAY
|| color_type == PNG_COLOR_TYPE_GRAY_ALPHA
|| color_type == PNG_COLOR_TYPE_PALETTE
)
{
// 8bpp
for (y=0; y<context->Height; y++)
Row_pointers[y] = (png_byte*) malloc(png_get_rowbytes(png_ptr,info_ptr));
row_pointers_allocated = 1;
png_read_image(png_ptr, Row_pointers);
for (y=0; y<context->Height; y++)
for (x=0; x<context->Width; x++)
Set_pixel(context, x, y, Row_pointers[y][x]);
}
else
{
switch (context->Type)
{
case CONTEXT_PREVIEW:
// 24bpp
// It's a preview
// Unfortunately we need to allocate loads of memory
for (y=0; y<context->Height; y++)
Row_pointers[y] = (png_byte*) malloc(png_get_rowbytes(png_ptr,info_ptr));
row_pointers_allocated = 1;
png_read_image(png_ptr, Row_pointers);
for (y=0; y<context->Height; y++)
for (x=0; x<context->Width; x++)
Set_pixel_24b(context, x, y, Row_pointers[y][x*3],Row_pointers[y][x*3+1],Row_pointers[y][x*3+2]);
break;
case CONTEXT_MAIN_IMAGE:
case CONTEXT_BRUSH:
case CONTEXT_SURFACE:
// It's loading an actual image
// We'll save memory and time by writing directly into
// our pre-allocated 24bit buffer
for (y=0; y<context->Height; y++)
Row_pointers[y] = (png_byte*) (&(context->Buffer_image_24b[y * context->Width]));
png_read_image(png_ptr, Row_pointers);
break;
case CONTEXT_PALETTE:
case CONTEXT_PREVIEW_PALETTE:
// No pixels to draw in a palette!
break;
}
}
}
else
File_error=2;
/* cleanup heap allocation */
if (row_pointers_allocated)
{
for (y=0; y<context->Height; y++) {
free(Row_pointers[y]);
Row_pointers[y] = NULL;
}
}
free(Row_pointers);
Row_pointers = NULL;
}
else
File_error=2;
}
else
// Unsupported image type
File_error=1;
}
else
File_error=1;
}
else
File_error=1;
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
}
}
/// Read PNG format files
///
/// just read/test the header and call Load_PNG_Sub()
void Load_PNG(T_IO_Context * context)
{
FILE *file;
byte png_header[8];
File_error=0;
if ((file=Open_file_read(context)))
{
// Load header (8 first bytes)
if (Read_bytes(file,png_header,8))
{
// Do we recognize a png file signature ?
if ( !png_sig_cmp(png_header, 0, 8))
Load_PNG_Sub(context, file, NULL, 0);
else
File_error=1;
}
else // Lecture header impossible: Error ne modifiant pas l'image
File_error=1;
fclose(file);
}
else // Ouv. fichier impossible: Error ne modifiant pas l'image
File_error=1;
}
/// Write to memory buffer
static void PNG_memory_write(png_structp png_ptr, png_bytep p, png_size_t count)
{
struct PNG_memory_buffer * buffer = (struct PNG_memory_buffer *)png_get_io_ptr(png_ptr);
GFX2_Log(GFX2_DEBUG, "PNG_memory_write(%p, %p, %u) (io_ptr=%p)\n", png_ptr, p, count, buffer);
if (buffer->size < buffer->offset + count)
{
char * tmp = realloc(buffer->buffer, buffer->offset + count + 1024);
if (tmp == NULL)
{
GFX2_Log(GFX2_ERROR, "PNG_memory_write() Failed to allocate %u bytes of memory\n", buffer->offset + count + 1024);
File_error = 1;
return;
}
buffer->buffer = tmp;
buffer->size = buffer->offset + count + 1024;
}
memcpy(buffer->buffer + buffer->offset, p, count);
buffer->offset += count;
}
/// do nothing
static void PNG_memory_flush(png_structp png_ptr)
{
struct PNG_memory_buffer * buffer = (struct PNG_memory_buffer *)png_get_io_ptr(png_ptr);
GFX2_Log(GFX2_DEBUG, "PNG_memory_flush(%p) (io_ptr=%p)\n", png_ptr, buffer);
}
/// Save a PNG to file or memory
/// @param context the IO context
/// @param file the FILE to write to or NULL to write to memory
/// @param buffer will receive a malloc'ed buffer if writting to memory
/// @param buffer_size will receive the PNG size in memory
void Save_PNG_Sub(T_IO_Context * context, FILE * file, char * * buffer, unsigned long * buffer_size)
{
static png_bytep * Row_pointers = NULL;
int y;
byte * pixel_ptr;
png_structp png_ptr;
png_infop info_ptr;
png_unknown_chunk crng_chunk;
byte cycle_data[16*6]; // Storage for color-cycling data, referenced by crng_chunk
struct PNG_memory_buffer memory_buffer;
assert((file != NULL) || ((buffer != NULL) && (buffer_size != NULL)));
memset(&memory_buffer, 0, sizeof(memory_buffer));
/* initialisation */
if ((png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL))
&& (info_ptr = png_create_info_struct(png_ptr)))
{
if (!setjmp(png_jmpbuf(png_ptr)))
{
if (file != NULL)
png_init_io(png_ptr, file);
else // to write to memory, use png_set_write_fn() instead of calling png_init_io()
png_set_write_fn(png_ptr, &memory_buffer, PNG_memory_write, PNG_memory_flush);
/* read PNG header */
if (!setjmp(png_jmpbuf(png_ptr)))
{
png_set_IHDR(png_ptr, info_ptr, context->Width, context->Height,
8, PNG_COLOR_TYPE_PALETTE, PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
png_set_PLTE(png_ptr, info_ptr, (png_colorp)context->Palette, 256);
{
// text chunks in PNG (optional)
png_text text_ptr[2] = {
#ifdef PNG_iTXt_SUPPORTED
{-1, "Software", "Grafx2", 6, 0, NULL, NULL},
{-1, "Title", NULL, 0, 0, NULL, NULL}
#else
{-1, "Software", "Grafx2", 6},
{-1, "Title", NULL, 0}
#endif
};
int nb_text_chunks=1;
if (context->Comment[0])
{
text_ptr[1].text=context->Comment;
text_ptr[1].text_length=strlen(context->Comment);
nb_text_chunks=2;
}
png_set_text(png_ptr, info_ptr, text_ptr, nb_text_chunks);
}
if (context->Background_transparent)
{
// Transparency
byte opacity[256];
// Need to fill a segment with '255', up to the transparent color
// which will have a 0. This piece of data (1 to 256 bytes)
// will be stored in the file.
memset(opacity, 255,context->Transparent_color);
opacity[context->Transparent_color]=0;
png_set_tRNS(png_ptr, info_ptr, opacity, (int)1 + context->Transparent_color,0);
}
// if using PNG_RESOLUTION_METER, unit is in dot per meter.
// 72 DPI = 2835, 600 DPI = 23622
// with PNG_RESOLUTION_UNKNOWN, it is arbitrary
switch(Pixel_ratio)
{
case PIXEL_WIDE:
case PIXEL_WIDE2:
png_set_pHYs(png_ptr, info_ptr, 1, 2, PNG_RESOLUTION_UNKNOWN);
break;
case PIXEL_TALL:
case PIXEL_TALL2:
png_set_pHYs(png_ptr, info_ptr, 2, 1, PNG_RESOLUTION_UNKNOWN);
break;
case PIXEL_TALL3:
png_set_pHYs(png_ptr, info_ptr, 4, 3, PNG_RESOLUTION_UNKNOWN);
break;
default:
break;
}
// Write cycling colors
if (context->Color_cycles)
{
// Save a chunk called 'crNg'
// The case is selected by the following rules from PNG standard:
// char 1: non-mandatory = lowercase
// char 2: private (not standard) = lowercase
// char 3: reserved = always uppercase
// char 4: can be copied by editors = lowercase
// First, turn our nice structure into byte array
// (just to avoid padding in structures)
byte *chunk_ptr = cycle_data;
int i;
for (i=0; i<context->Color_cycles; i++)
{
word flags=0;
flags|= context->Cycle_range[i].Speed?1:0; // Cycling or not
flags|= context->Cycle_range[i].Inverse?2:0; // Inverted
// Big end of Rate
*(chunk_ptr++) = (context->Cycle_range[i].Speed*78) >> 8;
// Low end of Rate
*(chunk_ptr++) = (context->Cycle_range[i].Speed*78) & 0xFF;
// Big end of Flags
*(chunk_ptr++) = (flags) >> 8;
// Low end of Flags
*(chunk_ptr++) = (flags) & 0xFF;
// Min color
*(chunk_ptr++) = context->Cycle_range[i].Start;
// Max color
*(chunk_ptr++) = context->Cycle_range[i].End;
}
// Build one unknown_chuck structure
memcpy(crng_chunk.name, "crNg",5);
crng_chunk.data=cycle_data;
crng_chunk.size=context->Color_cycles*6;
crng_chunk.location=PNG_HAVE_PLTE;
// Give it to libpng
png_set_unknown_chunks(png_ptr, info_ptr, &crng_chunk, 1);
// libpng seems to ignore the location I provided earlier.
png_set_unknown_chunk_location(png_ptr, info_ptr, 0, PNG_HAVE_PLTE);
}
png_write_info(png_ptr, info_ptr);
/* ecriture des pixels de l'image */
Row_pointers = (png_bytep*) malloc(sizeof(png_bytep) * context->Height);
pixel_ptr = context->Target_address;
for (y=0; y<context->Height; y++)
Row_pointers[y] = (png_byte*)(pixel_ptr+y*context->Pitch);
if (!setjmp(png_jmpbuf(png_ptr)))
{
png_write_image(png_ptr, Row_pointers);
/* cloture png */
if (!setjmp(png_jmpbuf(png_ptr)))
{
png_write_end(png_ptr, NULL);
}
else
File_error=1;
}
else
File_error=1;
}
else
File_error=1;
}
else
{
File_error=1;
}
png_destroy_write_struct(&png_ptr, &info_ptr);
}
else
File_error=1;
if (Row_pointers)
free(Row_pointers);
if (File_error == 0 && buffer != NULL)
{
*buffer = memory_buffer.buffer;
if (buffer_size != NULL)
*buffer_size = memory_buffer.offset;
}
else
free(memory_buffer.buffer);
}
/// Save a PNG file
void Save_PNG(T_IO_Context * context)
{
FILE *file;
File_error = 0;
file = Open_file_write(context);
if (file != NULL)
{
Save_PNG_Sub(context, file, NULL, NULL);
fclose(file);
// remove the file if there was an error
if (File_error)
Remove_file(context);
}
else
File_error = 1;
}
#endif // __no_pnglib__
/** @} */

806
src/pngformat.c Normal file
View File

@ -0,0 +1,806 @@
/* vim:expandtab:ts=2 sw=2:
*/
/* Grafx2 - The Ultimate 256-color bitmap paint program
Copyright 2018 Thomas Bernard
Copyright 2011 Pawel Góralski
Copyright 2009 Petter Lindquist
Copyright 2008 Yves Rizoud
Copyright 2008 Franck Charlet
Copyright 2007 Adrien Destugues
Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
Grafx2 is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; version 2
of the License.
Grafx2 is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Grafx2; if not, see <http://www.gnu.org/licenses/>
*/
///@file pngformat.c
/// Saving and loading of PNG file format
#ifndef __no_pnglib__
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <png.h>
#if !defined(PNG_HAVE_PLTE)
#define PNG_HAVE_PLTE 0x02
#endif
#if (PNG_LIBPNG_VER_MAJOR <= 1) && (PNG_LIBPNG_VER_MINOR < 4)
// Compatibility layer to allow us to use libng 1.4 or any older one.
// This function is renamed in 1.4
#define png_set_expand_gray_1_2_4_to_8(x) png_set_gray_1_2_4_to_8(x)
// Wrappers that are mandatory in 1.4. Older version allowed direct access.
#define png_get_rowbytes(png_ptr,info_ptr) ((info_ptr)->rowbytes)
#define png_get_image_width(png_ptr,info_ptr) ((info_ptr)->width)
#define png_get_image_height(png_ptr,info_ptr) ((info_ptr)->height)
#define png_get_bit_depth(png_ptr,info_ptr) ((info_ptr)->bit_depth)
#define png_get_color_type(png_ptr,info_ptr) ((info_ptr)->color_type)
#endif
#ifndef png_jmpbuf
# define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
#endif
#include "loadsave.h"
#include "loadsavefuncs.h"
#include "io.h"
#include "misc.h"
#include "gfx2log.h"
#ifndef MIN
#define MIN(a,b) ((a)<(b)?(a):(b))
#endif
//////////////////////////////////// PNG ////////////////////////////////////
/**
* @defgroup PNG PNG format
* @ingroup loadsaveformats
* Portable Network Graphics
*
* We make use of libpng : http://www.libpng.org/pub/png/libpng.html
* @{
*/
/// Test for PNG format
///
/// The 8 byte signature at the start of file is tested
void Test_PNG(T_IO_Context * context, FILE * file)
{
byte png_header[8];
(void)context;
File_error=1;
// Lecture du header du fichier
if (Read_bytes(file,png_header,8))
{
if ( !png_sig_cmp(png_header, 0, 8))
File_error=0;
}
}
/// Callback to handle our private chunks
///
/// We have one private chunk at the moment :
/// - "crNg" which is similar to a CRNG chunk in an IFF file
static int PNG_read_unknown_chunk(png_structp ptr, png_unknown_chunkp chunk)
{
T_IO_Context * context;
// png_unknown_chunkp members:
// png_byte name[5];
// png_byte *data;
// png_size_t size;
context = (T_IO_Context *)png_get_user_chunk_ptr(ptr);
GFX2_Log(GFX2_DEBUG, "PNG private chunk '%s' :\n", chunk->name);
GFX2_LogHexDump(GFX2_DEBUG, "", chunk->data, 0, chunk->size);
if (!strcmp((const char *)chunk->name, "crNg"))
{
unsigned int i;
const byte *chunk_ptr = chunk->data;
// Should be a multiple of 6
if (chunk->size % 6)
return (-1);
for(i=0;i<chunk->size/6 && i<16; i++)
{
word rate;
word flags;
byte min_col;
byte max_col;
// Rate (big-endian word)
rate = *(chunk_ptr++) << 8;
rate |= *(chunk_ptr++);
// Flags (big-endian)
flags = *(chunk_ptr++) << 8;
flags |= *(chunk_ptr++);
// Min color
min_col = *(chunk_ptr++);
// Max color
max_col = *(chunk_ptr++);
// Check validity
if (min_col != max_col)
{
// Valid cycling range
if (max_col<min_col)
SWAP_BYTES(min_col,max_col)
context->Cycle_range[i].Start=min_col;
context->Cycle_range[i].End=max_col;
context->Cycle_range[i].Inverse=(flags&2)?1:0;
context->Cycle_range[i].Speed=(flags&1) ? rate/78 : 0;
context->Color_cycles=i+1;
}
}
return (1); // >0 = success
}
return (0); /* did not recognize */
}
/// Private structure used in PNG_memory_read() and PNG_memory_write()
struct PNG_memory_buffer {
char * buffer;
unsigned long offset;
unsigned long size;
};
/// read from memory buffer
static void PNG_memory_read(png_structp png_ptr, png_bytep p, png_size_t count)
{
struct PNG_memory_buffer * buffer = (struct PNG_memory_buffer *)png_get_io_ptr(png_ptr);
GFX2_Log(GFX2_DEBUG, "PNG_memory_read(%p, %p, %u) (io_ptr=%p)\n", png_ptr, p, count, buffer);
if (buffer == NULL || p == NULL)
return;
if (buffer->offset + count <= buffer->size)
{
memcpy(p, buffer->buffer + buffer->offset, count);
buffer->offset += count;
}
else
{
unsigned long available_count = buffer->size - buffer->offset;
GFX2_Log(GFX2_DEBUG, "PNG_memory_read(): only %lu bytes available\n", available_count);
if (available_count > 0)
{
memcpy(p, buffer->buffer + buffer->offset, available_count);
buffer->offset += available_count;
}
}
}
/// Read PNG format file
void Load_PNG_Sub(T_IO_Context * context, FILE * file, const char * memory_buffer, unsigned long memory_buffer_size)
{
png_structp png_ptr;
png_infop info_ptr = NULL;
// Prepare internal PNG loader
png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (png_ptr)
{
// Prepare internal PNG loader
info_ptr = png_create_info_struct(png_ptr);
if (info_ptr)
{
png_byte color_type;
png_byte bit_depth;
byte bpp;
struct PNG_memory_buffer buffer;
// Setup a return point. If a pnglib loading error occurs
// in this if(), the else will be executed.
if (!setjmp(png_jmpbuf(png_ptr)))
{
// to read from memory, I need to use png_set_read_fn() instead of calling png_init_io()
if (file != NULL)
png_init_io(png_ptr, file);
else
{
buffer.buffer = (char *)memory_buffer;
buffer.offset = 8; // skip header
buffer.size = memory_buffer_size;
png_set_read_fn(png_ptr, &buffer, PNG_memory_read);
}
// Inform pnglib we already loaded the header.
png_set_sig_bytes(png_ptr, 8);
// Hook the handler for unknown chunks
png_set_read_user_chunk_fn(png_ptr, (png_voidp)context, &PNG_read_unknown_chunk);
// Load file information
png_read_info(png_ptr, info_ptr);
color_type = png_get_color_type(png_ptr,info_ptr);
bit_depth = png_get_bit_depth(png_ptr,info_ptr);
switch (color_type)
{
case PNG_COLOR_TYPE_GRAY_ALPHA:
// no more than 8bpp or else we enable true color picture loading
bpp = MIN(8, bit_depth * 2);
break;
case PNG_COLOR_TYPE_RGB:
bpp = bit_depth * 3;
break;
case PNG_COLOR_TYPE_RGB_ALPHA:
bpp = bit_depth * 4;
break;
case PNG_COLOR_TYPE_PALETTE:
case PNG_COLOR_TYPE_GRAY:
default:
// no more than 8bpp or else we enable true color picture loading
bpp = MIN(8, bit_depth);
}
GFX2_Log(GFX2_DEBUG, "PNG type=%u bit_depth=%u : %ubpp\n", color_type, bit_depth, bpp);
// If it's any supported file
// (Note: As of writing this, this test covers every possible
// image format of libpng)
if (color_type == PNG_COLOR_TYPE_PALETTE
|| color_type == PNG_COLOR_TYPE_GRAY
|| color_type == PNG_COLOR_TYPE_GRAY_ALPHA
|| color_type == PNG_COLOR_TYPE_RGB
|| color_type == PNG_COLOR_TYPE_RGB_ALPHA
)
{
enum PIXEL_RATIO ratio = PIXEL_SIMPLE;
int num_text;
png_text *text_ptr;
int unit_type;
png_uint_32 res_x;
png_uint_32 res_y;
// Comment (tEXt)
context->Comment[0]='\0'; // Clear the previous comment
if ((num_text=png_get_text(png_ptr, info_ptr, &text_ptr, NULL)))
{
while (num_text--)
{
int size = COMMENT_SIZE;
#ifdef PNG_iTXt_SUPPORTED
size_t length = (text_ptr[num_text].compression >= 1) ? text_ptr[num_text].itxt_length : text_ptr[num_text].text_length;
#else
size_t length = text_ptr[num_text].text_length;
if (text_ptr[num_text].compression >= 1)
continue; // skip iTXt
#endif
if (length > 0 && length < COMMENT_SIZE)
size = (int)length;
GFX2_Log(GFX2_DEBUG, "PNG Text %d \"%s\" (%lu bytes): %.*s\n",
text_ptr[num_text].compression, text_ptr[num_text].key,
(unsigned long)length,
(int)MIN(length, 160), text_ptr[num_text].text);
if (strcmp(text_ptr[num_text].key,"Title") == 0)
{
strncpy(context->Comment, text_ptr[num_text].text, size);
context->Comment[size]='\0';
break; // Skip all others tEXt chunks
}
else if(strcmp(text_ptr[num_text].key, "Comment") == 0)
{
strncpy(context->Comment, text_ptr[num_text].text, size);
context->Comment[size]='\0';
break; // Skip all others tEXt chunks
}
}
}
// Pixel Ratio (pHYs)
if (png_get_pHYs(png_ptr, info_ptr, &res_x, &res_y, &unit_type))
{
// Ignore unit, and use the X/Y ratio as a hint for
// WIDE or TALL pixels
if (res_x>0 && res_y>0)
{
GFX2_Log(GFX2_DEBUG, "PNG pHYs unit %d %dx%d\n", unit_type, res_x, res_y);
if (unit_type == 1)
GFX2_Log(GFX2_DEBUG, " %dx%d DPI\n", (res_x * 254 + 5000) / 10000, (res_y * 254 + 5000) / 10000);
if (res_y * 10 > res_x * 12) // X/Y < 1/1.2
ratio = PIXEL_WIDE;
else if (res_x * 10 > res_y * 12) // X/Y > 1.2
ratio = PIXEL_TALL;
}
}
Pre_load(context,
png_get_image_width(png_ptr, info_ptr),
png_get_image_height(png_ptr, info_ptr),
file != NULL ? File_length_file(file) : memory_buffer_size,
FORMAT_PNG, ratio, bpp);
if (File_error==0)
{
int x,y;
png_colorp palette;
int num_palette;
png_bytep * Row_pointers = NULL;
byte row_pointers_allocated = 0;
int num_trans;
png_bytep trans;
png_color_16p trans_values;
// 16-bit images
if (bit_depth == 16)
{
// Reduce to 8-bit
png_set_strip_16(png_ptr);
}
else if (bit_depth < 8)
{
// Inform libpng we want one byte per pixel,
// even though the file was less than 8bpp
png_set_packing(png_ptr);
}
// Images with alpha channel
if (color_type & PNG_COLOR_MASK_ALPHA)
{
// Tell libpng to ignore it
png_set_strip_alpha(png_ptr);
}
// Greyscale images :
if (color_type == PNG_COLOR_TYPE_GRAY || color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
{
// Map low bpp greyscales to full 8bit (0-255 range)
if (bit_depth < 8)
{
#if (PNG_LIBPNG_VER_MAJOR <= 1) && (PNG_LIBPNG_VER_MINOR < 4)
// Works well with png 1.2.8, but deprecated in 1.4 ...
png_set_gray_1_2_4_to_8(png_ptr);
#else
// ...where this seems to replace it:
png_set_expand_gray_1_2_4_to_8(png_ptr);
#endif
}
// Create greyscale palette
for (x=0;x<256;x++)
{
context->Palette[x].R=x;
context->Palette[x].G=x;
context->Palette[x].B=x;
}
}
else if (color_type == PNG_COLOR_TYPE_PALETTE) // Palette images
{
if (bit_depth < 8)
{
// Clear unused colors
if (Config.Clear_palette)
memset(context->Palette,0,sizeof(T_Palette));
}
// Get a pointer to the PNG palette
png_get_PLTE(png_ptr, info_ptr, &palette,
&num_palette);
// Copy all colors to the context
for (x=0;x<num_palette;x++)
{
context->Palette[x].R=palette[x].red;
context->Palette[x].G=palette[x].green;
context->Palette[x].B=palette[x].blue;
}
// The palette must not be freed: it is owned by libpng.
palette = NULL;
}
// Transparency (tRNS)
if (png_get_tRNS(png_ptr, info_ptr, &trans, &num_trans, &trans_values))
{
GFX2_Log(GFX2_DEBUG, "PNG transparency %d %p %p\n", num_trans, trans, trans_values);
if (color_type == PNG_COLOR_TYPE_PALETTE && trans!=NULL)
{
int i;
for (i=0; i<num_trans; i++)
{
// Look for the first color with alpha = 0 (full transparency)
if (trans[i]==0)
{
context->Transparent_color = i;
context->Background_transparent = 1;
break;
}
}
}
else if ((color_type == PNG_COLOR_TYPE_GRAY
|| color_type == PNG_COLOR_TYPE_RGB) && trans_values!=NULL)
{
// In this case, num_trans is supposed to be "1",
// and trans_values[0] contains the reference color
// (RGB triplet) that counts as transparent.
// Ideally, we should reserve this color in the palette,
// (so it's not merged and averaged with a neighbor one)
// and after creating the optimized palette, find its
// index and mark it transparent.
// Current implementation: ignore.
}
}
png_set_interlace_handling(png_ptr); // return number of image passes (7 for interlaced images)
png_read_update_info(png_ptr, info_ptr);
// Allocate row pointers
Row_pointers = (png_bytep*) malloc(sizeof(png_bytep) * context->Height);
row_pointers_allocated = 0;
/* read file */
if (!setjmp(png_jmpbuf(png_ptr)))
{
if (color_type == PNG_COLOR_TYPE_GRAY
|| color_type == PNG_COLOR_TYPE_GRAY_ALPHA
|| color_type == PNG_COLOR_TYPE_PALETTE
)
{
// 8bpp
for (y=0; y<context->Height; y++)
Row_pointers[y] = (png_byte*) malloc(png_get_rowbytes(png_ptr,info_ptr));
row_pointers_allocated = 1;
png_read_image(png_ptr, Row_pointers);
for (y=0; y<context->Height; y++)
for (x=0; x<context->Width; x++)
Set_pixel(context, x, y, Row_pointers[y][x]);
}
else
{
switch (context->Type)
{
case CONTEXT_PREVIEW:
// 24bpp
// It's a preview
// Unfortunately we need to allocate loads of memory
for (y=0; y<context->Height; y++)
Row_pointers[y] = (png_byte*) malloc(png_get_rowbytes(png_ptr,info_ptr));
row_pointers_allocated = 1;
png_read_image(png_ptr, Row_pointers);
for (y=0; y<context->Height; y++)
for (x=0; x<context->Width; x++)
Set_pixel_24b(context, x, y, Row_pointers[y][x*3],Row_pointers[y][x*3+1],Row_pointers[y][x*3+2]);
break;
case CONTEXT_MAIN_IMAGE:
case CONTEXT_BRUSH:
case CONTEXT_SURFACE:
// It's loading an actual image
// We'll save memory and time by writing directly into
// our pre-allocated 24bit buffer
for (y=0; y<context->Height; y++)
Row_pointers[y] = (png_byte*) (&(context->Buffer_image_24b[y * context->Width]));
png_read_image(png_ptr, Row_pointers);
break;
case CONTEXT_PALETTE:
case CONTEXT_PREVIEW_PALETTE:
// No pixels to draw in a palette!
break;
}
}
}
else
File_error=2;
/* cleanup heap allocation */
if (row_pointers_allocated)
{
for (y=0; y<context->Height; y++) {
free(Row_pointers[y]);
Row_pointers[y] = NULL;
}
}
free(Row_pointers);
Row_pointers = NULL;
}
else
File_error=2;
}
else
// Unsupported image type
File_error=1;
}
else
File_error=1;
}
else
File_error=1;
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
}
}
/// Read PNG format files
///
/// just read/test the header and call Load_PNG_Sub()
void Load_PNG(T_IO_Context * context)
{
FILE *file;
byte png_header[8];
File_error=0;
if ((file=Open_file_read(context)))
{
// Load header (8 first bytes)
if (Read_bytes(file,png_header,8))
{
// Do we recognize a png file signature ?
if ( !png_sig_cmp(png_header, 0, 8))
Load_PNG_Sub(context, file, NULL, 0);
else
File_error=1;
}
else // Lecture header impossible: Error ne modifiant pas l'image
File_error=1;
fclose(file);
}
else // Ouv. fichier impossible: Error ne modifiant pas l'image
File_error=1;
}
/// Write to memory buffer
static void PNG_memory_write(png_structp png_ptr, png_bytep p, png_size_t count)
{
struct PNG_memory_buffer * buffer = (struct PNG_memory_buffer *)png_get_io_ptr(png_ptr);
GFX2_Log(GFX2_DEBUG, "PNG_memory_write(%p, %p, %u) (io_ptr=%p)\n", png_ptr, p, count, buffer);
if (buffer->size < buffer->offset + count)
{
char * tmp = realloc(buffer->buffer, buffer->offset + count + 1024);
if (tmp == NULL)
{
GFX2_Log(GFX2_ERROR, "PNG_memory_write() Failed to allocate %u bytes of memory\n", buffer->offset + count + 1024);
File_error = 1;
return;
}
buffer->buffer = tmp;
buffer->size = buffer->offset + count + 1024;
}
memcpy(buffer->buffer + buffer->offset, p, count);
buffer->offset += count;
}
/// do nothing
static void PNG_memory_flush(png_structp png_ptr)
{
struct PNG_memory_buffer * buffer = (struct PNG_memory_buffer *)png_get_io_ptr(png_ptr);
GFX2_Log(GFX2_DEBUG, "PNG_memory_flush(%p) (io_ptr=%p)\n", png_ptr, buffer);
}
/// Save a PNG to file or memory
/// @param context the IO context
/// @param file the FILE to write to or NULL to write to memory
/// @param buffer will receive a malloc'ed buffer if writting to memory
/// @param buffer_size will receive the PNG size in memory
void Save_PNG_Sub(T_IO_Context * context, FILE * file, char * * buffer, unsigned long * buffer_size)
{
static png_bytep * Row_pointers = NULL;
int y;
byte * pixel_ptr;
png_structp png_ptr;
png_infop info_ptr;
png_unknown_chunk crng_chunk;
byte cycle_data[16*6]; // Storage for color-cycling data, referenced by crng_chunk
struct PNG_memory_buffer memory_buffer;
assert((file != NULL) || ((buffer != NULL) && (buffer_size != NULL)));
memset(&memory_buffer, 0, sizeof(memory_buffer));
/* initialisation */
if ((png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL))
&& (info_ptr = png_create_info_struct(png_ptr)))
{
if (!setjmp(png_jmpbuf(png_ptr)))
{
if (file != NULL)
png_init_io(png_ptr, file);
else // to write to memory, use png_set_write_fn() instead of calling png_init_io()
png_set_write_fn(png_ptr, &memory_buffer, PNG_memory_write, PNG_memory_flush);
/* read PNG header */
if (!setjmp(png_jmpbuf(png_ptr)))
{
png_set_IHDR(png_ptr, info_ptr, context->Width, context->Height,
8, PNG_COLOR_TYPE_PALETTE, PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
png_set_PLTE(png_ptr, info_ptr, (png_colorp)context->Palette, 256);
{
// text chunks in PNG (optional)
png_text text_ptr[2] = {
#ifdef PNG_iTXt_SUPPORTED
{-1, "Software", "Grafx2", 6, 0, NULL, NULL},
{-1, "Title", NULL, 0, 0, NULL, NULL}
#else
{-1, "Software", "Grafx2", 6},
{-1, "Title", NULL, 0}
#endif
};
int nb_text_chunks=1;
if (context->Comment[0])
{
text_ptr[1].text=context->Comment;
text_ptr[1].text_length=strlen(context->Comment);
nb_text_chunks=2;
}
png_set_text(png_ptr, info_ptr, text_ptr, nb_text_chunks);
}
if (context->Background_transparent)
{
// Transparency
byte opacity[256];
// Need to fill a segment with '255', up to the transparent color
// which will have a 0. This piece of data (1 to 256 bytes)
// will be stored in the file.
memset(opacity, 255,context->Transparent_color);
opacity[context->Transparent_color]=0;
png_set_tRNS(png_ptr, info_ptr, opacity, (int)1 + context->Transparent_color,0);
}
// if using PNG_RESOLUTION_METER, unit is in dot per meter.
// 72 DPI = 2835, 600 DPI = 23622
// with PNG_RESOLUTION_UNKNOWN, it is arbitrary
switch(Pixel_ratio)
{
case PIXEL_WIDE:
case PIXEL_WIDE2:
png_set_pHYs(png_ptr, info_ptr, 1, 2, PNG_RESOLUTION_UNKNOWN);
break;
case PIXEL_TALL:
case PIXEL_TALL2:
png_set_pHYs(png_ptr, info_ptr, 2, 1, PNG_RESOLUTION_UNKNOWN);
break;
case PIXEL_TALL3:
png_set_pHYs(png_ptr, info_ptr, 4, 3, PNG_RESOLUTION_UNKNOWN);
break;
default:
break;
}
// Write cycling colors
if (context->Color_cycles)
{
// Save a chunk called 'crNg'
// The case is selected by the following rules from PNG standard:
// char 1: non-mandatory = lowercase
// char 2: private (not standard) = lowercase
// char 3: reserved = always uppercase
// char 4: can be copied by editors = lowercase
// First, turn our nice structure into byte array
// (just to avoid padding in structures)
byte *chunk_ptr = cycle_data;
int i;
for (i=0; i<context->Color_cycles; i++)
{
word flags=0;
flags|= context->Cycle_range[i].Speed?1:0; // Cycling or not
flags|= context->Cycle_range[i].Inverse?2:0; // Inverted
// Big end of Rate
*(chunk_ptr++) = (context->Cycle_range[i].Speed*78) >> 8;
// Low end of Rate
*(chunk_ptr++) = (context->Cycle_range[i].Speed*78) & 0xFF;
// Big end of Flags
*(chunk_ptr++) = (flags) >> 8;
// Low end of Flags
*(chunk_ptr++) = (flags) & 0xFF;
// Min color
*(chunk_ptr++) = context->Cycle_range[i].Start;
// Max color
*(chunk_ptr++) = context->Cycle_range[i].End;
}
// Build one unknown_chuck structure
memcpy(crng_chunk.name, "crNg",5);
crng_chunk.data=cycle_data;
crng_chunk.size=context->Color_cycles*6;
crng_chunk.location=PNG_HAVE_PLTE;
// Give it to libpng
png_set_unknown_chunks(png_ptr, info_ptr, &crng_chunk, 1);
// libpng seems to ignore the location I provided earlier.
png_set_unknown_chunk_location(png_ptr, info_ptr, 0, PNG_HAVE_PLTE);
}
png_write_info(png_ptr, info_ptr);
/* ecriture des pixels de l'image */
Row_pointers = (png_bytep*) malloc(sizeof(png_bytep) * context->Height);
pixel_ptr = context->Target_address;
for (y=0; y<context->Height; y++)
Row_pointers[y] = (png_byte*)(pixel_ptr+y*context->Pitch);
if (!setjmp(png_jmpbuf(png_ptr)))
{
png_write_image(png_ptr, Row_pointers);
/* cloture png */
if (!setjmp(png_jmpbuf(png_ptr)))
{
png_write_end(png_ptr, NULL);
}
else
File_error=1;
}
else
File_error=1;
}
else
File_error=1;
}
else
{
File_error=1;
}
png_destroy_write_struct(&png_ptr, &info_ptr);
}
else
File_error=1;
if (Row_pointers)
free(Row_pointers);
if (File_error == 0 && buffer != NULL)
{
*buffer = memory_buffer.buffer;
if (buffer_size != NULL)
*buffer_size = memory_buffer.offset;
}
else
free(memory_buffer.buffer);
}
/// Save a PNG file
void Save_PNG(T_IO_Context * context)
{
FILE *file;
File_error = 0;
file = Open_file_write(context);
if (file != NULL)
{
Save_PNG_Sub(context, file, NULL, NULL);
fclose(file);
// remove the file if there was an error
if (File_error)
Remove_file(context);
}
else
File_error = 1;
}
/** @} */
#endif // __no_pnglib__