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X11 picture paste support (PNG format)

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works with what GIMP puts in the X11 CLIPBOARD
This commit is contained in:
Thomas Bernard
2018-12-30 10:20:50 +01:00
parent a68343d2ad
commit 7331ad9bdf
7 changed files with 155 additions and 14 deletions
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59
src/fileformats.c
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@@ -91,10 +91,6 @@
#include "fileformats.h"
#include "oldies.h"
#ifndef __no_pnglib__
static void Load_PNG_Sub(T_IO_Context * context, FILE * file);
#endif
#ifndef MIN
#define MIN(a,b) ((a)<(b)?(a):(b))
#endif
@@ -3769,7 +3765,7 @@ void Load_ICO(T_IO_Context * context)
#ifndef __no_pnglib__
if (png_sig_cmp(png_header, 0, 8) == 0)
{
Load_PNG_Sub(context, file);
Load_PNG_Sub(context, file, NULL, 0);
}
#else
if (0 == memcmp(png_header, "\x89PNG", 4))
@@ -6239,8 +6235,39 @@ static int PNG_read_unknown_chunk(png_structp ptr, png_unknown_chunkp chunk)
}
struct PNG_memory_buffer {
const 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
static void Load_PNG_Sub(T_IO_Context * context, FILE * 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;
@@ -6256,12 +6283,22 @@ static void Load_PNG_Sub(T_IO_Context * context, FILE * file)
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)))
{
png_init_io(png_ptr, file);
// 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 = 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);
@@ -6344,7 +6381,11 @@ static void Load_PNG_Sub(T_IO_Context * context, FILE * file)
ratio = PIXEL_TALL;
}
}
Pre_load(context,png_get_image_width(png_ptr,info_ptr),png_get_image_height(png_ptr,info_ptr),File_length_file(file),FORMAT_PNG,ratio,bpp);
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)
{
@@ -6569,7 +6610,7 @@ void Load_PNG(T_IO_Context * context)
{
// Do we recognize a png file signature ?
if ( !png_sig_cmp(png_header, 0, 8))
Load_PNG_Sub(context, file);
Load_PNG_Sub(context, file, NULL, 0);
else
File_error=1;
}