static gint
gegl_buffer_import_png (GeglBuffer *gegl_buffer,
GInputStream *stream,
gint dest_x,
gint dest_y,
gint *ret_width,
gint *ret_height,
const Babl *format, // can be NULL
GError **err)
{
gint width;
gint bit_depth;
gint bpp;
gint number_of_passes=1;
png_uint_32 w;
png_uint_32 h;
png_structp load_png_ptr;
png_infop load_info_ptr;
guchar *pixels;
/*png_bytep *rows;*/
unsigned int i;
png_bytep *row_p = NULL;
g_return_val_if_fail(stream, -1);
if (!check_valid_png_header(stream, err))
{
return -1;
}
load_png_ptr = png_create_read_struct (PNG_LIBPNG_VER_STRING, NULL, error_fn, NULL);
if (!load_png_ptr)
{
return -1;
}
load_info_ptr = png_create_info_struct (load_png_ptr);
if (!load_info_ptr)
{
png_destroy_read_struct (&load_png_ptr, &load_info_ptr, NULL);
return -1;
}
if (setjmp (png_jmpbuf (load_png_ptr)))
{
png_destroy_read_struct (&load_png_ptr, &load_info_ptr, NULL);
if (row_p)
g_free (row_p);
return -1;
}
png_set_read_fn(load_png_ptr, stream, read_fn);
png_set_sig_bytes (load_png_ptr, 8); // we already read header
png_read_info (load_png_ptr, load_info_ptr);
{
int color_type;
int interlace_type;
png_get_IHDR (load_png_ptr,
load_info_ptr,
&w, &h,
&bit_depth,
&color_type,
&interlace_type,
NULL, NULL);
width = w;
if (ret_width)
*ret_width = w;
if (ret_height)
*ret_height = h;
if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
{
png_set_expand (load_png_ptr);
bit_depth = 8;
}
if (png_get_valid (load_png_ptr, load_info_ptr, PNG_INFO_tRNS))
{
png_set_tRNS_to_alpha (load_png_ptr);
color_type |= PNG_COLOR_MASK_ALPHA;
}
switch (color_type)
{
case PNG_COLOR_TYPE_GRAY:
bpp = 1;
break;
case PNG_COLOR_TYPE_GRAY_ALPHA:
bpp = 2;
break;
case PNG_COLOR_TYPE_RGB:
bpp = 3;
break;
case PNG_COLOR_TYPE_RGB_ALPHA:
bpp = 4;
break;
case (PNG_COLOR_TYPE_PALETTE | PNG_COLOR_MASK_ALPHA):
bpp = 4;
break;
case PNG_COLOR_TYPE_PALETTE:
bpp = 3;
break;
default:
g_warning ("color type mismatch");
png_destroy_read_struct (&load_png_ptr, &load_info_ptr, NULL);
return -1;
}
if (color_type == PNG_COLOR_TYPE_PALETTE)
png_set_palette_to_rgb (load_png_ptr);
if (bit_depth == 16)
bpp = bpp << 1;
if (!format)
format = get_babl_format(bit_depth, color_type);
#if BYTE_ORDER == LITTLE_ENDIAN
if (bit_depth == 16)
png_set_swap (load_png_ptr);
#endif
if (interlace_type == PNG_INTERLACE_ADAM7)
number_of_passes = png_set_interlace_handling (load_png_ptr);
if (png_get_valid (load_png_ptr, load_info_ptr, PNG_INFO_gAMA))
{
gdouble gamma;
png_get_gAMA (load_png_ptr, load_info_ptr, &gamma);
png_set_gamma (load_png_ptr, 2.2, gamma);
}
else
{
png_set_gamma (load_png_ptr, 2.2, 0.45455);
}
png_read_update_info (load_png_ptr, load_info_ptr);
}
pixels = g_malloc0 (width*bpp);
{
gint pass;
GeglRectangle rect;
for (pass=0; pass<number_of_passes; pass++)
{
for(i=0; i<h; i++)
{
gegl_rectangle_set (&rect, 0, i, width, 1);
if (pass != 0)
gegl_buffer_get (gegl_buffer, &rect, 1.0, format, pixels, GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE);
png_read_rows (load_png_ptr, &pixels, NULL, 1);
gegl_buffer_set (gegl_buffer, &rect, 0, format, pixels,
GEGL_AUTO_ROWSTRIDE);
}
}
}
png_read_end (load_png_ptr, NULL);
png_destroy_read_struct (&load_png_ptr, &load_info_ptr, NULL);
g_free (pixels);
return 0;
}
static gint query_png (GInputStream *stream,
gint *width,
gint *height,
const Babl **format,
GError **err)
{
png_uint_32 w;
png_uint_32 h;
png_structp load_png_ptr;
png_infop load_info_ptr;
png_bytep *row_p = NULL;
g_return_val_if_fail(stream, -1);
if (!check_valid_png_header(stream, err))
{
return -1;
}
load_png_ptr = png_create_read_struct (PNG_LIBPNG_VER_STRING, NULL, error_fn, NULL);
if (!load_png_ptr)
{
return -1;
}
load_info_ptr = png_create_info_struct (load_png_ptr);
if (!load_info_ptr)
{
png_destroy_read_struct (&load_png_ptr, &load_info_ptr, NULL);
return -1;
}
if (setjmp (png_jmpbuf (load_png_ptr)))
{
png_destroy_read_struct (&load_png_ptr, &load_info_ptr, NULL);
g_free (row_p);
return -1;
}
png_set_read_fn(load_png_ptr, stream, read_fn);
png_set_sig_bytes (load_png_ptr, 8); // we already read header
png_read_info (load_png_ptr, load_info_ptr);
{
int bit_depth;
int color_type;
const Babl *f;
png_get_IHDR (load_png_ptr,
load_info_ptr,
&w, &h,
&bit_depth,
&color_type,
NULL, NULL, NULL);
*width = w;
*height = h;
if (png_get_valid (load_png_ptr, load_info_ptr, PNG_INFO_tRNS))
color_type |= PNG_COLOR_MASK_ALPHA;
f = get_babl_format(bit_depth, color_type);
if (!f)
{
png_destroy_read_struct (&load_png_ptr, &load_info_ptr, NULL);
return -1;
}
*format = f;
}
png_destroy_read_struct (&load_png_ptr, &load_info_ptr, NULL);
return 0;
}
