Commit e22687da authored by Nick Lamb /GIMP's avatar Nick Lamb /GIMP

Now PNGs with colormaps and tRNS (ie transparency info) load properly

Still convert to RGB for the best results. Save support is TODO
parent 9cf42624
Mon Sep 20 18:58:38 BST 1999 Nick Lamb <njl195@zepler.org>
* plug-ins/common/png.c: Now PNGs with colormaps and tRNS
(ie transparency info) load properly. Still convert to RGB for
the best results. Save support is TODO
Sat Oct 2 14:36:21 1999 Tim Janik <timj@gtk.org>
* plug-ins/common/csource.c: removed cruft (old test code)
......
......@@ -54,7 +54,7 @@
* Constants...
*/
#define PLUG_IN_VERSION "1.1.8 - 8 Sep 1999"
#define PLUG_IN_VERSION "1.1.9 - 2 Oct 1999"
#define SCALE_WIDTH 125
#define DEFAULT_GAMMA 2.20
......@@ -288,6 +288,7 @@ static gint32
load_image(char *filename) /* I - File to load */
{
int i, /* Looping var */
trns = 0, /* Transparency present */
bpp = 0, /* Bytes per pixel */
image_type = 0, /* Type of image */
layer_type = 0, /* Type of drawable/layer */
......@@ -307,7 +308,8 @@ load_image(char *filename) /* I - File to load */
guchar **pixels, /* Pixel rows */
*pixel; /* Pixel data */
char progress[255]; /* Title for progress display... */
guchar alpha[256], /* Index -> Alpha */
*alpha_ptr; /* Temporary pointer */
/*
* Setup the PNG data structures...
......@@ -364,15 +366,16 @@ load_image(char *filename) /* I - File to load */
png_read_info(pp, info);
/*
* Hopefully this is now fixed once and for all, please tell me if you
* have any problems with <8-bit images -- njl195@zepler.org.uk
* This is a new version with support for tRNS (alpha + colourmaps)
* Mail me if you have trouble -- njl195@zepler.org.uk
*/
if (info->bit_depth < 8)
{
png_set_packing(pp);
if (info->color_type != PNG_COLOR_TYPE_PALETTE)
if (info->color_type != PNG_COLOR_TYPE_PALETTE) {
png_set_expand(pp);
}
}
else if (info->bit_depth == 16)
png_set_strip_16(pp);
......@@ -386,6 +389,23 @@ load_image(char *filename) /* I - File to load */
else
num_passes = 1;
/*
* Special handling for INDEXED + tRNS (transparency palette)
*/
if (info->valid & PNG_INFO_tRNS &&
info->color_type == PNG_COLOR_TYPE_PALETTE)
{
png_get_tRNS(pp, info, &alpha_ptr, &num, NULL);
/* Copy the existing alpha values from the tRNS chunk */
for (i= 0; i < num; ++i)
alpha[i]= alpha_ptr[i];
/* And set any others to fully opaque (255) */
for (i= num; i < 256; ++i)
alpha[i]= 255;
trns= 1;
}
/*
* Update the info structures after the transformations take effect
*/
......@@ -503,11 +523,13 @@ load_image(char *filename) /* I - File to load */
num = end - begin;
if (pass != 0) /* to handle interlaced PiNGs */
gimp_pixel_rgn_get_rect(&pixel_rgn, pixel, 0, begin, drawable->width, num);
gimp_pixel_rgn_get_rect(&pixel_rgn, pixel, 0, begin,
drawable->width, num);
png_read_rows(pp, pixels, NULL, num);
gimp_pixel_rgn_set_rect(&pixel_rgn, pixel, 0, begin, drawable->width, num);
gimp_pixel_rgn_set_rect(&pixel_rgn, pixel, 0, begin,
drawable->width, num);
gimp_progress_update(((double)pass + (double)end / (double)info->height) /
(double)num_passes);
......@@ -528,6 +550,35 @@ load_image(char *filename) /* I - File to load */
fclose(fp);
if (trns) {
gimp_layer_add_alpha(layer);
drawable = gimp_drawable_get(layer);
gimp_pixel_rgn_init(&pixel_rgn, drawable, 0, 0, drawable->width,
drawable->height, TRUE, FALSE);
pixel = g_new(guchar, tile_height * drawable->width * 2); /* bpp == 1 */
for (begin = 0, end = tile_height;
begin < drawable->height;
begin += tile_height, end += tile_height)
{
if (end > drawable->height) end = drawable->height;
num= end - begin;
gimp_pixel_rgn_get_rect(&pixel_rgn, pixel, 0, begin,
drawable->width, num);
for (i= 0; i < tile_height * drawable->width; ++i) {
pixel[i*2+1]= alpha [ pixel[i*2] ];
}
gimp_pixel_rgn_set_rect(&pixel_rgn, pixel, 0, begin,
drawable->width, num);
}
g_free(pixel);
}
/*
* Update the display...
*/
......
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