evas: PNG save of ARGY88 needs unpremul

PNG saves unpremultiplied values, so we need to do that
for the newly supported ARGY88 colorspace as well. Fixes
the previous commit.

3 files changed, 39 insertions, 1 deletions

diff --git a/src/lib/evas/common/evas_convert_color.c b/src/lib/evas/common/evas_convert_color.c
index 421f425221..3558b341e0 100644
--- a/src/lib/evas/common/evas_convert_color.c
+++ b/src/lib/evas/common/evas_convert_color.c
@@ -26,6 +26,34 @@ evas_common_convert_ag_premul(DATA16 *data, unsigned int len)
    return nas;
 }
 
+EAPI void
+evas_common_convert_ag_unpremul(DATA16 *data, unsigned int len)
+{
+   DATA16 *de = data + len;
+   DATA16 p_val = 0x0000, p_res = 0x0000;
+
+   while (data < de)
+     {
+        if (p_val == *data) *data = p_res;
+        else
+          {
+             DATA16 a = (*data >> 8);
+
+             p_val = *data;
+             if ((a > 0) && (a < 255))
+               {
+                  *data = ((a << 8) | (((*data & 0xff) * 0xff) / a));
+               }
+             else if (a == 0)
+               {
+                  *data = 0x0000;
+               }
+             p_res = *data;
+          }
+        data++;
+     }
+}
+
 EAPI DATA32
 evas_common_convert_argb_premul(DATA32 *data, unsigned int len)
 {
diff --git a/src/lib/evas/common/evas_convert_color.h b/src/lib/evas/common/evas_convert_color.h
index c3c07a3ca9..54bd59e138 100644
--- a/src/lib/evas/common/evas_convert_color.h
+++ b/src/lib/evas/common/evas_convert_color.h
@@ -3,6 +3,7 @@
 
 
 EAPI DATA32 evas_common_convert_ag_premul                          (DATA16 *data, unsigned int len);
+EAPI void evas_common_convert_ag_unpremul                          (DATA16 *data, unsigned int len);
 EAPI DATA32 evas_common_convert_argb_premul                        (DATA32 *src, unsigned int len);
 EAPI void evas_common_convert_argb_unpremul                        (DATA32 *src, unsigned int len);
 EAPI void evas_common_convert_color_argb_premul                    (int a, int *r, int *g, int *b);
diff --git a/src/modules/evas/image_savers/png/evas_image_save_png.c b/src/modules/evas/image_savers/png/evas_image_save_png.c
index 6eef2fe221..eca98f8ab7 100644
--- a/src/modules/evas/image_savers/png/evas_image_save_png.c
+++ b/src/modules/evas/image_savers/png/evas_image_save_png.c
@@ -88,7 +88,16 @@ save_image_png(RGBA_Image *im, const char *file, int do_compress, int interlace)
      {
         agry88 = EINA_TRUE;
         pixel_size = 2;
-        data = im->image.data8;
+        data = malloc(im->cache_entry.w * im->cache_entry.h * pixel_size);
+        if (!data)
+          {
+             png_destroy_write_struct(&png_ptr, (png_infopp) & info_ptr);
+             png_destroy_info_struct(png_ptr, (png_infopp) & info_ptr);
+             goto close_file;
+          }
+        free_data = EINA_TRUE;
+        memcpy(data, im->image.data, im->cache_entry.w * im->cache_entry.h * pixel_size);
+        evas_common_convert_ag_unpremul((DATA16 *) data, im->cache_entry.w * im->cache_entry.h);
         png_init_io(png_ptr, f);
         png_set_IHDR(png_ptr, info_ptr, im->cache_entry.w, im->cache_entry.h, 8,
                      PNG_COLOR_TYPE_GRAY_ALPHA, interlace,