[Imtoolkit-users] Supporting Alpha in TGA files.

[Nicolas N. <ni...@no...>]

Hello,

  I recently was surprised to discover that IM doesn't support writing TGA
files that include an Alpha channel. I wrote a very simple patch for it, and
it seems to be working fine, so I figured I'd share it.

  Cheers,

  -- Nicolas Noble


--- im/src/im_format_tga.cpp<http://git.grumpycoder.net/cgi-bin/gitweb.cgi?p=lua-modules-iup;a=blob;f=im/src/im_format_tga.cpp;h=7c24a28a8d5f1ea1a500cba12b1534af0607006e>
+++ im/src/im_format_tga.cpp<http://git.grumpycoder.net/cgi-bin/gitweb.cgi?p=lua-modules-iup;a=blob;f=im/src/im_format_tga.cpp;h=f15b25f0a91d61c4c32a370e712f0532a884375e;hb=0a44ec3515eb9f7d2bed08cad79dff4d7524d818>
@@ -475,7<http://git.grumpycoder.net/cgi-bin/gitweb.cgi?p=lua-modules-iup;a=blob;f=im/src/im_format_tga.cpp;h=7c24a28a8d5f1ea1a500cba12b1534af0607006e#l475>
+475,13<http://git.grumpycoder.net/cgi-bin/gitweb.cgi?p=lua-modules-iup;a=blob;f=im/src/im_format_tga.cpp;h=f15b25f0a91d61c4c32a370e712f0532a884375e;hb=0a44ec3515eb9f7d2bed08cad79dff4d7524d818#l475>@@
 int imFileFormatTGA::WriteImageInfo()
       this->image_type = 1;
     break;
   case IM_RGB:
-    this->bpp = 24;
+    if (imColorModeHasAlpha(this->user_color_mode))
+    {
+      this->bpp = 32;
+      this->file_color_mode |= IM_ALPHA;
+    }
+    else
+      this->bpp = 24;
     this->file_color_mode |= IM_PACKED;
     if (imStrEqual(this->compression, "RLE"))
       this->image_type = 10;