I am having lots of fun trying to save a 32 bit TGA (with alpha channel).. I created some graphics with macromedia fireworks and saved them as PNG... I can load these up in both photoshop and paintshop and see that the alpha layer is there but both programs wont save a TGA in 32 bits.. Paintshop only allows 24 bits and Photoshop has the 'alpha layer' check box greyed out.. any ideas anybody ?? or does anybody know of a good PNG loader that I can use to load my PNG files into openGL textures.. Jumpman - Under Construction [edited by - Jumpman on September 11, 2003 1:19:41 PM]

If you only want to load 24bit RGB and 32bit RGBA png images you can grab the png loader (TextureLoaderPNG.h and TextureLoaderPNG.cpp) from the source of my LOTR TTT entry (Paul Kitchin).

Enigma

thanks a lot Paul..

Great demo by the way..

Cheers


Jumpman - Under Construction

tried using it but it comes with way too many compile errors (using VC++).. mainly bombing out with the fstream.h header.. will keep on plugging away at it..


Jumpman - Under Construction

Ah, it was built with the Borland compiler. If you hit any errors you can''t get rid of, post them here and I''ll see if I can help.

Enigma

seems most of the problems are with the fstream stuff..

is there any documentation on that as I would like to change it to a more generic fileopen set of commands..

really would like to get it working.. still can''t work out why both the major 2 graphic programs don''t support TGA with an alpha layer.. hmm..

I''ve worked with a 32-bit TGA in PSP with no problems. It''s how I did the alpha for the characters in my fonts. First of all you need to create a mask. You create a mask under "Masks->New" in the menu. You can either load the mask from an image, or you can create a new one that either hides or shows all the image. The rest of the controls are pretty self explanitory. ust fiddle and you''ll get the hang of it. Once you''re done select "Masks->Save to alpha channel", and just leave the default name PSP gives it (the name isn''t saved in the tga file anyway). Save the file, and you now have a 32-bit TGA.

Oh, and I forgot to mention, if you want to edit the alpha channel, you have to load the alpha channel from the file into a mask (the menu option is there for it), edit it, and make it the new alpha channel. Make sure you save over the existing alpha hcannel in the file, or delete it when you do. TGA only supports one alpha channel, and I''m not sure what PSP would do if you gave it two. It''d be best to just avoid the hassle.

Ok.. Managed to work it all out.. (and information incase anybody else wants to do something like this..)

I create my images in Fireworks (as I like it because of the realtime effect processing it does where you can tweak things and see the results)

I then save them as 32 bit TIFF

I load the TIFF up into photoshop

I Then select ''Selections/Load from Alpha Channel''

The alpha channel then magically apears..

save the file as a TGA and presto.. nice glowing edges with the correct alpha around my text..



Jumpman - Under Construction