Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!uwm.edu!uakari.primate.wisc.edu!aplcen!ginosko!uunet!microsoft!w-darekm From: w-darekm@microsoft.UUCP (Darek Mihocka) Newsgroups: comp.sys.atari.st Subject: Graphics file formats on new machines Message-ID: <7677@microsoft.UUCP> Date: 12 Sep 89 20:05:03 GMT References: <2600003@hprnd.HP.COM> Reply-To: w-darekm@microsoft.UUCP (Darek Mihocka) Organization: Microsoft Corp., Redmond WA Lines: 50 I've got a question about the new graphics modes, such as Hyperscreen, Moniterm, and the new graphics modes in the STE and TT. Is there a standard file format that will allow interchangability of graphics images from one machine to another. Up until now, .PI1, .PI2, .PI3 and .NEO seem to have been the standards because everybody had a 32000 byte screen. What will happen now that screens are larger than 320K? None of the above formats bother to include the screen resolution in their files. Does Getrez() on the STE and TT just return higher numbers, like 3, 4, 5, so you could theoretically update Degas to support .PI4, .PI5, etc, files. Or are we all going to start using TIFF or GIF or color Mac paint? Is TOS 1.4 smart enough to produce proper screen dumps on Hyperscreen and other resolutions, or is Alt-Help a thing of the past? Do the new graphics modes still work the same way (i.e. bit planes) or have they scrambled screen memory in new and wonderful ways? A simple modification to say, the Degas file format, might be to keep the first word which indicates the graphics mode (0, 1, 2, 3, etc, which would map on to an appropriate number of bit planes) followed by the color pallete and then the image. Now, if the screen is not the standard 32000 bytes, invert the high bit of the first word, and follow it immediately by two words indicating the screen resolution, then the pallete, then the image. i.e. a 1024x512 16 color image would have a header like this: word 0: $8000 ($8000 | $0000) word 1: $0400 word 2: $0200 words 3 thru 18: colors words 19 to end: graphics image That way normal Degas will puke if you try to load this new format, but not the other way around. Alternatively, you could go with a format that uses the normal Degas format and appends additional data to the end of the file. The image would then be stored in such a way that if you use Degas to load the image, it would think it's loading a 640x400 image and display the upper left 640x400 pixels of the much larger image. The reason I'd like to know is because I'm thinking of updating Megablit for the new graphics modes and up until now I never did figure out how to implement a feature to save the entire drawing area. (Megablit is a very cheap public domain larger-than- screen graphics editor which I wrote way before Touch Up came out, so don't believe those Touch Up ads ). Now that I've scared everybody away with the scary thought of a son of Megablit, can I get some input from whoever has bothered to read this far? ------------------------------------------------------------------------------- Darek Mihocka ST Xformer 2.5 CIS: 73657,2714 Box 2624, Station B MegaBlit GEnie: DAREKM Kitchener, Ontario Quick Utilities DELPHI: DAREKM N2H 6N2 BIX: darekm Canada CheapNet: ...!uw-beaver!microsoft!w-darekm (519)-747-0386 A mind is a terrible thing to waste, so just say no to TOS. -------------------------------------------------------------------------------