From: ao950 AT FreeNet DOT Carleton DOT CA (Paul Derbyshire) Newsgroups: comp.os.msdos.djgpp Subject: Some Allegro questions (Shawn?) Date: 3 Mar 1997 06:51:40 GMT Organization: The National Capital FreeNet Lines: 50 Message-ID: <5fdsds$p42@freenet-news.carleton.ca> Reply-To: ao950 AT FreeNet DOT Carleton DOT CA (Paul Derbyshire) NNTP-Posting-Host: freenet2.carleton.ca To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp I have several questions about Allegro, mostly out of curiosity... * Why, when using a SVGA mode e.g. GFX_AUTODETECT 640x480, does a fade_in(palette) or a fade_out() seem to do 4 fades in series instead of just 1? Fades work as expected in GFX_MODEX. Is it a bug or a "feature"? * Is the video manipulation ultimately done with super-fast nearptrs or far pointers? Near pointers are thought not to work on some DPMI hosts, so an optimal Allegro would detect the DPMI host, if it is a known safe one i.e. cwsdpmi use nearptrs, else use farptrs for safety... * What functions in allegro are typically inlined? * Which graphics functions use inline asm for optimisation? * Was Allegro compiled with -m486? * Compiled sprites seem to have four compiled routines in them. Why? (My guesses were: one for the screen, one for a sub bitmap of the screen, one for memory bitmaps, and one for a sub bitmap of a memory bitmap.) * Do you know where UniVBE 5.1 can be obtained? It seems to be the most up-to-date version that DOESN'T cripple itself after 21 days. * When an allegro program that uses sound starts, there is a popping noise. The noise also happens at exit. I have learned to dread this pop, since usually if it happens when I'm not expecting it, I find myself staring at a stack dump a few seconds later. What is it? * There is a definite link between using allegro and GCC making funny noises during compile. For instance, using RHIDE and Allegro, I ran a program, and it hit a breakpoint. I inspected a few variables, then changed some source and ran Make. GCC was called, and five seconds into the compile a bunch of queer repeating and *LOUD* sound effects started coming from my SB! It has happened a total of 3 times now. All 3 times after an allegro program a) used sound and b) never got to allegro_exit. I also have a suggestion: to create a new bitmap/sprite type, say MODEX_BITMAP. These would be like memory bitmaps but with a planar structure. They would answer TRUE to is_planar_bitmap and is_memory_bitmap. They might be made from a regular bitmap using a get_modex_bitmap function. This way, it might be possible to do blitting (and dare we hope, sprite and rle-sprite) operations from memory to the ModeX screen faster than usual (though not as fast as with latch registers, which I assume only works between two parts of video ram.) Also, using an S3, and lacking a non-crippled UniVBE supporting Vesa 2.0, is it possible to get a "modex" mode 320x240 that is not limited to 256 k? -- .*. Where feelings are concerned, answers are rarely simple [GeneDeWeese] -() < When I go to the theater, I always go straight to the "bag and mix" `*' bulk candy section...because variety is the spice of life... [me] Paul Derbyshire ao950 AT freenet DOT carleton DOT ca, http://chat.carleton.ca/~pderbysh