From: Shawn Hargreaves Newsgroups: comp.os.msdos.djgpp Subject: Re: Allegro & memory access Date: Mon, 2 Jun 1997 22:18:31 +0100 Organization: None Distribution: world Message-ID: References: <01bc6d4e$720f1900$ec3e63c3 AT default> NNTP-Posting-Host: talula.demon.co.uk MIME-Version: 1.0 Lines: 31 To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Precedence: bulk Thomas Harte writes: >with Allegro. I cannot find anything in the readme (although I am good at >missing stuff), There is a section titled "video memory access" in the documentation... >so I was just checking if it's alright for me to load >Allegro, have it initiate VGA mode (or whatever), and then just write to >the VRAM myself, allowing Allegro to do it's stuff for the enemies and >title screens. Yeah, you could go directly to the video RAM without using anything related to Allegro, but that will obviously only work if you and Allegro agree about what video mode you are in! (ie. you are only going to run your program in 13h, or you are going to handle the various SVGA and mode-X resolutions yourself). Alternatively, you could write your code so that it draws onto an Allegro bitmap object. If you want to write directly to the screen you'll need to use far pointers and the bank switching functions (this is described in the docs), but it is very easy to just draw onto an Allegro memory bitmap and then use blit() to copy the resulting image across to the screen (and that way your program will work in every resolution supported by Allegro). To set a pixel in a memory bitmap, just write: bmp->line[y][x] = color; -- Shawn Hargreaves - shawn AT talula DOT demon DOT co DOT uk - http://www.talula.demon.co.uk/ Beauty is a French phonetic corruption of a short cloth neck ornament.