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- This file has some notes from me to other programmers interested in the
- dirty details of drobos ie. nothing interesting, so please go away..
-
- When I ordered the book, all I knew about it was the name and a tiny 1
- inch high picture in an ad. If I had known it was a graphics library, I
- hadn't ordered it, but now.. Well, I don't like wasting money, so I
- desided to give it a try. After having done drobos, I'm content with it.
-
- GRAPHICS LIBRARY
- ================
-
- I've used "the graphics Programming PowerPack", which is "a special
- version of Genus Microprogramming's GX Development Series - a graphics
- library that supports all graphics primitives" library that I got with
- the "Graphics Programming PowerPack" (GPPP) book by Michael Jones (ISBN
- 0-672-30120-2 24.95 USD, floppy included with libs + one sample game).
-
- The sample game is "Apples & Oranges" (reversi), which is available in
- some ftp-places, too. IMHO not very encouraging sample, but at least it
- was a fully functional game to study.
-
- mode dh EGA 320x200x16
- mode eh EGA 640x200x16
- mode fh EGA 640x350x2
- mode 10h EGA 640x350x16
- mode 11h VGA 640x480x2
- mode 12h VGA 640x480x16
-
- There's total 104 functions selected from all the Genus GX libraries.
- There's pc speaker music, including background playing.
- There's 3 ROM fonts.
- There's 6 PCX functions.
- There's mouse routines, virtual screen support, 10 graphic effects.
-
- Hongkong Mahjong was written with Genus GX according to its manual.
-
- WEIRD BUGS
- ==========
-
- - it looks like background music disturbs writing on-screen, at least in
- Large model. When updating "points" numbers quite often got scrambled
- and the only reason for this that I can think of is background music. I
- recompiled drobos in Small model and haven't noticed it anymore. I must
- have misused something and then fixed it without knowing it. Now I'm
- back in Large model, keeping my fingers crossed and all is well..
-
- - using pcx-routines messed up the palette, but that was really caused
- by the pcx-file that was created with a Windows 3.1 application. I
- loaded the pic into DOS program and saved as another file. All fixed.
-
- - cursor flickered very badly, it looked like it was being drawn by the
- GPPP as a normal colored picture. Now I use my own mouse routines, so
- all troubles with mouse are caused by me.
-
- - doesn't restore the used mode *exactly* as it was (hi Ronny :), but
- neither do any other similar routine. This is really not a bug.. mode
- is just restored in a way, where I have no control over it whatsoever.
-
- - in one (network) machine the music was totally unrecognizable, like
- the timer INT rate was set way too slow. Could network activity have
- messed the background music playing.. it got better after a few tries.
-
- - gxSetPaletteColor works in EGA only, so I rewrote all the palette
- routines. If there are any trouble related to colors, that's because of
- me, not GPPP.
-
- - GPPP manual says: grOutText.. the CP does _not_ advance unless the
- horizontal justification setting is grTLEFT. Well, the following..
-
- grSetTextJustify(grTCENTER,grTCENTER);
- grMoveTo(100,100); grOutText("test line 1");
- grMoveRel(0,15); grOutText("test line 2");
- grMoveRel(0,15); grOutText("test line 3");
-
- ..proves that this is not true. The Current Position (CP) does advance.
-
- Summary: please don't get me wrong, I do like this library. There's no
- perfect bug-free and fully documented library. If you think you have
- one, just send it to and I'll find you a couple "undocumented features".
-
- BGI vs. GPPP
- ============
-
- IMHO GPPP could be faster than BGI and since the virtual screen routines
- offer over 64k get/putimage possibilities there's something extra, too.
- The graphics effects and music are quite cute..
-
- Still BGI has stroked fonts, 256 color palette routines and some useful
- functions such as draw/fillpoly, vertical text, arc etc.
-
- Most professional game writers want to use only their own routines or at
- least have the source available, but for amateurs like me GPPP isn't too
- bad, provided that you have some means to fill the holes/nags in GPPP.
- The full Genus GX libraries seem quite attractive, but as a poor student
- I don't even dare to think about the price..
-
- CD ROM SUPPORT
- ==============
-
- If CDTMP is set and current disk is write-protected, then use the cdtmp
- path, else use current directory. If you have a better idea about CD
- support, please tell me, too..
-
- char str[128], *cdtmp;
- cdtmp = getenv("CDTMP");
-
- if (*cdtmp && testdisk()) { strcpy(str,cdtmp); strcat(str,"\\"SCOREFILE); }
- else strcpy(str,SCOREFILE);
-
- if ((fp = fopen(str,"rb")) == NULL) bogus_score();
- else { ... }
-
-
- --jouni jon@stekt.oulu.fi
-
- You have been reading my own personal opinions and nobody has paid me
- anything to write good nor bad things about BGI or GPPP. Just IMHO..
-