*** PolyDemo v1.00 - By Carl Read - Public Domain *** PolyDemo is a demonstration of Blitz Basic's Poly and PolyF commands. Along with the program itself there should be a Blitz listing in both Blitz and ASCII/ANSI format. An explanation of the listing can be found in the diskmag ShareWorld #7 released in October 1996. What PolyDemo does is allow you to place polygons on the screen and animate them. This is not a serious attempt at producing a polygon animation program however as all you can do with it is show one polygon per frame. You're also limited to 40 sides per polygon and 200 polygons - or 200 frames of animation if you want to look at it that way. One other limitation is due to Blitz's PolyF command. It can't draw complex shapes so I suggest experimenting with PolyDemo to find out what shapes it can and can't draw. If you're lucky there should also be some animations (with a ".polys" extension on their file-names) with PolyDemo. *** Using PolyDemo *** When you first run PolyDemo you're presented with a totally blank screen. Start out by drawing some polygons on it (such as triangles) by clicking on the screen with the mouse and then moving the pointer and clicking again as you would in a paint program. To finish a polygon click on the start of the first line you drew. The polygon will then change colour. When you've a nice selection of shapes on your screen, press the right mouse button to access the menu at the top of the screen and select Play from it. Your polygons will then be displayed rapidly one after another and, if you're lucky, they'll now be solid shapes. Well, they won't be displayed too rapidly on an 68000 machine, I making the mistake of using a hi-res screen for the program. It's reasonably fast on an A1200 though. Click the mouse button to stop the animation and you can then add more polygons to the screen if you want or select another of the menu options. Which are... *** Menu Options *** New : Clears the screen so you can start afresh. Open... : Lets you load in a previously saved polygon file. Look for files with an extension of ".polys". Save : Will save your polygons to disk. It'll open a file requester if you haven't already set the save-path by using Save As or Open. Save As...: Opens a file requester so you can save your polygons to disk. Although you can give your polygon files any name you like, I've started out using a file-extension of ".polys" and it'd make sense to stick with this. Play : Animates any polygons on the screen. Click the mouse button to stop the animation. Quit : Exits the program. *** Other features of the program *** You can click in the top-right corner of the screen to move it to the back so you can get to the Workbench or other screens. This feature won't work while you're in the middle of drawing a polygon though else you wouldn't be able to draw anything in the top-right corner. PolyDemo's also very NTSC/PAL friendly. It'll open the appropriate screen for whatever mode your machine's in and the polygon files will be converted on loading to fit the screen as their artists (ho, ho) intended. Meaning a polygon file saved by an NTSC Amiga will be, when loaded into a PAL Amiga, expanded in the vertical so its apparent size will look the same as on the NTSC machine. And of course the opposite happens when files are moving the other way. This is one advantage of vector graphics over bitmaps. (I should have thought of this in the beginning and allowed for different screen resolutions too. Sorry about that.) This program and its listing are public domain so feel free to spread it and modify it to your heart's content. Given multiple polygons per frame and the option of different coloured polygons, (not to mention an editing facility), could turn it into a possibly useful (if pretty rough) polygon animation designer. Anyone wishing to get in touch can do so at the following address... Carl Read CyberCraft PO Box 14032 Mayfair Hastings 4201 NEW ZEALAND Enjoy. Carl Read - 6th October 1996.