atari

Written by: Vector/Vertigo (Brian Cowan) Email: cowan@gold.guate.net Vertigo Web Page: http://demoscene.interstat.net/~vertigo/ irc: #coders #vertcode Revision history: 10/06/97 v0.70Beta - Awesome tips from MidNight, touched up the doc 04/06/97 v0.60Beta - Added the tips section with help from Statix 01/06/97 v0.50Beta - A few typo fixes and a cool tip from Statix 30/05/97 v0.10Beta - Initial version INTRODUCTION Well, for the last 2 months or so I have been laying around the house, forcing my brain to try and come up with the perfect shadow algorithm, an algorithm that works beautifull...

by TimJ/Vertigo "I am he, as you are he, as you are me, and we are all together" email: tim@legend.co.uk irc: #coders #vertcode revision history: 16/02/97 v1.0 - Initial version INTRODUCTION First off, I hope this doc is of use to some people, and maybe other people will find it interesting. Recently, I've been thinking a lot about phong shading and lighting. There was something that was bugging me. I couldn't quite put my finger on it. It was something I knew to be true, but I had to explain it to myself. It all started when I was chatting to Vector about true phong shading. We'd both recently looked at Voltaire&#...

Just before Christmas, I rented two Sega Saturn games, Virtua Racing and Sega Rally Championship, in order to compare the two. Santa was only going to bring me one, so I had to choose: VR was my favorite in the arcades for a very long time, and I had heard just wonderful things about Rally. So I sat down and played both for few hours each, on separate occasions. I fell in love with Rally, but did not much care for the translation of VR -- it was missing the arcade feel. (though, since Santa also brought me an Arcade Racer steering wheel accessory, I happen to really like VR -- perhaps as much as Rally. The steering wheel makes all the dif...

by TheGlide/SpinningKids Milan, Italy - June 1 st , 1998 INTRODUCTION I assume here you know the basics of texture mapping, as explained in fatmap and fatmap2 docs by MRI/Doomsday. This doc is about texture mapping using texture maps stored as tiles, namely 8x8 pixels tiles. Storing the maps this way can improve very much cache access. Most of the time we have to traverse the texture through non-horizontal lines, and this causes many cache misses. The worst situation happens when we have to traverse the texture vertically: each texel we access will be on a different row, and this will require, from the processor side, a whole cach...

The information contained in document will allow you to realistically simulate jumping and interstellar maneuvers. The purpose of this document is to understand the physics of the world we live in, and apply realistic physics to your game. It will not give you optimized routines for your program, that is your job! But if you understand how things work, it will be a heck of a lot easier. Basics There are some key terms I will define to make sure we are talking about the same things: Distance : Total path of travel. Displacement : Difference between original position, and final position Speed : Change in displacement divided by the change i...

By Andre Yew (andrey@gluttony.ugcs.caltech.edu) This is how I learned perspective transforms --- it was intuitive and understandable to me, so perhaps it'll be to others as well. It does require knowledge of matrix math and homogeneous coordinates. IMO, if you want to write a serious renderer, you need to know both. First, let's look at what we're trying to do: S (screen) | * P (y, z) | /| | / | | / | |/ | * R | / | | / | | / | | E (eye)/ | | W ---------*-----|----*------------- <- d -><-z-> E is the eye, P is the point we're trying to project, and R is its projected position on ...

Introduction So, you've got your engine running, you have texture mapping, and some kind of shading in place, it runs fast, its smooth, but you feel somethings missing. You need to shade your texture maps. But you haven't got a clue how to do it! Well, I shall now explain the simple process of adding shading or transparency to your textures, in 256 colour mode. 16*16 Linear Palette The easiest way to make primitive shading is to change your palette. Firstly, you will only be able to have 256 / n shades, where n is the number of colours you will be using. Secondly, the image quality is very poor. But, I'll explain it anywa...

by Arne Steinarson (arst@ludd.luth.se) BRIEF Integer squareroot approximation which executes in 16-27 cycles through effective bitsearch and 256 byte LUT table. Higher value for 486, lower for Pentium systems. On both CPU:s this means a performance improvement of at least 330% compared to using the FPU. In addition one removes the overhead of converting the integer value to a float and back again. OBSERVATION Note that \sqrt{(2^{16})} = 2^{8} , \sqrt{(2^{10})} = 2^{5} . Interesting, just half the position of the bit. But what if we've got a multibit number such as 2710h (=10000 dec)? TRIAL Go looking for the bit in the highest positio...

Hello fellow coders. This is Sqrt(-1) speaking. Many demos nowadays feature 2d bump mapping (the effect in which highlight travels upon a bumpy surface (prolly with embossed writing or something on it) seen from above), so I decided to write something about it... As you'll soon see, I convert my page into this kind of a text articles w/ sample programs and source codes. I hope you will be happy now. (To you whom got this article from else where, consider visiting www.sci.fi/~zaphod) Ok, to the point. To really do REAL 2d bump mapping one has to calculate normals for every pixel in bump map (an image representing "heights" of p...

StEP oNE! - 12 muls / rotation rotate around z-axis: x' = x*cos(A) + y*sin(A) y' = x*sin(A) - y*cos(A) rotate around y-axis: x'' = x'*cos(B) + z*sin(B) z' = x'*sin(B) - z*cos(B) rotate around x-axis: y'' = y'*cos(C) + z'*sin(C) z'' = y'*sin(C) - z'*cos(C) after this the rotated vector is (x'',y'',z'') StEP tWO! - 9 muls / rotation + 14 muls init If we evaluate the rotations from the first step we get x'' = x * [cos(A)cos(B)] + + y * [sin(A)cos(B)] + + z * [sin(B)] y'' = x * [sin(A)cos(C) + cos(A)sin(B)sin(C)] + + y * [-cos(A)cos(C)...