SVGA 图形库 svgacc

REFERENCE MANUAL FOR SVGACC THE SUPER VGA GRAPHICS LIBRARY FOR USE WITH MICROSOFT AND BORLAND C/C++  1993-1994 by Zephyr Software - Stephen L. Balkum and Daniel A. Sill All rights reserved. No part of this book shall be reproduced or transmitted by any means, electronic, mechanical, photocopying, recording or otherwise, without written permission from Zephyr Software - Stephen L. Balkum and Daniel A. Sill. Although every effort has been made to insure the accuracy of the material in this book, Zephyr Software, Stephen L. Balkum and Daniel A. Sill assume no responsibility for errors or omissions. In addition no liability is assumed for damages resulting from the use of the information contained herein. Printed in the United States of America Trademarks The Graphics Interchange Format (c) is the Copyright property of CompuServe Incorporated. GIF (sm) is a Service Mark property of CompuServe Incorporated. Sound Blaster and Sound Blaster Pro are trademarks of Creative Labs, Inc. All others are trademarks of their respective owners. ii  SOFTWARE LICENSE AGREEMENT By using this software, you agree to the terms of this agreement. No warranties are expressed or implied. In no event shall Zephyr Software, Stephen L. Balkum or Daniel A. Sill be held liable for damages resulting from the use or misuse of this product, including but not limited to implied warranties of fitness for a particular purpose. The shareware version may be freely distributed as long as all files stay together and are not modified in any way. No cost may be charged for the shareware version beyond normal and reasonable copying and distribution expenses. No products developed with this software shall be sold unless this software has been registered with Zephyr Software, Stephen L. Balkum or Daniel A. Sill. At no time for any reason shall this software be reverse engineered, decompiled or disassembled. This software may not be rented or leased. This software may be used only on one terminal or one computer at any one given moment in time. This software may not be installed on a network of any type. Contact Zephyr Software, Stephen L. Balkum or Daniel A. Sill for networking options. United States Government Restricted Rights: Use, duplication or disclosure of this software and documentation by the U.S. Government is subject to the restrictions as set forth in subparagraph (c)(1)(ii) of the Rights in Technical Data and Computer Software clause at DFARS 252.227-7013. Contractor/manufacturer is Stephen L. Balkum and Daniel A. Sill, P.O. Box 7704, Austin, Texas 78713-7704. The ownership of this software may be transferred as long as Zephyr Software, Stephen L. Balkum or Daniel A. Sill is notified in writing of the transfer date and new owner. The new owner must agree to this contract. The transfer must include all registered updates and previously registered versions. The original owner may not retain any copies in any form of the registered software or its documents. iii  INTRODUCTION We spent weeks searching the depths of the internet ftp sites for a library that would allow the programmer full access to the abilities of Super VGA. We wanted the colors VGA could provide and better resolution than EGA could provide. Professionally developed libraries with this ability were definitely out of our price range. After our searches continuously returned nothing, we decided to fill the apparent void in the shareware market. Our searches did give two useful packages: John Bridges' VGAKIT and Finn Thoegersen's VGADOC. We began with these two works and developed a graphics library intended to allow the programmer access to the huge world of high resolution programming. On the surface the task appeared quite simple. However, it quickly became obvious that the routines in this library would be required to affect extremely large amounts of data. Operations must be quick to be successful. Therefore, every effort was made to create the fastest code possible - even at the expense of size. For this reason we opted to write code with the 32 bit instructions of the 80386 and 80486 chips. It is our opinion that anyone with a hi-res card in a lesser machine may have some priorities out of order. All routines are written in assembly and use absolutely no floating point values. Anytime a real number was required, fixed point notation was used. In addition we attempted to write the routines such that any reasonable argument passed can be interpreted intelligently by the library. With the numerous Super VGA cards available and no well established standard we chose John Bridges' identification and bank switching routines as a beginning. These two routines have undergone some modification, but not enough to justify copyrighting this portion of the library's code by Zephyr Software. We have no intentions of releasing our changes to these routines into the public domain. From that point onward all code is original. In some instances common algorithms were researched and original code written according to that algorithm. This Super VGA library gives the programmer transparent access to twenty different Super VGA cards. These cards include Acumos, Ahead, ATI Technologies, Avance, Chips and Technologies, Cirrus Logic, Everex, Genoa, MXIC, NCR, Oak Technologies, Paradise/Western Digital, Primus, Realtek, Trident, Tseng Labs, Video 7 and the VESA standard. Please see the WHICHVGA function for the specific chipsets. The programmer only needs to verify that the end user's card has been identified, but not which card was recognized. After proper identification, all functions react in exactly the same fashion. The library contains functions to draw all of the major primitives. In addition there are functions that modify the screen palette, write text on the screen with a choice of fonts and modify the reaction of the primitives. Identification routines include not only the video card, but also the amount of video memory, type of processor and