Header file for graph.c

graph.c

/*
** Filename: graph.c
**
** Copyright (C) 2001, Pete J. Jensen All Rights Reserved
**
** This program is free software: you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation, either version 3 of the License, or
** (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
** GNU General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program.  If not, see <http://www.gnu.org/licenses/>.
**
** This module handles all low level video operations, such as initializing a
** graphics mode, ending a graphics mode, puting pixels etc.
** 
** CONTENTS:
**   initializeGraphicsMode();
**   endGraphicsMode();
**   putPixel();
**   getPixel();
*/

#include <dos.h>
#include <conio.h>
#include <stdlib.h>
#include <stdio.h>
#include <dir.h>
#include <alloc.h>
#include <time.h>
#include <stdarg.h>
#include <string.h>
#include <math.h>
#include <ctype.h>
#include <io.h>
#include <limits.h>

/* Graphics Header File*/
#include "graph.h"

/**
 * Function: initializeGraphicsMode
 * Purpose : To initialize the graphics mode into mode 13H; it has the 
 *           properties of 320x200 screensize & 8 bits per pixel.
 * Inputs  : Void
 * Returns : Void
 * Modifies: The current graphics mode.
 * Sample Call : initializeGraphicsMode();
 */
void initializeGraphicsMode()
{
    asm MOV AL, 13H;
    asm MOV AH, 00H;
    asm INT VIDEO_BIOS; 
}

/*
 * Function: endGraphicsMode
 * Purpose : To take us out of the 13H graphics mode and back into dos text
 *           mode. This should be run anytime the program hits an error. 
 *           and displays an error message.
 * Inputs  : Void
 * Returns : Void.
 * Modifies: The Current Graphics Mode.
 * Sample Call : endGraphicsMode();
 */
void endGraphicsMode()
{
    asm MOV AL, 3H;
    asm MOV AH, 00H;
    asm INT VIDEO_BIOS;
}

/*
 * Function: putPixel
 * Purpose : To put a pixel @ x,y with given colorByte.
 * Inputs  : word X: The X location of the pixel.
             word Y: The Y location of the pixel.
 * Returns : Void
 * Modifies: Adds one pixel to the graphics screen.
 * Sample Call : putPixel(10, 10, 14);
 * Remarks: Adapted from "Using PCX Graphics Files", Roger T. Stevens
 */
void putPixel(word X, word Y, byte color)
{   
    asm mov DI, VIDEO_RAM;
    asm mov ES, DI;
    asm mov AX, Y;
    asm mov BX, Y;
    asm shl AX, 8;
    asm shl BX, 6;
    asm add AX, BX;
    asm add AX, X;
    asm mov DI, AX;
    asm mov AL, color;
    asm mov ES:[DI], AL;
}

/*
 * Function: getPixel
 * Purpose : To get a pixel @ x,y with & return colorByte.
 * Inputs  : word X: The X location of the pixel.
             word Y: The Y location of the pixel.
 * Returns : The byteColor @ x,y.
 * Sample Call : byteColor = getPixel(10, 10);
 */
byte getPixel(word X, word Y)
{
    byte getColor;
    
    asm MOV AH,0DH
    asm MOV CX,X 
    asm MOV DX,Y 
    asm INT VIDEO_BIOS
    asm MOV getColor, AL

    return getColor;
}

graph.h

/*
 **   Filename: graph.h
 **
 **   Copyright (C) 2001, Pete J. Jensen All Rights Reserved
 **
 **   This program is free software: you can redistribute it and/or modify
 **   it under the terms of the GNU General Public License as published by
 **   the Free Software Foundation, either version 3 of the License, or
 **   (at your option) any later version.
 **
 **   This program is distributed in the hope that it will be useful,
 **   but WITHOUT ANY WARRANTY; without even the implied warranty of
 **   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 **   GNU General Public License for more details.
 **
 **   You should have received a copy of the GNU General Public License
 **   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef __GRAPH_H
#define __GRAPH_H

/* Defines for graphics module */
#define VIDEO_BIOS      10H
#define VIDEO_RAM       0xA000 

/* Screen size, width & height defined */
#define SCREEN_WIDTH    320
#define SCREEN_HEIGHT   200
#define SCREEN_SIZE     (SCREEN_WIDTH * SCREEN_HEIGHT)

/* Typedefs for byte & word */
typedef unsigned char byte;
typedef unsigned short word;

/* Prototypes for Graphics Module */
void initializeGraphicsMode(void);
void endGraphicsMode(void);
void putPixel(word X, word Y, byte color);
byte getPixel(word X, word Y);

#endif