How to use BitMap in Turbo C++

This simple program explain you about how to use BitMap in Turbo C++.

NOTE :Before Running this program you have to copy one file in your "bgi" directory. That file either you have to download from the net or i will provide you. The file name is "SVGA256.BGI". Copy this file at your " tc\bgi\ ". Your tc path. I am not able to attach this file because the file extension is not supported.. If you need this file, i will provide you.

1) You have to use the BitMap structure, there is no need to change anything in this structure. Just copy this structure in one of the .cpp file like "BitMap.cpp".

Code:

//BitMap Structure 

struct A{
	char type[2];                 /* Magic identifier            */
	unsigned long size;                       /* File size in bytes          */
	unsigned short int reserved1, reserved2;
	unsigned long offset;                     /* Offset to image data, bytes */
};

extern A HEADER,HEADER1;

struct B{
	unsigned long size;               /* Header size in bytes      */
	unsigned long width,height;                /* Width and height of image */
	unsigned short int planes;       /* Number of colour planes   */
	unsigned short int bits;         /* Bits per pixel            */
	unsigned long compression;        /* Compression type          */
	unsigned long imagesize;          /* Image size in bytes       */
	unsigned long xresolution,yresolution;     /* Pixels per meter          */
	unsigned long ncolours;           /* Number of colours         */
	unsigned long importantcolours;   /* Important colours         */
};
extern B INFOHEADER,INFOHEADER1;

2) In the main file i mean the file which contain the "main" function write this code.

Code:

//MAIN FILE

#include<iostream.h>
#include<graphics.h>
#include<fstream.h>

#include "bitmap.h"

// This Global Function is used for the resolution of the bitmap. You can set the return value either 1,2 or 3. For me 3 is the best combination.

huge DetectSvga()
{
	return 3; 
}

void main()
{
	int gd = DETECT, md, a;  
	
	installuserdriver("SVGA256",&DetectSvga);
	initgraph(&gd,&md,"c:\\tc\\bgi"); //Path may be different in your computer.
	
	Show();
	Show1();
	
}

//Suppose you have one show function which read the bitmap from the disk. Then this show function looks like this.

void Show()
{
	fstream File;
	
	//Here you have to define the path of the bitmap file. Like according to this example i have to open one Board1.bmp file. So write you bitmap file path here.
	
	File.open("d:\\Chess\\Bitmaps\\Board1.bmp",ios::in); 
	
	unsigned char Ch;
	
	File.read((char*)&HEADER,14); //This is the header part of the Bitmap. It always looks like same. Don't change the content hear. The value remains 14 here.
	
	File.read((char*)&INFOHEADER,40); //This is another part of the bitmap, here also the value remains same like 40 here.
	
	unsigned int i;
	char ColorBytes[4];
	char*PaletteData;
	
	PaletteData=new char[256*3];
	
	if(PaletteData)//if memory allocated successfully
	{
		//read color data
		for(i=0;i<256;i++)
		{
			//Don't change the code here because i have done some shifting here. Its working fine.
			File.read(ColorBytes,4);
			PaletteData[(int)(i*3+2)]=ColorBytes[0]>>2;
			PaletteData[(int)(i*3+1)]=ColorBytes[1]>>2;
			PaletteData[(int)(i*3+0)]=ColorBytes[2]>>2;
		}
		
		outp(0x03c8,0);      //tell DAC that data is coming
		
		for(i=0;i<256*3;i++) //send data to SVGA DAC
		{
			outp(0x03c9,PaletteData[i]);
		}
		delete[]PaletteData;
	}
	
	for(i=0;i<INFOHEADER.height;i++)       //This for loop is used to display the bitmap.
	{
		for(int j=0;j<INFOHEADER.width;)
		{
			File.read(&Ch,1); // Here Ch reads the color of your bitmap.
			putpixel(XCor+j++,YCor+INFOHEADER.height-i-1,Ch); //XCor and YCor are the X and Y cordinates. It depends upon you.
			
		}
	}
	
	File.close();
	
}

//Another way to display the Bitmap is. Suppose i have another Show1() Function. This is simple as compare to previous show function.

void Show1()
{
	
	Char Ch;
	fstream File;
	File.open("d:\\Chess\\Bitmaps\\KingA.bmp",ios::in);
	
	File.seekg(54,ios::beg);   //Its remains same. Means value always remains 54
	File.seekg(256*4,ios::cur); //Its remains same means value always remain 256*4.
	
	for(int i=0;i<40;i++) //Here 40 shows the height of the bitmap. It may be differ it depends upon the size of your bitmap.
	{
		for(int j=0;j<36;j++) //Here 36 shows the width of the bitmap. It may be differ it depends upon the size of your bitmap.
		{
			File.read(&Ch,1); //Here Ch is the character which reads the color of your bitmap.
			
			putpixel(this->XCor+j,this->YCor+39-i ,Ch);
			
		}
	}
	
}

 

Hi,
I have written in the comment that you have to define you bitmap path or location. It is not fixed.