tga.cpp

//----------------------------------------------------------------------------//
// viewer.h                                                                   //
// Copyright (C) 2003 Desmecht Laurent                                        //
//----------------------------------------------------------------------------//
// 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 2 of the License, or (at your option)  //
// any later version.                                                         //
//----------------------------------------------------------------------------//

#include "tga.h"

#define TGA_TYPE_MAPPED 1
#define TGA_TYPE_COLOR 2
#define TGA_TYPE_GRAY 3
#define TGA_TYPE_MAPPED_RLE 9
#define TGA_TYPE_COLOR_RLE 10
#define TGA_TYPE_GRAY_RLE 11

/* Image descriptor.
      3-0: attribute bpp
      4:   left-to-right ordering
      5:   top-to-bottom ordering
      7-6: zero
*/
#define TGA_DESC_ABITS 0x0f
#define TGA_DESC_HORIZONTAL 0x10
#define TGA_DESC_VERTICAL 0x20




CTga::CTga()
{
    m_SizeX=0;
    m_SizeY=0;
    m_Bpp=0;
    m_dest=NULL;
}

int CTga::Release()
{
    if(m_dest!=NULL)
    {
        free(m_dest);
        m_dest=NULL;
        return -1;
    }
    return 0;
}

int CTga::ReadFile(const char *str)
{
    unsigned char l,r,g,b,a;
    unsigned char *tmp;
    
    if(m_dest!=NULL)
    {
        return -1;      
    }


    FILE *file;
    file=fopen(str,"rb");
    
    if(file==NULL)
        return 0;
        
    // Read the header
    
    TgaHeader.idlength=fgetc(file); 
    TgaHeader.colourmaptype=fgetc(file);
    TgaHeader.datatypecode=fgetc(file);
    TgaHeader.colourmaporigin=fgetc(file);
    TgaHeader.colourmaporigin+=fgetc(file)<<8;
    TgaHeader.colourmaplength=fgetc(file);
    TgaHeader.colourmaplength+=fgetc(file)<<8; 
    TgaHeader.colourmapdepth=fgetc(file);
    TgaHeader.x_origin=fgetc(file); 
    TgaHeader.x_origin+=fgetc(file)<<8; 
    TgaHeader.y_origin=fgetc(file);
    TgaHeader.y_origin+=fgetc(file)<<8;
    TgaHeader.SizeX=fgetc(file);
    TgaHeader.SizeX+=fgetc(file)<<8;
    TgaHeader.SizeY=fgetc(file);
    TgaHeader.SizeY+=fgetc(file)<<8;
    TgaHeader.Bpp=fgetc(file);
    TgaHeader.imagedescriptor=fgetc(file);
    
    // Return if the format is unsupported      
    
    if(TgaHeader.datatypecode!=TGA_TYPE_COLOR
            && TgaHeader.datatypecode!=TGA_TYPE_GRAY
            && TgaHeader.datatypecode!=TGA_TYPE_COLOR_RLE)
        return 0;

    
    if(TgaHeader.Bpp!=8
            && TgaHeader.Bpp!=24
            && TgaHeader.Bpp!=32)
        return 0;

    
    if(TgaHeader.Bpp==8)
        m_dest = (unsigned char*)malloc(TgaHeader.SizeX*TgaHeader.SizeY);
    if(TgaHeader.Bpp==32 || TgaHeader.Bpp==24)
        m_dest = (unsigned char*)malloc(TgaHeader.SizeX*TgaHeader.SizeY*4);


    if(TgaHeader.datatypecode==TGA_TYPE_COLOR || TgaHeader.datatypecode==TGA_TYPE_GRAY)
    {
        for(int y=0;y<TgaHeader.SizeY;y++)
            for(int x=0;x<TgaHeader.SizeX;x++)
            {
                if(TgaHeader.Bpp==8)
                {
                    r=fgetc(file);
                    m_dest[x+y*TgaHeader.SizeX]=r;
                }
                if(TgaHeader.Bpp==24 || TgaHeader.Bpp==32)
                {
                    b=fgetc(file);
                    g=fgetc(file);
                    r=fgetc(file);
                    if(TgaHeader.Bpp==24)
                        a=255;
                    else
                        a=fgetc(file);
                    
                    m_dest[(x+y*TgaHeader.SizeX)*4]=r;
                    m_dest[(x+y*TgaHeader.SizeX)*4+1]=g;
                    m_dest[(x+y*TgaHeader.SizeX)*4+2]=b;
                    m_dest[(x+y*TgaHeader.SizeX)*4+3]=a;
                }
            }
    }
    if(TgaHeader.datatypecode==TGA_TYPE_COLOR_RLE)
    {
        int x=0;
        while(x<TgaHeader.SizeX*TgaHeader.SizeY)
        {
            l=fgetc(file);
            if(l & 0x80)
            {
                l=l & 0x7F;
                b=fgetc(file);
                g=fgetc(file);
                r=fgetc(file);
                if(TgaHeader.Bpp==24)
                   a=255;
                else
                   a=fgetc(file);


                for(int i=0;i<l+1;i++)
                {
                    m_dest[x*4]=r;
                    m_dest[x*4+1]=g;
                    m_dest[x*4+2]=b;
                    m_dest[x*4+3]=a;
                    x++;
                }
            }
            else
            {
                l=l & 0x7F;
                for(int i=0;i<l+1;i++)
                {
                    b=fgetc(file);
                    g=fgetc(file);
                    r=fgetc(file);
                    
                    if(TgaHeader.Bpp==24)
                        a=255;
                    else
                        a=fgetc(file);


                    m_dest[x*4]=r;
                    m_dest[x*4+1]=g;
                    m_dest[x*4+2]=b;
                    m_dest[x*4+3]=a;
                    x++;
                }
            }
        }
    }


    m_SizeX=TgaHeader.SizeX;
    m_SizeY=TgaHeader.SizeY;
    m_Bpp=TgaHeader.Bpp;
    if(m_Bpp==24)m_Bpp=32;
    fclose(file);



    if((TgaHeader.imagedescriptor & 0x0020)==0)  //we flip the file
    {

        tmp=m_dest;

        if(TgaHeader.Bpp==8)
            m_dest = (unsigned char*)malloc(TgaHeader.SizeX*TgaHeader.SizeY);
        if(TgaHeader.Bpp==32 || TgaHeader.Bpp==24)
            m_dest = (unsigned char*)malloc(TgaHeader.SizeX*TgaHeader.SizeY*4);


        for(int y=0;y<TgaHeader.SizeY;y++)
        {
            for(int x=0;x<TgaHeader.SizeX;x++)
            {
                if(m_Bpp==8)
                {
                    r=tmp[x+(TgaHeader.SizeY-y-1)*TgaHeader.SizeX];
                    m_dest[x+y*TgaHeader.SizeX]=r;
                }
                if(m_Bpp==32)
                {
                    r=tmp[(x+(TgaHeader.SizeY-y-1)*TgaHeader.SizeX)*4];
                    g=tmp[(x+(TgaHeader.SizeY-y-1)*TgaHeader.SizeX)*4+1];
                    b=tmp[(x+(TgaHeader.SizeY-y-1)*TgaHeader.SizeX)*4+2];
                    a=tmp[(x+(TgaHeader.SizeY-y-1)*TgaHeader.SizeX)*4+3];
                    m_dest[(x+y*TgaHeader.SizeX)*4]=r;
                    m_dest[(x+y*TgaHeader.SizeX)*4+1]=g;
                    m_dest[(x+y*TgaHeader.SizeX)*4+2]=b;
                    m_dest[(x+y*TgaHeader.SizeX)*4+3]=a;


                }
            }

        }
        free(tmp);
    }


    return -1;

}

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