tga.cpp

一个国人自己实现图像库的程序（有参考价值）

#include "stdafx.h"
#include "..\..\Include\Pic\Image.h"
#include "..\..\Include\Compress\Rle.h"

//===================================================================
BOOL  FCImage::LoadTga (BYTE * pStart)
{
	TGAHEAD		* pTga = (TGAHEAD *) pStart ;
	BYTE		* pCurr ;

	if (pStart == NULL)
		return FALSE ;
	//	Create Dib
	if (!this->Create (pTga->wWidth, pTga->wHeight, pTga->byColorBits))
		return FALSE ;

	pCurr = pStart + sizeof(TGAHEAD) + pTga->byID_Length ;
	//	设置调色板
	if (pTga->byPalType == 1)
	{
		RGBQUAD		* pPalette = new RGBQUAD [pTga->wPalLength] ;
		if ((pTga->byPalBits == 24) || (pTga->byPalBits == 32)) // 24,32位调色板
			for (int i = 0 ; i < pTga->wPalLength ; i++)
			{
				pPalette[i].rgbBlue = *pCurr++ ;
				pPalette[i].rgbGreen = *pCurr++ ;
				pPalette[i].rgbRed = *pCurr++ ;
				if (pTga->byPalBits == 32)
					pPalette[i].rgbReserved = *pCurr++ ;
			}
		else // 不支持15, 16位色调色板
		{
			delete[] pPalette ;
			this->Unload () ;
			return FALSE ;
		}
		this->SetColorTable (pTga->wPalFirstNdx, pTga->wPalLength, pPalette) ;
		delete[] pPalette ;
	}

	//	解码像素
	DWORD	dwPitch = this->Width() * this->ColorBits() / 8 ;
	if ((pTga->byImageType == 0x09) || (pTga->byImageType == 0x0A)) // 压缩
		if (pStart[0x11] & 0x20) // 上下颠倒
			for (int i = 0 ; i < this->Height() ; i++)
				pCurr = ::RLE_TGA_DecodeLine (pCurr, this->ColorBits(), this->Width(), this->GetBits (i)) ;
		else // same as BMP
			for (int i = this->Height() - 1 ; i >= 0 ; i--)
				pCurr = ::RLE_TGA_DecodeLine (pCurr, this->ColorBits(), this->Width(), this->GetBits (i)) ;
	else // 未压缩
		if (pStart[0x11] & 0x20) // 上下颠倒
			for (int i = 0 ; i < this->Height() ; i++, pCurr += dwPitch)
				CopyMemory (this->GetBits (i), pCurr, dwPitch) ;
		else // same as BMP
			for (int i = this->Height() - 1 ; i >= 0 ; i--, pCurr += dwPitch)
				CopyMemory (this->GetBits (i), pCurr, dwPitch) ;
	return TRUE ;
}
//===================================================================
BOOL  FCImage::LoadTga (PCTSTR resName, PCTSTR resType)
{
	HRSRC	res = ::FindResource (NULL, resName, resType) ;
	HGLOBAL	gol = ::LoadResource (NULL, res) ;
	BYTE	* pTgaData = (BYTE *) ::LockResource (gol) ;
	return this->LoadTga (pTgaData) ;
}
//===================================================================
BOOL  FCImage::LoadTga (PCTSTR szFileName)
{
	BOOL			bRet = FALSE ;
	BYTE			* pStart = NULL ;
	HANDLE			hMap = NULL ;
	HANDLE			hFile = INVALID_HANDLE_VALUE ;

	__try
	{
		if (pFooDib->hBitmap != NULL)
			this->Unload () ;

		//	映射文件
		pStart = this->__fooImageReadFile (szFileName, &hFile, &hMap) ;
		if (pStart == NULL)
			__leave ;
		if (!this->LoadTga (pStart)) // 读文件
			__leave ;
		bRet = TRUE ;
	}
	__finally
	{
		this->__fooImageUnmapFile ((BYTE *)pStart, hMap, hFile) ;
		if (!bRet)
			this->Unload () ;
	}
	return bRet ;
}
//===================================================================

BOOL  FCImage::SaveTga (PCTSTR szFileName, bool bEncode)
{
	const char			fTgaInfo[] = {"foolish -- TGA"} ;
	BOOL				bRet = FALSE ;
	HANDLE				hMap = NULL ;
	HANDLE				hFile = INVALID_HANDLE_VALUE ;
	BYTE				* pStart = NULL, * pCurr = NULL ;

	__try
	{
		if (pFooDib->hBitmap == NULL)
			__leave ;
		if (this->ColorBits() < 8)
			this->ConvertColorTo (8) ; // 1,4位色 ==> 8位色

		//	创建文件
		pStart = this->__fooImageSaveFile (szFileName, &hFile, &hMap, this->GetPitch() * this->Height() * 2 + 2048) ;
		if (pStart == NULL)
			__leave ;
		pCurr = pStart ;

		//	设置头
		*pCurr++ = 14 ; // 附加信息
		*pCurr++ = (this->ColorBits() == 8) ? 1 : 0 ;
		*pCurr++ = (this->ColorBits() == 8) ? (bEncode ? 9 : 1)
											: (bEncode ? 10 : 2) ;
		* (WORD *) pCurr = 0 ; pCurr += 2 ;	// 调色板起始索引
		* (WORD *) pCurr = 256 ; pCurr += 2 ; // 调色板长度
		*pCurr++ = 24 ; // 调色板中每一颜色所占位数
		* (DWORD *) pCurr = 0 ; // 左下角(X,Y)坐标
		pCurr += 4 ;
		* (WORD *) pCurr = (WORD) this->Width() ; pCurr += 2 ; // 宽
		* (WORD *) pCurr = (WORD) this->Height() ; pCurr += 2 ; // 高
		*pCurr++ = (BYTE) this->ColorBits() ; // 色彩位数
		*pCurr++ = 0x20 ;
		memcpy (pCurr, fTgaInfo, 14) ;
		pCurr += 14 ; // 跳过14 BYTE

		//	写调色板
		if (this->ColorBits() == 8)
		{
			RGBQUAD		* prgb = new RGBQUAD [256] ;
			this->GetColorTable (0, 256, prgb) ;
			for (int i = 0 ; i < 256 ; i++)
			{
				*pCurr++ = prgb[i].rgbBlue ;
				*pCurr++ = prgb[i].rgbGreen ;
				*pCurr++ = prgb[i].rgbRed ;
			}
			delete[] prgb ;
		}

		//	写像素
		DWORD	dwLineByte = this->ColorBits() * this->Width() / 8 ;
		if (bEncode)
			for (int Y = 0 ; Y < this->Height() ; Y++)
				pCurr = ::RLE_TGA_EncodeLine (this->GetBits(Y), this->ColorBits(), this->Width(), pCurr) ;
		else
			for (int Y = 0 ; Y < this->Height() ; Y++, pCurr += dwLineByte)
				CopyMemory (pCurr, this->GetBits(Y), dwLineByte) ;
		bRet = TRUE ;
	}
	__finally
	{
		if (pStart != NULL)	::UnmapViewOfFile (pStart) ;
		if (hMap != NULL)
		{
			::CloseHandle (hMap) ;
			::SetFilePointer (hFile, pCurr - pStart, NULL, FILE_BEGIN) ;
			::SetEndOfFile (hFile) ; // 设置文件大小
		}
		if (hFile != INVALID_HANDLE_VALUE)	::CloseHandle (hFile) ;
	}
	return bRet ;
}

//===================================================================