www.pudn.com > CXIMAGE_SRC.ZIP > ximatga.cpp
/*
* File: ximatga.cpp
* Purpose: Platform Independent TGA Image Class Loader and Writer
* 05/Jan/2001
* CxImage version 5.00 23/Aug/2002
*/
#include "ximatga.h"
#if CXIMAGE_SUPPORT_TGA
#include "ximaiter.h"
// Definitions for image types.
#define TGA_Null 0
#define TGA_Map 1
#define TGA_RGB 2
#define TGA_Mono 3
#define TGA_RLEMap 9
#define TGA_RLERGB 10
#define TGA_RLEMono 11
#define TGA_CompMap 32
#define TGA_CompMap4 33
////////////////////////////////////////////////////////////////////////////////
bool CxImageTGA::Decode(CxFile *hFile)
{
if (hFile == NULL) return false;
TGAHEADER tgaHead;
try
{
if (hFile->Read(&tgaHead,sizeof(tgaHead),1)==0)
throw "Not a TGA";
if (tgaHead.IdLength>0) hFile->Seek(tgaHead.IdLength,SEEK_CUR); //skip descriptor
Create(tgaHead.ImageWidth, tgaHead.ImageHeight, tgaHead.PixelDepth, CXIMAGE_FORMAT_TGA);
#if CXIMAGE_SUPPORT_ALPHA //
if (tgaHead.PixelDepth==16 || tgaHead.PixelDepth==32) AlphaCreate(); // Image has alpha channel
#endif //CXIMAGE_SUPPORT_ALPHA
if (!IsValid()) throw "TGA Create failed";
if (info.nEscape) throw "Cancelled"; // - cancel decoding
if (tgaHead.CmapType != 0){ // read the palette
rgb_color pal[256];
hFile->Read(pal,tgaHead.CmapLength*sizeof(rgb_color), 1);
for (int i=0;i - cancel decoding
if (hFile == NULL || hFile->Eof()) throw "corrupted TGA";
if (bYReversed) pDest = iter.GetRow(tgaHead.ImageHeight-y-1);
else pDest = iter.GetRow(y);
if (bCompressed) ExpandCompressedLine(pDest,&tgaHead,hFile,tgaHead.ImageWidth,y);
else ExpandUncompressedLine (pDest,&tgaHead,hFile,tgaHead.ImageWidth,y,0);
}
if (bXReversed) Mirror();
} catch (char *message) {
strncpy(info.szLastError,message,255);
return FALSE;
}
return true;
}
////////////////////////////////////////////////////////////////////////////////
bool CxImageTGA::Encode(CxFile * hFile)
{
if (hFile==NULL || pDib==NULL) return false;
if (head.biBitCount<8){
strcpy(info.szLastError,"Bit depth must be 8 or 24");
return false;
}
TGAHEADER tgaHead;
tgaHead.IdLength = 0; // Image ID Field Length
tgaHead.CmapType = GetPalette()!=0; // Color Map Type
tgaHead.ImageType = (head.biBitCount == 8) ? (BYTE)TGA_Map : (BYTE)TGA_RGB; // Image Type
tgaHead.CmapIndex=0; // First Entry Index
tgaHead.CmapLength=(head.biBitCount == 8) ? (BYTE)255 : (BYTE)0; // Color Map Length
tgaHead.CmapEntrySize=(head.biBitCount == 8) ? (BYTE)24 : (BYTE)0; // Color Map Entry Size
tgaHead.X_Origin=0; // X-origin of Image
tgaHead.Y_Origin=0; // Y-origin of Image
tgaHead.ImageWidth=(WORD)head.biWidth; // Image Width
tgaHead.ImageHeight=(WORD)head.biHeight; // Image Height
tgaHead.PixelDepth=(BYTE)head.biBitCount; // Pixel Depth
tgaHead.ImagDesc=0; // Image Descriptor
if (pAlpha && head.biBitCount==24) tgaHead.PixelDepth=32;
hFile->Write(&tgaHead,sizeof(TGAHEADER),1);
if (head.biBitCount==8){
rgb_color pal[256];
RGBQUAD* ppal = GetPalette();
for (int i=0;i<256; i++){
pal[i].r = ppal[i].rgbBlue;
pal[i].g = ppal[i].rgbGreen;
pal[i].b = ppal[i].rgbRed;
}
hFile->Write(&pal,256*sizeof(rgb_color),1);
}
CImageIterator iter(this);
BYTE* pDest;
if (pAlpha==0 || head.biBitCount==8){
for (int y=0; y < tgaHead.ImageHeight; y++){
pDest = iter.GetRow(y);
hFile->Write(pDest,tgaHead.ImageWidth * (head.biBitCount >> 3),1);
}
} else {
pDest = (BYTE*)malloc(4*tgaHead.ImageWidth);
RGBQUAD c;
for (int y=0; y < tgaHead.ImageHeight; y++){
for(int x=0, x4=0;x
pDest[x4+3]=(BYTE)((AlphaGet(x,y)*info.nAlphaMax)/255);
#else
pDest[x4+3]=0;
#endif //CXIMAGE_SUPPORT_ALPHA
}
hFile->Write(pDest,4*tgaHead.ImageWidth,1);
}
free(pDest);
}
return true;
}
////////////////////////////////////////////////////////////////////////////////
void CxImageTGA::ExpandCompressedLine(BYTE* pDest,TGAHEADER* ptgaHead,CxFile *hFile,int width, int y)
{
try{
BYTE rle;
for (int x=0; xRead(&rle,1,1);
if (rle & 128) { // RLE-Encoded packet
rle -= 127; // Calculate real repeat count.
switch (ptgaHead->PixelDepth)
{
case 32: {
RGBQUAD color;
hFile->Read(&color,4,1);
for (int ix = 0; ix < rle; ix++){
memcpy(&pDest[3*ix],&color,3);
#if CXIMAGE_SUPPORT_ALPHA //
AlphaSet(ix+x,y,color.rgbReserved);
#endif //CXIMAGE_SUPPORT_ALPHA
}
break;
}
case 24: {
rgb_color triple;
hFile->Read(&triple,3,1);
for (int ix = 0; ix < rle; ix++) memcpy(&pDest[3*ix],&triple,3);
break;
}
case 15:
case 16: {
WORD pixel;
hFile->Read(&pixel,2,1);
rgb_color triple;
triple.r = (BYTE)(( pixel & 0x1F ) * 8); // red
triple.g = (BYTE)(( pixel >> 2 ) & 0x0F8); // green
triple.b = (BYTE)(( pixel >> 7 ) & 0x0F8); // blue
for (int ix = 0; ix < rle; ix++){
memcpy(&pDest[3*ix],&triple,3);
#if CXIMAGE_SUPPORT_ALPHA //
AlphaSet(ix+x,y,(BYTE)(pixel & 32786 >> 8));
#endif //CXIMAGE_SUPPORT_ALPHA
}
break;
}
case 8: {
BYTE pixel;
hFile->Read(&pixel,1,1);
for (int ix = 0; ix < rle; ix++) pDest[ix] = pixel;
}
}
} else { // Raw packet
rle += 1; // Calculate real repeat count.
ExpandUncompressedLine(pDest,ptgaHead,hFile,rle,y,x);
}
if (head.biBitCount == 24) pDest += rle*3; else pDest += rle;
x += rle;
}
} catch(...){ }
}
////////////////////////////////////////////////////////////////////////////////
void CxImageTGA::ExpandUncompressedLine(BYTE* pDest,TGAHEADER* ptgaHead,CxFile *hFile,int width, int y, int xoffset)
{
try{
switch (ptgaHead->PixelDepth){
case 8:
hFile->Read(pDest,width,1);
break;
case 15:
case 16:{
BYTE* dst=pDest;
WORD pixel;
for (int x=0; xRead(&pixel,2,1);
*dst++ = (BYTE)(( pixel & 0x1F ) * 8); // blue
*dst++ = (BYTE)(( pixel >> 2 ) & 0x0F8); // green
*dst++ = (BYTE)(( pixel >> 7 ) & 0x0F8); // red
#if CXIMAGE_SUPPORT_ALPHA //
AlphaSet(x+xoffset,y,(BYTE)(pixel & 32786 >> 8)); //alpha
#endif //CXIMAGE_SUPPORT_ALPHA
}
break;
}
case 24:
hFile->Read(pDest,3*width,1);
break;
case 32:{
BYTE* dst=pDest;
for (int x=0; xRead(&pixel,4,1);
*dst++ = pixel.rgbBlue;
*dst++ = pixel.rgbGreen;
*dst++ = pixel.rgbRed;
#if CXIMAGE_SUPPORT_ALPHA //
AlphaSet(x+xoffset,y,pixel.rgbReserved); //alpha
#endif //CXIMAGE_SUPPORT_ALPHA
}
break;
}
}
} catch(...){ }
}
////////////////////////////////////////////////////////////////////////////////
#endif // CXIMAGE_SUPPORT_TGA