tr_image.c

quakeIII源码这个不用我多说吧

Upload32

===============
*/
extern qboolean charSet;
static void Upload32( unsigned *data, 
						  int width, int height, 
						  qboolean mipmap, 
						  qboolean picmip, 
							qboolean lightMap,
						  int *format, 
						  int *pUploadWidth, int *pUploadHeight )
{
	int			samples;
	unsigned	*scaledBuffer = NULL;
	unsigned	*resampledBuffer = NULL;
	int			scaled_width, scaled_height;
	int			i, c;
	byte		*scan;
	GLenum		internalFormat = GL_RGB;
	float		rMax = 0, gMax = 0, bMax = 0;

	//
	// convert to exact power of 2 sizes
	//
	for (scaled_width = 1 ; scaled_width < width ; scaled_width<<=1)
		;
	for (scaled_height = 1 ; scaled_height < height ; scaled_height<<=1)
		;
	if ( r_roundImagesDown->integer && scaled_width > width )
		scaled_width >>= 1;
	if ( r_roundImagesDown->integer && scaled_height > height )
		scaled_height >>= 1;

	if ( scaled_width != width || scaled_height != height ) {
		resampledBuffer = ri.Hunk_AllocateTempMemory( scaled_width * scaled_height * 4 );
		ResampleTexture (data, width, height, resampledBuffer, scaled_width, scaled_height);
		data = resampledBuffer;
		width = scaled_width;
		height = scaled_height;
	}

	//
	// perform optional picmip operation
	//
	if ( picmip ) {
		scaled_width >>= r_picmip->integer;
		scaled_height >>= r_picmip->integer;
	}

	//
	// clamp to minimum size
	//
	if (scaled_width < 1) {
		scaled_width = 1;
	}
	if (scaled_height < 1) {
		scaled_height = 1;
	}

	//
	// clamp to the current upper OpenGL limit
	// scale both axis down equally so we don't have to
	// deal with a half mip resampling
	//
	while ( scaled_width > glConfig.maxTextureSize
		|| scaled_height > glConfig.maxTextureSize ) {
		scaled_width >>= 1;
		scaled_height >>= 1;
	}

	scaledBuffer = ri.Hunk_AllocateTempMemory( sizeof( unsigned ) * scaled_width * scaled_height );

	//
	// scan the texture for each channel's max values
	// and verify if the alpha channel is being used or not
	//
	c = width*height;
	scan = ((byte *)data);
	samples = 3;
	if (!lightMap) {
		for ( i = 0; i < c; i++ )
		{
			if ( scan[i*4+0] > rMax )
			{
				rMax = scan[i*4+0];
			}
			if ( scan[i*4+1] > gMax )
			{
				gMax = scan[i*4+1];
			}
			if ( scan[i*4+2] > bMax )
			{
				bMax = scan[i*4+2];
			}
			if ( scan[i*4 + 3] != 255 ) 
			{
				samples = 4;
				break;
			}
		}
		// select proper internal format
		if ( samples == 3 )
		{
			if ( glConfig.textureCompression == TC_S3TC )
			{
				internalFormat = GL_RGB4_S3TC;
			}
			else if ( r_texturebits->integer == 16 )
			{
				internalFormat = GL_RGB5;
			}
			else if ( r_texturebits->integer == 32 )
			{
				internalFormat = GL_RGB8;
			}
			else
			{
				internalFormat = 3;
			}
		}
		else if ( samples == 4 )
		{
			if ( r_texturebits->integer == 16 )
			{
				internalFormat = GL_RGBA4;
			}
			else if ( r_texturebits->integer == 32 )
			{
				internalFormat = GL_RGBA8;
			}
			else
			{
				internalFormat = 4;
			}
		}
	} else {
		internalFormat = 3;
	}
	// copy or resample data as appropriate for first MIP level
	if ( ( scaled_width == width ) && 
		( scaled_height == height ) ) {
		if (!mipmap)
		{
			qglTexImage2D (GL_TEXTURE_2D, 0, internalFormat, scaled_width, scaled_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, data);
			*pUploadWidth = scaled_width;
			*pUploadHeight = scaled_height;
			*format = internalFormat;

			goto done;
		}
		Com_Memcpy (scaledBuffer, data, width*height*4);
	}
	else
	{
		// use the normal mip-mapping function to go down from here
		while ( width > scaled_width || height > scaled_height ) {
			R_MipMap( (byte *)data, width, height );
			width >>= 1;
			height >>= 1;
			if ( width < 1 ) {
				width = 1;
			}
			if ( height < 1 ) {
				height = 1;
			}
		}
		Com_Memcpy( scaledBuffer, data, width * height * 4 );
	}

	R_LightScaleTexture (scaledBuffer, scaled_width, scaled_height, !mipmap );

	*pUploadWidth = scaled_width;
	*pUploadHeight = scaled_height;
	*format = internalFormat;

	qglTexImage2D (GL_TEXTURE_2D, 0, internalFormat, scaled_width, scaled_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, scaledBuffer );

	if (mipmap)
	{
		int		miplevel;

		miplevel = 0;
		while (scaled_width > 1 || scaled_height > 1)
		{
			R_MipMap( (byte *)scaledBuffer, scaled_width, scaled_height );
			scaled_width >>= 1;
			scaled_height >>= 1;
			if (scaled_width < 1)
				scaled_width = 1;
			if (scaled_height < 1)
				scaled_height = 1;
			miplevel++;

			if ( r_colorMipLevels->integer ) {
				R_BlendOverTexture( (byte *)scaledBuffer, scaled_width * scaled_height, mipBlendColors[miplevel] );
			}

			qglTexImage2D (GL_TEXTURE_2D, miplevel, internalFormat, scaled_width, scaled_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, scaledBuffer );
		}
	}
done:

	if (mipmap)
	{
		qglTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, gl_filter_min);
		qglTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, gl_filter_max);
	}
	else
	{
		qglTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
		qglTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
	}

	GL_CheckErrors();

	if ( scaledBuffer != 0 )
		ri.Hunk_FreeTempMemory( scaledBuffer );
	if ( resampledBuffer != 0 )
		ri.Hunk_FreeTempMemory( resampledBuffer );
}


/*
================
R_CreateImage

This is the only way any image_t are created
================
*/
image_t *R_CreateImage( const char *name, const byte *pic, int width, int height, 
					   qboolean mipmap, qboolean allowPicmip, int glWrapClampMode ) {
	image_t		*image;
	qboolean	isLightmap = qfalse;
	long		hash;

	if (strlen(name) >= MAX_QPATH ) {
		ri.Error (ERR_DROP, "R_CreateImage: \"%s\" is too long\n", name);
	}
	if ( !strncmp( name, "*lightmap", 9 ) ) {
		isLightmap = qtrue;
	}

	if ( tr.numImages == MAX_DRAWIMAGES ) {
		ri.Error( ERR_DROP, "R_CreateImage: MAX_DRAWIMAGES hit\n");
	}

	image = tr.images[tr.numImages] = ri.Hunk_Alloc( sizeof( image_t ), h_low );
	image->texnum = 1024 + tr.numImages;
	tr.numImages++;

	image->mipmap = mipmap;
	image->allowPicmip = allowPicmip;

	strcpy (image->imgName, name);

	image->width = width;
	image->height = height;
	image->wrapClampMode = glWrapClampMode;

	// lightmaps are always allocated on TMU 1
	if ( qglActiveTextureARB && isLightmap ) {
		image->TMU = 1;
	} else {
		image->TMU = 0;
	}

	if ( qglActiveTextureARB ) {
		GL_SelectTexture( image->TMU );
	}

	GL_Bind(image);

	Upload32( (unsigned *)pic, image->width, image->height, 
								image->mipmap,
								allowPicmip,
								isLightmap,
								&image->internalFormat,
								&image->uploadWidth,
								&image->uploadHeight );

	qglTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, glWrapClampMode );
	qglTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, glWrapClampMode );

	qglBindTexture( GL_TEXTURE_2D, 0 );

	if ( image->TMU == 1 ) {
		GL_SelectTexture( 0 );
	}

	hash = generateHashValue(name);
	image->next = hashTable[hash];
	hashTable[hash] = image;

	return image;
}


/*
=========================================================

BMP LOADING

=========================================================
*/
typedef struct
{
	char id[2];
	unsigned long fileSize;
	unsigned long reserved0;
	unsigned long bitmapDataOffset;
	unsigned long bitmapHeaderSize;
	unsigned long width;
	unsigned long height;
	unsigned short planes;
	unsigned short bitsPerPixel;
	unsigned long compression;
	unsigned long bitmapDataSize;
	unsigned long hRes;
	unsigned long vRes;
	unsigned long colors;
	unsigned long importantColors;
	unsigned char palette[256][4];
} BMPHeader_t;

static void LoadBMP( const char *name, byte **pic, int *width, int *height )
{
	int		columns, rows, numPixels;
	byte	*pixbuf;
	int		row, column;
	byte	*buf_p;
	byte	*buffer;
	int		length;
	BMPHeader_t bmpHeader;
	byte		*bmpRGBA;

	*pic = NULL;

	//
	// load the file
	//
	length = ri.FS_ReadFile( ( char * ) name, (void **)&buffer);
	if (!buffer) {
		return;
	}

	buf_p = buffer;

	bmpHeader.id[0] = *buf_p++;
	bmpHeader.id[1] = *buf_p++;
	bmpHeader.fileSize = LittleLong( * ( long * ) buf_p );
	buf_p += 4;
	bmpHeader.reserved0 = LittleLong( * ( long * ) buf_p );
	buf_p += 4;
	bmpHeader.bitmapDataOffset = LittleLong( * ( long * ) buf_p );
	buf_p += 4;
	bmpHeader.bitmapHeaderSize = LittleLong( * ( long * ) buf_p );
	buf_p += 4;
	bmpHeader.width = LittleLong( * ( long * ) buf_p );
	buf_p += 4;
	bmpHeader.height = LittleLong( * ( long * ) buf_p );
	buf_p += 4;
	bmpHeader.planes = LittleShort( * ( short * ) buf_p );
	buf_p += 2;
	bmpHeader.bitsPerPixel = LittleShort( * ( short * ) buf_p );
	buf_p += 2;
	bmpHeader.compression = LittleLong( * ( long * ) buf_p );
	buf_p += 4;
	bmpHeader.bitmapDataSize = LittleLong( * ( long * ) buf_p );
	buf_p += 4;
	bmpHeader.hRes = LittleLong( * ( long * ) buf_p );
	buf_p += 4;
	bmpHeader.vRes = LittleLong( * ( long * ) buf_p );
	buf_p += 4;
	bmpHeader.colors = LittleLong( * ( long * ) buf_p );
	buf_p += 4;
	bmpHeader.importantColors = LittleLong( * ( long * ) buf_p );
	buf_p += 4;

	Com_Memcpy( bmpHeader.palette, buf_p, sizeof( bmpHeader.palette ) );

	if ( bmpHeader.bitsPerPixel == 8 )
		buf_p += 1024;

	if ( bmpHeader.id[0] != 'B' && bmpHeader.id[1] != 'M' ) 
	{
		ri.Error( ERR_DROP, "LoadBMP: only Windows-style BMP files supported (%s)\n", name );
	}
	if ( bmpHeader.fileSize != length )
	{
		ri.Error( ERR_DROP, "LoadBMP: header size does not match file size (%d vs. %d) (%s)\n", bmpHeader.fileSize, length, name );
	}
	if ( bmpHeader.compression != 0 )
	{
		ri.Error( ERR_DROP, "LoadBMP: only uncompressed BMP files supported (%s)\n", name );
	}
	if ( bmpHeader.bitsPerPixel < 8 )
	{
		ri.Error( ERR_DROP, "LoadBMP: monochrome and 4-bit BMP files not supported (%s)\n", name );
	}

	columns = bmpHeader.width;
	rows = bmpHeader.height;
	if ( rows < 0 )
		rows = -rows;
	numPixels = columns * rows;

	if ( width ) 
		*width = columns;
	if ( height )
		*height = rows;

	bmpRGBA = ri.Malloc( numPixels * 4 );
	*pic = bmpRGBA;


	for ( row = rows-1; row >= 0; row-- )
	{
		pixbuf = bmpRGBA + row*columns*4;

		for ( column = 0; column < columns; column++ )
		{
			unsigned char red, green, blue, alpha;
			int palIndex;
			unsigned short shortPixel;

			switch ( bmpHeader.bitsPerPixel )
			{
			case 8:
				palIndex = *buf_p++;
				*pixbuf++ = bmpHeader.palette[palIndex][2];
				*pixbuf++ = bmpHeader.palette[palIndex][1];
				*pixbuf++ = bmpHeader.palette[palIndex][0];
				*pixbuf++ = 0xff;
				break;
			case 16:
				shortPixel = * ( unsigned short * ) pixbuf;
				pixbuf += 2;
				*pixbuf++ = ( shortPixel & ( 31 << 10 ) ) >> 7;
				*pixbuf++ = ( shortPixel & ( 31 << 5 ) ) >> 2;
				*pixbuf++ = ( shortPixel & ( 31 ) ) << 3;
				*pixbuf++ = 0xff;
				break;

			case 24:
				blue = *buf_p++;
				green = *buf_p++;
				red = *buf_p++;
				*pixbuf++ = red;
				*pixbuf++ = green;
				*pixbuf++ = blue;
				*pixbuf++ = 255;
				break;
			case 32:
				blue = *buf_p++;
				green = *buf_p++;
				red = *buf_p++;
				alpha = *buf_p++;
				*pixbuf++ = red;
				*pixbuf++ = green;
				*pixbuf++ = blue;
				*pixbuf++ = alpha;
				break;
			default:
				ri.Error( ERR_DROP, "LoadBMP: illegal pixel_size '%d' in file '%s'\n", bmpHeader.bitsPerPixel, name );
				break;
			}
		}
	}

	ri.FS_FreeFile( buffer );

}


/*
=================================================================

PCX LOADING

=================================================================
*/


/*
==============
LoadPCX
==============
*/
static void LoadPCX ( const char *filename, byte **pic, byte **palette, int *width, int *height)
{
	byte	*raw;
	pcx_t	*pcx;
	int		x, y;
	int		len;
	int		dataByte, runLength;