gl_draw.c

quake1 dos源代码最新版本

{
	int		i, j;
	unsigned	*inrow;
	unsigned	frac, fracstep;

	fracstep = inwidth*0x10000/outwidth;
	for (i=0 ; i<outheight ; i++, out += outwidth)
	{
		inrow = in + inwidth*(i*inheight/outheight);
		frac = fracstep >> 1;
		for (j=0 ; j<outwidth ; j+=4)
		{
			out[j] = inrow[frac>>16];
			frac += fracstep;
			out[j+1] = inrow[frac>>16];
			frac += fracstep;
			out[j+2] = inrow[frac>>16];
			frac += fracstep;
			out[j+3] = inrow[frac>>16];
			frac += fracstep;
		}
	}
}

/*
================
GL_Resample8BitTexture -- JACK
================
*/
void GL_Resample8BitTexture (unsigned char *in, int inwidth, int inheight, unsigned char *out,  int outwidth, int outheight)
{
	int		i, j;
	unsigned	char *inrow;
	unsigned	frac, fracstep;

	fracstep = inwidth*0x10000/outwidth;
	for (i=0 ; i<outheight ; i++, out += outwidth)
	{
		inrow = in + inwidth*(i*inheight/outheight);
		frac = fracstep >> 1;
		for (j=0 ; j<outwidth ; j+=4)
		{
			out[j] = inrow[frac>>16];
			frac += fracstep;
			out[j+1] = inrow[frac>>16];
			frac += fracstep;
			out[j+2] = inrow[frac>>16];
			frac += fracstep;
			out[j+3] = inrow[frac>>16];
			frac += fracstep;
		}
	}
}


/*
================
GL_MipMap

Operates in place, quartering the size of the texture
================
*/
void GL_MipMap (byte *in, int width, int height)
{
	int		i, j;
	byte	*out;

	width <<=2;
	height >>= 1;
	out = in;
	for (i=0 ; i<height ; i++, in+=width)
	{
		for (j=0 ; j<width ; j+=8, out+=4, in+=8)
		{
			out[0] = (in[0] + in[4] + in[width+0] + in[width+4])>>2;
			out[1] = (in[1] + in[5] + in[width+1] + in[width+5])>>2;
			out[2] = (in[2] + in[6] + in[width+2] + in[width+6])>>2;
			out[3] = (in[3] + in[7] + in[width+3] + in[width+7])>>2;
		}
	}
}

/*
================
GL_MipMap8Bit

Mipping for 8 bit textures
================
*/
void GL_MipMap8Bit (byte *in, int width, int height)
{
	int		i, j;
	unsigned short	r,g,b;
	byte	*out, *at1, *at2, *at3, *at4;

//	width <<=2;
	height >>= 1;
	out = in;
	for (i=0 ; i<height ; i++, in+=width)
	{
		for (j=0 ; j<width ; j+=2, out+=1, in+=2)
		{
			at1 = (byte *) (d_8to24table + in[0]);
			at2 = (byte *) (d_8to24table + in[1]);
			at3 = (byte *) (d_8to24table + in[width+0]);
			at4 = (byte *) (d_8to24table + in[width+1]);

 			r = (at1[0]+at2[0]+at3[0]+at4[0]); r>>=5;
 			g = (at1[1]+at2[1]+at3[1]+at4[1]); g>>=5;
 			b = (at1[2]+at2[2]+at3[2]+at4[2]); b>>=5;

			out[0] = d_15to8table[(r<<0) + (g<<5) + (b<<10)];
		}
	}
}

/*
===============
GL_Upload32
===============
*/
void GL_Upload32 (unsigned *data, int width, int height,  qboolean mipmap, qboolean alpha)
{
	int			samples;
static	unsigned	scaled[1024*512];	// [512*256];
	int			scaled_width, scaled_height;

	for (scaled_width = 1 ; scaled_width < width ; scaled_width<<=1)
		;
	for (scaled_height = 1 ; scaled_height < height ; scaled_height<<=1)
		;

	scaled_width >>= (int)gl_picmip->value;
	scaled_height >>= (int)gl_picmip->value;

	if (scaled_width > gl_max_size->value)
		scaled_width = gl_max_size->value;
	if (scaled_height > gl_max_size->value)
		scaled_height = gl_max_size->value;

	if (scaled_width * scaled_height > sizeof(scaled)/4)
		Sys_Error ("GL_LoadTexture: too big");

	samples = alpha ? gl_alpha_format : gl_solid_format;

#if 0
	if (mipmap)
		gluBuild2DMipmaps (GL_TEXTURE_2D, samples, width, height, GL_RGBA, GL_UNSIGNED_BYTE, trans);
	else if (scaled_width == width && scaled_height == height)
		glTexImage2D (GL_TEXTURE_2D, 0, samples, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, trans);
	else
	{
		gluScaleImage (GL_RGBA, width, height, GL_UNSIGNED_BYTE, trans,
			scaled_width, scaled_height, GL_UNSIGNED_BYTE, scaled);
		glTexImage2D (GL_TEXTURE_2D, 0, samples, scaled_width, scaled_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, scaled);
	}
#else
texels += scaled_width * scaled_height;

	if (scaled_width == width && scaled_height == height)
	{
		if (!mipmap)
		{
			glTexImage2D (GL_TEXTURE_2D, 0, samples, scaled_width, scaled_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, data);
			goto done;
		}
		memcpy (scaled, data, width*height*4);
	}
	else
		GL_ResampleTexture (data, width, height, scaled, scaled_width, scaled_height);

	glTexImage2D (GL_TEXTURE_2D, 0, samples, scaled_width, scaled_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, scaled);
	if (mipmap)
	{
		int		miplevel;

		miplevel = 0;
		while (scaled_width > 1 || scaled_height > 1)
		{
			GL_MipMap ((byte *)scaled, 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++;
			glTexImage2D (GL_TEXTURE_2D, miplevel, samples, scaled_width, scaled_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, scaled);
		}
	}
done: ;
#endif


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

void GL_Upload8_EXT (byte *data, int width, int height,  qboolean mipmap, qboolean alpha)
{
	int			i, s;
	qboolean	noalpha;
	int			p;
//	static unsigned j;	// 2001-12-10 Reduced compiler warnings by Jeff Ford
	int			samples;
	static unsigned char	scaled[1024*512];	// [512*256];
	int			scaled_width, scaled_height;

	s = width*height;
	// if there are no transparent pixels, make it a 3 component
	// texture even if it was specified as otherwise
	if (alpha)
	{
		noalpha = true;
		for (i=0 ; i<s ; i++)
		{
			if (data[i] == 255)
				noalpha = false;
		}

		if (alpha && noalpha)
			alpha = false;
	}
	for (scaled_width = 1 ; scaled_width < width ; scaled_width<<=1)
		;
	for (scaled_height = 1 ; scaled_height < height ; scaled_height<<=1)
		;

	scaled_width >>= (int)gl_picmip->value;
	scaled_height >>= (int)gl_picmip->value;

	if (scaled_width > gl_max_size->value)
		scaled_width = gl_max_size->value;
	if (scaled_height > gl_max_size->value)
		scaled_height = gl_max_size->value;

	if (scaled_width * scaled_height > sizeof(scaled))
		Sys_Error ("GL_LoadTexture: too big");

	samples = 1; // alpha ? gl_alpha_format : gl_solid_format;

	texels += scaled_width * scaled_height;

	if (scaled_width == width && scaled_height == height)
	{
		if (!mipmap)
		{
			glTexImage2D (GL_TEXTURE_2D, 0, GL_COLOR_INDEX8_EXT, scaled_width, scaled_height, 0, GL_COLOR_INDEX , GL_UNSIGNED_BYTE, data);
			goto done;
		}
		memcpy (scaled, data, width*height);
	}
	else
		GL_Resample8BitTexture (data, width, height, scaled, scaled_width, scaled_height);

	glTexImage2D (GL_TEXTURE_2D, 0, GL_COLOR_INDEX8_EXT, scaled_width, scaled_height, 0, GL_COLOR_INDEX, GL_UNSIGNED_BYTE, scaled);
	if (mipmap)
	{
		int		miplevel;

		miplevel = 0;
		while (scaled_width > 1 || scaled_height > 1)
		{
			GL_MipMap8Bit ((byte *)scaled, 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++;
			glTexImage2D (GL_TEXTURE_2D, miplevel, GL_COLOR_INDEX8_EXT, scaled_width, scaled_height, 0, GL_COLOR_INDEX, GL_UNSIGNED_BYTE, scaled);
		}
	}
done: ;


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

/*
===============
GL_Upload8
===============
*/
void GL_Upload8 (byte *data, int width, int height,  qboolean mipmap, qboolean alpha)
{
static	unsigned	trans[640*480];		// FIXME, temporary
	int			i, s;
	qboolean	noalpha;
	int			p;

	s = width*height;
	// if there are no transparent pixels, make it a 3 component
	// texture even if it was specified as otherwise
	if (alpha)
	{
		noalpha = true;
		for (i=0 ; i<s ; i++)
		{
			p = data[i];
			if (p == 255)
				noalpha = false;
			trans[i] = d_8to24table[p];
		}

		if (alpha && noalpha)
			alpha = false;
	}
	else
	{
		if (s&3)
			Sys_Error ("GL_Upload8: s&3");
		for (i=0 ; i<s ; i+=4)
		{
			trans[i] = d_8to24table[data[i]];
			trans[i+1] = d_8to24table[data[i+1]];
			trans[i+2] = d_8to24table[data[i+2]];
			trans[i+3] = d_8to24table[data[i+3]];
		}
	}

 	if (VID_Is8bit() && !alpha && (data!=scrap_texels[0])) {
 		GL_Upload8_EXT (data, width, height, mipmap, alpha);
 		return;
	}
	GL_Upload32 (trans, width, height, mipmap, alpha);
}

/*
================
GL_LoadTexture
================
*/
int lhcsumtable[256];	// 2001-09-09 GL Texture memory leak fix by LordHavoc
int GL_LoadTexture (char *identifier, int width, int height, byte *data, qboolean mipmap, qboolean alpha)
{
	qboolean	noalpha;
	int			i, p, s;
	gltexture_t	*glt;

// 2001-09-09 GL Texture memory leak fix by LordHavoc  start
	int			lhcsum;

	// do a checksum to confirm the data really is the same as previous
	// occurances. well this isn't exactly a checksum, it's better than
	// that but not following any standards.
	for (i=0 ; i<256 ; i++)
	{
		lhcsumtable[i] = i + 1;
	}

	s = width * height;
	lhcsum = 0;
	for (i=0; i<s ; i++)
	{
		lhcsum += (lhcsumtable[data[i] & 255]++);
	}
// 2001-09-09 GL Texture memory leak fix by LordHavoc  end

	// see if the texture is already present
	if (identifier[0])
	{
		for (i=0, glt=gltextures ; i<numgltextures ; i++, glt++)
		{
			if (!strcmp (identifier, glt->identifier))
			{
// 2001-09-09 GL Texture memory leak fix by LordHavoc  start
/*
				if (width != glt->width || height != glt->height)
					Sys_Error ("GL_LoadTexture: cache mismatch");
				return gltextures[i].texnum;
*/
				// everyone hates cache mismatchs, so I fixed it
				if (lhcsum != glt->lhcsum || width != glt->width || height != glt->height)
				{
					Con_DPrintf("GL_LoadTexture: cache mismatch, replacing old texture\n");
					goto GL_LoadTexture_setup;	// drop out with glt pointing to the texture to replace
				}
				return glt->texnum;
// 2001-09-09 GL Texture memory leak fix by LordHavoc  end
			}
		}
	}
// 2001-09-09 GL Texture memory leak fix by LordHavoc/Maddes  start
	// this was an else condition, causing disasterous results,
	// whoever at id or threewave must've been half asleep...
//	else {

	// additional leak check by Maddes  start
	if (numgltextures >= MAX_GLTEXTURES)
	{
		Sys_Error ("GL_LoadTexture: cache full, max is %i textures", MAX_GLTEXTURES);
	}
	// additional leak check by Maddes  end
// 2001-09-09 GL Texture memory leak fix by LordHavoc/Maddes  end
		glt = &gltextures[numgltextures];
		numgltextures++;
//	}	// 2001-09-09 GL Texture memory leak fix by LordHavoc

	strcpy (glt->identifier, identifier);
	glt->texnum = texture_extension_number;
// 2001-09-09 GL Texture memory leak fix by LordHavoc  start
	texture_extension_number++;

// label to drop out of the loop into the setup code
GL_LoadTexture_setup:
	glt->lhcsum = lhcsum;	// used to verify textures are identical
// 2001-09-09 GL Texture memory leak fix by LordHavoc  end
	glt->width = width;
	glt->height = height;
	glt->mipmap = mipmap;

// 2000-07-09 Dedicated server bug in GLQuake fix by Nathan Cline  start
	if (cls.state != ca_dedicated)
	{
// 2000-07-09 Dedicated server bug in GLQuake fix by Nathan Cline  end
// 2001-09-09 GL Texture memory leak fix by LordHavoc  start
//		GL_Bind(texture_extension_number );
		GL_Bind(glt->texnum);	// use value stored in structure
// 2001-09-09 GL Texture memory leak fix by LordHavoc  end

		GL_Upload8 (data, width, height, mipmap, alpha);
	}	// 2000-07-09 Dedicated server bug in GLQuake fix by Nathan Cline

// 2001-09-09 GL Texture memory leak fix by LordHavoc  start
/*
	texture_extension_number++;

	return texture_extension_number-1;
*/
	return glt->texnum;	// use value stored in structure
// 2001-09-09 GL Texture memory leak fix by LordHavoc  end
}

/*
================
GL_LoadPicTexture
================
*/
int GL_LoadPicTexture (qpic_t *pic)
{
	return GL_LoadTexture ("", pic->width, pic->height, pic->data, false, true);
}

/****************************************/

static GLenum oldtarget = TEXTURE0_SGIS;

void GL_SelectTexture (GLenum target)
{
	if (!gl_mtexable)
		return;
	qglSelectTextureSGIS(target);
	if (target == oldtarget)
		return;
	cnttextures[oldtarget-TEXTURE0_SGIS] = currenttexture;
	currenttexture = cnttextures[target-TEXTURE0_SGIS];
	oldtarget = target;
}