src/mesa/main/texformat.c

/* $Id: texformat.c,v 1.7 2001/03/30 14:44:43 gareth Exp $ */

/*
 * Mesa 3-D graphics library
 * Version:  3.5
 *
 * Copyright (C) 1999-2001  Brian Paul   All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 * Author:
 *    Gareth Hughes <gareth@valinux.com>
 */

#ifdef PC_HEADER
#include "all.h"
#else
#include "glheader.h"
#include "colormac.h"
#include "context.h"
#include "image.h"
#include "mem.h"
#include "mmath.h"
#include "mtypes.h"
#include "texformat.h"
#include "teximage.h"
#include "texstate.h"
#include "swrast/s_span.h"
#endif


/* Texel fetch routines for all supported formats:
 */
#define DIM 1
#include "texformat_tmp.h"

#define DIM 2
#include "texformat_tmp.h"

#define DIM 3
#include "texformat_tmp.h"

/* Have to have this so the FetchTexel function pointer is never NULL.
 */
static void fetch_null_texel( const struct gl_texture_image *texImage,
			      GLint i, GLint j, GLint k, GLvoid *texel )
{
   GLchan *rgba = (GLchan *) texel;
   rgba[RCOMP] = 0;
   rgba[GCOMP] = 0;
   rgba[BCOMP] = 0;
   rgba[ACOMP] = 0;
}


/* =============================================================
 * Default GLchan-based formats:
 */

const struct gl_texture_format _mesa_texformat_rgba = {
   MESA_FORMAT_RGBA,			/* MesaFormat */
   GL_RGBA,				/* IntFormat */
   CHAN_TYPE,				/* Type */
   CHAN_BITS,				/* RedBits */
   CHAN_BITS,				/* GreenBits */
   CHAN_BITS,				/* BlueBits */
   CHAN_BITS,				/* AlphaBits */
   0,					/* LuminanceBits */
   0,					/* IntensityBits */
   0,					/* IndexBits */
   0,					/* DepthBits */
   4 * CHAN_BITS / 8,			/* TexelBytes */
   fetch_1d_texel_rgba,			/* FetchTexel1D */
   fetch_2d_texel_rgba,			/* FetchTexel2D */
   fetch_3d_texel_rgba,			/* FetchTexel3D */
};

const struct gl_texture_format _mesa_texformat_rgb = {
   MESA_FORMAT_RGB,			/* MesaFormat */
   GL_RGB,				/* IntFormat */
   CHAN_TYPE,				/* Type */
   CHAN_BITS,				/* RedBits */
   CHAN_BITS,				/* GreenBits */
   CHAN_BITS,				/* BlueBits */
   0,					/* AlphaBits */
   0,					/* LuminanceBits */
   0,					/* IntensityBits */
   0,					/* IndexBits */
   0,					/* DepthBits */
   3 * CHAN_BITS / 8,			/* TexelBytes */
   fetch_1d_texel_rgb,			/* FetchTexel1D */
   fetch_2d_texel_rgb,			/* FetchTexel2D */
   fetch_3d_texel_rgb,			/* FetchTexel3D */
};

const struct gl_texture_format _mesa_texformat_alpha = {
   MESA_FORMAT_ALPHA,			/* MesaFormat */
   GL_ALPHA,				/* IntFormat */
   CHAN_TYPE,				/* Type */
   0,					/* RedBits */
   0,					/* GreenBits */
   0,					/* BlueBits */
   CHAN_BITS,				/* AlphaBits */
   0,					/* LuminanceBits */
   0,					/* IntensityBits */
   0,					/* IndexBits */
   0,					/* DepthBits */
   CHAN_BITS / 8,			/* TexelBytes */
   fetch_1d_texel_alpha,		/* FetchTexel1D */
   fetch_2d_texel_alpha,		/* FetchTexel2D */
   fetch_3d_texel_alpha,		/* FetchTexel3D */
};

const struct gl_texture_format _mesa_texformat_luminance = {
   MESA_FORMAT_LUMINANCE,		/* MesaFormat */
   GL_LUMINANCE,			/* IntFormat */
   CHAN_TYPE,				/* Type */
   0,					/* RedBits */
   0,					/* GreenBits */
   0,					/* BlueBits */
   0,					/* AlphaBits */
   CHAN_BITS,				/* LuminanceBits */
   0,					/* IntensityBits */
   0,					/* IndexBits */
   0,					/* DepthBits */
   CHAN_BITS / 8,			/* TexelBytes */
   fetch_1d_texel_luminance,		/* FetchTexel1D */
   fetch_2d_texel_luminance,		/* FetchTexel2D */
   fetch_3d_texel_luminance,		/* FetchTexel3D */
};

const struct gl_texture_format _mesa_texformat_luminance_alpha = {
   MESA_FORMAT_LUMINANCE_ALPHA,		/* MesaFormat */
   GL_LUMINANCE_ALPHA,			/* IntFormat */
   CHAN_TYPE,				/* Type */
   0,					/* RedBits */
   0,					/* GreenBits */
   0,					/* BlueBits */
   CHAN_BITS,				/* AlphaBits */
   CHAN_BITS,				/* LuminanceBits */
   0,					/* IntensityBits */
   0,					/* IndexBits */
   0,					/* DepthBits */
   2 * CHAN_BITS / 8,			/* TexelBytes */
   fetch_1d_texel_luminance_alpha,	/* FetchTexel1D */
   fetch_2d_texel_luminance_alpha,	/* FetchTexel2D */
   fetch_3d_texel_luminance_alpha,	/* FetchTexel3D */
};

const struct gl_texture_format _mesa_texformat_intensity = {
   MESA_FORMAT_INTENSITY,		/* MesaFormat */
   GL_INTENSITY,			/* IntFormat */
   CHAN_TYPE,				/* Type */
   0,					/* RedBits */
   0,					/* GreenBits */
   0,					/* BlueBits */
   0,					/* AlphaBits */
   0,					/* LuminanceBits */
   CHAN_BITS,				/* IntensityBits */
   0,					/* IndexBits */
   0,					/* DepthBits */
   CHAN_BITS / 8,			/* TexelBytes */
   fetch_1d_texel_intensity,		/* FetchTexel1D */
   fetch_2d_texel_intensity,		/* FetchTexel2D */
   fetch_3d_texel_intensity,		/* FetchTexel3D */
};

const struct gl_texture_format _mesa_texformat_color_index = {
   MESA_FORMAT_COLOR_INDEX,		/* MesaFormat */
   GL_COLOR_INDEX,			/* IntFormat */
   CHAN_TYPE,				/* Type */
   0,					/* RedBits */
   0,					/* GreenBits */
   0,					/* BlueBits */
   0,					/* AlphaBits */
   0,					/* LuminanceBits */
   0,					/* IntensityBits */
   CHAN_BITS,				/* IndexBits */
   0,					/* DepthBits */
   CHAN_BITS / 8,			/* TexelBytes */
   fetch_1d_texel_color_index,		/* FetchTexel1D */
   fetch_2d_texel_color_index,		/* FetchTexel2D */
   fetch_3d_texel_color_index,		/* FetchTexel3D */
};

const struct gl_texture_format _mesa_texformat_depth_component = {
   MESA_FORMAT_DEPTH_COMPONENT,		/* MesaFormat */
   GL_DEPTH_COMPONENT,			/* IntFormat */
   GL_FLOAT,				/* Type */
   0,					/* RedBits */
   0,					/* GreenBits */
   0,					/* BlueBits */
   0,					/* AlphaBits */
   0,					/* LuminanceBits */
   0,					/* IntensityBits */
   0,					/* IndexBits */
   sizeof(GLfloat) * 8,			/* DepthBits */
   sizeof(GLfloat),			/* TexelBytes */
   fetch_1d_texel_depth_component,	/* FetchTexel1D */
   fetch_2d_texel_depth_component,	/* FetchTexel2D */
   fetch_3d_texel_depth_component,	/* FetchTexel3D */
};


/* =============================================================
 * Hardware formats:
 */

const struct gl_texture_format _mesa_texformat_rgba8888 = {
   MESA_FORMAT_RGBA8888,		/* MesaFormat */
   GL_RGBA,				/* IntFormat */
   GL_UNSIGNED_INT_8_8_8_8,		/* Type */
   8,					/* RedBits */
   8,					/* GreenBits */
   8,					/* BlueBits */
   8,					/* AlphaBits */
   0,					/* LuminanceBits */
   0,					/* IntensityBits */
   0,					/* IndexBits */
   0,					/* DepthBits */
   4,					/* TexelBytes */
   fetch_1d_texel_rgba8888,		/* FetchTexel1D */
   fetch_2d_texel_rgba8888,		/* FetchTexel2D */
   fetch_3d_texel_rgba8888,		/* FetchTexel3D */
};

const struct gl_texture_format _mesa_texformat_argb8888 = {
   MESA_FORMAT_ARGB8888,		/* MesaFormat */
   GL_BGRA,				/* IntFormat */
   GL_UNSIGNED_INT_8_8_8_8_REV,		/* Type */
   8,					/* RedBits */
   8,					/* GreenBits */
   8,					/* BlueBits */
   8,					/* AlphaBits */
   0,					/* LuminanceBits */
   0,					/* IntensityBits */
   0,					/* IndexBits */
   0,					/* DepthBits */
   4,					/* TexelBytes */
   fetch_1d_texel_argb8888,		/* FetchTexel1D */
   fetch_2d_texel_argb8888,		/* FetchTexel2D */
   fetch_3d_texel_argb8888,		/* FetchTexel3D */
};

const struct gl_texture_format _mesa_texformat_rgb888 = {
   MESA_FORMAT_RGB888,			/* MesaFormat */
   GL_BGR,				/* IntFormat */
   GL_UNSIGNED_BYTE,			/* Type */
   8,					/* RedBits */
   8,					/* GreenBits */
   8,					/* BlueBits */
   0,					/* AlphaBits */
   0,					/* LuminanceBits */
   0,					/* IntensityBits */
   0,					/* IndexBits */
   0,					/* DepthBits */
   3,					/* TexelBytes */
   fetch_1d_texel_rgb888,		/* FetchTexel1D */
   fetch_2d_texel_rgb888,		/* FetchTexel2D */
   fetch_3d_texel_rgb888,		/* FetchTexel3D */
};

const struct gl_texture_format _mesa_texformat_rgb565 = {
   MESA_FORMAT_RGB565,			/* MesaFormat */
   GL_RGB,				/* IntFormat */
   GL_UNSIGNED_SHORT_5_6_5,		/* Type */
   5,					/* RedBits */
   6,					/* GreenBits */
   5,					/* BlueBits */
   0,					/* AlphaBits */
   0,					/* LuminanceBits */
   0,					/* IntensityBits */
   0,					/* IndexBits */
   0,					/* DepthBits */
   2,					/* TexelBytes */
   fetch_1d_texel_rgb565,		/* FetchTexel1D */
   fetch_2d_texel_rgb565,		/* FetchTexel2D */
   fetch_3d_texel_rgb565,		/* FetchTexel3D */
};

const struct gl_texture_format _mesa_texformat_argb4444 = {
   MESA_FORMAT_ARGB4444,		/* MesaFormat */
   GL_BGRA,				/* IntFormat */
   GL_UNSIGNED_SHORT_4_4_4_4_REV,	/* Type */
   4,					/* RedBits */
   4,					/* GreenBits */
   4,					/* BlueBits */
   4,					/* AlphaBits */
   0,					/* LuminanceBits */
   0,					/* IntensityBits */
   0,					/* IndexBits */
   0,					/* DepthBits */
   2,					/* TexelBytes */
   fetch_1d_texel_argb4444,		/* FetchTexel1D */
   fetch_2d_texel_argb4444,		/* FetchTexel2D */
   fetch_3d_texel_argb4444,		/* FetchTexel3D */
};

const struct gl_texture_format _mesa_texformat_argb1555 = {
   MESA_FORMAT_ARGB1555,		/* MesaFormat */
   GL_BGRA,				/* IntFormat */
   GL_UNSIGNED_SHORT_1_5_5_5_REV,	/* Type */
   5,					/* RedBits */
   5,					/* GreenBits */
   5,					/* BlueBits */
   1,					/* AlphaBits */
   0,					/* LuminanceBits */
   0,					/* IntensityBits */
   0,					/* IndexBits */
   0,					/* DepthBits */
   2,					/* TexelBytes */
   fetch_1d_texel_argb1555,		/* FetchTexel1D */
   fetch_2d_texel_argb1555,		/* FetchTexel2D */
   fetch_3d_texel_argb1555,		/* FetchTexel3D */
};

const struct gl_texture_format _mesa_texformat_al88 = {
   MESA_FORMAT_AL88,			/* MesaFormat */
   GL_LUMINANCE_ALPHA,			/* IntFormat */
   GL_UNSIGNED_BYTE,			/* Type */
   0,					/* RedBits */
   0,					/* GreenBits */
   0,					/* BlueBits */
   8,					/* AlphaBits */
   8,					/* LuminanceBits */
   0,					/* IntensityBits */
   0,					/* IndexBits */
   0,					/* DepthBits */
   2,					/* TexelBytes */
   fetch_1d_texel_al88,			/* FetchTexel1D */
   fetch_2d_texel_al88,			/* FetchTexel2D */
   fetch_3d_texel_al88,			/* FetchTexel3D */
};

const struct gl_texture_format _mesa_texformat_rgb332 = {
   MESA_FORMAT_RGB332,			/* MesaFormat */
   GL_RGB,				/* IntFormat */
   GL_UNSIGNED_BYTE_3_3_2,		/* Type */
   3,					/* RedBits */
   3,					/* GreenBits */
   2,					/* BlueBits */
   0,					/* AlphaBits */
   0,					/* LuminanceBits */
   0,					/* IntensityBits */
   0,					/* IndexBits */
   0,					/* DepthBits */
   1,					/* TexelBytes */
   fetch_1d_texel_rgb332,		/* FetchTexel1D */
   fetch_2d_texel_rgb332,		/* FetchTexel2D */
   fetch_3d_texel_rgb332,		/* FetchTexel3D */
};

const struct gl_texture_format _mesa_texformat_a8 = {
   MESA_FORMAT_A8,			/* MesaFormat */
   GL_ALPHA,				/* IntFormat */
   GL_UNSIGNED_BYTE,			/* Type */
   0,					/* RedBits */
   0,					/* GreenBits */
   0,					/* BlueBits */
   8,					/* AlphaBits */
   0,					/* LuminanceBits */
   0,					/* IntensityBits */
   0,					/* IndexBits */
   0,					/* DepthBits */
   1,					/* TexelBytes */
   fetch_1d_texel_a8,			/* FetchTexel1D */
   fetch_2d_texel_a8,			/* FetchTexel2D */
   fetch_3d_texel_a8,			/* FetchTexel3D */
};

const struct gl_texture_format _mesa_texformat_l8 = {
   MESA_FORMAT_L8,			/* MesaFormat */
   GL_LUMINANCE,			/* IntFormat */
   GL_UNSIGNED_BYTE,			/* Type */
   0,					/* RedBits */
   0,					/* GreenBits */
   0,					/* BlueBits */
   0,					/* AlphaBits */
   8,					/* LuminanceBits */
   0,					/* IntensityBits */
   0,					/* IndexBits */
   0,					/* DepthBits */
   1,					/* TexelBytes */
   fetch_1d_texel_l8,			/* FetchTexel1D */
   fetch_2d_texel_l8,			/* FetchTexel2D */
   fetch_3d_texel_l8,			/* FetchTexel3D */
};

const struct gl_texture_format _mesa_texformat_i8 = {
   MESA_FORMAT_I8,			/* MesaFormat */
   GL_INTENSITY,			/* IntFormat */
   GL_UNSIGNED_BYTE,			/* Type */
   0,					/* RedBits */
   0,					/* GreenBits */
   0,					/* BlueBits */
   0,					/* AlphaBits */
   0,					/* LuminanceBits */
   8,					/* IntensityBits */
   0,					/* IndexBits */
   0,					/* DepthBits */
   1,					/* TexelBytes */
   fetch_1d_texel_i8,			/* FetchTexel1D */
   fetch_2d_texel_i8,			/* FetchTexel2D */
   fetch_3d_texel_i8,			/* FetchTexel3D */
};

const struct gl_texture_format _mesa_texformat_ci8 = {
   MESA_FORMAT_CI8,			/* MesaFormat */
   GL_COLOR_INDEX,			/* IntFormat */
   GL_UNSIGNED_BYTE,			/* Type */
   0,					/* RedBits */
   0,					/* GreenBits */
   0,					/* BlueBits */
   0,					/* AlphaBits */
   0,					/* LuminanceBits */
   0,					/* IntensityBits */
   8,					/* IndexBits */
   0,					/* DepthBits */
   1,					/* TexelBytes */
   fetch_1d_texel_ci8,			/* FetchTexel1D */
   fetch_2d_texel_ci8,			/* FetchTexel2D */
   fetch_3d_texel_ci8,			/* FetchTexel3D */
};


/* =============================================================
 * Null format:
 */

const struct gl_texture_format _mesa_null_texformat = {
   -1,					/* MesaFormat */
   0,					/* IntFormat */
   0,					/* Type */
   0,					/* RedBits */
   0,					/* GreenBits */
   0,					/* BlueBits */
   0,					/* AlphaBits */
   0,					/* LuminanceBits */
   0,					/* IntensityBits */
   0,					/* IndexBits */
   0,					/* DepthBits */
   0,					/* TexelBytes */
   fetch_null_texel,			/* FetchTexel1D */
   fetch_null_texel,			/* FetchTexel2D */
   fetch_null_texel,			/* FetchTexel3D */
};



/* Given an internal texture format or 1, 2, 3, 4 initialize the texture
 * image structure's default format and type information.  Drivers will
 * initialize these fields accordingly if they override the default
 * storage format.
 */
void _mesa_init_tex_format( GLcontext *ctx, GLenum internalFormat,
			    struct gl_texture_image *texImage )
{
   const struct gl_texture_format *texFormat;

   /* Ask the driver for the base format, if it doesn't know, it will
    * return -1;
    */
   if ( ctx->Driver.BaseCompressedTexFormat ) {
      GLint format = 0;			/* Silence compiler warning */
      format = (*ctx->Driver.BaseCompressedTexFormat)( ctx, format );
      if ( format >= 0 ) {
	 internalFormat = format;
      }
   }

   switch ( internalFormat ) {
      /* GH: Bias towards GL_RGB, GL_RGBA texture formats.  This has
       * got to be better than sticking them way down the end of this
       * huge list.
       */
   case 4:				/* Quake3 uses this... */
   case GL_RGBA:
      texFormat = &_mesa_texformat_rgba;
      break;

   case 3:				/* ... and this. */
   case GL_RGB:
      texFormat = &_mesa_texformat_rgb;
      break;

      /* GH: Okay, keep checking as normal.  Still test for GL_RGB,
       * GL_RGBA formats first.
       */
   case GL_RGBA2:
   case GL_RGBA4:
   case GL_RGB5_A1:
   case GL_RGBA8:
   case GL_RGB10_A2:
   case GL_RGBA12:
   case GL_RGBA16:
      texFormat = &_mesa_texformat_rgba;
      break;

   case GL_R3_G3_B2:
   case GL_RGB4:
   case GL_RGB5:
   case GL_RGB8:
   case GL_RGB10:
   case GL_RGB12:
   case GL_RGB16:
      texFormat = &_mesa_texformat_rgb;
      break;

   case GL_ALPHA:
   case GL_ALPHA4:
   case GL_ALPHA8:
   case GL_ALPHA12:
   case GL_ALPHA16:
      texFormat = &_mesa_texformat_alpha;
      break;

   case 1:
   case GL_LUMINANCE:
   case GL_LUMINANCE4:
   case GL_LUMINANCE8:
   case GL_LUMINANCE12:
   case GL_LUMINANCE16:
      texFormat = &_mesa_texformat_luminance;
      break;

   case 2:
   case GL_LUMINANCE_ALPHA:
   case GL_LUMINANCE4_ALPHA4:
   case GL_LUMINANCE6_ALPHA2:
   case GL_LUMINANCE8_ALPHA8:
   case GL_LUMINANCE12_ALPHA4:
   case GL_LUMINANCE12_ALPHA12:
   case GL_LUMINANCE16_ALPHA16:
      texFormat = &_mesa_texformat_luminance_alpha;
      break;

   case GL_INTENSITY:
   case GL_INTENSITY4:
   case GL_INTENSITY8:
   case GL_INTENSITY12:
   case GL_INTENSITY16:
      texFormat = &_mesa_texformat_intensity;
      break;

   case GL_COLOR_INDEX:
   case GL_COLOR_INDEX1_EXT:
   case GL_COLOR_INDEX2_EXT:
   case GL_COLOR_INDEX4_EXT:
   case GL_COLOR_INDEX8_EXT:
   case GL_COLOR_INDEX12_EXT:
   case GL_COLOR_INDEX16_EXT:
      texFormat = &_mesa_texformat_color_index;
      break;

   case GL_DEPTH_COMPONENT:
   case GL_DEPTH_COMPONENT16_SGIX:
   case GL_DEPTH_COMPONENT24_SGIX:
   case GL_DEPTH_COMPONENT32_SGIX:
      if ( !ctx->Extensions.SGIX_depth_texture )
	 _mesa_problem( ctx, "depth format without GL_SGIX_depth_texture" );
      texFormat = &_mesa_texformat_depth_component;
      break;

   default:
      _mesa_problem( ctx, "unexpected format in _mesa_init_tex_format" );
      return;
   }

   texImage->TexFormat = texFormat;
}