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/*

 * Mesa 3-D graphics library

 * Version:  7.1

 *

 * Copyright (C) 1999-2008  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.

 */

/**

 * \file pixel.c

 * Pixel transfer functions (glPixelZoom, glPixelMap, glPixelTransfer)

 */

#include "glheader.h"

#include "bufferobj.h"

#include "colormac.h"

#include "context.h"

#include "macros.h"

#include "pixel.h"

#include "mtypes.h"

#include "main/dispatch.h"

#if FEATURE_pixel_transfer

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

/*****                    glPixelZoom                             *****/

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

static void GLAPIENTRY

_mesa_PixelZoom( GLfloat xfactor, GLfloat yfactor )

{

   GET_CURRENT_CONTEXT(ctx);

   if (ctx->Pixel.ZoomX == xfactor &&

       ctx->Pixel.ZoomY == yfactor)

      return;

   FLUSH_VERTICES(ctx, _NEW_PIXEL);

   ctx->Pixel.ZoomX = xfactor;

   ctx->Pixel.ZoomY = yfactor;

}

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

/*****                         glPixelMap                         *****/

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

/**

 * Return pointer to a pixelmap by name.

 */

static struct gl_pixelmap *

get_pixelmap(struct gl_context *ctx, GLenum map)

{

   switch (map) {

   case GL_PIXEL_MAP_I_TO_I:

      return &ctx->PixelMaps.ItoI;

   case GL_PIXEL_MAP_S_TO_S:

      return &ctx->PixelMaps.StoS;

   case GL_PIXEL_MAP_I_TO_R:

      return &ctx->PixelMaps.ItoR;

   case GL_PIXEL_MAP_I_TO_G:

      return &ctx->PixelMaps.ItoG;

   case GL_PIXEL_MAP_I_TO_B:

      return &ctx->PixelMaps.ItoB;

   case GL_PIXEL_MAP_I_TO_A:

      return &ctx->PixelMaps.ItoA;

   case GL_PIXEL_MAP_R_TO_R:

      return &ctx->PixelMaps.RtoR;

   case GL_PIXEL_MAP_G_TO_G:

      return &ctx->PixelMaps.GtoG;

   case GL_PIXEL_MAP_B_TO_B:

      return &ctx->PixelMaps.BtoB;

   case GL_PIXEL_MAP_A_TO_A:

      return &ctx->PixelMaps.AtoA;

   default:

      return NULL;

   }

}

/**

 * Helper routine used by the other _mesa_PixelMap() functions.

 */

static void

store_pixelmap(struct gl_context *ctx, GLenum map, GLsizei mapsize,

               const GLfloat *values)

{

   GLint i;

   struct gl_pixelmap *pm = get_pixelmap(ctx, map);

   if (!pm) {

      _mesa_error(ctx, GL_INVALID_ENUM, "glPixelMap(map)");

      return;

   }

   switch (map) {

   case GL_PIXEL_MAP_S_TO_S:

      /* special case */

      ctx->PixelMaps.StoS.Size = mapsize;

      for (i = 0; i < mapsize; i++) {

         ctx->PixelMaps.StoS.Map[i] = (GLfloat)IROUND(values[i]);

      }

      break;

   case GL_PIXEL_MAP_I_TO_I:

      /* special case */

      ctx->PixelMaps.ItoI.Size = mapsize;

      for (i = 0; i < mapsize; i++) {

         ctx->PixelMaps.ItoI.Map[i] = values[i];

      }

      break;

   default:

      /* general case */

      pm->Size = mapsize;

      for (i = 0; i < mapsize; i++) {

         GLfloat val = CLAMP(values[i], 0.0F, 1.0F);

         pm->Map[i] = val;

         pm->Map8[i] = (GLint) (val * 255.0F);

      }

   }

}

/**

 * Convenience wrapper for _mesa_validate_pbo_access() for gl[Get]PixelMap().

 */

static GLboolean

validate_pbo_access(struct gl_context *ctx, struct gl_pixelstore_attrib *pack,

                    GLsizei mapsize, GLenum format, GLenum type,

                    const GLvoid *ptr)

{

   GLboolean ok;

   /* Note, need to use DefaultPacking and Unpack's buffer object */

   _mesa_reference_buffer_object(ctx,

                                 &ctx->DefaultPacking.BufferObj,

                                 pack->BufferObj);

   ok = _mesa_validate_pbo_access(1, &ctx->DefaultPacking, mapsize, 1, 1,

                                  format, type, ptr);

   /* restore */

   _mesa_reference_buffer_object(ctx,

                                 &ctx->DefaultPacking.BufferObj,

                                 ctx->Shared->NullBufferObj);

   if (!ok) {

      _mesa_error(ctx, GL_INVALID_OPERATION,

                  "glPixelMap(invalid PBO access)");

   }

   return ok;

}

static void GLAPIENTRY

_mesa_PixelMapfv( GLenum map, GLsizei mapsize, const GLfloat *values )

{

   GET_CURRENT_CONTEXT(ctx);

   ASSERT_OUTSIDE_BEGIN_END(ctx);

   /* XXX someday, test against ctx->Const.MaxPixelMapTableSize */

   if (mapsize < 1 || mapsize > MAX_PIXEL_MAP_TABLE) {

      _mesa_error( ctx, GL_INVALID_VALUE, "glPixelMapfv(mapsize)" );

      return;

   }

   if (map >= GL_PIXEL_MAP_S_TO_S && map <= GL_PIXEL_MAP_I_TO_A) {

      /* test that mapsize is a power of two */

      if (!_mesa_is_pow_two(mapsize)) {

	 _mesa_error( ctx, GL_INVALID_VALUE, "glPixelMapfv(mapsize)" );

         return;

      }

   }

   FLUSH_VERTICES(ctx, _NEW_PIXEL);

   if (!validate_pbo_access(ctx, &ctx->Unpack, mapsize,

                            GL_INTENSITY, GL_FLOAT, values)) {

      return;

   }

   values = (const GLfloat *) _mesa_map_pbo_source(ctx, &ctx->Unpack, values);

   if (!values) {

      if (_mesa_is_bufferobj(ctx->Unpack.BufferObj)) {

         _mesa_error(ctx, GL_INVALID_OPERATION,

                     "glPixelMapfv(PBO is mapped)");

      }

      return;

   }

   store_pixelmap(ctx, map, mapsize, values);

   _mesa_unmap_pbo_source(ctx, &ctx->Unpack);

}

static void GLAPIENTRY

_mesa_PixelMapuiv(GLenum map, GLsizei mapsize, const GLuint *values )

{

   GLfloat fvalues[MAX_PIXEL_MAP_TABLE];

   GET_CURRENT_CONTEXT(ctx);

   ASSERT_OUTSIDE_BEGIN_END(ctx);

   if (mapsize < 1 || mapsize > MAX_PIXEL_MAP_TABLE) {

      _mesa_error( ctx, GL_INVALID_VALUE, "glPixelMapuiv(mapsize)" );

      return;

   }

   if (map >= GL_PIXEL_MAP_S_TO_S && map <= GL_PIXEL_MAP_I_TO_A) {

      /* test that mapsize is a power of two */

      if (!_mesa_is_pow_two(mapsize)) {

	 _mesa_error( ctx, GL_INVALID_VALUE, "glPixelMapuiv(mapsize)" );

         return;

      }

   }

   FLUSH_VERTICES(ctx, _NEW_PIXEL);

   if (!validate_pbo_access(ctx, &ctx->Unpack, mapsize,

                            GL_INTENSITY, GL_UNSIGNED_INT, values)) {

      return;

   }

   values = (const GLuint *) _mesa_map_pbo_source(ctx, &ctx->Unpack, values);

   if (!values) {

      if (_mesa_is_bufferobj(ctx->Unpack.BufferObj)) {

         _mesa_error(ctx, GL_INVALID_OPERATION,

                     "glPixelMapuiv(PBO is mapped)");

      }

      return;

   }

   /* convert to floats */

   if (map == GL_PIXEL_MAP_I_TO_I || map == GL_PIXEL_MAP_S_TO_S) {

      GLint i;

      for (i = 0; i < mapsize; i++) {

         fvalues[i] = (GLfloat) values[i];

      }

   }

   else {

      GLint i;

      for (i = 0; i < mapsize; i++) {

         fvalues[i] = UINT_TO_FLOAT( values[i] );

      }

   }

   _mesa_unmap_pbo_source(ctx, &ctx->Unpack);

   store_pixelmap(ctx, map, mapsize, fvalues);

}

static void GLAPIENTRY

_mesa_PixelMapusv(GLenum map, GLsizei mapsize, const GLushort *values )

{

   GLfloat fvalues[MAX_PIXEL_MAP_TABLE];

   GET_CURRENT_CONTEXT(ctx);

   ASSERT_OUTSIDE_BEGIN_END(ctx);

   if (mapsize < 1 || mapsize > MAX_PIXEL_MAP_TABLE) {

      _mesa_error( ctx, GL_INVALID_VALUE, "glPixelMapusv(mapsize)" );

      return;

   }

   if (map >= GL_PIXEL_MAP_S_TO_S && map <= GL_PIXEL_MAP_I_TO_A) {

      /* test that mapsize is a power of two */

      if (!_mesa_is_pow_two(mapsize)) {

	 _mesa_error( ctx, GL_INVALID_VALUE, "glPixelMapuiv(mapsize)" );

         return;

      }

   }

   FLUSH_VERTICES(ctx, _NEW_PIXEL);

   if (!validate_pbo_access(ctx, &ctx->Unpack, mapsize,

                            GL_INTENSITY, GL_UNSIGNED_SHORT, values)) {

      return;

   }

   values = (const GLushort *) _mesa_map_pbo_source(ctx, &ctx->Unpack, values);

   if (!values) {

      if (_mesa_is_bufferobj(ctx->Unpack.BufferObj)) {

         _mesa_error(ctx, GL_INVALID_OPERATION,

                     "glPixelMapusv(PBO is mapped)");

      }

      return;

   }

   /* convert to floats */

   if (map == GL_PIXEL_MAP_I_TO_I || map == GL_PIXEL_MAP_S_TO_S) {

      GLint i;

      for (i = 0; i < mapsize; i++) {

         fvalues[i] = (GLfloat) values[i];

      }

   }

   else {

      GLint i;

      for (i = 0; i < mapsize; i++) {

         fvalues[i] = USHORT_TO_FLOAT( values[i] );

      }

   }

   _mesa_unmap_pbo_source(ctx, &ctx->Unpack);

   store_pixelmap(ctx, map, mapsize, fvalues);

}

static void GLAPIENTRY

_mesa_GetPixelMapfv( GLenum map, GLfloat *values )

{

   GET_CURRENT_CONTEXT(ctx);

   GLuint mapsize, i;

   const struct gl_pixelmap *pm;

   ASSERT_OUTSIDE_BEGIN_END(ctx);

   pm = get_pixelmap(ctx, map);

   if (!pm) {

      _mesa_error(ctx, GL_INVALID_ENUM, "glGetPixelMapfv(map)");

      return;

   }

   mapsize = pm->Size;

   if (!validate_pbo_access(ctx, &ctx->Pack, mapsize,

                            GL_INTENSITY, GL_FLOAT, values)) {

      return;

   }

   values = (GLfloat *) _mesa_map_pbo_dest(ctx, &ctx->Pack, values);

   if (!values) {

      if (_mesa_is_bufferobj(ctx->Pack.BufferObj)) {

         _mesa_error(ctx, GL_INVALID_OPERATION,

                     "glGetPixelMapfv(PBO is mapped)");

      }

      return;

   }

   if (map == GL_PIXEL_MAP_S_TO_S) {

      /* special case */

      for (i = 0; i < mapsize; i++) {

         values[i] = (GLfloat) ctx->PixelMaps.StoS.Map[i];

      }

   }

   else {

      memcpy(values, pm->Map, mapsize * sizeof(GLfloat));

   }

   _mesa_unmap_pbo_dest(ctx, &ctx->Pack);

}

static void GLAPIENTRY

_mesa_GetPixelMapuiv( GLenum map, GLuint *values )

{

   GET_CURRENT_CONTEXT(ctx);

   GLint mapsize, i;

   const struct gl_pixelmap *pm;

   ASSERT_OUTSIDE_BEGIN_END(ctx);

   pm = get_pixelmap(ctx, map);

   if (!pm) {

      _mesa_error(ctx, GL_INVALID_ENUM, "glGetPixelMapuiv(map)");

      return;

   }

   mapsize = pm->Size;

   if (!validate_pbo_access(ctx, &ctx->Pack, mapsize,

                            GL_INTENSITY, GL_UNSIGNED_INT, values)) {

      return;

   }

   values = (GLuint *) _mesa_map_pbo_dest(ctx, &ctx->Pack, values);

   if (!values) {

      if (_mesa_is_bufferobj(ctx->Pack.BufferObj)) {

         _mesa_error(ctx, GL_INVALID_OPERATION,

                     "glGetPixelMapuiv(PBO is mapped)");

      }

      return;

   }

   if (map == GL_PIXEL_MAP_S_TO_S) {

      /* special case */

      memcpy(values, ctx->PixelMaps.StoS.Map, mapsize * sizeof(GLint));

   }

   else {

      for (i = 0; i < mapsize; i++) {

         values[i] = FLOAT_TO_UINT( pm->Map[i] );

      }

   }

   _mesa_unmap_pbo_dest(ctx, &ctx->Pack);

}

static void GLAPIENTRY

_mesa_GetPixelMapusv( GLenum map, GLushort *values )

{

   GET_CURRENT_CONTEXT(ctx);

   GLint mapsize, i;

   const struct gl_pixelmap *pm;

   ASSERT_OUTSIDE_BEGIN_END(ctx);

   pm = get_pixelmap(ctx, map);

   if (!pm) {

      _mesa_error(ctx, GL_INVALID_ENUM, "glGetPixelMapusv(map)");

      return;

   }

   mapsize = pm->Size;

   if (!validate_pbo_access(ctx, &ctx->Pack, mapsize,

                            GL_INTENSITY, GL_UNSIGNED_SHORT, values)) {

      return;

   }

   values = (GLushort *) _mesa_map_pbo_dest(ctx, &ctx->Pack, values);

   if (!values) {

      if (_mesa_is_bufferobj(ctx->Pack.BufferObj)) {

         _mesa_error(ctx, GL_INVALID_OPERATION,

                     "glGetPixelMapusv(PBO is mapped)");

      }

      return;

   }

   switch (map) {

   /* special cases */

   case GL_PIXEL_MAP_I_TO_I:

      for (i = 0; i < mapsize; i++) {

         values[i] = (GLushort) CLAMP(ctx->PixelMaps.ItoI.Map[i], 0.0, 65535.);

      }

      break;

   case GL_PIXEL_MAP_S_TO_S:

      for (i = 0; i < mapsize; i++) {

         values[i] = (GLushort) CLAMP(ctx->PixelMaps.StoS.Map[i], 0.0, 65535.);

      }

      break;

   default:

      for (i = 0; i < mapsize; i++) {

         CLAMPED_FLOAT_TO_USHORT(values[i], pm->Map[i] );

      }

   }

   _mesa_unmap_pbo_dest(ctx, &ctx->Pack);

}

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

/*****                       glPixelTransfer                      *****/

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

/*

 * Implements glPixelTransfer[fi] whether called immediately or from a

 * display list.

 */

static void GLAPIENTRY

_mesa_PixelTransferf( GLenum pname, GLfloat param )

{

   GET_CURRENT_CONTEXT(ctx);

   ASSERT_OUTSIDE_BEGIN_END(ctx);

   switch (pname) {

      case GL_MAP_COLOR:

         if (ctx->Pixel.MapColorFlag == (param ? GL_TRUE : GL_FALSE))

	    return;

	 FLUSH_VERTICES(ctx, _NEW_PIXEL);

         ctx->Pixel.MapColorFlag = param ? GL_TRUE : GL_FALSE;

	 break;

      case GL_MAP_STENCIL:

         if (ctx->Pixel.MapStencilFlag == (param ? GL_TRUE : GL_FALSE))

	    return;

	 FLUSH_VERTICES(ctx, _NEW_PIXEL);

         ctx->Pixel.MapStencilFlag = param ? GL_TRUE : GL_FALSE;

	 break;

      case GL_INDEX_SHIFT:

         if (ctx->Pixel.IndexShift == (GLint) param)

	    return;

	 FLUSH_VERTICES(ctx, _NEW_PIXEL);

         ctx->Pixel.IndexShift = (GLint) param;

	 break;

      case GL_INDEX_OFFSET:

         if (ctx->Pixel.IndexOffset == (GLint) param)

	    return;

	 FLUSH_VERTICES(ctx, _NEW_PIXEL);

         ctx->Pixel.IndexOffset = (GLint) param;

	 break;

      case GL_RED_SCALE:

         if (ctx->Pixel.RedScale == param)

	    return;

	 FLUSH_VERTICES(ctx, _NEW_PIXEL);

         ctx->Pixel.RedScale = param;

	 break;

      case GL_RED_BIAS:

         if (ctx->Pixel.RedBias == param)

	    return;

	 FLUSH_VERTICES(ctx, _NEW_PIXEL);

         ctx->Pixel.RedBias = param;

	 break;

      case GL_GREEN_SCALE:

         if (ctx->Pixel.GreenScale == param)

	    return;

	 FLUSH_VERTICES(ctx, _NEW_PIXEL);

         ctx->Pixel.GreenScale = param;

	 break;

      case GL_GREEN_BIAS:

         if (ctx->Pixel.GreenBias == param)

	    return;

	 FLUSH_VERTICES(ctx, _NEW_PIXEL);

         ctx->Pixel.GreenBias = param;

	 break;

      case GL_BLUE_SCALE:

         if (ctx->Pixel.BlueScale == param)

	    return;

	 FLUSH_VERTICES(ctx, _NEW_PIXEL);

         ctx->Pixel.BlueScale = param;

	 break;

      case GL_BLUE_BIAS:

         if (ctx->Pixel.BlueBias == param)

	    return;

	 FLUSH_VERTICES(ctx, _NEW_PIXEL);

         ctx->Pixel.BlueBias = param;

	 break;

      case GL_ALPHA_SCALE:

         if (ctx->Pixel.AlphaScale == param)

	    return;

	 FLUSH_VERTICES(ctx, _NEW_PIXEL);

         ctx->Pixel.AlphaScale = param;

	 break;

      case GL_ALPHA_BIAS:

         if (ctx->Pixel.AlphaBias == param)

	    return;

	 FLUSH_VERTICES(ctx, _NEW_PIXEL);

         ctx->Pixel.AlphaBias = param;

	 break;

      case GL_DEPTH_SCALE:

         if (ctx->Pixel.DepthScale == param)

	    return;

	 FLUSH_VERTICES(ctx, _NEW_PIXEL);

         ctx->Pixel.DepthScale = param;

	 break;

      case GL_DEPTH_BIAS:

         if (ctx->Pixel.DepthBias == param)

	    return;

	 FLUSH_VERTICES(ctx, _NEW_PIXEL);

         ctx->Pixel.DepthBias = param;

	 break;

      default:

         _mesa_error( ctx, GL_INVALID_ENUM, "glPixelTransfer(pname)" );

         return;

   }

}

static void GLAPIENTRY

_mesa_PixelTransferi( GLenum pname, GLint param )

{

   _mesa_PixelTransferf( pname, (GLfloat) param );

}

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

/*****                    State Management                        *****/

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

/*

 * Return a bitmask of IMAGE_*_BIT flags which to indicate which

 * pixel transfer operations are enabled.

 */

static void

update_image_transfer_state(struct gl_context *ctx)

{

   GLuint mask = 0;

   if (ctx->Pixel.RedScale   != 1.0F || ctx->Pixel.RedBias   != 0.0F ||

       ctx->Pixel.GreenScale != 1.0F || ctx->Pixel.GreenBias != 0.0F ||

       ctx->Pixel.BlueScale  != 1.0F || ctx->Pixel.BlueBias  != 0.0F ||

       ctx->Pixel.AlphaScale != 1.0F || ctx->Pixel.AlphaBias != 0.0F)

      mask |= IMAGE_SCALE_BIAS_BIT;

   if (ctx->Pixel.IndexShift || ctx->Pixel.IndexOffset)

      mask |= IMAGE_SHIFT_OFFSET_BIT;

   if (ctx->Pixel.MapColorFlag)

      mask |= IMAGE_MAP_COLOR_BIT;

   ctx->_ImageTransferState = mask;

}

/**

 * Update mesa pixel transfer derived state.

 */

void _mesa_update_pixel( struct gl_context *ctx, GLuint new_state )

{

   if (new_state & _MESA_NEW_TRANSFER_STATE)

      update_image_transfer_state(ctx);

}

void

_mesa_init_pixel_dispatch(struct _glapi_table *disp)

{

   SET_GetPixelMapfv(disp, _mesa_GetPixelMapfv);

   SET_GetPixelMapuiv(disp, _mesa_GetPixelMapuiv);

   SET_GetPixelMapusv(disp, _mesa_GetPixelMapusv);

   SET_PixelMapfv(disp, _mesa_PixelMapfv);

   SET_PixelMapuiv(disp, _mesa_PixelMapuiv);

   SET_PixelMapusv(disp, _mesa_PixelMapusv);

   SET_PixelTransferf(disp, _mesa_PixelTransferf);

   SET_PixelTransferi(disp, _mesa_PixelTransferi);

   SET_PixelZoom(disp, _mesa_PixelZoom);

}

#endif /* FEATURE_pixel_transfer */

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

/*****                      Initialization                        *****/

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

static void

init_pixelmap(struct gl_pixelmap *map)

{

   map->Size = 1;

   map->Map[0] = 0.0;

   map->Map8[0] = 0;

}

/**

 * Initialize the context's PIXEL attribute group.

 */

void

_mesa_init_pixel( struct gl_context *ctx )

{

   /* Pixel group */

   ctx->Pixel.RedBias = 0.0;

   ctx->Pixel.RedScale = 1.0;

   ctx->Pixel.GreenBias = 0.0;

   ctx->Pixel.GreenScale = 1.0;

   ctx->Pixel.BlueBias = 0.0;

   ctx->Pixel.BlueScale = 1.0;

   ctx->Pixel.AlphaBias = 0.0;

   ctx->Pixel.AlphaScale = 1.0;

   ctx->Pixel.DepthBias = 0.0;

   ctx->Pixel.DepthScale = 1.0;

   ctx->Pixel.IndexOffset = 0;

   ctx->Pixel.IndexShift = 0;

   ctx->Pixel.ZoomX = 1.0;

   ctx->Pixel.ZoomY = 1.0;

   ctx->Pixel.MapColorFlag = GL_FALSE;

   ctx->Pixel.MapStencilFlag = GL_FALSE;

   init_pixelmap(&ctx->PixelMaps.StoS);

   init_pixelmap(&ctx->PixelMaps.ItoI);

   init_pixelmap(&ctx->PixelMaps.ItoR);

   init_pixelmap(&ctx->PixelMaps.ItoG);

   init_pixelmap(&ctx->PixelMaps.ItoB);

   init_pixelmap(&ctx->PixelMaps.ItoA);

   init_pixelmap(&ctx->PixelMaps.RtoR);

   init_pixelmap(&ctx->PixelMaps.GtoG);

   init_pixelmap(&ctx->PixelMaps.BtoB);

   init_pixelmap(&ctx->PixelMaps.AtoA);

   /* GL_SGI_texture_color_table */

   ASSIGN_4V(ctx->Pixel.TextureColorTableScale, 1.0, 1.0, 1.0, 1.0);

   ASSIGN_4V(ctx->Pixel.TextureColorTableBias, 0.0, 0.0, 0.0, 0.0);

   if (ctx->Visual.doubleBufferMode) {

      ctx->Pixel.ReadBuffer = GL_BACK;

   }

   else {

      ctx->Pixel.ReadBuffer = GL_FRONT;

   }

   /* Miscellaneous */

   ctx->_ImageTransferState = 0;

}