texstate.c

Mesa is an open-source implementation of the OpenGL specification - a system for rendering interacti

/*
 * Mesa 3-D graphics library
 * Version:  7.1
 *
 * Copyright (C) 1999-2007  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 texstate.c
 *
 * Texture state handling.
 */

#include "glheader.h"
#include "colormac.h"
#include "colortab.h"
#include "context.h"
#include "enums.h"
#include "macros.h"
#include "texcompress.h"
#include "texobj.h"
#include "teximage.h"
#include "texstate.h"
#include "texenvprogram.h"
#include "mtypes.h"
#include "math/m_xform.h"


#define ENUM_TO_FLOAT(X) ((GLfloat)(GLint)(X))
#define ENUM_TO_DOUBLE(X) ((GLdouble)(GLint)(X))


/**
 * Default texture combine environment state.  This is used to initialize
 * a context's texture units and as the basis for converting "classic"
 * texture environmnets to ARB_texture_env_combine style values.
 */
static const struct gl_tex_env_combine_state default_combine_state = {
   GL_MODULATE, GL_MODULATE,
   { GL_TEXTURE, GL_PREVIOUS, GL_CONSTANT },
   { GL_TEXTURE, GL_PREVIOUS, GL_CONSTANT },
   { GL_SRC_COLOR, GL_SRC_COLOR, GL_SRC_ALPHA },
   { GL_SRC_ALPHA, GL_SRC_ALPHA, GL_SRC_ALPHA },
   0, 0,
   2, 2
};



/**
 * Used by glXCopyContext to copy texture state from one context to another.
 */
void
_mesa_copy_texture_state( const GLcontext *src, GLcontext *dst )
{
   GLuint i;

   ASSERT(src);
   ASSERT(dst);

   dst->Texture.CurrentUnit = src->Texture.CurrentUnit;
   dst->Texture._GenFlags = src->Texture._GenFlags;
   dst->Texture._TexGenEnabled = src->Texture._TexGenEnabled;
   dst->Texture._TexMatEnabled = src->Texture._TexMatEnabled;
   dst->Texture.SharedPalette = src->Texture.SharedPalette;

   /* per-unit state */
   for (i = 0; i < src->Const.MaxTextureUnits; i++) {
      dst->Texture.Unit[i].Enabled = src->Texture.Unit[i].Enabled;
      dst->Texture.Unit[i].EnvMode = src->Texture.Unit[i].EnvMode;
      COPY_4V(dst->Texture.Unit[i].EnvColor, src->Texture.Unit[i].EnvColor);
      dst->Texture.Unit[i].TexGenEnabled = src->Texture.Unit[i].TexGenEnabled;
      dst->Texture.Unit[i].GenModeS = src->Texture.Unit[i].GenModeS;
      dst->Texture.Unit[i].GenModeT = src->Texture.Unit[i].GenModeT;
      dst->Texture.Unit[i].GenModeR = src->Texture.Unit[i].GenModeR;
      dst->Texture.Unit[i].GenModeQ = src->Texture.Unit[i].GenModeQ;
      dst->Texture.Unit[i]._GenBitS = src->Texture.Unit[i]._GenBitS;
      dst->Texture.Unit[i]._GenBitT = src->Texture.Unit[i]._GenBitT;
      dst->Texture.Unit[i]._GenBitR = src->Texture.Unit[i]._GenBitR;
      dst->Texture.Unit[i]._GenBitQ = src->Texture.Unit[i]._GenBitQ;
      dst->Texture.Unit[i]._GenFlags = src->Texture.Unit[i]._GenFlags;
      COPY_4V(dst->Texture.Unit[i].ObjectPlaneS, src->Texture.Unit[i].ObjectPlaneS);
      COPY_4V(dst->Texture.Unit[i].ObjectPlaneT, src->Texture.Unit[i].ObjectPlaneT);
      COPY_4V(dst->Texture.Unit[i].ObjectPlaneR, src->Texture.Unit[i].ObjectPlaneR);
      COPY_4V(dst->Texture.Unit[i].ObjectPlaneQ, src->Texture.Unit[i].ObjectPlaneQ);
      COPY_4V(dst->Texture.Unit[i].EyePlaneS, src->Texture.Unit[i].EyePlaneS);
      COPY_4V(dst->Texture.Unit[i].EyePlaneT, src->Texture.Unit[i].EyePlaneT);
      COPY_4V(dst->Texture.Unit[i].EyePlaneR, src->Texture.Unit[i].EyePlaneR);
      COPY_4V(dst->Texture.Unit[i].EyePlaneQ, src->Texture.Unit[i].EyePlaneQ);
      dst->Texture.Unit[i].LodBias = src->Texture.Unit[i].LodBias;

      /* GL_EXT_texture_env_combine */
      dst->Texture.Unit[i].Combine.ModeRGB = src->Texture.Unit[i].Combine.ModeRGB;
      dst->Texture.Unit[i].Combine.ModeA = src->Texture.Unit[i].Combine.ModeA;
      COPY_3V(dst->Texture.Unit[i].Combine.SourceRGB, src->Texture.Unit[i].Combine.SourceRGB);
      COPY_3V(dst->Texture.Unit[i].Combine.SourceA, src->Texture.Unit[i].Combine.SourceA);
      COPY_3V(dst->Texture.Unit[i].Combine.OperandRGB, src->Texture.Unit[i].Combine.OperandRGB);
      COPY_3V(dst->Texture.Unit[i].Combine.OperandA, src->Texture.Unit[i].Combine.OperandA);
      dst->Texture.Unit[i].Combine.ScaleShiftRGB = src->Texture.Unit[i].Combine.ScaleShiftRGB;
      dst->Texture.Unit[i].Combine.ScaleShiftA = src->Texture.Unit[i].Combine.ScaleShiftA;

      /* copy texture object bindings, not contents of texture objects */
      _mesa_lock_context_textures(dst);

      _mesa_reference_texobj(&dst->Texture.Unit[i].Current1D,
                             src->Texture.Unit[i].Current1D);
      _mesa_reference_texobj(&dst->Texture.Unit[i].Current2D,
                             src->Texture.Unit[i].Current2D);
      _mesa_reference_texobj(&dst->Texture.Unit[i].Current3D,
                             src->Texture.Unit[i].Current3D);
      _mesa_reference_texobj(&dst->Texture.Unit[i].CurrentCubeMap,
                             src->Texture.Unit[i].CurrentCubeMap);
      _mesa_reference_texobj(&dst->Texture.Unit[i].CurrentRect,
                             src->Texture.Unit[i].CurrentRect);
      _mesa_reference_texobj(&dst->Texture.Unit[i].Current1DArray,
                             src->Texture.Unit[i].Current1DArray);
      _mesa_reference_texobj(&dst->Texture.Unit[i].Current2DArray,
                             src->Texture.Unit[i].Current2DArray);

      _mesa_unlock_context_textures(dst);
   }
}


/*
 * For debugging
 */
void
_mesa_print_texunit_state( GLcontext *ctx, GLuint unit )
{
   const struct gl_texture_unit *texUnit = ctx->Texture.Unit + unit;
   _mesa_printf("Texture Unit %d\n", unit);
   _mesa_printf("  GL_TEXTURE_ENV_MODE = %s\n", _mesa_lookup_enum_by_nr(texUnit->EnvMode));
   _mesa_printf("  GL_COMBINE_RGB = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.ModeRGB));
   _mesa_printf("  GL_COMBINE_ALPHA = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.ModeA));
   _mesa_printf("  GL_SOURCE0_RGB = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.SourceRGB[0]));
   _mesa_printf("  GL_SOURCE1_RGB = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.SourceRGB[1]));
   _mesa_printf("  GL_SOURCE2_RGB = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.SourceRGB[2]));
   _mesa_printf("  GL_SOURCE0_ALPHA = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.SourceA[0]));
   _mesa_printf("  GL_SOURCE1_ALPHA = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.SourceA[1]));
   _mesa_printf("  GL_SOURCE2_ALPHA = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.SourceA[2]));
   _mesa_printf("  GL_OPERAND0_RGB = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.OperandRGB[0]));
   _mesa_printf("  GL_OPERAND1_RGB = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.OperandRGB[1]));
   _mesa_printf("  GL_OPERAND2_RGB = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.OperandRGB[2]));
   _mesa_printf("  GL_OPERAND0_ALPHA = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.OperandA[0]));
   _mesa_printf("  GL_OPERAND1_ALPHA = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.OperandA[1]));
   _mesa_printf("  GL_OPERAND2_ALPHA = %s\n", _mesa_lookup_enum_by_nr(texUnit->Combine.OperandA[2]));
   _mesa_printf("  GL_RGB_SCALE = %d\n", 1 << texUnit->Combine.ScaleShiftRGB);
   _mesa_printf("  GL_ALPHA_SCALE = %d\n", 1 << texUnit->Combine.ScaleShiftA);
   _mesa_printf("  GL_TEXTURE_ENV_COLOR = (%f, %f, %f, %f)\n", texUnit->EnvColor[0], texUnit->EnvColor[1], texUnit->EnvColor[2], texUnit->EnvColor[3]);
}



/**********************************************************************/
/*                       Texture Environment                          */
/**********************************************************************/

/**
 * Convert "classic" texture environment to ARB_texture_env_combine style
 * environments.
 * 
 * \param state  texture_env_combine state vector to be filled-in.
 * \param mode   Classic texture environment mode (i.e., \c GL_REPLACE,
 *               \c GL_BLEND, \c GL_DECAL, etc.).
 * \param texBaseFormat  Base format of the texture associated with the
 *               texture unit.
 */
static void
calculate_derived_texenv( struct gl_tex_env_combine_state *state,
			  GLenum mode, GLenum texBaseFormat )
{
   GLenum mode_rgb;
   GLenum mode_a;

   *state = default_combine_state;

   switch (texBaseFormat) {
   case GL_ALPHA:
      state->SourceRGB[0] = GL_PREVIOUS;
      break;

   case GL_LUMINANCE_ALPHA:
   case GL_INTENSITY:
   case GL_RGBA:
      break;

   case GL_LUMINANCE:
   case GL_RGB:
   case GL_YCBCR_MESA:
      state->SourceA[0] = GL_PREVIOUS;
      break;
      
   default:
      _mesa_problem(NULL, "Invalid texBaseFormat in calculate_derived_texenv");
      return;
   }

   if (mode == GL_REPLACE_EXT)
      mode = GL_REPLACE;

   switch (mode) {
   case GL_REPLACE:
   case GL_MODULATE:
      mode_rgb = (texBaseFormat == GL_ALPHA) ? GL_REPLACE : mode;
      mode_a   = mode;
      break;
   
   case GL_DECAL:
      mode_rgb = GL_INTERPOLATE;
      mode_a   = GL_REPLACE;

      state->SourceA[0] = GL_PREVIOUS;

      /* Having alpha / luminance / intensity textures replace using the
       * incoming fragment color matches the definition in NV_texture_shader.
       * The 1.5 spec simply marks these as "undefined".
       */
      switch (texBaseFormat) {
      case GL_ALPHA:
      case GL_LUMINANCE:
      case GL_LUMINANCE_ALPHA:
      case GL_INTENSITY:
	 state->SourceRGB[0] = GL_PREVIOUS;
	 break;
      case GL_RGB:
      case GL_YCBCR_MESA:
	 mode_rgb = GL_REPLACE;
	 break;
      case GL_RGBA:
	 state->SourceRGB[2] = GL_TEXTURE;
	 break;
      }
      break;

   case GL_BLEND:
      mode_rgb = GL_INTERPOLATE;
      mode_a   = GL_MODULATE;

      switch (texBaseFormat) {
      case GL_ALPHA:
	 mode_rgb = GL_REPLACE;
	 break;
      case GL_INTENSITY:
	 mode_a = GL_INTERPOLATE;
	 state->SourceA[0] = GL_CONSTANT;
	 state->OperandA[2] = GL_SRC_ALPHA;
	 /* FALLTHROUGH */
      case GL_LUMINANCE:
      case GL_RGB:
      case GL_LUMINANCE_ALPHA:
      case GL_RGBA:
      case GL_YCBCR_MESA:
	 state->SourceRGB[2] = GL_TEXTURE;
	 state->SourceA[2]   = GL_TEXTURE;
	 state->SourceRGB[0] = GL_CONSTANT;
	 state->OperandRGB[2] = GL_SRC_COLOR;
	 break;
      }
      break;

   case GL_ADD:
      mode_rgb = (texBaseFormat == GL_ALPHA) ? GL_REPLACE : GL_ADD;
      mode_a   = (texBaseFormat == GL_INTENSITY) ? GL_ADD : GL_MODULATE;
      break;

   default:
      _mesa_problem(NULL,
                    "Invalid texture env mode in calculate_derived_texenv");
      return;
   }
   
   state->ModeRGB = (state->SourceRGB[0] != GL_PREVIOUS)
       ? mode_rgb : GL_REPLACE;
   state->ModeA   = (state->SourceA[0]   != GL_PREVIOUS)
       ? mode_a   : GL_REPLACE;
}


void GLAPIENTRY
_mesa_TexEnvfv( GLenum target, GLenum pname, const GLfloat *param )
{
   GLuint maxUnit;
   GET_CURRENT_CONTEXT(ctx);
   struct gl_texture_unit *texUnit;
   ASSERT_OUTSIDE_BEGIN_END(ctx);

   maxUnit = (target == GL_POINT_SPRITE_NV && pname == GL_COORD_REPLACE_NV)
      ? ctx->Const.MaxTextureCoordUnits : ctx->Const.MaxTextureImageUnits;
   if (ctx->Texture.CurrentUnit >= maxUnit) {
      _mesa_error(ctx, GL_INVALID_OPERATION, "glTexEnvfv(current unit)");
      return;
   }

   texUnit = &ctx->Texture.Unit[ctx->Texture.CurrentUnit];

#define TE_ERROR(errCode, msg, value)				\
   _mesa_error(ctx, errCode, msg, _mesa_lookup_enum_by_nr(value));

   if (target == GL_TEXTURE_ENV) {
      switch (pname) {
      case GL_TEXTURE_ENV_MODE:
         {
            GLenum mode = (GLenum) (GLint) *param;
            if (mode == GL_REPLACE_EXT)
               mode = GL_REPLACE;
	    if (texUnit->EnvMode == mode)
	       return;
            if (mode == GL_MODULATE ||
                mode == GL_BLEND ||
                mode == GL_DECAL ||
                mode == GL_REPLACE ||
                (mode == GL_ADD && ctx->Extensions.EXT_texture_env_add) ||
                (mode == GL_COMBINE &&
                 (ctx->Extensions.EXT_texture_env_combine ||
                  ctx->Extensions.ARB_texture_env_combine))) {
               /* legal */
               FLUSH_VERTICES(ctx, _NEW_TEXTURE);
               texUnit->EnvMode = mode;
            }
            else {
               TE_ERROR(GL_INVALID_ENUM, "glTexEnv(param=%s)", mode);
               return;
            }
         }
         break;
      case GL_TEXTURE_ENV_COLOR:
         {
            GLfloat tmp[4];
            tmp[0] = CLAMP( param[0], 0.0F, 1.0F );
            tmp[1] = CLAMP( param[1], 0.0F, 1.0F );
            tmp[2] = CLAMP( param[2], 0.0F, 1.0F );
            tmp[3] = CLAMP( param[3], 0.0F, 1.0F );
            if (TEST_EQ_4V(tmp, texUnit->EnvColor))
               return;
            FLUSH_VERTICES(ctx, _NEW_TEXTURE);
            COPY_4FV(texUnit->EnvColor, tmp);
         }
         break;
      case GL_COMBINE_RGB:
	 if (ctx->Extensions.EXT_texture_env_combine ||
             ctx->Extensions.ARB_texture_env_combine) {
	    const GLenum mode = (GLenum) (GLint) *param;
	    if (texUnit->Combine.ModeRGB == mode)
	       return;
	    switch (mode) {
	    case GL_REPLACE:
	    case GL_MODULATE:
	    case GL_ADD:
	    case GL_ADD_SIGNED:
	    case GL_INTERPOLATE:
               /* OK */
	       break;
            case GL_SUBTRACT:
               if (!ctx->Extensions.ARB_texture_env_combine) {
                  TE_ERROR(GL_INVALID_ENUM, "glTexEnv(param=%s)", mode);
                  return;
               }
               break;
	    case GL_DOT3_RGB_EXT:
	    case GL_DOT3_RGBA_EXT:
	       if (!ctx->Extensions.EXT_texture_env_dot3) {
                  TE_ERROR(GL_INVALID_ENUM, "glTexEnv(param=%s)", mode);
		  return;
	       }
	       break;
	    case GL_DOT3_RGB:
	    case GL_DOT3_RGBA: