mga_texstate.c

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

{
   /* Unit 0:
    */
   {
      /* GL_REPLACE
       * Cv = Cf
       * Av = As
       */
      (TD0_color_arg2_diffuse |
       TD0_color_sel_arg2 |
       TD0_alpha_sel_arg1),
      
      /* GL_MODULATE
       * Cv = Cf
       * Av = Af As
       */
      (TD0_color_arg2_diffuse |
       TD0_color_sel_arg2 |
       TD0_alpha_arg2_diffuse |
       TD0_alpha_sel_mul),

      /* GL_DECAL (undefined)
       * Cv = Cf
       * Av = Af
       */
      (TD0_color_arg2_diffuse |
       TD0_color_sel_arg2 |
       TD0_alpha_arg2_diffuse |
       TD0_alpha_sel_arg2),

      /* GL_ADD
       * Cv = Cf
       * Av = Af As
       */
      (TD0_color_arg2_diffuse |
       TD0_color_sel_arg2 |
       TD0_alpha_arg2_diffuse |
       TD0_alpha_sel_mul),
   },

   /* Unit 1:
    */
   {
      /* GL_REPLACE
       * Cv = Cp
       * Av = As
       */
      (TD0_color_arg2_prevstage |
       TD0_color_sel_arg2 |
       TD0_alpha_sel_arg1),
      
      /* GL_MODULATE
       * Cv = Cp
       * Av = Ap As
       */
      (TD0_color_arg2_prevstage |
       TD0_color_sel_arg2 |
       TD0_alpha_arg2_prevstage |
       TD0_alpha_sel_mul),

      /* GL_DECAL (undefined)
       * Cv = Cp
       * Av = Ap
       */
      (TD0_color_arg2_prevstage |
       TD0_color_sel_arg2 |
       TD0_alpha_arg2_prevstage |
       TD0_alpha_sel_arg2),

      /* GL_ADD
       * Cv = Cp
       * Av = Ap As
       */
      (TD0_color_arg2_prevstage |
       TD0_color_sel_arg2 |
       TD0_alpha_arg2_prevstage |
       TD0_alpha_sel_mul),
   },
};

static GLboolean mgaUpdateTextureEnvBlend( GLcontext *ctx, int unit )
{
   mgaContextPtr mmesa = MGA_CONTEXT(ctx);
   const int source = mmesa->tmu_source[unit];
   const struct gl_texture_unit *texUnit = &ctx->Texture.Unit[source];
   const struct gl_texture_object *tObj = texUnit->_Current;
   GLuint *reg = ((GLuint *)&mmesa->setup.tdualstage0 + unit);
   GLenum format = tObj->Image[0][tObj->BaseLevel]->_BaseFormat;

   *reg = 0;

   if (format == GL_ALPHA) {
      /* Cv = Cf */
      *reg |= (TD0_color_arg2_diffuse |
               TD0_color_sel_arg2);
      /* Av = Af As */
      *reg |= (TD0_alpha_arg2_diffuse |
               TD0_alpha_sel_mul);
      return GL_TRUE;
   }

   /* C1 = Cf ( 1 - Cs ) */
   *reg |= (TD0_color_arg1_inv_enable |
            TD0_color_arg2_diffuse |
            TD0_color_sel_mul);

   if (format == GL_RGB || format == GL_LUMINANCE) {
      /* A1 = Af */
      *reg |= (TD0_alpha_arg2_diffuse |
               TD0_alpha_sel_arg2);
   } else
   if (format == GL_RGBA || format == GL_LUMINANCE_ALPHA) {
      /* A1 = Af As */
      *reg |= (TD0_alpha_arg2_diffuse |
               TD0_alpha_sel_mul);
   } else
   if (format == GL_INTENSITY) {
      /* A1 = Af ( 1 - As ) */
      *reg |= (TD0_alpha_arg1_inv_enable |
               TD0_alpha_arg2_diffuse |
               TD0_alpha_sel_mul);
   }
   
   if (RGB_ZERO(mmesa->envcolor[source]) &&
       (format != GL_INTENSITY || ALPHA_ZERO(mmesa->envcolor[source])))
      return GL_TRUE; /* all done */

   if (ctx->Texture._EnabledUnits == 0x03)
      return GL_FALSE; /* need both units */

   mmesa->force_dualtex = GL_TRUE;
   reg = &mmesa->setup.tdualstage1;
   *reg = 0;

   if (RGB_ZERO(mmesa->envcolor[source])) {
      /* Cv = C1 */
      *reg |= (TD0_color_arg2_prevstage |
               TD0_color_sel_arg2);
   } else
   if (RGB_ONE(mmesa->envcolor[source])) {
      /* Cv = C1 + Cs */
      *reg |= (TD0_color_arg2_prevstage |
               TD0_color_add_add |
               TD0_color_sel_add);
   } else
   if (RGBA_EQUAL(mmesa->envcolor[source])) {
      /* Cv = C1 + Cc Cs */
      *reg |= (TD0_color_arg2_prevstage |
               TD0_color_alpha_fcol |
               TD0_color_arg2mul_alpha2 |
               TD0_color_arg1add_mulout |
               TD0_color_add_add |
               TD0_color_sel_add);

      mmesa->setup.fcol = mmesa->envcolor[source];
   } else {
      return GL_FALSE;
   }

   if (format != GL_INTENSITY || ALPHA_ZERO(mmesa->envcolor[source])) {
      /* Av = A1 */
      *reg |= (TD0_alpha_arg2_prevstage |
               TD0_alpha_sel_arg2);
   } else
   if (ALPHA_ONE(mmesa->envcolor[source])) {
      /* Av = A1 + As */
      *reg |= (TD0_alpha_arg2_prevstage |
               TD0_alpha_add_enable |
               TD0_alpha_sel_add);
   } else {
      return GL_FALSE;
   }

   return GL_TRUE;
}

static void mgaUpdateTextureEnvG400( GLcontext *ctx, GLuint unit )
{
   mgaContextPtr mmesa = MGA_CONTEXT( ctx );
   const int source = mmesa->tmu_source[unit];
   const struct gl_texture_unit *texUnit = &ctx->Texture.Unit[source];
   const struct gl_texture_object *tObj = texUnit->_Current;
   GLuint *reg = ((GLuint *)&mmesa->setup.tdualstage0 + unit);
   mgaTextureObjectPtr t = (mgaTextureObjectPtr) tObj->DriverData;
   GLenum format = tObj->Image[0][tObj->BaseLevel]->_BaseFormat;

   if (tObj != ctx->Texture.Unit[source].Current2D &&
       tObj != ctx->Texture.Unit[source].CurrentRect)
      return;

   switch (ctx->Texture.Unit[source].EnvMode) {
   case GL_REPLACE:
      if (format == GL_ALPHA) {
         *reg = g400_alpha_combine[unit][MGA_REPLACE];
      } else if (format == GL_RGB || format == GL_LUMINANCE) {
         *reg = g400_color_combine[unit][MGA_REPLACE];
      } else {
         *reg = g400_color_alpha_combine[unit][MGA_REPLACE];
      }
      break;

   case GL_MODULATE:
      if (format == GL_ALPHA) {
         *reg = g400_alpha_combine[unit][MGA_MODULATE];
      } else if (format == GL_RGB || format == GL_LUMINANCE) {
         *reg = g400_color_combine[unit][MGA_MODULATE];
      } else {
         *reg = g400_color_alpha_combine[unit][MGA_MODULATE];
      }
      break;

   case GL_DECAL:
      if (format == GL_RGB) {
         *reg = g400_color_combine[unit][MGA_DECAL];
      } else if (format == GL_RGBA) {
         *reg = g400_color_alpha_combine[unit][MGA_DECAL];
         if (ctx->Texture._EnabledUnits != 0x03) {
            /* Linear blending mode needs dual texturing enabled */
            *(reg+1) = (TD0_color_arg2_prevstage |
                        TD0_color_sel_arg2 |
                        TD0_alpha_arg2_prevstage |
                        TD0_alpha_sel_arg2);
            mmesa->force_dualtex = GL_TRUE;
         }
      } else {
         /* Undefined */
         *reg = g400_alpha_combine[unit][MGA_DECAL];
      }
      break;

   case GL_ADD:
      if (format == GL_ALPHA) {
         *reg = g400_alpha_combine[unit][MGA_ADD];
      } else if (format == GL_RGB || format == GL_LUMINANCE) {
         *reg = g400_color_combine[unit][MGA_ADD];
      } else if (format == GL_RGBA || format == GL_LUMINANCE_ALPHA) {
         *reg = g400_color_alpha_combine[unit][MGA_ADD];
      } else if (format == GL_INTENSITY) {
         /* Cv = Cf + Cs
          * Av = Af + As
          */
         if (unit == 0) {
            *reg = (TD0_color_arg2_diffuse |
                    TD0_color_add_add |
                    TD0_color_sel_add |
                    TD0_alpha_arg2_diffuse |
                    TD0_alpha_add_enable |
                    TD0_alpha_sel_add);
         } else {
            *reg = (TD0_color_arg2_prevstage |
                    TD0_color_add_add |
                    TD0_color_sel_add |
                    TD0_alpha_arg2_prevstage |
                    TD0_alpha_add_enable |
                    TD0_alpha_sel_add);
         }
      }
      break;

   case GL_BLEND:
      if (!mgaUpdateTextureEnvBlend(ctx, unit))
         t->texenv_fallback = GL_TRUE;
      break;

   case GL_COMBINE:
      if (!mgaUpdateTextureEnvCombine(ctx, unit))
         t->texenv_fallback = GL_TRUE;
      break;
   default:
      break;
   }
}

static void disable_tex( GLcontext *ctx, int unit )
{
   mgaContextPtr mmesa = MGA_CONTEXT( ctx );

   /* Texture unit disabled */

   if ( mmesa->CurrentTexObj[unit] != NULL ) {
      /* The old texture is no longer bound to this texture unit.
       * Mark it as such.
       */

      mmesa->CurrentTexObj[unit]->base.bound &= ~(1UL << unit);
      mmesa->CurrentTexObj[unit] = NULL;
   }

   if ( unit != 0 && !mmesa->force_dualtex ) {
      mmesa->setup.tdualstage1 = mmesa->setup.tdualstage0;
   }

   if ( ctx->Texture._EnabledUnits == 0 ) {
      mmesa->setup.dwgctl &= DC_opcod_MASK;
      mmesa->setup.dwgctl |= DC_opcod_trap;
      mmesa->hw.alpha_sel = AC_alphasel_diffused;
   }

   mmesa->dirty |= MGA_UPLOAD_CONTEXT | (MGA_UPLOAD_TEX0 << unit);
}

static GLboolean enable_tex( GLcontext *ctx, int unit )
{
   mgaContextPtr mmesa = MGA_CONTEXT(ctx);
   const int source = mmesa->tmu_source[unit];
   const struct gl_texture_unit *texUnit = &ctx->Texture.Unit[source];
   const struct gl_texture_object *tObj = texUnit->_Current;
   mgaTextureObjectPtr t = (mgaTextureObjectPtr) tObj->DriverData;

   /* Upload teximages (not pipelined)
    */
   if (t->base.dirty_images[0]) {
      FLUSH_BATCH( mmesa );
      mgaSetTexImages( mmesa, tObj );
      if ( t->base.memBlock == NULL ) {
	 return GL_FALSE;
      }
   }

   return GL_TRUE;
}

static GLboolean update_tex_common( GLcontext *ctx, int unit )
{
   mgaContextPtr mmesa = MGA_CONTEXT(ctx);
   const int source = mmesa->tmu_source[unit];
   const struct gl_texture_unit *texUnit = &ctx->Texture.Unit[source];
   struct gl_texture_object	*tObj = texUnit->_Current;
   mgaTextureObjectPtr t = (mgaTextureObjectPtr) tObj->DriverData;

   /* Fallback if there's a texture border */
   if ( tObj->Image[0][tObj->BaseLevel]->Border > 0 ) {
      return GL_FALSE;
   }


   /* Update state if this is a different texture object to last
    * time.
    */
   if ( mmesa->CurrentTexObj[unit] != t ) {
      if ( mmesa->CurrentTexObj[unit] != NULL ) {
	 /* The old texture is no longer bound to this texture unit.
	  * Mark it as such.
	  */

	 mmesa->CurrentTexObj[unit]->base.bound &= ~(1UL << unit);
      }

      mmesa->CurrentTexObj[unit] = t;
      t->base.bound |= (1UL << unit);

      driUpdateTextureLRU( (driTextureObject *) t ); /* done too often */
   }

   /* register setup */
   if ( unit == 1 ) {
      mmesa->setup.tdualstage1 = mmesa->setup.tdualstage0;
   }

   t->texenv_fallback = GL_FALSE;

   /* Set this before mgaUpdateTextureEnvG400() since
    * GL_ARB_texture_env_crossbar may have to disable texturing.
    */
   mmesa->setup.dwgctl &= DC_opcod_MASK;
   mmesa->setup.dwgctl |= DC_opcod_texture_trap;

   /* FIXME: The Radeon has some cached state so that it can avoid calling
    * FIXME: UpdateTextureEnv in some cases.  Is that possible here?
    */
   if (MGA_IS_G400(mmesa)) {
      /* G400: Regardless of texture env mode, we use the alpha from the
       * texture unit (AC_alphasel_fromtex) since it will have already
       * been modulated by the incoming fragment color, if needed.
       * We don't want (AC_alphasel_modulate) since that'll effectively
       * do the modulation twice.
       */
      mmesa->hw.alpha_sel = AC_alphasel_fromtex;

      mgaUpdateTextureEnvG400( ctx, unit );
   } else {
      mgaUpdateTextureEnvG200( ctx, unit );
   }

   t->setup.texctl2 &= TMC_dualtex_MASK;
   if (ctx->Texture._EnabledUnits == 0x03 || mmesa->force_dualtex) {
      t->setup.texctl2 |= TMC_dualtex_enable;
   }

   mmesa->dirty |= MGA_UPLOAD_CONTEXT | (MGA_UPLOAD_TEX0 << unit);

   FALLBACK( ctx, MGA_FALLBACK_BORDER_MODE, t->border_fallback );
   return !t->border_fallback && !t->texenv_fallback;
}


static GLboolean updateTextureUnit( GLcontext *ctx, int unit )
{
   mgaContextPtr mmesa = MGA_CONTEXT( ctx );
   const int source = mmesa->tmu_source[unit];
   const struct gl_texture_unit *texUnit = &ctx->Texture.Unit[source];


   if ( texUnit->_ReallyEnabled == TEXTURE_2D_BIT ||
        texUnit->_ReallyEnabled == TEXTURE_RECT_BIT ) {
      return(enable_tex( ctx, unit ) &&
	     update_tex_common( ctx, unit ));
   }
   else if ( texUnit->_ReallyEnabled ) {
      return GL_FALSE;
   }
   else {
      disable_tex( ctx, unit );
      return GL_TRUE;
   }
}

/* The G400 is now programmed quite differently wrt texture environment.
 */
void mgaUpdateTextureState( GLcontext *ctx )
{
   mgaContextPtr mmesa = MGA_CONTEXT( ctx );
   GLboolean ok;
   unsigned  i;

   mmesa->force_dualtex = GL_FALSE;
   mmesa->fcol_used = GL_FALSE;

   /* This works around a quirk with the MGA hardware.  If only OpenGL 
    * TEXTURE1 is enabled, then the hardware TEXTURE0 must be used.  The
    * hardware TEXTURE1 can ONLY be used when hardware TEXTURE0 is also used.
    */

   mmesa->tmu_source[0] = 0;
   mmesa->tmu_source[1] = 1;

   if ((ctx->Texture._EnabledUnits & 0x03) == 0x02) {
      /* only texture 1 enabled */
      mmesa->tmu_source[0] = 1;
      mmesa->tmu_source[1] = 0;
   }

   for ( i = 0, ok = GL_TRUE 
	 ; (i < ctx->Const.MaxTextureUnits) && ok
	 ; i++ ) {
      ok = updateTextureUnit( ctx, i );
   }

   FALLBACK( ctx, MGA_FALLBACK_TEXTURE, !ok );
}