tdfx_texstate.c

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

            env->Color.SourceC = GR_CMBX_ZERO;
            env->Color.InvertC = FXTRUE;
            env->Color.SourceD = GR_CMBX_ZERO;
            env->Color.InvertD = FXFALSE;
        }
        else {
            /* Rv = Rf * (1 - Rt) + Rc * Rt */
            env->Color.SourceA = GR_CMBX_TMU_CCOLOR;
            env->Color.ModeA = GR_FUNC_MODE_X;
            env->Color.SourceB = incomingRGB;
            env->Color.ModeB = GR_FUNC_MODE_NEGATIVE_X;
            env->Color.SourceC = GR_CMBX_LOCAL_TEXTURE_RGB;
            env->Color.InvertC = FXFALSE;
            env->Color.SourceD = GR_CMBX_B;
            env->Color.InvertD = FXFALSE;
        }
        /* -- Setup Alpha combiner */
        if (baseFormat == GL_LUMINANCE || baseFormat == GL_RGB) {
            /* Av = Af */
            env->Alpha.SourceA = incomingAlpha;
            env->Alpha.ModeA = GR_FUNC_MODE_X;
            env->Alpha.SourceB = GR_CMBX_ZERO;
            env->Alpha.ModeB = GR_FUNC_MODE_ZERO;
            env->Alpha.SourceC = GR_CMBX_ZERO;
            env->Alpha.InvertC = FXTRUE;
            env->Alpha.SourceD = GR_CMBX_ZERO;
            env->Alpha.InvertD = FXFALSE;
        }
        else if (baseFormat == GL_INTENSITY) {
            /* Av = Af * (1 - It) + Ac * It */
            env->Alpha.SourceA = GR_CMBX_TMU_CALPHA;
            env->Alpha.ModeA = GR_FUNC_MODE_X;
            env->Alpha.SourceB = incomingAlpha;
            env->Alpha.ModeB = GR_FUNC_MODE_NEGATIVE_X;
            env->Alpha.SourceC = GR_CMBX_LOCAL_TEXTURE_ALPHA;
            env->Alpha.InvertC = FXFALSE;
            env->Alpha.SourceD = GR_CMBX_B;
            env->Alpha.InvertD = FXFALSE;
        }
        else {
            /* Av = Af * At */
            env->Alpha.SourceA = GR_CMBX_LOCAL_TEXTURE_ALPHA;
            env->Alpha.ModeA = GR_FUNC_MODE_X;
            env->Alpha.SourceB = GR_CMBX_ITALPHA;
            env->Alpha.ModeB = GR_FUNC_MODE_ZERO;
            env->Alpha.SourceC = incomingAlpha;
            env->Alpha.InvertC = FXFALSE;
            env->Alpha.SourceD = GR_CMBX_ZERO;
            env->Alpha.InvertD = FXFALSE;
        }
        /* Also have to set up the tex env constant color */
        env->EnvColor = PACK_RGBA32(texUnit->EnvColor[0] * 255.0F,
                                    texUnit->EnvColor[1] * 255.0F,
                                    texUnit->EnvColor[2] * 255.0F,
                                    texUnit->EnvColor[3] * 255.0F);
        break;
    case GL_ADD:
        /* -- Setup RGB combiner */
        if (baseFormat == GL_ALPHA) {
            /* Rv = Rf */
           env->Color.SourceB = GR_CMBX_ZERO;
           env->Color.ModeB = GR_FUNC_MODE_ZERO;
        }
        else {
            /* Rv = Rf + Tt */
           env->Color.SourceB = GR_CMBX_LOCAL_TEXTURE_RGB;
           env->Color.ModeB = GR_FUNC_MODE_X;
        }
        env->Color.SourceA = incomingRGB;
        env->Color.ModeA = GR_FUNC_MODE_X;
        env->Color.SourceC = GR_CMBX_ZERO;
        env->Color.InvertC = FXTRUE;
        env->Color.SourceD = GR_CMBX_ZERO;
        env->Color.InvertD = FXFALSE;
        /* -- Setup Alpha combiner */
        if (baseFormat == GL_LUMINANCE || baseFormat == GL_RGB) {
            /* Av = Af */
           env->Alpha.SourceA = incomingAlpha;
           env->Alpha.SourceB = GR_CMBX_ITALPHA;
           env->Alpha.ModeB = GR_FUNC_MODE_ZERO;
           env->Alpha.SourceC = GR_CMBX_ZERO;
           env->Alpha.InvertC = FXTRUE;

        }
        else if (baseFormat == GL_INTENSITY) {
            /* Av = Af + It */
           env->Alpha.SourceA = incomingAlpha;
           env->Alpha.SourceB = GR_CMBX_LOCAL_TEXTURE_ALPHA;
           env->Alpha.ModeB = GR_FUNC_MODE_X;
           env->Alpha.SourceC = GR_CMBX_ZERO;
           env->Alpha.InvertC = FXTRUE;
        }
        else {
            /* Av = Af * At */
           env->Alpha.SourceA = GR_CMBX_LOCAL_TEXTURE_ALPHA;
           env->Alpha.SourceB = GR_CMBX_ITALPHA;
           env->Alpha.ModeB = GR_FUNC_MODE_ZERO;
           env->Alpha.SourceC = incomingAlpha;
           env->Alpha.InvertC = FXFALSE;
        }
        env->Alpha.ModeA = GR_FUNC_MODE_X;
        env->Alpha.SourceD = GR_CMBX_ZERO;
        env->Alpha.InvertD = FXFALSE;
        break;

    case GL_COMBINE_EXT:
        {
            FxU32 A_RGB, B_RGB, C_RGB, D_RGB;
            FxU32 Amode_RGB, Bmode_RGB;
            FxBool Cinv_RGB, Dinv_RGB, Ginv_RGB;
            FxU32 Shift_RGB;
            FxU32 A_A, B_A, C_A, D_A;
            FxU32 Amode_A, Bmode_A;
            FxBool Cinv_A, Dinv_A, Ginv_A;
            FxU32 Shift_A;

           /*
            *
            * In the formulas below, we write:
            *  o "1(x)" for the identity function applied to x,
            *    so 1(x) = x.
            *  o "0(x)" for the constant function 0, so
            *    0(x) = 0 for all values of x.
            *
            * Calculate the color combination.
            */
            Shift_RGB = texUnit->Combine.ScaleShiftRGB;
            Shift_A = texUnit->Combine.ScaleShiftA;
            switch (texUnit->Combine.ModeRGB) {
            case GL_REPLACE:
               /*
                * The formula is: Arg0
                * We implement this by the formula:
                *   (Arg0 + 0(0))*(1-0) + 0
                */
                TEXENV_SETUP_ARG_RGB(A_RGB,
                                     texUnit->Combine.SourceRGB[0],
                                     texUnit->Combine.OperandRGB[0],
                                     incomingRGB, incomingAlpha);
                TEXENV_SETUP_MODE_RGB(Amode_RGB,
                                      texUnit->Combine.OperandRGB[0]);
                B_RGB = C_RGB = D_RGB = GR_CMBX_ZERO;
                Bmode_RGB = GR_FUNC_MODE_ZERO;
                Cinv_RGB = FXTRUE;
                Dinv_RGB = Ginv_RGB = FXFALSE;
                break;
            case GL_MODULATE:
               /*
                * The formula is: Arg0 * Arg1
                *
                * We implement this by the formula
                *   (Arg0 + 0(0)) * Arg1 + 0(0)
                */
                TEXENV_SETUP_ARG_RGB(A_RGB,
                                     texUnit->Combine.SourceRGB[0],
                                     texUnit->Combine.OperandRGB[0],
                                     incomingRGB, incomingAlpha);
                TEXENV_SETUP_MODE_RGB(Amode_RGB,
                                      texUnit->Combine.OperandRGB[0]);
                B_RGB = GR_CMBX_ZERO;
                Bmode_RGB = GR_CMBX_ZERO;
                TEXENV_SETUP_ARG_RGB(C_RGB,
                                     texUnit->Combine.SourceRGB[1],
                                     texUnit->Combine.OperandRGB[1],
                                     incomingRGB, incomingAlpha);
                Cinv_RGB = TEXENV_OPERAND_INVERTED
                               (texUnit->Combine.OperandRGB[1]);
                D_RGB = GR_CMBX_ZERO;
                Dinv_RGB = Ginv_RGB = FXFALSE;
                break;
            case GL_ADD:
               /*
                * The formula is Arg0 + Arg1
                */
                TEXENV_SETUP_ARG_RGB(A_RGB,
                                     texUnit->Combine.SourceRGB[0],
                                     texUnit->Combine.OperandRGB[0],
                                     incomingRGB, incomingAlpha);
                TEXENV_SETUP_MODE_RGB(Amode_RGB,
                                      texUnit->Combine.OperandRGB[0]);
                TEXENV_SETUP_ARG_RGB(B_RGB,
                                     texUnit->Combine.SourceRGB[1],
                                     texUnit->Combine.OperandRGB[1],
                                     incomingRGB, incomingAlpha);
                TEXENV_SETUP_MODE_RGB(Bmode_RGB,
                                      texUnit->Combine.OperandRGB[1]);
                C_RGB = D_RGB = GR_CMBX_ZERO;
                Cinv_RGB = FXTRUE;
                Dinv_RGB = Ginv_RGB = FXFALSE;
                break;
            case GL_ADD_SIGNED_EXT:
               /*
                * The formula is: Arg0 + Arg1 - 0.5.
                * We compute this by calculating:
                *      (Arg0 - 1/2) + Arg1         if op0 is SRC_{COLOR,ALPHA}
                *      Arg0 + (Arg1 - 1/2)         if op1 is SRC_{COLOR,ALPHA}
                * If both op0 and op1 are ONE_MINUS_SRC_{COLOR,ALPHA}
                * we cannot implement the formula properly.
                */
                TEXENV_SETUP_ARG_RGB(A_RGB,
                                     texUnit->Combine.SourceRGB[0],
                                     texUnit->Combine.OperandRGB[0],
                                     incomingRGB, incomingAlpha);
                TEXENV_SETUP_ARG_RGB(B_RGB,
                                     texUnit->Combine.SourceRGB[1],
                                     texUnit->Combine.OperandRGB[1],
                                     incomingRGB, incomingAlpha);
                if (!TEXENV_OPERAND_INVERTED(texUnit->Combine.OperandRGB[0])) {
                   /*
                    * A is not inverted.  So, choose it.
                    */
                    Amode_RGB = GR_FUNC_MODE_X_MINUS_HALF;
                    if (!TEXENV_OPERAND_INVERTED
                            (texUnit->Combine.OperandRGB[1])) {
                        Bmode_RGB = GR_FUNC_MODE_X;
                    }
                    else {
                        Bmode_RGB = GR_FUNC_MODE_ONE_MINUS_X;
                    }
                }
                else {
                   /*
                    * A is inverted, so try to subtract 1/2
                    * from B.
                    */
                    Amode_RGB = GR_FUNC_MODE_ONE_MINUS_X;
                    if (!TEXENV_OPERAND_INVERTED
                            (texUnit->Combine.OperandRGB[1])) {
                        Bmode_RGB = GR_FUNC_MODE_X_MINUS_HALF;
                    }
                    else {
                       /*
                        * Both are inverted.  This is the case
                        * we cannot handle properly.  We just
                        * choose to not add the - 1/2.
                        */
                        Bmode_RGB = GR_FUNC_MODE_ONE_MINUS_X;
                        return GL_FALSE;
                    }
                }
                C_RGB = D_RGB = GR_CMBX_ZERO;
                Cinv_RGB = FXTRUE;
                Dinv_RGB = Ginv_RGB = FXFALSE;
                break;
            case GL_INTERPOLATE_EXT:
               /*
                * The formula is: Arg0 * Arg2 + Arg1 * (1 - Arg2).
                * We compute this by the formula:
                *            (Arg0 - Arg1) * Arg2 + Arg1
                *               == Arg0 * Arg2 - Arg1 * Arg2 + Arg1
                *               == Arg0 * Arg2 + Arg1 * (1 - Arg2)
                * However, if both Arg1 is ONE_MINUS_X, the HW does
                * not support it properly.
                */
                TEXENV_SETUP_ARG_RGB(A_RGB,
                                     texUnit->Combine.SourceRGB[0],
                                     texUnit->Combine.OperandRGB[0],
                                     incomingRGB, incomingAlpha);
                TEXENV_SETUP_MODE_RGB(Amode_RGB,
                                      texUnit->Combine.OperandRGB[0]);
                TEXENV_SETUP_ARG_RGB(B_RGB,
                                     texUnit->Combine.SourceRGB[1],
                                     texUnit->Combine.OperandRGB[1],
                                     incomingRGB, incomingAlpha);
                if (TEXENV_OPERAND_INVERTED(texUnit->Combine.OperandRGB[1])) {
                   /*
                    * This case is wrong.
                    */
                   Bmode_RGB = GR_FUNC_MODE_NEGATIVE_X;
                   return GL_FALSE;
                }
                else {
                    Bmode_RGB = GR_FUNC_MODE_NEGATIVE_X;
                }
               /*
                * The Source/Operand for the C value must
                * specify some kind of alpha value.
                */
                TEXENV_SETUP_ARG_A(C_RGB,
                                   texUnit->Combine.SourceRGB[2],
                                   texUnit->Combine.OperandRGB[2],
                                   incomingAlpha);
                Cinv_RGB = FXFALSE;
                D_RGB = GR_CMBX_B;
                Dinv_RGB = Ginv_RGB = FXFALSE;
                break;
            default:
               /*
                * This is here mostly to keep from getting
                * a compiler warning about these not being set.
                * However, this should set all the texture values
                * to zero.
                */
                A_RGB = B_RGB = C_RGB = D_RGB = GR_CMBX_ZERO;
                Amode_RGB = Bmode_RGB = GR_FUNC_MODE_X;
                Cinv_RGB = Dinv_RGB = Ginv_RGB = FXFALSE;
                break;
            }
           /*
            * Calculate the alpha combination.
            */
            switch (texUnit->Combine.ModeA) {
            case GL_REPLACE: