Exemplo n.º 1
0
void GGLAssembler::build_blend_factor(
        integer_t& factor, int f, int component,
        const pixel_t& dst_pixel,
        integer_t& fragment,
        integer_t& fb,
        Scratch& scratches)
{
    integer_t src_alpha(fragment);

    // src_factor/dst_factor won't be used after blending,
    // so it's fine to mark them as CORRUPTIBLE (if not aliased)
    factor.flags |= CORRUPTIBLE;

    switch(f) {
    case GGL_ONE_MINUS_SRC_ALPHA:
    case GGL_SRC_ALPHA:
        if (component==GGLFormat::ALPHA && !isAlphaSourceNeeded()) {
            // we're processing alpha, so we already have
            // src-alpha in fragment, and we need src-alpha just this time.
        } else {
           // alpha-src will be needed for other components
            if (!mBlendFactorCached || mBlendFactorCached==f) {
                src_alpha = mAlphaSource;
                factor = mAlphaSource;
                factor.flags &= ~CORRUPTIBLE;           
                // we already computed the blend factor before, nothing to do.
                if (mBlendFactorCached)
                    return;
                // this is the first time, make sure to compute the blend
                // factor properly.
                mBlendFactorCached = f;
                break;
            } else {
                // we have a cached alpha blend factor, but we want another one,
                // this should really not happen because by construction,
                // we cannot have BOTH source and destination
                // blend factors use ALPHA *and* ONE_MINUS_ALPHA (because
                // the blending stage uses the f/(1-f) optimization
                
                // for completeness, we handle this case though. Since there
                // are only 2 choices, this meens we want "the other one"
                // (1-factor)
                factor = mAlphaSource;
                factor.flags &= ~CORRUPTIBLE;           
                RSB(AL, 0, factor.reg, factor.reg, imm((1<<factor.s)));
                mBlendFactorCached = f;
                return;
            }                
        }
        // fall-through...
    case GGL_ONE_MINUS_DST_COLOR:
    case GGL_DST_COLOR:
    case GGL_ONE_MINUS_SRC_COLOR:
    case GGL_SRC_COLOR:
    case GGL_ONE_MINUS_DST_ALPHA:
    case GGL_DST_ALPHA:
    case GGL_SRC_ALPHA_SATURATE:
        // help us find out what register we can use for the blend-factor
        // CORRUPTIBLE registers are chosen first, or a new one is allocated.
        if (fragment.flags & CORRUPTIBLE) {
            factor.setTo(fragment.reg, 32, CORRUPTIBLE);
            fragment.flags &= ~CORRUPTIBLE;
        } else if (fb.flags & CORRUPTIBLE) {
            factor.setTo(fb.reg, 32, CORRUPTIBLE);
            fb.flags &= ~CORRUPTIBLE;
        } else {
            factor.setTo(scratches.obtain(), 32, CORRUPTIBLE);
        } 
        break;
    }

    // XXX: doesn't work if size==1

    switch(f) {
    case GGL_ONE_MINUS_DST_COLOR:
    case GGL_DST_COLOR:
        factor.s = fb.s;
        ADD(AL, 0, factor.reg, fb.reg, reg_imm(fb.reg, LSR, fb.s-1));
        break;
    case GGL_ONE_MINUS_SRC_COLOR:
    case GGL_SRC_COLOR:
        factor.s = fragment.s;
        ADD(AL, 0, factor.reg, fragment.reg,
            reg_imm(fragment.reg, LSR, fragment.s-1));
        break;
    case GGL_ONE_MINUS_SRC_ALPHA:
    case GGL_SRC_ALPHA:
        factor.s = src_alpha.s;
        ADD(AL, 0, factor.reg, src_alpha.reg,
                reg_imm(src_alpha.reg, LSR, src_alpha.s-1));
        break;
    case GGL_ONE_MINUS_DST_ALPHA:
    case GGL_DST_ALPHA:
        // XXX: should be precomputed
        extract(factor, dst_pixel, GGLFormat::ALPHA);
        ADD(AL, 0, factor.reg, factor.reg,
                reg_imm(factor.reg, LSR, factor.s-1));
        break;
    case GGL_SRC_ALPHA_SATURATE:
        // XXX: should be precomputed
        // XXX: f = min(As, 1-Ad)
        // btw, we're guaranteed that Ad's size is <= 8, because
        // it's extracted from the framebuffer
        break;
    }

    switch(f) {
    case GGL_ONE_MINUS_DST_COLOR:
    case GGL_ONE_MINUS_SRC_COLOR:
    case GGL_ONE_MINUS_DST_ALPHA:
    case GGL_ONE_MINUS_SRC_ALPHA:
        RSB(AL, 0, factor.reg, factor.reg, imm((1<<factor.s)));
    }
    
    // don't need more than 8-bits for the blend factor
    // and this will prevent overflows in the multiplies later
    if (factor.s > 8) {
        MOV(AL, 0, factor.reg, reg_imm(factor.reg, LSR, factor.s-8));
        factor.s = 8;
    }
}
int GGLAssembler::scanline_core(const needs_t& needs, context_t const* c)
{
    int64_t duration = ggl_system_time();

    mBlendFactorCached = 0;
    mBlending = 0;
    mMasking = 0;
    mAA        = GGL_READ_NEEDS(P_AA, needs.p);
    mDithering = GGL_READ_NEEDS(P_DITHER, needs.p);
    mAlphaTest = GGL_READ_NEEDS(P_ALPHA_TEST, needs.p) + GGL_NEVER;
    mDepthTest = GGL_READ_NEEDS(P_DEPTH_TEST, needs.p) + GGL_NEVER;
    mFog       = GGL_READ_NEEDS(P_FOG, needs.p) != 0;
    mSmooth    = GGL_READ_NEEDS(SHADE, needs.n) != 0;
    mBuilderContext.needs = needs;
    mBuilderContext.c = c;
    mBuilderContext.Rctx = reserveReg(R0); // context always in R0
    mCbFormat = c->formats[ GGL_READ_NEEDS(CB_FORMAT, needs.n) ];

    // ------------------------------------------------------------------------

    decodeLogicOpNeeds(needs);

    decodeTMUNeeds(needs, c);

    mBlendSrc  = ggl_needs_to_blendfactor(GGL_READ_NEEDS(BLEND_SRC, needs.n));
    mBlendDst  = ggl_needs_to_blendfactor(GGL_READ_NEEDS(BLEND_DST, needs.n));
    mBlendSrcA = ggl_needs_to_blendfactor(GGL_READ_NEEDS(BLEND_SRCA, needs.n));
    mBlendDstA = ggl_needs_to_blendfactor(GGL_READ_NEEDS(BLEND_DSTA, needs.n));

    if (!mCbFormat.c[GGLFormat::ALPHA].h) {
        if ((mBlendSrc == GGL_ONE_MINUS_DST_ALPHA) ||
            (mBlendSrc == GGL_DST_ALPHA)) {
            mBlendSrc = GGL_ONE;
        }
        if ((mBlendSrcA == GGL_ONE_MINUS_DST_ALPHA) ||
            (mBlendSrcA == GGL_DST_ALPHA)) {
            mBlendSrcA = GGL_ONE;
        }
        if ((mBlendDst == GGL_ONE_MINUS_DST_ALPHA) ||
            (mBlendDst == GGL_DST_ALPHA)) {
            mBlendDst = GGL_ONE;
        }
        if ((mBlendDstA == GGL_ONE_MINUS_DST_ALPHA) ||
            (mBlendDstA == GGL_DST_ALPHA)) {
            mBlendDstA = GGL_ONE;
        }
    }

    // if we need the framebuffer, read it now
    const int blending =    blending_codes(mBlendSrc, mBlendDst) |
                            blending_codes(mBlendSrcA, mBlendDstA);

    // XXX: handle special cases, destination not modified...
    if ((mBlendSrc==GGL_ZERO) && (mBlendSrcA==GGL_ZERO) &&
        (mBlendDst==GGL_ONE) && (mBlendDstA==GGL_ONE)) {
        // Destination unmodified (beware of logic ops)
    } else if ((mBlendSrc==GGL_ZERO) && (mBlendSrcA==GGL_ZERO) &&
        (mBlendDst==GGL_ZERO) && (mBlendDstA==GGL_ZERO)) {
        // Destination is zero (beware of logic ops)
    }
    
    int fbComponents = 0;
    const int masking = GGL_READ_NEEDS(MASK_ARGB, needs.n);
    for (int i=0 ; i<4 ; i++) {
        const int mask = 1<<i;
        component_info_t& info = mInfo[i];
        int fs = i==GGLFormat::ALPHA ? mBlendSrcA : mBlendSrc;
        int fd = i==GGLFormat::ALPHA ? mBlendDstA : mBlendDst;
        if (fs==GGL_SRC_ALPHA_SATURATE && i==GGLFormat::ALPHA)
            fs = GGL_ONE;
        info.masked =   !!(masking & mask);
        info.inDest =   !info.masked && mCbFormat.c[i].h && 
                        ((mLogicOp & LOGIC_OP_SRC) || (!mLogicOp));
        if (mCbFormat.components >= GGL_LUMINANCE &&
                (i==GGLFormat::GREEN || i==GGLFormat::BLUE)) {
            info.inDest = false;
        }
        info.needed =   (i==GGLFormat::ALPHA) && 
                        (isAlphaSourceNeeded() || mAlphaTest != GGL_ALWAYS);
        info.replaced = !!(mTextureMachine.replaced & mask);
        info.iterated = (!info.replaced && (info.inDest || info.needed)); 
        info.smooth =   mSmooth && info.iterated;
        info.fog =      mFog && info.inDest && (i != GGLFormat::ALPHA);
        info.blend =    (fs != int(GGL_ONE)) || (fd > int(GGL_ZERO));

        mBlending |= (info.blend ? mask : 0);
        mMasking |= (mCbFormat.c[i].h && info.masked) ? mask : 0;
        fbComponents |= mCbFormat.c[i].h ? mask : 0;
    }

    mAllMasked = (mMasking == fbComponents);
    if (mAllMasked) {
        mDithering = 0;
    }
    
    fragment_parts_t parts;

    // ------------------------------------------------------------------------
    prolog();
    // ------------------------------------------------------------------------

    build_scanline_prolog(parts, needs);

    if (registerFile().status())
        return registerFile().status();

    // ------------------------------------------------------------------------
    label("fragment_loop");
    // ------------------------------------------------------------------------
    {
        Scratch regs(registerFile());

        if (mDithering) {
            // update the dither index.
            MOV(AL, 0, parts.count.reg,
                    reg_imm(parts.count.reg, ROR, GGL_DITHER_ORDER_SHIFT));
            ADD(AL, 0, parts.count.reg, parts.count.reg,
                    imm( 1 << (32 - GGL_DITHER_ORDER_SHIFT)));
            MOV(AL, 0, parts.count.reg,
                    reg_imm(parts.count.reg, ROR, 32 - GGL_DITHER_ORDER_SHIFT));
        }

        // XXX: could we do an early alpha-test here in some cases?
        // It would probaly be used only with smooth-alpha and no texture
        // (or no alpha component in the texture).

        // Early z-test
        if (mAlphaTest==GGL_ALWAYS) {
            build_depth_test(parts, Z_TEST|Z_WRITE);
        } else {
            // we cannot do the z-write here, because
            // it might be killed by the alpha-test later
            build_depth_test(parts, Z_TEST);
        }

        { // texture coordinates
            Scratch scratches(registerFile());

            // texel generation
            build_textures(parts, regs);
            if (registerFile().status())
                return registerFile().status();
        }

        if ((blending & (FACTOR_DST|BLEND_DST)) || 
                (mMasking && !mAllMasked) ||
                (mLogicOp & LOGIC_OP_DST)) 
        {
            // blending / logic_op / masking need the framebuffer
            mDstPixel.setTo(regs.obtain(), &mCbFormat);

            // load the framebuffer pixel
            comment("fetch color-buffer");
            load(parts.cbPtr, mDstPixel);
        }

        if (registerFile().status())
            return registerFile().status();

        pixel_t pixel;
        int directTex = mTextureMachine.directTexture;
        if (directTex | parts.packed) {
            // note: we can't have both here
            // iterated color or direct texture
            pixel = directTex ? parts.texel[directTex-1] : parts.iterated;
            pixel.flags &= ~CORRUPTIBLE;
        } else {
            if (mDithering) {
                const int ctxtReg = mBuilderContext.Rctx;
                const int mask = GGL_DITHER_SIZE-1;
                parts.dither = reg_t(regs.obtain());
                AND(AL, 0, parts.dither.reg, parts.count.reg, imm(mask));
                ADDR_ADD(AL, 0, parts.dither.reg, ctxtReg, parts.dither.reg);
                LDRB(AL, parts.dither.reg, parts.dither.reg,
                        immed12_pre(GGL_OFFSETOF(ditherMatrix)));
            }
        
            // allocate a register for the resulting pixel
            pixel.setTo(regs.obtain(), &mCbFormat, FIRST);

            build_component(pixel, parts, GGLFormat::ALPHA,    regs);

            if (mAlphaTest!=GGL_ALWAYS) {
                // only handle the z-write part here. We know z-test
                // was successful, as well as alpha-test.
                build_depth_test(parts, Z_WRITE);
            }

            build_component(pixel, parts, GGLFormat::RED,      regs);
            build_component(pixel, parts, GGLFormat::GREEN,    regs);
            build_component(pixel, parts, GGLFormat::BLUE,     regs);

            pixel.flags |= CORRUPTIBLE;
        }

        if (registerFile().status())
            return registerFile().status();
        
        if (pixel.reg == -1) {
            // be defensive here. if we're here it's probably
            // that this whole fragment is a no-op.
            pixel = mDstPixel;
        }
        
        if (!mAllMasked) {
            // logic operation
            build_logic_op(pixel, regs);
    
            // masking
            build_masking(pixel, regs); 
    
            comment("store");
            store(parts.cbPtr, pixel, WRITE_BACK);
        }
    }

    if (registerFile().status())
        return registerFile().status();

    // update the iterated color...
    if (parts.reload != 3) {
        build_smooth_shade(parts);
    }

    // update iterated z
    build_iterate_z(parts);

    // update iterated fog
    build_iterate_f(parts);

    SUB(AL, S, parts.count.reg, parts.count.reg, imm(1<<16));
    B(PL, "fragment_loop");
    label("epilog");
    epilog(registerFile().touched());

    if ((mAlphaTest!=GGL_ALWAYS) || (mDepthTest!=GGL_ALWAYS)) {
        if (mDepthTest!=GGL_ALWAYS) {
            label("discard_before_textures");
            build_iterate_texture_coordinates(parts);
        }
        label("discard_after_textures");
        build_smooth_shade(parts);
        build_iterate_z(parts);
        build_iterate_f(parts);
        if (!mAllMasked) {
            ADDR_ADD(AL, 0, parts.cbPtr.reg, parts.cbPtr.reg, imm(parts.cbPtr.size>>3));
        }
        SUB(AL, S, parts.count.reg, parts.count.reg, imm(1<<16));
        B(PL, "fragment_loop");
        epilog(registerFile().touched());
    }