agg_pixfmt_rgba.h

来自「这是VCF框架的代码」· C头文件 代码 · 共 1,565 行 · 第 1/5 页

        typedef Order order_type;
        typedef typename color_type::value_type value_type;
        typedef typename color_type::calc_type calc_type;
        enum base_scale_e
        { 
            base_shift = color_type::base_shift,
            base_mask  = color_type::base_mask
        };

        //   Dca' = Sca + Dca.(1 - Sa)
        //   Da'  = Sa + Da - Sa.Da 
        static AGG_INLINE void blend_pix(value_type* p, 
                                         unsigned sr, unsigned sg, unsigned sb, 
                                         unsigned sa, unsigned cover)
        {
            if(cover < 255)
            {
                sr = (sr * cover + 255) >> 8;
                sg = (sg * cover + 255) >> 8;
                sb = (sb * cover + 255) >> 8;
                sa = (sa * cover + 255) >> 8;
            }
            calc_type s1a = base_mask - sa;
            p[Order::R] = (value_type)(sr + ((p[Order::R] * s1a + base_mask) >> base_shift));
            p[Order::G] = (value_type)(sg + ((p[Order::G] * s1a + base_mask) >> base_shift));
            p[Order::B] = (value_type)(sb + ((p[Order::B] * s1a + base_mask) >> base_shift));
            p[Order::A] = (value_type)(sa + p[Order::A] - ((sa * p[Order::A] + base_mask) >> base_shift));
        }
    };

    //======================================================comp_op_rgba_dst_over
    template<class ColorT, class Order> struct comp_op_rgba_dst_over
    {
        typedef ColorT color_type;
        typedef Order order_type;
        typedef typename color_type::value_type value_type;
        typedef typename color_type::calc_type calc_type;
        enum base_scale_e
        { 
            base_shift = color_type::base_shift,
            base_mask  = color_type::base_mask
        };

        // Dca' = Dca + Sca.(1 - Da)
        // Da'  = Sa + Da - Sa.Da 
        static AGG_INLINE void blend_pix(value_type* p, 
                                         unsigned sr, unsigned sg, unsigned sb, 
                                         unsigned sa, unsigned cover)
        {
            if(cover < 255)
            {
                sr = (sr * cover + 255) >> 8;
                sg = (sg * cover + 255) >> 8;
                sb = (sb * cover + 255) >> 8;
                sa = (sa * cover + 255) >> 8;
            }
            calc_type d1a = base_mask - p[Order::A];
            p[Order::R] = (value_type)(p[Order::R] + ((sr * d1a + base_mask) >> base_shift));
            p[Order::G] = (value_type)(p[Order::G] + ((sg * d1a + base_mask) >> base_shift));
            p[Order::B] = (value_type)(p[Order::B] + ((sb * d1a + base_mask) >> base_shift));
            p[Order::A] = (value_type)(sa + p[Order::A] - ((sa * p[Order::A] + base_mask) >> base_shift));
        }
    };

    //======================================================comp_op_rgba_src_in
    template<class ColorT, class Order> struct comp_op_rgba_src_in
    {
        typedef ColorT color_type;
        typedef Order order_type;
        typedef typename color_type::value_type value_type;
        typedef typename color_type::calc_type calc_type;
        enum base_scale_e
        { 
            base_shift = color_type::base_shift,
            base_mask  = color_type::base_mask
        };

        // Dca' = Sca.Da
        // Da'  = Sa.Da 
        static AGG_INLINE void blend_pix(value_type* p, 
                                         unsigned sr, unsigned sg, unsigned sb, 
                                         unsigned sa, unsigned cover)
        {
            calc_type da = p[Order::A];
            if(cover < 255)
            {
                unsigned alpha = 255 - cover;
                p[Order::R] = (value_type)(((p[Order::R] * alpha + 255) >> 8) + ((((sr * da + base_mask) >> base_shift) * cover + 255) >> 8));
                p[Order::G] = (value_type)(((p[Order::G] * alpha + 255) >> 8) + ((((sg * da + base_mask) >> base_shift) * cover + 255) >> 8));
                p[Order::B] = (value_type)(((p[Order::B] * alpha + 255) >> 8) + ((((sb * da + base_mask) >> base_shift) * cover + 255) >> 8));
                p[Order::A] = (value_type)(((p[Order::A] * alpha + 255) >> 8) + ((((sa * da + base_mask) >> base_shift) * cover + 255) >> 8));
            }
            else
            {
                p[Order::R] = (value_type)((sr * da + base_mask) >> base_shift);
                p[Order::G] = (value_type)((sg * da + base_mask) >> base_shift);
                p[Order::B] = (value_type)((sb * da + base_mask) >> base_shift);
                p[Order::A] = (value_type)((sa * da + base_mask) >> base_shift);
            }
        }
    };

    //======================================================comp_op_rgba_dst_in
    template<class ColorT, class Order> struct comp_op_rgba_dst_in
    {
        typedef ColorT color_type;
        typedef Order order_type;
        typedef typename color_type::value_type value_type;
        typedef typename color_type::calc_type calc_type;
        enum base_scale_e
        { 
            base_shift = color_type::base_shift,
            base_mask  = color_type::base_mask
        };

        // Dca' = Dca.Sa
        // Da'  = Sa.Da 
        static AGG_INLINE void blend_pix(value_type* p, 
                                         unsigned, unsigned, unsigned, 
                                         unsigned sa, unsigned cover)
        {
            if(cover < 255)
            {
                sa = base_mask - ((cover * (base_mask - sa) + 255) >> 8);
            }
            p[Order::R] = (value_type)((p[Order::R] * sa + base_mask) >> base_shift);
            p[Order::G] = (value_type)((p[Order::G] * sa + base_mask) >> base_shift);
            p[Order::B] = (value_type)((p[Order::B] * sa + base_mask) >> base_shift);
            p[Order::A] = (value_type)((p[Order::A] * sa + base_mask) >> base_shift);
        }
    };

    //======================================================comp_op_rgba_src_out
    template<class ColorT, class Order> struct comp_op_rgba_src_out
    {
        typedef ColorT color_type;
        typedef Order order_type;
        typedef typename color_type::value_type value_type;
        typedef typename color_type::calc_type calc_type;
        enum base_scale_e
        { 
            base_shift = color_type::base_shift,
            base_mask  = color_type::base_mask
        };

        // Dca' = Sca.(1 - Da)
        // Da'  = Sa.(1 - Da) 
        static AGG_INLINE void blend_pix(value_type* p, 
                                         unsigned sr, unsigned sg, unsigned sb, 
                                         unsigned sa, unsigned cover)
        {
            calc_type da = base_mask - p[Order::A];
            if(cover < 255)
            {
                unsigned alpha = 255 - cover;
                p[Order::R] = (value_type)(((p[Order::R] * alpha + 255) >> 8) + ((((sr * da + base_mask) >> base_shift) * cover + 255) >> 8));
                p[Order::G] = (value_type)(((p[Order::G] * alpha + 255) >> 8) + ((((sg * da + base_mask) >> base_shift) * cover + 255) >> 8));
                p[Order::B] = (value_type)(((p[Order::B] * alpha + 255) >> 8) + ((((sb * da + base_mask) >> base_shift) * cover + 255) >> 8));
                p[Order::A] = (value_type)(((p[Order::A] * alpha + 255) >> 8) + ((((sa * da + base_mask) >> base_shift) * cover + 255) >> 8));
            }
            else
            {
                p[Order::R] = (value_type)((sr * da + base_mask) >> base_shift);
                p[Order::G] = (value_type)((sg * da + base_mask) >> base_shift);
                p[Order::B] = (value_type)((sb * da + base_mask) >> base_shift);
                p[Order::A] = (value_type)((sa * da + base_mask) >> base_shift);
            }
        }
    };

    //======================================================comp_op_rgba_dst_out
    template<class ColorT, class Order> struct comp_op_rgba_dst_out
    {
        typedef ColorT color_type;
        typedef Order order_type;
        typedef typename color_type::value_type value_type;
        typedef typename color_type::calc_type calc_type;
        enum base_scale_e
        { 
            base_shift = color_type::base_shift,
            base_mask  = color_type::base_mask
        };

        // Dca' = Dca.(1 - Sa) 
        // Da'  = Da.(1 - Sa) 
        static AGG_INLINE void blend_pix(value_type* p, 
                                         unsigned, unsigned, unsigned, 
                                         unsigned sa, unsigned cover)
        {
            if(cover < 255)
            {
                sa = (sa * cover + 255) >> 8;
            }
            sa = base_mask - sa;
            p[Order::R] = (value_type)((p[Order::R] * sa + base_shift) >> base_shift);
            p[Order::G] = (value_type)((p[Order::G] * sa + base_shift) >> base_shift);
            p[Order::B] = (value_type)((p[Order::B] * sa + base_shift) >> base_shift);
            p[Order::A] = (value_type)((p[Order::A] * sa + base_shift) >> base_shift);
        }
    };

    //=====================================================comp_op_rgba_src_atop
    template<class ColorT, class Order> struct comp_op_rgba_src_atop
    {
        typedef ColorT color_type;
        typedef Order order_type;
        typedef typename color_type::value_type value_type;
        typedef typename color_type::calc_type calc_type;
        enum base_scale_e
        { 
            base_shift = color_type::base_shift,
            base_mask  = color_type::base_mask
        };

        // Dca' = Sca.Da + Dca.(1 - Sa)
        // Da'  = Da
        static AGG_INLINE void blend_pix(value_type* p, 
                                         unsigned sr, unsigned sg, unsigned sb, 
                                         unsigned sa, unsigned cover)
        {
            if(cover < 255)
            {
                sr = (sr * cover + 255) >> 8;
                sg = (sg * cover + 255) >> 8;
                sb = (sb * cover + 255) >> 8;
                sa = (sa * cover + 255) >> 8;
            }
            calc_type da = p[Order::A];
            sa = base_mask - sa;
            p[Order::R] = (value_type)((sr * da + p[Order::R] * sa + base_mask) >> base_shift);
            p[Order::G] = (value_type)((sg * da + p[Order::G] * sa + base_mask) >> base_shift);
            p[Order::B] = (value_type)((sb * da + p[Order::B] * sa + base_mask) >> base_shift);
        }
    };

    //=====================================================comp_op_rgba_dst_atop
    template<class ColorT, class Order> struct comp_op_rgba_dst_atop
    {
        typedef ColorT color_type;
        typedef Order order_type;
        typedef typename color_type::value_type value_type;
        typedef typename color_type::calc_type calc_type;
        enum base_scale_e
        { 
            base_shift = color_type::base_shift,
            base_mask  = color_type::base_mask
        };

        // Dca' = Dca.Sa + Sca.(1 - Da)
        // Da'  = Sa 
        static AGG_INLINE void blend_pix(value_type* p, 
                                         unsigned sr, unsigned sg, unsigned sb, 
                                         unsigned sa, unsigned cover)
        {
            calc_type da = base_mask - p[Order::A];
            if(cover < 255)
            {
                unsigned alpha = 255 - cover;
                sr = (p[Order::R] * sa + sr * da + base_mask) >> base_shift;
                sg = (p[Order::G] * sa + sg * da + base_mask) >> base_shift;
                sb = (p[Order::B] * sa + sb * da + base_mask) >> base_shift;
                p[Order::R] = (value_type)(((p[Order::R] * alpha + 255) >> 8) + ((sr * cover + 255) >> 8));
                p[Order::G] = (value_type)(((p[Order::G] * alpha + 255) >> 8) + ((sg * cover + 255) >> 8));
                p[Order::B] = (value_type)(((p[Order::B] * alpha + 255) >> 8) + ((sb * cover + 255) >> 8));
                p[Order::A] = (value_type)(((p[Order::A] * alpha + 255) >> 8) + ((sa * cover + 255) >> 8));

            }
            else
            {
                p[Order::R] = (value_type)((p[Order::R] * sa + sr * da + base_mask) >> base_shift);
                p[Order::G] = (value_type)((p[Order::G] * sa + sg * da + base_mask) >> base_shift);
                p[Order::B] = (value_type)((p[Order::B] * sa + sb * da + base_mask) >> base_shift);
                p[Order::A] = (value_type)sa;
            }
        }
    };

    //=========================================================comp_op_rgba_xor
    template<class ColorT, class Order> struct comp_op_rgba_xor
    {
        typedef ColorT color_type;
        typedef Order order_type;
        typedef typename color_type::value_type value_type;
        typedef typename color_type::calc_type calc_type;
        enum base_scale_e
        { 
            base_shift = color_type::base_shift,
            base_mask  = color_type::base_mask
        };

        // Dca' = Sca.(1 - Da) + Dca.(1 - Sa)
        // Da'  = Sa + Da - 2.Sa.Da 
        static AGG_INLINE void blend_pix(value_type* p, 
                                         unsigned sr, unsigned sg, unsigned sb, 
                                         unsigned sa, unsigned cover)
        {
            if(cover < 255)
            {
                sr = (sr * cover + 255) >> 8;
                sg = (sg * cover + 255) >> 8;
                sb = (sb * cover + 255) >> 8;
                sa = (sa * cover + 255) >> 8;
            }
            calc_type s1a = base_mask - sa;
            calc_type d1a = base_mask - p[Order::A];
            p[Order::R] = (value_type)((p[Order::R] * s1a + sr * d1a + base_mask) >> base_shift);
            p[Order::G] = (value_type)((p[Order::G] * s1a + sg * d1a + base_mask) >> base_shift);
            p[Order::B] = (value_type)((p[Order::B] * s1a + sb * d1a + base_mask) >> base_shift);
            p[Order::A] = (value_type)(sa + p[Order::A] - ((sa * p[Order::A] + base_mask/2) >> (base_shift - 1)));
        }
    };

    //=========================================================comp_op_rgba_plus