23 class Sk4px : public Sk16b {
25     static Sk4px DupAlpha(SkAlpha a) { return Sk16b(a); }  //    a -> aaaa aaaa aaaa aaaa  in DupAlpha()
26     static Sk4px DupPMColor(SkPMColor c);                  // argb -> argb argb argb argb
28     Sk4px(const Sk16b& v) : INHERITED(v) {}  in Sk4px()  function
30     Sk4px alphas() const;  // ARGB argb XYZW xyzw -> AAAA aaaa XXXX xxxx
33     Sk4px zeroColors() const;  // ARGB argb XYZW xyzw -> A000 a000 X000 x000
34     Sk4px zeroAlphas() const;  // ARGB argb XYZW xyzw -> 0RGB 0rgb 0YZW 0yzw
36     Sk4px inv() const { return Sk16b(255) - *this; }  in inv()
39     static Sk4px Load4(const SkPMColor[4]);  // PMColor[4] -> ARGB argb XYZW xyzw
40     static Sk4px Load2(const SkPMColor[2]);  // PMColor[2] -> ARGB argb ???? ????
41     static Sk4px Load1(const SkPMColor[1]);  // PMColor[1] -> ARGB ???? ???? ????
44     static Sk4px Load4Alphas(const SkAlpha[4]);  // AaXx -> AAAA aaaa XXXX xxxx
45     static Sk4px Load2Alphas(const SkAlpha[2]);  // Aa   -> AAAA aaaa ???? ????
58         Sk4px addNarrowHi(const Sk16h&) const;
61         Sk4px div255() const;
82     Wide operator * (const Sk4px& o) const { return this->mulWiden(o); }
85     Sk4px operator + (const Sk4px& o) const { return INHERITED::operator+(o); }
86     Sk4px operator - (const Sk4px& o) const { return INHERITED::operator-(o); }
87     Sk4px operator < (const Sk4px& o) const { return INHERITED::operator<(o); }
88     Sk4px thenElse(const Sk4px& t, const Sk4px& e) const { return INHERITED::thenElse(t,e); }  in thenElse()
92     Sk4px approxMulDiv255(const Sk16b& o) const {  in approxMulDiv255()
108                 Sk4px dst0 = fn(Load4(src+0)),  in MapSrc()
138                 Sk4px dst0 = fn(Load4(dst+0), Load4(src+0)),  in MapDstSrc()
168                 Sk4px dst0 = fn(Load4(dst+0), Load4Alphas(a+0)),  in MapDstAlpha()
200                 Sk4px dst0 = fn(Load4(dst+0), Load4(src+0), Load4Alphas(a+0)),  in MapDstSrcAlpha()