25     static inline SkAlpha CatchOverflow(int alpha) {  in CatchOverflow()  argument
26         SkASSERT(alpha >= 0 && alpha <= 256);  in CatchOverflow()
27         return alpha - (alpha >> 8);  in CatchOverflow()
61         uint8_t*    alpha = fAlpha + offsetX;  in add()  local
62         uint8_t*    lastAlpha = alpha;  in add()
66             SkAlphaRuns::Break(runs, alpha, x, 1);  in add()
72             unsigned tmp = alpha[x] + startAlpha;  in add()
74 …alpha[x] = SkToU8(tmp - (tmp >> 8));    // was (tmp >> 7), but that seems wrong if we're trying to…  in add()
77             alpha += x + 1;  in add()
83             SkAlphaRuns::Break(runs, alpha, x, middleCount);  in add()
84             alpha += x;  in add()
88                 alpha[0] = SkToU8(CatchOverflow(alpha[0] + maxValue));  in add()
91                 alpha += n;  in add()
96             lastAlpha = alpha;  in add()
100             SkAlphaRuns::Break(runs, alpha, x, 1);  in add()
101             alpha += x;  in add()
102             alpha[0] = SkToU8(alpha[0] + stopAlpha);  in add()
104             lastAlpha = alpha;  in add()
121     static void Break(int16_t runs[], uint8_t alpha[], int x, int count) {
128         uint8_t*  next_alpha = alpha + x;
135                 alpha[x] = alpha[0];
141             alpha += n;
146         alpha = next_alpha;
154                 alpha[x] = alpha[0];
164             alpha += n;
174     static void BreakAt(int16_t runs[], uint8_t alpha[], int x) {  in BreakAt()  argument
180                 alpha[x] = alpha[0];  in BreakAt()
186             alpha += n;  in BreakAt()