diff options
Diffstat (limited to 'src/state.c')
| -rw-r--r-- | src/state.c | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/src/state.c b/src/state.c index 5387828..895d096 100644 --- a/src/state.c +++ b/src/state.c @@ -36,10 +36,23 @@ static int fincmp(const void *a, const void *b) return ((struct FingerState *)a)->id - ((struct FingerState *)b)->id; } -inline float dist2(const struct FingerData *a, const struct FingerData *b) +/* seander@cs.stanford.edu */ +inline unsigned abs32(int x) { - float dx = a->position_x - b->position_x; - float dy = a->position_y - b->position_y; + int const m = x >> 31; + return (x + m) ^ m; +} + +inline int abs15(int x) +{ + return 32767 & abs32(x); +} + +/* abslute scale is assumed to fit in 15 bits */ +inline int dist2(const struct FingerData *a, const struct FingerData *b) +{ + int dx = abs15(a->position_x - b->position_x); + int dy = abs15(a->position_y - b->position_y); return dx * dx + dy * dy; } @@ -71,7 +84,7 @@ void modify_state(struct State *s, const struct HWData *hw, const struct Capabilities *caps) { - float A[DIM2_FINGER], *row; + int A[DIM2_FINGER], *row; int sid[DIM_FINGER], hw2s[DIM_FINGER]; int id, sk, hwk; |