diff options
| -rw-r--r-- | balls.c | 28 |
1 files changed, 22 insertions, 6 deletions
@@ -52,6 +52,8 @@ void spawnball(void); void drawbg(Image *walls, Image *bg); void spawnballs(int n); Channel **allocchans(int nchans, int elsize, int nel); +void mcopycolskip(Channel *vec[], Channel **matrix[], int n, int col, int skip); +void vcopyskip(Channel *dst[], Channel *src[], int n, int skip); void nooverlapcircles(Point centers[], int n); Point randptinrect(Rectangle r); int randint(int lo, int hi); @@ -175,15 +177,11 @@ spawnballs(int n) { if ((b->posin = malloc((n-1)*sizeof(Channel *))) == nil) sysfatal("failed to allocate array of incoming position channels"); - for (j = 0; j < i; j++) - b->posin[j] = poschans[j][i]; - for (j = i+1; j < n; j++) - b->posin[j-1] = poschans[j][i]; + mcopycolskip(b->posin, poschans, n, i, i); if ((b->posout = malloc((n-1)*sizeof(Channel *))) == nil) sysfatal("failed to allocate array of outgoing position channels"); - memmove(b->posout, poschans[i], i*sizeof(Channel *)); - memmove(b->posout, poschans[i]+i+1, (n-i-1)*sizeof(Channel *)); + vcopyskip(b->posout, poschans[i], n, i); b->nothers = n-1; @@ -218,6 +216,24 @@ allocchans(int nchans, int elsize, int nel) { return cs; } +/* copy column col of nxn matrix, except for element skip, into n-1 length vec */ +void +mcopycolskip(Channel *vec[], Channel **matrix[], int n, int col, int skip) { + int i; + + for (i = 0; i < skip; i++) + vec[i] = matrix[i][col]; + for (i = skip+1; i < n; i++) + vec[i-1] = matrix[i][col]; +} + +/* copy each element in n-length src, except for element skip, into n-1 length dst */ +void +vcopyskip(Channel *dst[], Channel *src[], int n, int skip) { + memmove(dst, src, skip*sizeof(Channel *)); + memmove(dst, src+skip+1, (n-skip-1)*sizeof(Channel *)); +} + void nooverlapcircles(Point centers[], int n) { int i, j; |