diff options
Diffstat (limited to 'balls.c')
| -rw-r--r-- | balls.c | 40 |
1 files changed, 31 insertions, 9 deletions
@@ -21,7 +21,7 @@ enum { DEFAULT_NBALLS = 3, VMAX = 3, - MASS = 10, + G_PER_KG = 1000, FPS = 60, NS_PER_SEC = 1000000000, @@ -44,6 +44,7 @@ typedef struct { } BallArg; static int ballcolors[] = { DRed, DGreen, DBlue }; +static uint radii[] = { 20, 30, 50 }; static Rectangle bounds = {{PAD, PAD}, {PAD+WIDTH, PAD+HEIGHT}}; int init(char *label, Mousectl **mctl, Keyboardctl **kctl); @@ -52,9 +53,11 @@ 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); +void nooverlapcircles(Point centers[], int n, uint radius); Point randptinrect(Rectangle r); int randint(int lo, int hi); +uint maxelem(uint arr[], uint n); +double mass(uint radius); void ball(void *arg); void broadcast(Point p, Channel *cs[], int n); void frametick(void *arg); @@ -143,7 +146,7 @@ spawnballs(int n) { if ((ps = malloc(n*sizeof(Point))) == nil) sysfatal("failed to allocate position array"); - nooverlapcircles(ps, n); + nooverlapcircles(ps, n, maxelem(radii, NELEMS(radii))); if ((cs = malloc(n*sizeof(Channel **))) == nil) sysfatal("failed to allocate channel matrix"); @@ -164,7 +167,8 @@ spawnballs(int n) { arg->b.p = ps[i]; arg->b.v = V((double) randint(-VMAX, VMAX+1), (double) randint(-VMAX, VMAX+1)); - arg->b.m = MASS; + arg->b.r = radii[randint(0, NELEMS(radii))]; + arg->b.m = mass(arg->b.r); arg->color = ballcolors[randint(0, NELEMS(ballcolors))]; @@ -234,14 +238,14 @@ vcopyskip(Channel *dst[], Channel *src[], int n, int skip) { } void -nooverlapcircles(Point centers[], int n) { +nooverlapcircles(Point centers[], int n, uint radius) { int i, j; srand(time(0)); for (i = 0; i < n; i++) { - centers[i] = randptinrect(insetrect(bounds, RADIUS)); + centers[i] = randptinrect(insetrect(bounds, radius)); for (j = 0; j < i; j++) - if (iscollision(centers[j], centers[i])) + if (iscollision(centers[j], radius, centers[i], radius)) break; if (j < i) { /* overlapping */ i--; @@ -260,6 +264,24 @@ randint(int lo, int hi) { return (rand() % (hi-lo)) + lo; } +uint +maxelem(uint arr[], uint n) { + uint max; + + if (n == 0) + return 0; + max = arr[--n]; + while (n-- > 0) + if (arr[n] > max) + max = arr[n]; + return max; +} + +double +mass(uint radius) { + return (double) radius / 10 / G_PER_KG; +} + void ball(void *arg) { BallArg *barg; @@ -273,8 +295,8 @@ ball(void *arg) { barg = (BallArg *) arg; b = (Ball) barg->b; - fill = alloccircle(barg->color, DTransparent); - erase = alloccircle(BG, DTransparent); + fill = alloccircle(barg->color, DTransparent, b.r); + erase = alloccircle(BG, DTransparent, b.r); if (fill == nil ||erase == nil) sysfatal("failed to allocate image"); |