// timers for rock generation.
float rtimers[4];
-int nrocks;
+
+uint32_t nrocks;
+uint32_t nrocks_timer;
+uint32_t nrocks_inc_ticks = 2*60*1000/(F_ROCKS-I_ROCKS);
// constants for rock generation.
#define KH 32.0 // 32 s for a speed=1 rock to cross the screen horizontally.
NULLERROR(surf_rock[i] = SDL_DisplayFormat(temp));
get_shape(surf_rock[i], &rock_shapes[i]);
}
- nrocks = 41;
return 0;
}
int i;
for(i = 0; i<MAXROCKS; i++) rock[i].active = 0;
+ nrocks = I_ROCKS;
+ nrocks_timer = 0;
}
enum { LEFT, RIGHT, TOP, BOTTOM };
+
+// compute the number of rocks/seccond that should be coming from each side
+
+// compute the speed ranges of rocks coming from each side
void
-rock_timer_increments(float *ti)
+rock_sides(float *ti, float *speed_min, float *speed_max)
{
float dx0,dx1, dy0,dy1;
+ float hfactor, vfactor;
int i;
for(i=0; i<4; i++) ti[i] = 0;
+ for(i=0; i<4; i++) speed_min[i] = 0;
+ for(i=0; i<4; i++) speed_max[i] = 0;
+ hfactor = nrocks/KH; vfactor = nrocks/KV;
dx0 = -RDX - screendx; dx1 = RDX - screendx;
dy0 = -RDY - screendy; dy1 = RDY - screendy;
if(dx0 != 0) {
if(dx0 < 0) {
- if(dx1 < 0) ti[RIGHT] = -(dx0+dx1)/2;
- else {
+ speed_max[RIGHT] = -dx0;
+ if(dx1 < 0) {
+ // Rocks moving left only. So the RIGHT side of the screen
+ speed_min[RIGHT] = -dx1;
+ ti[RIGHT] = -(dx0+dx1)/2;
+ } else {
+ // Rocks moving left and right
+ speed_max[LEFT] = dx1;
ti[RIGHT] = -dx0/2;
ti[LEFT] = dx1/2;
}
- } else ti[LEFT] = (dx0+dx1)/2;
+ } else {
+ // Rocks moving right only. So the LEFT side of the screen
+ speed_min[LEFT] = dx0;
+ speed_max[LEFT] = dx1;
+ ti[LEFT] = (dx0+dx1)/2;
+ }
}
+ ti[LEFT] *= hfactor;
+ ti[RIGHT] *= hfactor;
if(dy0 != 0) {
if(dy0 < 0) {
- if(dy1 < 0) ti[BOTTOM] = -(dy0+dy1)/2;
- else {
+ speed_max[BOTTOM] = -dy0;
+ if(dy1 < 0) {
+ // Rocks moving up only. So the BOTTOM of the screen
+ speed_min[BOTTOM] = -dy1;
+ ti[BOTTOM] = -(dy0+dy1)/2;
+ } else {
+ // Rocks moving up and down
+ speed_max[TOP] = dy1;
ti[BOTTOM] = -dy0/2;
ti[TOP] = dy1/2;
}
- } else ti[TOP] = (dy0+dy1)/2;
+ } else {
+ // Rocks moving down only. so the TOP of the screen
+ speed_min[TOP] = dy0;
+ speed_max[TOP] = dy1;
+ ti[TOP] = (dy0+dy1)/2;
+ }
}
+ ti[TOP] *= vfactor;
+ ti[BOTTOM] *= vfactor;
+}
+
+float
+weighted_rnd_range(float min, float max) {
+ return sqrt(min * min + rnd() * (max * max - min * min));
}
void
{
int i,j;
float ti[4];
- float x, y;
+ float rmin[4];
+ float rmax[4];
+
+ if(nrocks < F_ROCKS) {
+ nrocks_timer += ticks_since_last;
+ if(nrocks_timer >= nrocks_inc_ticks) {
+ nrocks_timer -= nrocks_inc_ticks;
+ nrocks++;
+ }
+ }
- rock_timer_increments(ti);
+ rock_sides(ti, rmin, rmax);
+ // loop through the four sides of the screen
for(i=0; i<4; i++) {
+ // see if we generate a rock for this side this frame
rtimers[i] += ti[i]*gamerate/20;
- if(rtimers[i] >= 1) {
+ while(rtimers[i] >= 1) {
+ rtimers[i] -= 1;
j=0;
while(rockptr->active && j<MAXROCKS) {
if(++rockptr - rock >= MAXROCKS) rockptr = rock;
j++;
}
if(!rockptr->active) {
- rtimers[i] -= 1;
rockptr->type_number = random() % NROCKS;
rockptr->image = surf_rock[rockptr->type_number];
rockptr->shape = &rock_shapes[rockptr->type_number];
case RIGHT:
rockptr->x = XSIZE;
rockptr->y = rnd()*(YSIZE + rockptr->image->h);
+
+ rockptr->dx = -weighted_rnd_range(rmin[i], rmax[i]) + screendx;
+ rockptr->dy = RDY*crnd();
break;
case LEFT:
rockptr->x = -rockptr->image->w;
rockptr->y = rnd()*(YSIZE + rockptr->image->h);
+
+ rockptr->dx = weighted_rnd_range(rmin[i], rmax[i]) + screendx;
+ rockptr->dy = RDY*crnd();
break;
case BOTTOM:
rockptr->x = rnd()*(XSIZE + rockptr->image->w);
rockptr->y = YSIZE;
+
+ rockptr->dx = RDY*crnd();
+ rockptr->dy = -weighted_rnd_range(rmin[i], rmax[i]) + screendy;
break;
case TOP:
rockptr->x = rnd()*(XSIZE + rockptr->image->w);
rockptr->y = -rockptr->image->h;
+
+ rockptr->dx = RDY*crnd();
+ rockptr->dy = weighted_rnd_range(rmin[i], rmax[i]) + screendy;
break;
}
- j=0;
- do {
- rockptr->dx = RDX*crnd();
- rockptr->dy = RDY*crnd();
- x = (rockptr->dx-screendx)*gamerate;
- y = (rockptr->dy-screendy)*gamerate;
- j++;
- } while(x < -rockptr->image->w || x >= XSIZE
- || y < -rockptr->image->h || y >= YSIZE);
- if(j > 1) printf("had to try %d times.\n", j);
-
rockptr->active = 1;
}
}
int i;
float dx, dy, n;
+ if(onlyslow) return;
+
for(i = 0; i<MAXROCKS; i++ ) {
if(rock[i].x <= 0) continue;
n = sqrt(dx*dx + dy*dy);
if(n < radius) {
- n *= 20;
- rock[i].dx += 54.0*(dx+30)/n;
+ n *= 15;
+ rock[i].dx += 54.0*dx/n;
rock[i].dy += 54.0*dy/n;
}
}