#include "shape.h"
struct rock_struct {
+ struct rock_struct *next;
float x,y,dx,dy;
- int active;
SDL_Surface *image;
struct shape *shape;
int type_number;
};
-struct rock_struct rock[MAXROCKS], *rockptr = rock;
+struct rock_struct rocks[MAXROCKS], *free_rocks;
+
+struct rock_struct **rock_buckets[2];
+int n_buckets, p;
+int bw, bh;
+int grid_size;
SDL_Surface *surf_rock[NROCKS];
struct shape rock_shapes[NROCKS];
#define RDX 2.5 // range for rock dx values (+/-)
#define RDY 2.5 // range for rock dy values (+/-)
+static inline int bucket(int x, int y) { return (1+x/grid_size) + bw*(1+y/grid_size); }
+
+void
+init_buckets(void)
+{
+ bw = (XSIZE+2*grid_size-1) / grid_size;
+ bh = (YSIZE+2*grid_size-1) / grid_size;
+ n_buckets = bw * bh;
+
+ rock_buckets[0] = malloc(n_buckets * sizeof(struct rock_struct *));
+ rock_buckets[1] = malloc(n_buckets * sizeof(struct rock_struct *));
+ if(!rock_buckets[0] || !rock_buckets[1]) {
+ fprintf(stderr, "Can't allocate rock buckets.\n");
+ exit(1);
+ }
+ p = 0;
+}
+
+void
+sort_rock(struct rock_struct *q, struct rock_struct *r, int p)
+{
+ int b = bucket(r->x, r->y);
+ q->next = r->next; // remove from old list
+ r->next = rock_buckets[p][b]; // insert into new list
+ rock_buckets[p][b] = r;
+}
+
+void
+reset_rocks(void)
+{
+ int i;
+
+ for(i=0; i<MAXROCKS; i++) rocks[i].image = NULL;
+ rocks[0].next = NULL; free_rocks = &rocks[MAXROCKS-1];
+ for(i = 1; i<MAXROCKS; i++) rocks[i].next = &rocks[i-1];
+ for(i = 0; i<n_buckets; i++) {
+ rock_buckets[0][i] = NULL;
+ rock_buckets[1][i] = NULL;
+ }
+
+ nrocks = I_ROCKS;
+ nrocks_timer = 0;
+}
+
int
init_rocks(void)
{
int i;
char a[MAX_PATH_LEN];
SDL_Surface *temp;
+ int maxw=0, maxh=0;
for(i = 0; i<NROCKS; i++) {
snprintf(a,MAX_PATH_LEN,add_path("sprites/rock%02d.png"),i);
NULLERROR(temp = IMG_Load(a));
NULLERROR(surf_rock[i] = SDL_DisplayFormat(temp));
get_shape(surf_rock[i], &rock_shapes[i]);
+ maxw = max(maxw, rock_shapes[i].w);
+ maxh = max(maxh, rock_shapes[i].h);
}
+ grid_size = max(maxw, maxh) * 3 / 2;
+ init_buckets();
reset_rocks();
return 0;
}
-void
-reset_rocks(void)
-{
- 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/second that should be coming from each side
-
-// compute the speed ranges of rocks coming from each side
+// compute the number of rocks/tick that should be coming from each side,
+// and the speed ranges of rocks coming from each side
void
rock_sides(float *ti, float *speed_min, float *speed_max)
{
void
new_rocks(void)
{
- int i,j;
+ int i;
+ struct rock_struct *r;
float ti[4];
float rmin[4];
float rmax[4];
rock_sides(ti, rmin, rmax);
- // loop through the four sides of the screen
+ // increment timers
+ for(i=0; i<4; i++) rtimers[i] += ti[i]*t_frame;
+
+ // generate rocks
for(i=0; i<4; i++) {
- // see if we generate a rock for this side this frame
- rtimers[i] += ti[i]*t_frame;
while(rtimers[i] >= 1) {
rtimers[i] -= 1;
- j=0;
- while(rockptr->active && j<MAXROCKS) {
- if(++rockptr - rock >= MAXROCKS) rockptr = rock;
- j++;
- }
- if(!rockptr->active) {
- rockptr->type_number = random() % NROCKS;
- rockptr->image = surf_rock[rockptr->type_number];
- rockptr->shape = &rock_shapes[rockptr->type_number];
- switch(i) {
- case RIGHT:
- rockptr->x = XSIZE;
- rockptr->y = frnd()*(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 = frnd()*(YSIZE + rockptr->image->h);
-
- rockptr->dx = weighted_rnd_range(rmin[i], rmax[i]) + screendx;
- rockptr->dy = RDY*crnd();
- break;
- case BOTTOM:
- rockptr->x = frnd()*(XSIZE + rockptr->image->w);
- rockptr->y = YSIZE;
-
- rockptr->dx = RDX*crnd();
- rockptr->dy = -weighted_rnd_range(rmin[i], rmax[i]) + screendy;
- break;
- case TOP:
- rockptr->x = frnd()*(XSIZE + rockptr->image->w);
- rockptr->y = -rockptr->image->h;
-
- rockptr->dx = RDX*crnd();
- rockptr->dy = weighted_rnd_range(rmin[i], rmax[i]) + screendy;
- break;
- }
-
- rockptr->active = 1;
+ if(!free_rocks) return; // sorry, we ran out of rocks!
+ r = free_rocks;
+ r->type_number = urnd() % NROCKS;
+ r->image = surf_rock[r->type_number];
+ r->shape = &rock_shapes[r->type_number];
+ switch(i) {
+ case RIGHT:
+ r->x = XSIZE;
+ r->y = frnd()*(YSIZE + r->image->h);
+
+ r->dx = -weighted_rnd_range(rmin[i], rmax[i]) + screendx;
+ r->dy = RDY*crnd();
+ break;
+ case LEFT:
+ r->x = -r->image->w;
+ r->y = frnd()*(YSIZE + r->image->h);
+
+ r->dx = weighted_rnd_range(rmin[i], rmax[i]) + screendx;
+ r->dy = RDY*crnd();
+ break;
+ case BOTTOM:
+ r->x = frnd()*(XSIZE + r->image->w);
+ r->y = YSIZE;
+
+ r->dx = RDX*crnd();
+ r->dy = -weighted_rnd_range(rmin[i], rmax[i]) + screendy;
+ break;
+ case TOP:
+ r->x = frnd()*(XSIZE + r->image->w);
+ r->y = -r->image->h;
+
+ r->dx = RDX*crnd();
+ r->dy = weighted_rnd_range(rmin[i], rmax[i]) + screendy;
+ break;
}
+ sort_rock((struct rock_struct *)&free_rocks, r, p);
}
}
}
void
move_rocks(void)
{
- int i;
+ int b;
+ struct rock_struct *q,*r;
// Move all the rocks
- for(i = 0; i < MAXROCKS; i++) {
- if(rock[i].active) {
+ for(b=0; b<n_buckets; b++) {
+ q=(struct rock_struct *)&rock_buckets[p][b]; r=q->next;
+ while(r) {
// move
- rock[i].x += (rock[i].dx-screendx)*t_frame;
- rock[i].y += (rock[i].dy-screendy)*t_frame;
+ r->x += (r->dx - screendx)*t_frame;
+ r->y += (r->dy - screendy)*t_frame;
+
// clip
- if(rock[i].x < -rock[i].image->w || rock[i].x >= XSIZE
- || rock[i].y < -rock[i].image->h || rock[i].y >= YSIZE) {
- rock[i].active = 0;
- }
+ if(r->x + r->image->w < 0 || r->x >= XSIZE
+ || r->y + r->image->h < 0 || r->y >= YSIZE) {
+ q->next = r->next;
+ r->next = free_rocks; free_rocks = r;
+ r->image = NULL;
+ } else sort_rock(q,r,1-p);
+ if(q->next == r) q = q->next;
+ if(q) r = q->next; else r = NULL;
}
}
+ p = 1-p; // switch current set of buckets.
}
void
draw_rocks(void)
{
int i;
- SDL_Rect src, dest;
-
- src.x = 0; src.y = 0;
-
- for(i = 0; i<MAXROCKS; i++) {
- if(rock[i].active) {
- src.w = rock[i].image->w;
- src.h = rock[i].image->h;
+ SDL_Rect dest;
- dest.w = src.w;
- dest.h = src.h;
- dest.x = (int) rock[i].x;
- dest.y = (int) rock[i].y;
+ for(i=0; i<MAXROCKS; i++) {
+ if(!rocks[i].image) continue;
+ dest.x = rocks[i].x; dest.y = rocks[i].y;
+ SDL_BlitSurface(rocks[i].image,NULL,surf_screen,&dest);
+ }
+}
- SDL_BlitSurface(rock[i].image,&src,surf_screen,&dest);
+int
+hit_in_bucket(int b, float x, float y, struct shape *shape)
+{
+ struct rock_struct *r;
- }
+ for(r=rock_buckets[p][b]; r; r=r->next) {
+ if(collide(x - r->x, y - r->y, r->shape, shape)) return 1;
}
+ return 0;
}
int
hit_rocks(float x, float y, struct shape *shape)
{
- int i;
-
- for(i=0; i<MAXROCKS; i++) {
- if(rock[i].active) {
- if(collide(x-rock[i].x, y-rock[i].y, rock[i].shape, shape))
- return 1;
- }
- }
+ int b = bucket(x, y);
+ int bdx = ((int)x+shape->w)/grid_size - (int)x/grid_size;
+ int bdy = ((int)y+shape->h)/grid_size - (int)y/grid_size;
+ if(hit_in_bucket(b, x, y, shape)) return 1;
+ if(bdx && hit_in_bucket(b+1, x, y, shape)) return 1;
+ if(bdy && hit_in_bucket(b+bw, x, y, shape)) return 1;
+ if(bdx && bdy && hit_in_bucket(b+bw+1, x, y, shape)) return 1;
return 0;
}
int
pixel_hit_rocks(float x, float y)
{
- int i;
- float xoff, yoff;
+ int b;
+ struct rock_struct *r;
- for(i=0; i<MAXROCKS; i++) {
- if(rock[i].active) {
- xoff = x - rock[i].x; if(xoff < 0) continue;
- yoff = y - rock[i].y; if(yoff < 0) continue;
- if(pixel_collide(xoff, yoff, rock[i].shape)) return 1;
- }
+ b = bucket(x, y);
+ for(r=rock_buckets[p][b]; r; r=r->next) {
+ if(x < r->x || y < r->y) continue;
+ if(pixel_collide(x - r->x, y - r->y, r->shape)) return 1;
}
return 0;
}
void
blast_rocks(float x, float y, float radius, int onlyslow)
{
- int i;
+ int b;
+ struct rock_struct *r;
float dx, dy, n;
if(onlyslow) return;
- for(i = 0; i<MAXROCKS; i++ ) {
- if(rock[i].x <= 0) continue;
+ for(b=0; b<n_buckets; b++) {
+ for(r=rock_buckets[p][b]; r; r=r->next) {
+ if(r->x <= 0) continue;
- // This makes it so your explosion from dying magically doesn't leave
- // any rocks that aren't moving much on the x axis. If onlyslow is set,
- // only rocks that are barely moving will be pushed.
- if(onlyslow && (rock[i].dx-screendx < -4 || rock[i].dx-screendx > 3)) continue;
+ // This makes it so your explosion from dying magically doesn't leave
+ // any rocks that aren't moving much on the x axis. If onlyslow is set,
+ // only rocks that are barely moving will be pushed.
+ if(onlyslow && (r->dx - screendx < -4 || r->dx - screendx > 3)) continue;
- dx = rock[i].x - x;
- dy = rock[i].y - y;
+ dx = r->x - x;
+ dy = r->y - y;
- n = sqrt(dx*dx + dy*dy);
- if(n < radius) {
- n *= 15;
- rock[i].dx += 54.0*dx/n;
- rock[i].dy += 54.0*dy/n;
+ n = sqrt(dx*dx + dy*dy);
+ if(n < radius) {
+ n *= 15;
+ r->dx += 54.0*dx/n;
+ r->dy += 54.0*dy/n;
+ }
}
}
}
Got questions, comments, patches, etc.? Contact Jason Woofenden