#include "rocks.h"
#include "shape.h"
+SDL_Surface *load_image(char *filename);
+
struct rock_struct {
struct rock_struct *next;
float x,y,dx,dy;
struct rock_struct rocks[MAXROCKS], *free_rocks;
struct rock_struct **rock_buckets[2];
-int n_buckets, p;
+int n_buckets;
+// we have two sets of buckets -- this variable tells which we are using.
+int p;
int bw, bh;
int grid_size;
float nrocks_inc_ticks = 2*60*20/(F_ROCKS-I_ROCKS);
// constants for rock generation.
-#define KH (32.0*20) // 32 s for a speed=1 rock to cross the screen horizontally.
-#define KV (24.0*20) // 24 s for a speed=1 rock to cross the screen vertically.
+#define KH (32*20) // 32 s for a speed=1 rock to cross the screen horizontally.
+#define KV (24*20) // 24 s for a speed=1 rock to cross the screen vertically.
#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); }
+static inline struct rock_struct **
+bucket(int x, int y, int p)
+{
+ int b = (x+grid_size)/grid_size + bw*((y+grid_size)/grid_size);
+ return &rock_buckets[p][b];
+}
void
init_buckets(void)
{
- bw = (XSIZE+2*grid_size-1) / grid_size;
- bh = (YSIZE+2*grid_size-1) / grid_size;
+ int scr_grid_w = (XSIZE+2*grid_size-1) / grid_size;
+ int scr_grid_h = (YSIZE+2*grid_size-1) / grid_size;
+ bw = 1 + scr_grid_w + 1;
+ bh = 1 + scr_grid_h + 1;
n_buckets = bw * bh;
rock_buckets[0] = malloc(n_buckets * sizeof(struct rock_struct *));
}
void
-sort_rock(struct rock_struct *q, struct rock_struct *r, int p)
+transfer_rock(struct rock_struct *r, struct rock_struct **from, struct rock_struct **to)
{
- 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;
+ *from = r->next;
+ r->next = *to;
+ *to = r;
}
void
nrocks_timer = 0;
}
+#define ROCK_LEN sizeof("sprites/rockXX.png")
+
int
init_rocks(void)
{
int i;
- char a[MAX_PATH_LEN];
- SDL_Surface *temp;
+ char a[ROCK_LEN];
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));
+ snprintf(a, ROCK_LEN, "sprites/rock%02d.png", i);
+ NULLERROR(surf_rock[i] = load_image(a));
get_shape(surf_rock[i], &rock_shapes[i]);
maxw = max(maxw, rock_shapes[i].w);
maxh = max(maxh, rock_shapes[i].h);
r->dy = weighted_rnd_range(rmin[i], rmax[i]) + screendy;
break;
}
- sort_rock((struct rock_struct *)&free_rocks, r, p);
+ transfer_rock(r, &free_rocks, bucket(r->x, r->y, p));
}
}
}
move_rocks(void)
{
int b;
- struct rock_struct *q,*r;
+ struct rock_struct **head;
+ struct rock_struct *r;
// Move all the rocks
for(b=0; b<n_buckets; b++) {
- q=(struct rock_struct *)&rock_buckets[p][b]; r=q->next;
- while(r) {
+ head=&rock_buckets[p][b]; r=*head;
+ while(*head) {
+ r=*head;
+
// move
r->x += (r->dx - screendx)*t_frame;
r->y += (r->dy - screendy)*t_frame;
- // clip
+ // clip it, or sort it into the other bucket set
+ // (either way we move it out of this list).
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;
+ transfer_rock(r, head, &free_rocks);
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;
+ } else transfer_rock(r, head, bucket(r->x, r->y, 1-p));
}
}
p = 1-p; // switch current set of buckets.
}
int
-hit_in_bucket(int b, float x, float y, struct shape *shape)
+hit_in_bucket(struct rock_struct *r, float x, float y, struct shape *shape)
{
- struct rock_struct *r;
-
- for(r=rock_buckets[p][b]; r; r=r->next) {
+ for(; 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 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 ix, iy;
+ int l, r, t, b;
+ struct rock_struct **bucket;
+
+ ix = x + grid_size; iy = y + grid_size;
+ l = ix / grid_size; r = (ix+shape->w)/grid_size;
+ t = iy / grid_size; b = (iy+shape->h)/grid_size;
+ bucket = &rock_buckets[p][l + t*bw];
+
+ if(hit_in_bucket(*bucket, x, y, shape)) return true;
+ if(l > 0 && hit_in_bucket(*(bucket-1), x, y, shape)) return true;
+ if(t > 0 && hit_in_bucket(*(bucket-bw), x, y, shape)) return true;
+ if(l > 0 && t > 0 && hit_in_bucket(*(bucket-1-bw), x, y, shape)) return true;
+
+ if(r > l) {
+ if(hit_in_bucket(*(bucket+1), x, y, shape)) return true;
+ if(t > 0 && hit_in_bucket(*(bucket+1-bw), x, y, shape)) return true;
+ }
+ if(b > t) {
+ if(hit_in_bucket(*(bucket+bw), x, y, shape)) return true;
+ if(l > 0 && hit_in_bucket(*(bucket-1+bw), x, y, shape)) return true;
+ }
+ if(r > l && b > t && hit_in_bucket(*(bucket+1+bw), x, y, shape)) return true;
+ return false;
}
int
-pixel_hit_in_bucket(int b, float x, float y)
+pixel_hit_in_bucket(struct rock_struct *r, float x, float y)
{
- struct rock_struct *r;
- for(r=rock_buckets[p][b]; r; r=r->next) {
+ for(; 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;
}
int
pixel_hit_rocks(float x, float y)
{
- int b = bucket(x, y);
- if(pixel_hit_in_bucket(b, x, y)) return 1;
- if(pixel_hit_in_bucket(b-1, x, y)) return 1;
- if(pixel_hit_in_bucket(b-bw, x, y)) return 1;
- if(pixel_hit_in_bucket(b-bw-1, x, y)) return 1;
- return 0;
+ int ix, iy;
+ int l, t;
+ struct rock_struct **bucket;
+
+ ix = x + grid_size; iy = y + grid_size;
+ l = ix / grid_size; t = iy / grid_size;
+ bucket = &rock_buckets[p][l + t*bw];
+ if(pixel_hit_in_bucket(*bucket, x, y)) return true;
+ if(l > 0 && pixel_hit_in_bucket(*(bucket-1), x, y)) return true;
+ if(t > 0 && pixel_hit_in_bucket(*(bucket-bw), x, y)) return true;
+ if(l > 0 && t > 0 && pixel_hit_in_bucket(*(bucket-1-bw), x, y)) return true;
+ return false;
}
void
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