+#include <math.h>
#include <stdlib.h>
#include <string.h>
#include "config.h"
uint16_t *px, transp;
uint32_t bits = 0, bit, *p;
+ s->area = 0;
if(s->image->format->BytesPerPixel != 2) {
fprintf(stderr, "get_shape(): not a 16-bit image!\n");
exit(1);
bit = 0;
for(x=0; x<s->image->w; x++) {
if(!bit) { bits = 0; bit = 0x80000000; }
- if(*px++ != transp) { bits |= bit; }
+ if(*px++ != transp) { bits |= bit; s->area++; }
bit >>= 1;
if(!bit || x == s->image->w - 1) { *(p++) = bits; }
}
}
void
+reset_sprites(void)
+{
+ int i;
+
+ for(i=0; i<gw*gh; i++)
+ while(sprites[set][i]) {
+ Sprite *s = remove_sprite(&sprites[set][i]);
+ insert_sprite(&free_sprites[s->type], s);
+ s->flags = 0;
+ }
+}
+
+void
move_sprite(Sprite *s)
{
- // move it.
- s->x += (s->dx - screendx)*t_frame;
- s->y += (s->dy - screendy)*t_frame;
+ if(s->flags & MOVE) {
+ s->x += (s->dx - screendx)*t_frame;
+ s->y += (s->dy - screendy)*t_frame;
+ }
}
void
if(s->x + s->w < 0 || s->x >= XSIZE
|| s->y + s->h < 0 || s->y >= YSIZE) {
insert_sprite(&free_sprites[s->type], s);
- s->type = NONE;
+ s->flags = 0;
} else insert_sprite(square(s->x, s->y, 1-set), s);
}
int sq;
Sprite **head;
- // Move all the sprites (position and set)
+ // Move all the sprites
for(sq=0; sq<gw*gh; sq++) {
head=&sprites[set][sq];
while(*head) {
{
int dx, dy, xov, yov;
+ if(!COLLIDES(a) || !COLLIDES(b)) return false;
+
if(b->x < a->x) { Sprite *tmp = a; a = b; b = tmp; }
dx = b->x - a->x;
xov = max(min(a->w - dx, b->w), 0);
if(dy >= 0) yov = max(min(a->h - dy, b->h), 0);
- else yov = -max(min(a->h - -dy, b->h), 0);
+ else yov = -max(min(b->h - -dy, a->h), 0);
if(xov == 0 || yov == 0) return false;
else return mask_collide(xov, yov, a, b);
}
-int
-hit_in_square(Sprite *r, Sprite *s)
+void
+collide_with_list(Sprite *s, Sprite *list)
{
- for(; r; r=r->next) {
- if(collide(r, s)) return true;
+ for(; list; list=list->next)
+ if(collide(s, list)) do_collision(s, list);
+}
+
+void
+collisions(void)
+{
+ int i, end = gw*gh;
+ Sprite *s;
+ for(i=0; i<end; i++) {
+ for(s=sprites[set][i]; s; s=s->next) {
+ collide_with_list(s, s->next);
+ if(i+1 < end) collide_with_list(s, sprites[set][i+1]);
+ if(i+gw < end) collide_with_list(s, sprites[set][i+gw]);
+ if(i+gw+1 < end) collide_with_list(s, sprites[set][i+gw+1]);
+ }
}
- return false;
}
-int
+Sprite *
+hit_in_square(Sprite *r, Sprite *s)
+{
+ for(; r; r=r->next)
+ if(collide(r, s)) break;
+ return r;
+}
+
+Sprite *
collides(Sprite *s)
{
int l, r, t, b;
Sprite **sq;
+ Sprite *c;
l = (s->x + grid_size) / grid_size;
r = (s->x + s->w + grid_size) / grid_size;
b = (s->y + s->h + grid_size) / grid_size;
sq = &sprites[set][l + t*gw];
- if(hit_in_square(*sq, s)) return true;
- if(l > 0 && hit_in_square(*(sq-1), s)) return true;
- if(t > 0 && hit_in_square(*(sq-gw), s)) return true;
- if(l > 0 && t > 0 && hit_in_square(*(sq-1-gw), s)) return true;
+ if((c = hit_in_square(*sq, s))) return c;
+ if(l > 0 && (c = hit_in_square(*(sq-1), s))) return c;
+ if(t > 0 && (c = hit_in_square(*(sq-gw), s))) return c;
+ if(l > 0 && t > 0 && (c = hit_in_square(*(sq-1-gw), s))) return c;
if(r > l) {
- if(hit_in_square(*(sq+1), s)) return true;
- if(t > 0 && hit_in_square(*(sq+1-gw), s)) return true;
+ if((c = hit_in_square(*(sq+1), s))) return c;
+ if(t > 0 && hit_in_square(*(sq+1-gw), s)) return c;
}
if(b > t) {
- if(hit_in_square(*(sq+gw), s)) return true;
- if(l > 0 && hit_in_square(*(sq-1+gw), s)) return true;
+ if((c = hit_in_square(*(sq+gw), s))) return c;
+ if(l > 0 && (c = hit_in_square(*(sq-1+gw), s))) return c;
}
- if(r > l && b > t && hit_in_square(*(sq+1+gw), s)) return true;
- return false;
+ if(r > l && b > t && (c = hit_in_square(*(sq+1+gw), s))) return c;
+ return NULL;
}
int
pixel_collide(Sprite *s, int x, int y)
{
uint32_t pmask;
+
+ if(!COLLIDES(s)) return false;
if(x < s->x || y < s->y || x >= s->x + s->w || y >= s->y + s->h) return 0;
return s->mask[(y*s->mask_w) + (x>>5)] & pmask;
}
-int
+Sprite *
pixel_hit_in_square(Sprite *r, float x, float y)
{
for(; r; r=r->next) {
- if(pixel_collide(r, x, y)) return 1;
+ if(COLLIDES(r) && pixel_collide(r, x, y)) return r;
}
return 0;
}
-int
+Sprite *
pixel_collides(float x, float y)
{
int l, t;
Sprite **sq;
+ Sprite *ret;
l = (x + grid_size) / grid_size; t = (y + grid_size) / grid_size;
sq = &sprites[set][l + t*gw];
- if(pixel_hit_in_square(*sq, x, y)) return true;
- if(l > 0 && pixel_hit_in_square(*(sq-1), x, y)) return true;
- if(t > 0 && pixel_hit_in_square(*(sq-gw), x, y)) return true;
- if(l > 0 && t > 0 && pixel_hit_in_square(*(sq-1-gw), x, y)) return true;
- return false;
+ if((ret = pixel_hit_in_square(*sq, x, y))) return ret;
+ if(l > 0 && (ret = pixel_hit_in_square(*(sq-1), x, y))) return ret;
+ if(t > 0 && (ret = pixel_hit_in_square(*(sq-gw), x, y))) return ret;
+ if(l > 0 && t > 0 && (ret = pixel_hit_in_square(*(sq-1-gw), x, y))) return ret;
+ return 0;
+}
+
+
+float
+sprite_mass(Sprite *s)
+{
+ if(s->type == SHIP) return s->area;
+ else if(s->type == ROCK) return 3 * s->area;
+ else return 0;
+}
+
+void
+bounce(Sprite *a, Sprite *b)
+{
+ float x, y, n;
+ float va, vb, vc;
+ float ma, mb;
+
+ // (x, y) is unit vector pointing from A's center to B's center.
+ x = (b->x + b->w / 2) - (a->x + a->w / 2);
+ y = (b->y + b->h / 2) - (a->y + a->h / 2);
+ n = sqrt(x*x + y*y); x /= n; y /= n;
+
+ // velocities along (x, y), or 0 if already moving away.
+ va = x*a->dx + y*a->dy;
+ vb = x*b->dx + y*b->dy;
+ if(vb-va > 0) return;
+
+ ma = sprite_mass(a); mb = sprite_mass(b);
+ vc = (va*ma + vb*mb) / (ma+mb);
+
+ a->dx += 2*x*(vc-va); a->dy += 2*y*(vc-va);
+ b->dx += 2*x*(vc-vb); b->dy += 2*y*(vc-vb);
}
Got questions, comments, patches, etc.? Contact Jason Woofenden