#include "sprite.h"
void
-load_sprite(Sprite *sprite, char *filename)
+load_sprite(Sprite *s, char *filename)
{
- struct base_sprite *spr = &sprite->sprite;
- spr->image = load_image(filename);
- if(!spr->image) return;
- if(!spr->shape) {
- spr->shape = malloc(sizeof(struct shape));
- if(!spr->shape) {
- fprintf(stderr, "load_sprite(): can't allocate shape structure.\n");
- exit(1);
- }
- get_shape(spr->image, spr->shape);
- }
+ s->image = load_image(filename);
+ if(s->image) get_shape(s);
}
void
-get_shape(SDL_Surface *img, struct shape *s)
+get_shape(Sprite *s)
{
int x, y;
uint16_t *px, transp;
uint32_t bits = 0, bit, *p;
- if(img->format->BytesPerPixel != 2) {
+ if(s->image->format->BytesPerPixel != 2) {
fprintf(stderr, "get_shape(): not a 16-bit image!\n");
exit(1);
}
- s->area = 0;
- s->w = img->w; s->h = img->h;
- s->mw = ((img->w+31)>>5);
- s->mask = malloc(4*s->mw*s->h);
+ s->w = s->image->w; s->h = s->image->h;
+ s->mask_w = ((s->image->w+31)>>5);
+ s->mask = malloc(4*s->mask_w*s->h);
if(!s->mask) {
fprintf(stderr, "get_shape(): can't allocate bitmask.\n");
exit(1);
}
- SDL_LockSurface(img);
- px = img->pixels;
- transp = img->format->colorkey;
+ SDL_LockSurface(s->image);
+ px = s->image->pixels;
+ transp = s->image->format->colorkey;
p = s->mask;
- for(y=0; y<img->h; y++) {
+ for(y=0; y<s->image->h; y++) {
bit = 0;
- for(x=0; x<img->w; x++) {
+ for(x=0; x<s->image->w; x++) {
if(!bit) { bits = 0; bit = 0x80000000; }
- if(*px++ != transp) { bits |= bit; s->area++; }
+ if(*px++ != transp) { bits |= bit; }
bit >>= 1;
- if(!bit || x == img->w - 1) { *(p++) = bits; }
+ if(!bit || x == s->image->w - 1) { *(p++) = bits; }
}
- px = (uint16_t *) ((uint8_t *) px + img->pitch - 2*img->w);
+ px = (uint16_t *) ((uint8_t *) px + s->image->pitch - 2*s->image->w);
}
- SDL_UnlockSurface(img);
+ SDL_UnlockSurface(s->image);
}
static int
-line_collide(int xov, struct shape *r, uint32_t *rbits, struct shape *s, uint32_t *sbits)
+line_collide(int xov, unsigned bit, uint32_t *amask, uint32_t *bmask)
{
- int lshift, n, i, ret = 0;
- uint32_t lbits;
- struct shape *st;
- uint32_t *bt;
-
-
- if(xov < 0) {
- st = r; r = s; s = st;
- bt = rbits; rbits = sbits; sbits = bt;
- xov = -xov;
- }
-
+ int i, words = (xov-1) >> 5;
+ uint32_t abits;
- lshift = (r->w - xov) & 31;
- rbits += (r->w - xov) >> 5;
- n = (xov + 31) >> 5;
- for(i=0; i<n-1; i++) {
- lbits = *rbits++ << lshift;
- lbits |= *rbits >> (32 - lshift);
- if(lbits & *sbits++) ret = 1;
+ for(i=0; i<words; i++) {
+ abits = *amask++ << bit;
+ abits |= *amask >> (32-bit);
+ if(abits & *bmask++) return true;
}
- lbits = *rbits << lshift;
- if(lbits & *sbits) ret = 1;
+ abits = *amask << bit;
+ if(abits & *bmask) return true;
- return ret;
+ return false;
}
static int
-mask_collide(int xov, int yov, struct shape *r, struct shape *s)
+mask_collide(int xov, int yov, Sprite *a, Sprite *b)
{
- int y, ry, sy;
- uint32_t *rbits, *sbits;
+ int y;
+ int xoffset = a->w - xov;
+ int word = xoffset >> 5, bit = xoffset & 31;
+ uint32_t *amask = a->mask, *bmask = b->mask;
if(yov > 0) {
- ry = r->h - yov; sy = 0;
- rbits = r->mask + (r->h - yov) * r->mw;
- sbits = s->mask;
+ amask = a->mask + ((a->h - yov) * a->mask_w) + word;
+ bmask = b->mask;
} else {
- ry = 0; sy = s->h + yov;
- rbits = r->mask;
- sbits = s->mask + (s->h + yov) * s->mw;
+ yov = -yov;
+ amask = a->mask;
+ bmask = b->mask + ((b->h - yov) * b->mask_w) + word;
}
- for(y=0; y<abs(yov); y++) {
- if(line_collide(xov, r, rbits, s, sbits)) return 1;
- rbits += r->mw; sbits += s->mw;
+ for(y=0; y<yov; y++) {
+ if(line_collide(xov, bit, amask, bmask)) return 1;
+ amask += a->mask_w; bmask += b->mask_w;
}
return 0;
}
int
-collide(Sprite *r, Sprite *s)
+collide(Sprite *a, Sprite *b)
{
- struct shape *rs = r->sprite.shape;
- struct shape *ss = s->sprite.shape;
- int dx = s->sprite.x - r->sprite.x;
- int dy = s->sprite.y - r->sprite.y;
- int xov, yov;
+ int dx, dy, xov, yov;
+
+ if(b->x < a->x) { Sprite *tmp = a; a = b; b = tmp; }
+
+ dx = b->x - a->x;
+ dy = b->y - a->y;
- if(dx >= 0) xov = max(min(rs->w - dx, ss->w), 0);
- else xov = -max(min(ss->w + dx, rs->w), 0);
+ xov = max(min(a->w - dx, b->w), 0);
- if(dy >= 0) yov = max(min(rs->h - dy, ss->h), 0);
- else yov = -max(min(ss->h + dy, rs->h), 0);
+ if(dy >= 0) yov = max(min(a->h - dy, b->h), 0);
+ else yov = -max(min(a->h - -dy, b->h), 0);
if(xov == 0 || yov == 0) return false;
- else return mask_collide(xov, yov, rs, ss);
+ else return mask_collide(xov, yov, a, b);
}
int
-pixel_collide(unsigned int xoff, unsigned int yoff, struct shape *r)
+pixel_collide(Sprite *s, int x, int y)
{
uint32_t pmask;
- if(xoff >= r->w || yoff >= r->h) return 0;
+ if(x < s->x || y < s->y || x >= s->x + s->w || y >= s->y + s->h) return 0;
- pmask = 0x80000000 >> (xoff&0x1f);
- return r->mask[(yoff*r->mw) + (xoff>>5)] & pmask;
+ x -= s->x; y -= s->y;
+ pmask = 0x80000000 >> (x&0x1f);
+ return s->mask[(y*s->mask_w) + (x>>5)] & pmask;
}