data/indicators/life.png: now built by povray from ship graphic.

[vor.git] / shape.c

diff --git a/shape.c b/shape.c
new file mode 100644 (file)
index 0000000..9d0501c
--- /dev/null
+++ b/shape.c
@@ -0,0 +1,63 @@
+#include <stdlib.h>
+#include "shape.h"
+
+void
+get_shape(SDL_Surface *img, struct shape *s)
+{
+       int x, y;
+       uint16_t *px, transp;
+       uint32_t bits;
+
+       if(img->format->BytesPerPixel != 2) {
+               fprintf(stderr, "get_shape(): not a 16-bit image!\n");
+               exit(1);
+       }
+
+       s->w = img->w; s->h = img->h;
+       s->mw = ((img->w+31)>>5) * img->h;
+       s->mask = malloc(4*s->mw);
+       if(!s->mask) {
+               fprintf(stderr, "can't malloc bitmask");
+               exit(1);
+       }
+
+       SDL_LockSurface(img);
+       px = img->pixels;
+       transp = img->format->colorkey;
+       bits = 0;
+       for(y=0; y<img->h; y++) {
+               for(x=0; x<img->w; x++) {
+                       if(*px++ != transp) bits |= 1;
+                       if(x == img->w-1 || !(x+1)%32) {
+                               *(s->mask++) = bits;
+                               bits = 0;
+                       } else bits = bits << 1;
+               }
+               px = (uint16_t *) ((uint8_t *) px + img->pitch - 2*img->w);
+       }
+       SDL_UnlockSurface(img);
+}
+
+#ifndef max
+#define max(a, b) ((a) > (b) ? (a) : (b))
+#endif
+
+#ifndef min
+#define min(a, b) ((a) < (b) ? (a) : (b))
+#endif
+
+int
+collide(int xdiff, int ydiff, struct shape *r, struct shape *s)
+{
+       int xov, yov;
+
+       if(xdiff >= 0) xov = max(min(r->w-xdiff, s->w), 0);
+       else xov = -max(min(s->w+xdiff, r->w), 0);
+
+       if(ydiff >= 0) yov = max(min(r->h-ydiff, s->h), 0);
+       else yov = -max(min(s->h+ydiff, r->h), 0);
+
+       if(xov == 0 && yov == 0) return 0;
+
+       return 0;
+}