oops, have to check all 9 buckets.

maybe I should consider doing the 4 resort/check cycles instead...

diff --git a/rocks.c b/rocks.c
index e098fa0..f68a57a 100644 (file)
--- a/rocks.c
+++ b/rocks.c
@@ -301,8 +301,18 @@ hit_rocks(float x, float y, struct shape *shape)
        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(hit_in_bucket(b-1, x, y, shape)) return 1;
+       if(hit_in_bucket(b-bw, x, y, shape)) return 1;
+       if(hit_in_bucket(b-bw-1, x, y, shape)) return 1;
+
+       if(bdx) {
+               if(hit_in_bucket(b+1, x, y, shape)) return 1;
+               if(hit_in_bucket(b+1-bw, x, y, shape)) return 1;
+       }
+       if(bdy) {
+               if(hit_in_bucket(b+bw, x, y, shape)) return 1;
+               if(hit_in_bucket(b+bw-1, x, y, shape)) return 1;
+       }
        if(bdx && bdy && hit_in_bucket(b+bw+1, x, y, shape)) return 1;
        return 0;
 }

diff --git a/shape.c b/shape.c
index 92729e9..75424ef 100644 (file)
--- a/shape.c
+++ b/shape.c
@@ -116,6 +116,6 @@ pixel_collide(unsigned int xoff, unsigned int yoff, struct shape *r)
        
        if(xoff >= r->w || yoff >= r->h) return 0;
 
-       pmask = 1 << (32 - (xoff&0x1f));
+       pmask = 0x80000000 >> (xoff&0x1f);
        return r->mask[(yoff*r->mw) + (xoff>>5)] & pmask;
 }