1 files changed, 47 insertions, 27 deletions

diff --git a/physics.c b/physics.c
index 94b15e8..c583d22 100644
--- a/physics.c
+++ b/physics.c
@@ -7,6 +7,7 @@
 static void mink(Body *a, Body *b, float *minx, float *miny, float *maxx, float *maxy);
 static int checkcollision(Body *a, Body *b);
 static void resolvecoll(Body *a, Body *b, float p[2]);
+static void mapcollision(Body *a);
 
 static EntityCollision ecoll[2048];
 static int             ecollstart, ecollend, ecollsi;
@@ -19,33 +20,7 @@ entphysics(float delta)
 		if(!e->active)
 			continue;
 
-		for(int y = 0; y < map_height; y++)
-			for(int x = 0; x < map_width; x++) {
-				if(!map_data[x + y * map_width])
-					continue;
-
-				Body b = {
-					.pos = {
-						x * ENTITY_SIZE * 2.0,
-						y * ENTITY_SIZE * 2.0,
-					},
-					.size = { ENTITY_SIZE, ENTITY_SIZE },
-				};
-
-				if(checkcollision(&e->body, &b)) {
-					float p[2];
-					resolvecoll(&e->body, &b, p);
-
-					for(int i = 0; i < 2; i++)
-						e->body.pos[i] -= p[i];
-
-					if(p[0] != 0.0) {
-						e->body.vel[0] = 0;
-					} else {
-						e->body.vel[1] = 0;
-					}
-				}
-			}
+		mapcollision(&e->body);
 
 		for(int j = i; j >= 0; j--) {
 			Entity *f = entitybuffer + j;
@@ -147,4 +122,49 @@ deqcoll(void)
 	return c;
 }
 
+void
+mapcollision(Body *a)
+{
+	int minx, miny, maxx, maxy;
+
+	minx = ((int)(a->pos[0] - a->size[0]) / ENTITY_SIZE) * ENTITY_SIZE;
+	maxx = ((int)(a->pos[0] + a->size[0]) / ENTITY_SIZE) * ENTITY_SIZE;
+	miny = ((int)(a->pos[1] - a->size[1]) / ENTITY_SIZE) * ENTITY_SIZE;
+	maxy = ((int)(a->pos[1] + a->size[1]) / ENTITY_SIZE) * ENTITY_SIZE;
+
+	for(int y = miny; y <= maxy + ENTITY_SIZE; y += ENTITY_SIZE)
+		for(int x = minx; x <= maxx + ENTITY_SIZE; x += ENTITY_SIZE) {
+			int tilex = x / (2 * ENTITY_SIZE);
+			int tiley = y / (2 * ENTITY_SIZE);
 
+			if(tilex < 0 || tilex >= map_width)
+				continue;
+			if(tiley < 0 || tiley >= map_height)
+				continue;
+
+			if(!map_data[tilex + tiley * map_width])
+				continue;
+
+			Body b = {
+				.pos = {
+					tilex * ENTITY_SIZE * 2.0,
+					tiley * ENTITY_SIZE * 2.0,
+				},
+				.size = { ENTITY_SIZE, ENTITY_SIZE },
+			};
+
+			if(checkcollision(a, &b)) {
+				float p[2];
+				resolvecoll(a, &b, p);
+
+				for(int i = 0; i < 2; i++)
+					a->pos[i] -= p[i];
+
+				if(p[0] != 0.0) {
+					a->vel[0] = 0;
+				} else {
+					a->vel[1] = 0;
+				}
+			}
+		}
+}