1 files changed, 11 insertions, 2 deletions

diff --git a/src/isogfx.c b/src/isogfx.c
index 5d23ae4..c3a87bf 100644
--- a/src/isogfx.c
+++ b/src/isogfx.c
@@ -84,6 +84,12 @@ static inline ivec2 iso2cart(ivec2 iso, int s, int t, int w) {
                  .y = (iso.x + iso.y) * (t / 2)};
 }
 
+static inline vec2 vec2_add(vec2 a, vec2 b) {
+  return (vec2){.x = a.x + b.x, .y = a.y + b.y};
+}
+
+static inline vec2 ivec2_to_vec2(ivec2 a) { return (vec2){a.x, a.y}; }
+
 // Method 1.
 // static inline vec2 cart2iso(vec2 cart, int s, int t, int w) {
 //  const double x    = cart.x - (double)(w / 2);
@@ -682,9 +688,12 @@ void isogfx_pick_tile(
   assert(xiso);
   assert(yiso);
 
+  const vec2 camera  = ivec2_to_vec2(iso->camera);
+  const vec2 xy_cart = vec2_add(camera, (vec2){xcart, ycart});
+
   const vec2 xy_iso = cart2iso(
-      (vec2){.x = xcart, .y = ycart}, iso->map->base_tile_width,
-      iso->map->base_tile_height, iso->screen.width);
+      xy_cart, iso->map->base_tile_width, iso->map->base_tile_height,
+      iso->screen.width);
 
   if ((0 <= xy_iso.x) && (xy_iso.x < iso->map->world_width) &&
       (0 <= xy_iso.y) && (xy_iso.y < iso->map->world_height)) {