fix: crash when dragging out of the window

1 files changed, 5 insertions, 4 deletions

diff --git a/game.c b/game.c
index e05f39b..04e7ba2 100644
--- a/game.c
+++ b/game.c
@@ -220,9 +220,10 @@ void init(struct image canvas) {
 void draw( struct image canvas, struct image texture, size_t xpos, size_t ypos, bool vertical) {
   for (size_t y = 0; y < texture.height; y++) {
     for (size_t x = 0; x < texture.width; x++) {
-      size_t canvas_y = vertical ? x : y;
-      size_t canvas_x = vertical ? y : x;
-      canvas.buf[(ypos + canvas_y) * canvas.width + xpos + canvas_x] = texture.buf[y * texture.width + x];
+      int canvas_y = (vertical ? x : y) + ypos;
+      int canvas_x = (vertical ? y : x) + xpos;
+      if (canvas_x < 0 || canvas_x >= (int) canvas.width - 1 || canvas_y < 0 || canvas_y >= (int) canvas.height - 1) continue;
+      canvas.buf[canvas_y * canvas.width + canvas_x] = texture.buf[y * texture.width + x];
     }
   }
 }
@@ -280,7 +281,7 @@ void render(struct image canvas) {
 
   // active
   if (has_active) {
-    draw(canvas, red_and_peach_dominoes[active.back.val][active.front.val], CLAMP(mouse_x + active.front.x, 0, canvas.width), CLAMP(mouse_y + active.front.y, 0, canvas.height), active.front.vertical);
+    draw(canvas, red_and_peach_dominoes[active.back.val][active.front.val], mouse_x + active.front.x, mouse_y + active.front.y, active.front.vertical);
   }
 
   // character