From 185c9ded6ed6603b42354264494214492eb1e37c Mon Sep 17 00:00:00 2001
From: Klemen Plestenjak <plestenjak.klemen@gmail.com>
Date: Thu, 9 Nov 2023 10:48:33 +0100
Subject: [PATCH] Fix collision checking when building

---
 engine/breeze/world/map.c     |  4 +---
 engine/breeze/world/tileset.c |  8 ++++++++
 game/main.c                   | 33 ++++++++++++++++++++++++++++++---
 3 files changed, 39 insertions(+), 6 deletions(-)

diff --git a/engine/breeze/world/map.c b/engine/breeze/world/map.c
index 5d03052..ff0da67 100644
--- a/engine/breeze/world/map.c
+++ b/engine/breeze/world/map.c
@@ -264,9 +264,7 @@ void bzTileMapDrawColliders(BzTileMap *map) {
                         DrawRectangleLines(posX, posY, sizeX, sizeY, color);
                         break;
                     case BZ_TILE_SHAPE_ELLIPSE:
-                        sizeX *= 0.5f;
-                        sizeY *= 0.5f;
-                        DrawEllipseLines(posX + sizeX, posY + sizeY, sizeX, sizeY, color);
+                        DrawEllipseLines(posX, posY, sizeX, sizeY, color);
                         break;
                 }
             }
diff --git a/engine/breeze/world/tileset.c b/engine/breeze/world/tileset.c
index 48484c5..fac7cf5 100644
--- a/engine/breeze/world/tileset.c
+++ b/engine/breeze/world/tileset.c
@@ -22,6 +22,14 @@ BzTileShape bzCuteObjectToTileShape(cute_tiled_object_t *object) {
     shape.sizeX = object->width;
     shape.sizeY = object->height;
 
+    if (shape.type == BZ_TILE_SHAPE_ELLIPSE) {
+        // Adjust to use radius and position to be center
+        shape.sizeX *= 0.5f;
+        shape.sizeY *= 0.5f;
+        shape.x += shape.sizeX;
+        shape.y += shape.sizeY;
+    }
+
     return shape;
 }
 
diff --git a/game/main.c b/game/main.c
index 7c32082..e1acefe 100644
--- a/game/main.c
+++ b/game/main.c
@@ -29,10 +29,13 @@ bool handleGameObjects(BzTileObjectLayer *objectLayer) {
 
 bool canBuildOn(BzTileMap *map, i32 tileX, i32 tileY, i32 sizeX, i32 sizeY) {
     // Ensure that it is within the map
-    if (tileX < 0 || tileX >= map->width ||
-        tileY < 0 || tileY >= map->height)
+    if (tileX < 0 || tileX + sizeX > map->width ||
+        tileY < 0 || tileY + sizeY > map->height)
         return false;
 
+    Rectangle buildArea = {tileX * map->tileWidth, tileY * map->tileHeight,
+                           sizeX * map->tileWidth, sizeY * map->tileHeight};
+
     // Need to check neighbour tiles
     // FIXME: Can't place right next to obstacle
     tileX -= 1;
@@ -44,7 +47,31 @@ bool canBuildOn(BzTileMap *map, i32 tileX, i32 tileY, i32 sizeX, i32 sizeY) {
     for (i32 y = tileY; y < tileY + sizeY; y++) {
         for (i32 x = tileX; x < tileX + sizeX; x++) {
             BzTileCollider collider = bzTileMapGetCollider(map, x, y);
-            if (collider.shapes[0].type != BZ_TILE_SHAPE_NONE) return false;
+            f32 posX = x * map->tileWidth;
+            f32 posY = y * map->tileHeight;
+            for (int i = 0; i < BZ_MAP_COLLIDER_DEPTH; i++) {
+                BzTileShape shape = collider.shapes[i];
+                shape.x += posX;
+                shape.y += posY;
+                switch (shape.type) {
+                    case BZ_TILE_SHAPE_NONE:
+                    case BZ_TILE_SHAPE_POINT:
+                        break;
+                    case BZ_TILE_SHAPE_RECT: {
+                        Rectangle shapeRec = {shape.x, shape.y, shape.sizeX, shape.sizeY};
+                        if (CheckCollisionRecs(buildArea, shapeRec))
+                            return false;
+                        break;
+                    }
+                    case BZ_TILE_SHAPE_ELLIPSE: {
+                        Vector2 pos = {shape.x, shape.y};
+                        f32 radius = (shape.sizeX + shape.sizeY) * 0.5f;
+                        if (CheckCollisionCircleRec(pos, radius, buildArea))
+                            return false;
+                        break;
+                    }
+                }
+            }
         }
     }