Removed box2d physics because of linking problems (and nothing's using it yet). Also tests work now.

```
ln -s ../tests/assets build/assets
cd build
make test
```

src/actor.c

@@ -1,6 +1,5 @@
 #include <SDL3/SDL.h>
 #include <SDL3_image/SDL_image.h>
-#include <box2d/box2d.h>
 #include <string.h>
 #include <sdlerror.h>
 

src/character.c

@@ -1,6 +1,5 @@
 #include <SDL3/SDL.h>
 #include <SDL3_image/SDL_image.h>
-#include <box2d/box2d.h>
 #include <sdlerror.h>
 #include <string.h>
 #include <jansson.h>

src/draw.c

@@ -1,7 +1,6 @@
 #include <SDL3/SDL.h>
 #include <SDL3_image/SDL_image.h>
 #include <SDL3_mixer/SDL_mixer.h>
-#include <box2d/box2d.h>
 #include <sdl3game/game.h>
 
 /* Draw a Gimpish background pattern to show transparency in the image */

src/game.c

@@ -1,12 +1,10 @@
 #include <SDL3/SDL.h>
 #include <SDL3_image/SDL_image.h>
 #include <SDL3_mixer/SDL_mixer.h>
-#include <box2d/box2d.h>
 #include <stdio.h>
 #include <sdlerror.h>
 
 #include <sdl3game/game.h>
-#include <sdl3game/physics.h>
 #include <sdl3game/tilemap.h>
 #include <sdl3game/sprite.h>
 #include <sdl3game/heap.h>
@@ -23,5 +21,6 @@ GAME_frame table;
 tilemap gamemap;
 MIX_Audio *bgm = NULL;
 MIX_Mixer *GAME_mixer = NULL;
+MIX_Track *GAME_tracks[64];
 SDL_FRect camera;
 GameState gamestate;

src/physics.c

@@ -1,52 +0,0 @@
-#include <SDL3/SDL.h>
-#include <SDL3_image/SDL_image.h>
-#include <SDL3_mixer/SDL_mixer.h>
-#include <box2d/box2d.h>
-#include <sdl3game/physics.h>
-
-b2WorldDef physicsWorldDef;
-b2WorldId physicsWorldId;
-b2BodyDef physicsGroundBodyDef;
-b2BodyId physicsGroundBodyId;
-b2Polygon physicsGroundBox;
-b2ShapeDef physicsGroundShapeDef;
-b2BodyDef physicsBallBodyDef;
-b2BodyId physicsBallBodyId;
-b2Polygon physicsBallBodyBox;
-b2ShapeDef physicsBallShapeDef;
-
-// Should do this more intelligently at some point -
-//        https://gafferongames.com/post/fix_your_timestep/
-
-float physicsTimeStep = 1.0f / 60.0f;
-int physicsSubStepCount = 4;
-
-void GAME_init_physics(void)
-{
-  /* Create the physics world */
-  physicsWorldDef = b2DefaultWorldDef();
-  physicsWorldDef.gravity = (b2Vec2){0.0f, 10.0f};
-  physicsWorldId = b2CreateWorld(&physicsWorldDef);
-
-  /* Create the ground box */
-  physicsGroundBodyDef = b2DefaultBodyDef();
-  physicsGroundBodyDef.position = (b2Vec2){0.0f, PHYSICS_SCREEN_SCALE(480.0f)};
-  physicsGroundBodyId = b2CreateBody(physicsWorldId, &physicsGroundBodyDef);
-  physicsGroundBox = b2MakeBox(PHYSICS_SCREEN_SCALE(320.0f), PHYSICS_SCREEN_SCALE(1.0f));
-  physicsGroundShapeDef = b2DefaultShapeDef();
-  b2CreatePolygonShape(physicsGroundBodyId, &physicsGroundShapeDef, &physicsGroundBox);
-
-  /* Create a dynamic physics body for the ball */
-  physicsBallBodyDef = b2DefaultBodyDef();
-  physicsBallBodyDef.type = b2_dynamicBody;
-  physicsBallBodyDef.position = (b2Vec2){0.0f, 0.0f};
-  physicsBallBodyId = b2CreateBody(physicsWorldId, &physicsBallBodyDef);
-  physicsBallBodyBox = b2MakeBox(PHYSICS_SCREEN_SCALE(128.0f), PHYSICS_SCREEN_SCALE(128.0f));
-  physicsBallShapeDef = b2DefaultShapeDef();
-  physicsBallShapeDef.density = 1.0f;
-  physicsBallShapeDef.restitution = 0.75f;
-  physicsBallShapeDef.friction = 0.3f;
-  b2CreatePolygonShape(physicsBallBodyId, &physicsBallShapeDef, &physicsBallBodyBox);
-  //b2CreateFixture(physicsBallBodyId, &physicsBallShapeDef);
-}
-

src/sprite.c

@@ -1,6 +1,5 @@
 #include <SDL3/SDL.h>
 #include <SDL3_image/SDL_image.h>
-#include <box2d/box2d.h>
 #include <string.h>
 #include <jansson.h>
 #include <sdlerror.h>