ysge.scene source code

1 /// contains the Scene class
2 module ysge.scene;
3 
4 import ysge.project;
5 public import ysge.objects.simpleBox;
6 
7 /// individual scene containing objects
8 class Scene {
9 	GameObject[] objects;
10 	UIElement[]  ui;
11 	SDL_Color    bg;
12 	Vec2!int     camera;
13 	bool         cameraFollowsObject;
14 	Vec2!int*    cameraFollow;
15 
16 	/// called when this scene is set as the project's current scene
17 	abstract void Init(Project parent);
18 	/// run every frame
19 	abstract void Update(Project parent);
20 	/// run when an event is created
21 	abstract void HandleEvent(Project parent, SDL_Event e);
22 
23 	/// makes the camera follow an object
24 	void CameraFollowObject(SimpleBox obj) {
25 		cameraFollowsObject = true;
26 		cameraFollow        = cast(Vec2!int*) &obj.box;
27 	}
28 
29 	/// stops the camera from following an object
30 	void StopFollowingObject() {
31 		cameraFollowsObject = false;
32 		cameraFollow        = null;
33 	}
34 
35 	/// adds a game object to the scene's object array
36 	void AddObject(GameObject object) {
37 		objects ~= object;
38 	}
39 
40 	/// adds a UI element to the scene
41 	void AddUI(UIElement element) {
42 		ui ~= element;
43 	}
44 
45 	/**
46 	* makes the camera follow an object if enabled
47 	* should not be called by the user
48 	*/
49 	void UpdateCamera(Project parent) {
50 		if (cameraFollowsObject) {
51 			auto     screenRes = parent.GetResolution();
52 			Vec2!int pos       = Vec2!int(cameraFollow.x, cameraFollow.y);
53 			Vec2!int size      = Vec2!int(cameraFollow.x, cameraFollow.y);
54 
55 			camera.x = pos.x - (screenRes.x / 2);
56 			camera.y = pos.y - (screenRes.y / 2);
57 		}
58 	}
59 
60 	/**
61 	* calls the update function of all objects in the scene
62 	* should not be called by the user
63 	*/
64 	void UpdateObjects(Project parent) {
65 		foreach (ref object ; objects) {
66 			object.Update(parent);
67 		}
68 	}
69 
70 	/**
71 	* sends event to UI elements
72 	* should not be called by the user
73 	*/
74 	bool HandleUIEvent(Project parent, SDL_Event e) {
75 		foreach (ref element ; ui) {
76 			if (element.HandleEvent(parent, e)) {
77 				return true;
78 			}
79 		}
80 		return false;
81 	}
82 
83 	/// render the scene, should not be called by the user
84 	void Render(Project parent) {
85 		SDL_SetRenderDrawColor(parent.renderer, bg.r, bg.g, bg.b, bg.a);
86 		SDL_RenderClear(parent.renderer);
87 
88 		foreach (ref object ; objects) {
89 			object.Render(parent);
90 		}
91 		
92 		foreach (ref element ; ui) {
93 			element.Render(parent);
94 		}
95 
96 		SDL_RenderPresent(parent.renderer);
97 	}
98 }