Godot - Zeichnen ohne Regeln

Manchmal kommt es vor, dass der Motor einfach den nie endenden Ideenstrom begrenzt. Also, einmal wollte ich von überall, irgendetwas und überall zeichnen. Dies wird diskutiert.

Stellen wir uns zunächst eine so triviale Aufgabe vor: Durch Klicken mit der Maus müssen Sie ein Grundelement zeichnen, das der Benutzer beispielsweise durch Drücken von Tasten angibt. Klingt einfach, aber bei Godot kann es Kopfschmerzen geben.

, : Godot _draw



CanvasItem



, .. , , , _process



. , , _draw



, . . , ? ? ? .

– «» . Godot – , - , . godot API , – VisualServer



. ( ) Godot. , , VisualServer



.

CanvasItem



- , , ? , . RID



(Resource ID), World2D



. CanvasItem



get_canvas_item()



, , _draw



. , , :

: Controller



Drawer



.

"" , . Controller



:

extends Node2D

onready var drawer = $"../Drawer"

var counter = 0

func custom_draw_line(start, goal, color, width=1.0, antialising=false):
	VisualServer.canvas_item_add_line(drawer.get_canvas_item(), start, goal, color, width, antialising)

func _process(delta):
	if Input.is_action_just_pressed("mouse_left"):
		counter += 2
		custom_draw_line(Vector2(100, 100)+Vector2(counter, counter), Vector2(300, 150)+Vector2(counter, counter), Color.green)
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

custom_draw_line(...)



, VisualServer



canvas_item_add_line(...)



, Drawer



. , Controller



, , , .

, . , , . ? Godot, . , :

void CanvasItem::_update_callback() {
	if (!is_inside_tree()) {
		pending_update = false;
		return;
	}

	RenderingServer::get_singleton()->canvas_item_clear(get_canvas_item());
	//todo updating = true - only allow drawing here
	if (is_visible_in_tree()) { //todo optimize this!!
		if (first_draw) {
			notification(NOTIFICATION_VISIBILITY_CHANGED);
			first_draw = false;
		}
		drawing = true;
		current_item_drawn = this;
		notification(NOTIFICATION_DRAW);
		emit_signal(SceneStringNames::get_singleton()->draw);
		if (get_script_instance()) {
			get_script_instance()->call(SceneStringNames::get_singleton()->_draw);
		}
		current_item_drawn = nullptr;
		drawing = false;
	}
	//todo updating = false
	pending_update = false; // don't change to false until finished drawing (avoid recursive update)
}
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

7:

RenderingServer::get_singleton()->canvas_item_clear(get_canvas_item())
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

, . , .. , . , Drawer



. VisualServer.canvas_item_create()



, , , , World2D.canvas



( "" ) .. Drawer



, . VisualServer



VisualServer.canvas_item_set_parent(item, parent)



. : , . , , . :VisualServer.canvas_item_clear(surface)



. :

extends Node2D

onready var drawer = $"../Drawer"

var counter = 0

var surface

func _ready():
	surface = VisualServer.canvas_item_create()
	VisualServer.canvas_item_set_parent(surface, drawer.get_canvas_item())

func custom_draw_line(start, goal, color, width=1.0, antialising=false):
	VisualServer.canvas_item_add_line(surface, start, goal, color, width, antialising)

func _process(delta):
	if Input.is_action_just_pressed("mouse_left"):
		counter += 2
		custom_draw_line(Vector2(100, 100)+Vector2(counter, counter), Vector2(300, 150)+Vector2(counter, counter), Color.green)
	elif Input.is_action_just_pressed("mouse_right"):
		VisualServer.canvas_item_clear(surface)
		counter = 0
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

, . , Drawer



, .

, , . , CanvasItem



, CanvasItem



( ):

void CanvasItem::draw_line(const Point2 &p_from, const Point2 &p_to, const Color &p_color, real_t p_width) {
	ERR_FAIL_COND_MSG(!drawing, "Drawing is only allowed inside NOTIFICATION_DRAW, _draw() function or 'draw' signal.");

	RenderingServer::get_singleton()->canvas_item_add_line(canvas_item, p_from, p_to, p_color, p_width);
}
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

4, VisualServer



, , .

? , .. - , . , Resource



, . , , .

, , . , " ". , , ( ), , " ", .

- , . , .

, .. .

, , . , , _draw



CanvasItem



. , 3D , , , .

. : , Godot . , !