Godot - dessiner sans règles

Parfois, il arrive que le moteur limite simplement le flux interminable d'idées. Donc, une fois que j'ai voulu dessiner de n'importe où, n'importe quoi et n'importe où. C'est ce qui sera discuté.

Pour commencer, imaginons une tâche aussi triviale: en cliquant sur la souris, vous devez dessiner une primitive que l'utilisateur spécifie, par exemple, en appuyant sur des touches. Cela semble simple, mais avec Godot, cela peut être un casse-tête.

, : Godot _draw



CanvasItem



, .. , , , _process



. , , _draw



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– «» . 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



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- , . , .

, .. .

, , . , , _draw



CanvasItem



. , 3D , , , .

. : , Godot . , !