CanvasItem¶
Category: Core
Brief Description¶
Base class of anything 2D.
Member Functions¶
Signals¶
- draw ( )
Emitted when the CanvasItem must redraw. This can only be connected realtime, as deferred will not allow drawing.
- hide ( )
Emitted when becoming hidden.
- item_rect_changed ( )
Emitted when the item rect has changed.
- visibility_changed ( )
Emitted when the visibility (hidden/visible) changes.
Numeric Constants¶
- BLEND_MODE_MIX = 0 — Mix blending mode. Colors are assumed to be independent of the alpha (opacity) value.
- BLEND_MODE_ADD = 1 — Additive blending mode.
- BLEND_MODE_SUB = 2 — Subtractive blending mode.
- BLEND_MODE_MUL = 3 — Multiplicative blending mode.
- BLEND_MODE_PREMULT_ALPHA = 4 — Mix blending mode. Colors are assumed to be premultiplied by the alpha (opacity) value.
- NOTIFICATION_DRAW = 30 — CanvasItem is requested to draw.
- NOTIFICATION_VISIBILITY_CHANGED = 31 — Canvas item visibility has changed.
- NOTIFICATION_ENTER_CANVAS = 32 — Canvas item has entered the canvas.
- NOTIFICATION_EXIT_CANVAS = 33 — Canvas item has exited the canvas.
- NOTIFICATION_TRANSFORM_CHANGED = 29 — Canvas item transform has changed. Only received if requested.
Description¶
Base class of anything 2D. Canvas items are laid out in a tree and children inherit and extend the transform of their parent. CanvasItem is extended by Control, for anything GUI related, and by Node2D for anything 2D engine related.
Any CanvasItem can draw. For this, the “update” function must be called, then NOTIFICATION_DRAW will be received on idle time to request redraw. Because of this, canvas items don’t need to be redraw on every frame, improving the performance significantly. Several functions for drawing on the CanvasItem are provided (see draw_* functions). They can only be used inside the notification, signal or _draw() overrides function, though.
Canvas items are draw in tree order. By default, children are on top of their parents so a root CanvasItem will be drawn behind everything (this can be changed per item though).
Canvas items can also be hidden (hiding also their subtree). They provide many means for changing standard parameters such as opacity (for it and the subtree) and self opacity, blend mode.
Ultimately, a transform notification can be requested, which will notify the node that its global position changed in case the parent tree changed.
Member Function Description¶
- void _draw ( ) virtual
Called (if exists) to draw the canvas item.
Draw a string character using a custom font. Returns the advance, depending on the char width and kerning with an optional next char.
Draw a colored circle.
- void draw_colored_polygon ( PoolVector2Array points, Color color, PoolVector2Array uvs=null, Texture texture=PoolVector2Array( ), Texture normal_map=null, bool antialiased=null )
Draw a colored polygon of any amount of points, convex or concave.
Draw a line from a 2D point to another, with a given color and width. It can be optionally antialiased.
- void draw_polygon ( PoolVector2Array points, PoolColorArray colors, PoolVector2Array uvs=null, Texture texture=PoolVector2Array( ), Texture normal_map=null, bool antialiased=null )
Draw a polygon of any amount of points, convex or concave.
- void draw_polyline ( PoolVector2Array points, Color color, float width=null, bool antialiased=null )
- void draw_polyline_colors ( PoolVector2Array points, PoolColorArray colors, float width=null, bool antialiased=null )
- void draw_primitive ( PoolVector2Array points, PoolColorArray colors, PoolVector2Array uvs, Texture texture=null, float width=null, Texture normal_map=null )
Draw a custom primitive, 1 point for a point, 2 points for a line, 3 points for a triangle and 4 points for a quad.
Draw a colored rectangle.
Set a custom transform for drawing. Anything drawn afterwards will be transformed by this.
- void draw_set_transform_matrix ( Transform2D xform )
Draw a string using a custom font.
Draw a styled rectangle.
Draw a texture at a given position.
- void draw_texture_rect ( Texture texture, Rect2 rect, bool tile, Color modulate=null, bool transpose=null, Texture normal_map=null )
Draw a textured rectangle at a given position, optionally modulated by a color. Transpose swaps the x and y coordinates when reading the texture.
- void draw_texture_rect_region ( Texture texture, Rect2 rect, Rect2 src_rect, Color modulate=Color( 1, 1, 1, 1 ), bool transpose=null, Texture normal_map=null, bool clip_uv=null )
Draw a textured rectangle region at a given position, optionally modulated by a color. Transpose swaps the x and y coordinates when reading the texture.
- Variant edit_get_state ( ) const
Used for editing, returns an opaque value representing the transform state.
- void edit_rotate ( float degrees )
Used for editing, handle rotation.
- void edit_set_rect ( Rect2 rect )
- void edit_set_state ( Variant state )
Set the transform state of this CanvasItem. For Node2D, this is an Array with (in order) a Vector2 for position, a float for rotation (radians) and another Vector2 for scale. For Control this is a Rect2 with the position and size.
- RID get_canvas ( ) const
Return the RID of the World2D canvas where this item is in.
- RID get_canvas_item ( ) const
Return the canvas item RID used by VisualServer for this item.
- Transform2D get_canvas_transform ( ) const
Get the transform matrix of this item’s canvas.
- Vector2 get_global_mouse_position ( ) const
Get the global position of the mouse.
- Transform2D get_global_transform ( ) const
Get the global transform matrix of this item.
- Transform2D get_global_transform_with_canvas ( ) const
Get the global transform matrix of this item in relation to the canvas.
- Rect2 get_item_and_children_rect ( ) const
Get a Rect2 with the boundaries of this item and its children.
- Rect2 get_item_rect ( ) const
Return a rect containing the editable boundaries of the item.
- int get_light_mask ( ) const
Get this item’s light mask number.
- Vector2 get_local_mouse_pos ( ) const
Get the mouse position relative to this item’s position.
- Material get_material ( ) const
Get the material of this item.
- Color get_modulate ( ) const
Get the modulate of the CanvasItem, which affects children items too.
- Color get_self_modulate ( ) const
Get the self-modulate of the CanvasItem.
- Transform2D get_transform ( ) const
Get the transform matrix of this item.
- bool get_use_parent_material ( ) const
Get whether this item uses its parent’s material.
- Rect2 get_viewport_rect ( ) const
Get the viewport’s boundaries as a Rect2.
- Transform2D get_viewport_transform ( ) const
Get this item’s transform in relation to the viewport.
- World2D get_world_2d ( ) const
Get the World2D where this item is in.
- void hide ( )
Hide the CanvasItem currently visible.
- bool is_draw_behind_parent_enabled ( ) const
Return whether the item is drawn behind its parent.
- bool is_local_transform_notification_enabled ( ) const
- bool is_set_as_toplevel ( ) const
Return if set as toplevel. See set_as_toplevel.
- bool is_transform_notification_enabled ( ) const
- bool is_visible ( ) const
Return true if this CanvasItem is visible. It may be invisible because itself or a parent canvas item is hidden.
- bool is_visible_in_tree ( ) const
- InputEvent make_input_local ( InputEvent event ) const
- void set_as_toplevel ( bool enable )
Set as top level. This means that it will not inherit transform from parent canvas items.
- void set_draw_behind_parent ( bool enable )
Set whether the canvas item is drawn behind its parent.
- void set_light_mask ( int light_mask )
Set the ligtht mask number of this item.
- void set_material ( Material material )
Set the material of this item.
- void set_modulate ( Color modulate )
Set the modulate of the CanvasItem. This affects the modulation of children items.
- void set_notify_local_transform ( bool enable )
- void set_notify_transform ( bool enable )
- void set_self_modulate ( Color self_modulate )
Set the self-modulate of the CanvasItem. This does not affect the modulation of children items.
- void set_use_parent_material ( bool enable )
Set whether or not this item should use its parent’s material.
- void set_visible ( bool visible )
Set whether this item should be visible or not.
Note that a hidden CanvasItem will make all children hidden too, so no matter what is set here this item won’t be shown if its parent or grandparents nodes are hidden.
- void show ( )
Show the CanvasItem currently hidden.
- void update ( )
Queue the CanvasItem for update. NOTIFICATION_DRAW
will be called on idle time to request redraw.