CanvasItem

Inherited By: , Node2D

Category: Core

Base class of anything 2D.

Properties

Methods

• 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.

Enumerations

enum BlendMode:

• 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.
• BLEND_MODE_DISABLED = 5 — Disable blending mode. Colors including alpha are written as-is. Only applicable for render targets with a transparent background. No lighting will be applied.

Constants

• NOTIFICATION_TRANSFORM_CHANGED = 29 — The CanvasItem’s transform has changed. This notification is only received if enabled by or set_notify_local_transform.
• NOTIFICATION_DRAW = 30 — The CanvasItem is requested to draw.
• NOTIFICATION_VISIBILITY_CHANGED = 31 — The CanvasItem’s visibility has changed.
• NOTIFICATION_ENTER_CANVAS = 32 — The CanvasItem has entered the canvas.
• NOTIFICATION_EXIT_CANVAS = 33 — The CanvasItem has exited the canvas.

Base class of anything 2D. Canvas items are laid out in a tree; children inherit and extend their parent’s transform. CanvasItem is extended by for anything GUI-related, and by Node2D for anything related to the 2D engine.

Any CanvasItem can draw. For this, 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 redrawn on every frame, improving the performance significantly. Several functions for drawing on the CanvasItem are provided (see functions). However, they can only be used inside the , signal or _draw virtual functions.

Canvas items are drawn in tree order. By default, children are on top of their parents so a root CanvasItem will be drawn behind everything. This behavior can be changed on a per-item basis.

A CanvasItem can also be hidden, which will also hide its children. It provides many ways to change parameters such as modulation (for itself and its children) and self modulation (only for itself), as well as its 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.

Tutorials

Property Descriptions

• int light_mask

The rendering layers in which this CanvasItem responds to nodes. Default value: 1.

• Material material

The material applied to textures on this CanvasItem. Default value: null.

• modulate

The color applied to textures on this CanvasItem. Default value: Color(1, 1, 1, 1) (opaque “white”).

• Color self_modulate

The color applied to textures on this CanvasItem. This is not inherited by children CanvasItems. Default value: Color(1, 1, 1, 1) (opaque “white”)..

• show_behind_parent

If true, the object draws behind its parent. Default value: false.

• bool show_on_top

If true, the object draws on top of its parent. Default value: true.

• use_parent_material

If true, the parent CanvasItem’s material property is used as this one’s material. Default value: false.

• visible

• void _draw ( ) virtual

Called (if exists) to draw the canvas item.

• float draw_char ( font, Vector2 position, char, String next, modulate=Color( 1, 1, 1, 1 ) )

Draws a string character using a custom font. Returns the advance, depending on the character width and kerning with an optional next character.

• void draw_circle ( Vector2 position, radius, Color color )

Draws a colored circle.

• void draw_colored_polygon ( points, Color color, uvs=PoolVector2Array( ), Texture texture=null, normal_map=null, bool antialiased=false )

Draws a colored polygon of any amount of points, convex or concave.

• void draw_line ( from, Vector2 to, color, float width=1.0, antialiased=false )

Draws a line from a 2D point to another, with a given color and width. It can be optionally antialiased.

• void draw_mesh ( Mesh mesh, texture, Texture normal_map=null )

• void draw_multiline ( points, Color color, width=1.0, bool antialiased=false )

Draws multiple, parallel lines with a uniform color. width and antialiased are currently not implemented and have no effect.

• void draw_multiline_colors ( points, PoolColorArray colors, width=1.0, bool antialiased=false )

Draws multiple, parallel lines with a uniform width, segment-by-segment coloring, and optional antialiasing. Colors assigned to line segments match by index between points and colors.

• void draw_multimesh ( multimesh, Texture texture, normal_map=null )

• void draw_polygon ( PoolVector2Array points, colors, PoolVector2Array uvs=PoolVector2Array( ), texture=null, Texture normal_map=null, antialiased=false )

Draws a polygon of any amount of points, convex or concave.

• void draw_polyline ( PoolVector2Array points, color, float width=1.0, antialiased=false )

Draws interconnected line segments with a uniform color and width and optional antialiasing.

• void draw_polyline_colors ( PoolVector2Array points, colors, float width=1.0, antialiased=false )

Draws interconnected line segments with a uniform width, segment-by-segment coloring, and optional antialiasing. Colors assigned to line segments match by index between points and colors.

• void draw_primitive ( PoolVector2Array points, colors, PoolVector2Array uvs, texture=null, float width=1.0, normal_map=null )

Draws a custom primitive. 1 point for a point, 2 points for a line, 3 points for a triangle and 4 points for a quad.

• void draw_rect ( Rect2 rect, color, bool filled=true )

Draws a colored rectangle.

• void draw_set_transform ( position, float rotation, scale )

Sets a custom transform for drawing via components. Anything drawn afterwards will be transformed by this.

• void draw_set_transform_matrix ( Transform2D xform )

Sets a custom transform for drawing via matrix. Anything drawn afterwards will be transformed by this.

• void draw_string ( font, Vector2 position, text, Color modulate=Color( 1, 1, 1, 1 ), clip_w=-1 )

Draws a string using a custom font.

• void draw_style_box ( StyleBox style_box, rect )

Draws a styled rectangle.

Draws a texture at a given position.

• void draw_texture_rect ( Texture texture, rect, bool tile, modulate=Color( 1, 1, 1, 1 ), bool transpose=false, normal_map=null )

Draws a textured rectangle at a given position, optionally modulated by a color. If transpose is true, the texture will have its X and Y coordinates swapped.

• void draw_texture_rect_region ( Texture texture, rect, Rect2 src_rect, modulate=Color( 1, 1, 1, 1 ), bool transpose=false, normal_map=null, bool clip_uv=true )

Draws a textured rectangle region at a given position, optionally modulated by a color. If is true, the texture will have its X and Y coordinates swapped.

• void force_update_transform ( )

• get_canvas ( ) const

Returns the RID of the canvas where this item is in.

• RID get_canvas_item ( ) const

• 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.

• 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.

• get_local_mouse_position ( ) const

Get the mouse position relative to this item’s position.

• Transform2D get_transform ( ) const

Get the transform matrix of this item.

• get_viewport_rect ( ) const

Get the viewport’s boundaries as a Rect2.

• get_viewport_transform ( ) const

Get this item’s transform in relation to the viewport.

• World2D get_world_2d ( ) const

Get the where this item is in.

• void hide ( )

Hide the CanvasItem if it’s currently visible.

• bool is_local_transform_notification_enabled ( ) const

Returns true if local transform notifications are communicated to children.

• is_set_as_toplevel ( ) const

Returns true if the node is set as top-level. See set_as_toplevel.

• is_transform_notification_enabled ( ) const

Returns true if global transform notifications are communicated to children.

• bool is_visible_in_tree ( ) const

Returns true if the node is present in the , its visible property is true and its inherited visibility is also true.

• make_canvas_position_local ( Vector2 screen_point ) const

Assigns screen_point as this node’s new local transform.

• make_input_local ( InputEvent event ) const

Transformations issued by event’s inputs are applied in local space instead of global space.

• void set_as_toplevel ( enable )

If enable is true, the node won’t inherit its transform from parent canvas items.

• void set_notify_local_transform ( bool enable )

If enable is true, children will be updated with local transform data.

• void set_notify_transform ( enable )

If enable is true, children will be updated with global transform data.

• void show ( )

Show the CanvasItem if it’s currently hidden. For controls that inherit Popup, the correct way to make them visible is to call one of the multiple popup*() functions instead.

• void update ( )