CanvasItem

Inherits: Node < Object

Inherited By: Control, Node2D

Base class of anything 2D.

Description

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 Control for anything GUI-related, and by Node2D for anything related to the 2D engine.

Any CanvasItem can draw. For this, queue_redraw is called by the engine, 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 draw_* functions). However, they can only be used inside _draw, its corresponding Object._notification or methods connected to the draw signal.

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.

Note: Unless otherwise specified, all methods that have angle parameters must have angles specified as radians. To convert degrees to radians, use @GlobalScope.deg_to_rad.

Tutorials

Properties

ClipChildrenMode

clip_children

0

int

light_mask

1

Material

material

Color

modulate

Color(1, 1, 1, 1)

Color

self_modulate

Color(1, 1, 1, 1)

bool

show_behind_parent

false

TextureFilter

texture_filter

0

TextureRepeat

texture_repeat

0

bool

top_level

false

bool

use_parent_material

false

int

visibility_layer

1

bool

visible

true

bool

y_sort_enabled

false

bool

z_as_relative

true

int

z_index

0

Methods

void

_draw ( ) virtual

void

draw_animation_slice ( float animation_length, float slice_begin, float slice_end, float offset=0.0 )

void

draw_arc ( Vector2 center, float radius, float start_angle, float end_angle, int point_count, Color color, float width=1.0, bool antialiased=false )

void

draw_char ( Font font, Vector2 pos, String char, int font_size=16, Color modulate=Color(1, 1, 1, 1) ) const

void

draw_char_outline ( Font font, Vector2 pos, String char, int font_size=16, int size=-1, Color modulate=Color(1, 1, 1, 1) ) const

void

draw_circle ( Vector2 position, float radius, Color color )

void

draw_colored_polygon ( PackedVector2Array points, Color color, PackedVector2Array uvs=PackedVector2Array(), Texture2D texture=null )

void

draw_dashed_line ( Vector2 from, Vector2 to, Color color, float width=1.0, float dash=2.0 )

void

draw_end_animation ( )

void

draw_lcd_texture_rect_region ( Texture2D texture, Rect2 rect, Rect2 src_rect, Color modulate=Color(1, 1, 1, 1) )

void

draw_line ( Vector2 from, Vector2 to, Color color, float width=1.0, bool antialiased=false )

void

draw_mesh ( Mesh mesh, Texture2D texture, Transform2D transform=Transform2D(1, 0, 0, 1, 0, 0), Color modulate=Color(1, 1, 1, 1) )

void

draw_msdf_texture_rect_region ( Texture2D texture, Rect2 rect, Rect2 src_rect, Color modulate=Color(1, 1, 1, 1), float outline=0.0, float pixel_range=4.0, float scale=1.0 )

void

draw_multiline ( PackedVector2Array points, Color color, float width=1.0 )

void

draw_multiline_colors ( PackedVector2Array points, PackedColorArray colors, float width=1.0 )

void

draw_multiline_string ( Font font, Vector2 pos, String text, HorizontalAlignment alignment=0, float width=-1, int font_size=16, int max_lines=-1, Color modulate=Color(1, 1, 1, 1), LineBreakFlag brk_flags=3, JustificationFlag jst_flags=3, Direction direction=0, Orientation orientation=0 ) const

void

draw_multiline_string_outline ( Font font, Vector2 pos, String text, HorizontalAlignment alignment=0, float width=-1, int font_size=16, int max_lines=-1, int size=1, Color modulate=Color(1, 1, 1, 1), LineBreakFlag brk_flags=3, JustificationFlag jst_flags=3, Direction direction=0, Orientation orientation=0 ) const

void

draw_multimesh ( MultiMesh multimesh, Texture2D texture )

void

draw_polygon ( PackedVector2Array points, PackedColorArray colors, PackedVector2Array uvs=PackedVector2Array(), Texture2D texture=null )

void

draw_polyline ( PackedVector2Array points, Color color, float width=1.0, bool antialiased=false )

void

draw_polyline_colors ( PackedVector2Array points, PackedColorArray colors, float width=1.0, bool antialiased=false )

void

draw_primitive ( PackedVector2Array points, PackedColorArray colors, PackedVector2Array uvs, Texture2D texture=null, float width=1.0 )

void

draw_rect ( Rect2 rect, Color color, bool filled=true, float width=1.0 )

void

draw_set_transform ( Vector2 position, float rotation=0.0, Vector2 scale=Vector2(1, 1) )

void

draw_set_transform_matrix ( Transform2D xform )

void

draw_string ( Font font, Vector2 pos, String text, HorizontalAlignment alignment=0, float width=-1, int font_size=16, Color modulate=Color(1, 1, 1, 1), JustificationFlag jst_flags=3, Direction direction=0, Orientation orientation=0 ) const

void

draw_string_outline ( Font font, Vector2 pos, String text, HorizontalAlignment alignment=0, float width=-1, int font_size=16, int size=1, Color modulate=Color(1, 1, 1, 1), JustificationFlag jst_flags=3, Direction direction=0, Orientation orientation=0 ) const

void

draw_style_box ( StyleBox style_box, Rect2 rect )

void

draw_texture ( Texture2D texture, Vector2 position, Color modulate=Color(1, 1, 1, 1) )

void

draw_texture_rect ( Texture2D texture, Rect2 rect, bool tile, Color modulate=Color(1, 1, 1, 1), bool transpose=false )

void

draw_texture_rect_region ( Texture2D texture, Rect2 rect, Rect2 src_rect, Color modulate=Color(1, 1, 1, 1), bool transpose=false, bool clip_uv=true )

void

force_update_transform ( )

RID

get_canvas ( ) const

RID

get_canvas_item ( ) const

Transform2D

get_canvas_transform ( ) const

Vector2

get_global_mouse_position ( ) const

Transform2D

get_global_transform ( ) const

Transform2D

get_global_transform_with_canvas ( ) const

Vector2

get_local_mouse_position ( ) const

Transform2D

get_screen_transform ( ) const

Transform2D

get_transform ( ) const

Rect2

get_viewport_rect ( ) const

Transform2D

get_viewport_transform ( ) const

bool

get_visibility_layer_bit ( int layer ) const

World2D

get_world_2d ( ) const

void

hide ( )

bool

is_local_transform_notification_enabled ( ) const

bool

is_transform_notification_enabled ( ) const

bool

is_visible_in_tree ( ) const

Vector2

make_canvas_position_local ( Vector2 screen_point ) const

InputEvent

make_input_local ( InputEvent event ) const

void

move_to_front ( )

void

queue_redraw ( )

void

set_notify_local_transform ( bool enable )

void

set_notify_transform ( bool enable )

void

set_visibility_layer_bit ( int layer, bool enabled )

void

show ( )


Signals

draw ( )

Emitted when the CanvasItem must redraw, after the related NOTIFICATION_DRAW notification, and before _draw is called.

Note: Deferred connections do not allow drawing through the draw_* methods.


hidden ( )

Emitted when becoming hidden.


item_rect_changed ( )

Emitted when the item's Rect2 boundaries (position or size) have changed, or when an action is taking place that may have impacted these boundaries (e.g. changing Sprite2D.texture).


visibility_changed ( )

Emitted when the visibility (hidden/visible) changes.


Enumerations

enum TextureFilter:

TextureFilter TEXTURE_FILTER_PARENT_NODE = 0

The CanvasItem will inherit the filter from its parent.

TextureFilter TEXTURE_FILTER_NEAREST = 1

The texture filter reads from the nearest pixel only. The simplest and fastest method of filtering. Useful for pixel art.

TextureFilter TEXTURE_FILTER_LINEAR = 2

The texture filter blends between the nearest four pixels. Use this for most cases where you want to avoid a pixelated style.

TextureFilter TEXTURE_FILTER_NEAREST_WITH_MIPMAPS = 3

The texture filter reads from the nearest pixel in the nearest mipmap. This is the fastest way to read from textures with mipmaps.

TextureFilter TEXTURE_FILTER_LINEAR_WITH_MIPMAPS = 4

The texture filter blends between the nearest 4 pixels and between the nearest 2 mipmaps. Use this for non-pixel art textures that may be viewed at a low scale (e.g. due to Camera2D zoom), as mipmaps are important to smooth out pixels that are smaller than on-screen pixels.

TextureFilter TEXTURE_FILTER_NEAREST_WITH_MIPMAPS_ANISOTROPIC = 5

The texture filter reads from the nearest pixel, but selects a mipmap based on the angle between the surface and the camera view. This reduces artifacts on surfaces that are almost in line with the camera. The anisotropic filtering level can be changed by adjusting ProjectSettings.rendering/textures/default_filters/anisotropic_filtering_level.

Note: This texture filter is rarely useful in 2D projects. TEXTURE_FILTER_NEAREST_WITH_MIPMAPS is usually more appropriate.

TextureFilter TEXTURE_FILTER_LINEAR_WITH_MIPMAPS_ANISOTROPIC = 6

The texture filter blends between the nearest 4 pixels and selects a mipmap based on the angle between the surface and the camera view. This reduces artifacts on surfaces that are almost in line with the camera. This is the slowest of the filtering options, but results in the highest quality texturing. The anisotropic filtering level can be changed by adjusting ProjectSettings.rendering/textures/default_filters/anisotropic_filtering_level.

Note: This texture filter is rarely useful in 2D projects. TEXTURE_FILTER_LINEAR_WITH_MIPMAPS is usually more appropriate.

TextureFilter TEXTURE_FILTER_MAX = 7

Represents the size of the TextureFilter enum.


enum TextureRepeat:

TextureRepeat TEXTURE_REPEAT_PARENT_NODE = 0

The CanvasItem will inherit the filter from its parent.

TextureRepeat TEXTURE_REPEAT_DISABLED = 1

Texture will not repeat.

TextureRepeat TEXTURE_REPEAT_ENABLED = 2

Texture will repeat normally.

TextureRepeat TEXTURE_REPEAT_MIRROR = 3

Texture will repeat in a 2x2 tiled mode, where elements at even positions are mirrored.

TextureRepeat TEXTURE_REPEAT_MAX = 4

Represents the size of the TextureRepeat enum.


enum ClipChildrenMode:

ClipChildrenMode CLIP_CHILDREN_DISABLED = 0

Child draws over parent and is not clipped.

ClipChildrenMode CLIP_CHILDREN_ONLY = 1

Parent is used for the purposes of clipping only. Child is clipped to the parent's visible area, parent is not drawn.

ClipChildrenMode CLIP_CHILDREN_AND_DRAW = 2

Parent is used for clipping child, but parent is also drawn underneath child as normal before clipping child to its visible area.

ClipChildrenMode CLIP_CHILDREN_MAX = 3

Represents the size of the ClipChildrenMode enum.


Constants

NOTIFICATION_TRANSFORM_CHANGED = 2000

The CanvasItem's global transform has changed. This notification is only received if enabled by set_notify_transform.

NOTIFICATION_LOCAL_TRANSFORM_CHANGED = 35

The CanvasItem's local transform has changed. This notification is only received if enabled by set_notify_local_transform.

NOTIFICATION_DRAW = 30

The CanvasItem is requested to draw (see _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.


Property Descriptions

ClipChildrenMode clip_children = 0

Allows the current node to clip children nodes, essentially acting as a mask.


int light_mask = 1

  • void set_light_mask ( int value )

  • int get_light_mask ( )

The rendering layers in which this CanvasItem responds to Light2D nodes.


Material material

The material applied to textures on this CanvasItem.


Color modulate = Color(1, 1, 1, 1)

  • void set_modulate ( Color value )

  • Color get_modulate ( )

The color applied to textures on this CanvasItem.


Color self_modulate = Color(1, 1, 1, 1)

  • void set_self_modulate ( Color value )

  • Color get_self_modulate ( )

The color applied to textures on this CanvasItem. This is not inherited by children CanvasItems.


bool show_behind_parent = false

  • void set_draw_behind_parent ( bool value )

  • bool is_draw_behind_parent_enabled ( )

If true, the object draws behind its parent.


TextureFilter texture_filter = 0

The texture filtering mode to use on this CanvasItem.


TextureRepeat texture_repeat = 0

The texture repeating mode to use on this CanvasItem.


bool top_level = false

  • void set_as_top_level ( bool value )

  • bool is_set_as_top_level ( )

If true, this CanvasItem will not inherit its transform from parent CanvasItems. Its draw order will also be changed to make it draw on top of other CanvasItems that do not have top_level set to true. The CanvasItem will effectively act as if it was placed as a child of a bare Node.


bool use_parent_material = false

  • void set_use_parent_material ( bool value )

  • bool get_use_parent_material ( )

If true, the parent CanvasItem's material property is used as this one's material.


int visibility_layer = 1

  • void set_visibility_layer ( int value )

  • int get_visibility_layer ( )

The rendering layer in which this CanvasItem is rendered by Viewport nodes. A Viewport will render a CanvasItem if it and all its parents share a layer with the Viewport's canvas cull mask.


bool visible = true

  • void set_visible ( bool value )

  • bool is_visible ( )

If true, this CanvasItem is drawn. The node is only visible if all of its antecedents are visible as well (in other words, is_visible_in_tree must return true).

Note: For controls that inherit Popup, the correct way to make them visible is to call one of the multiple popup*() functions instead.


bool y_sort_enabled = false

  • void set_y_sort_enabled ( bool value )

  • bool is_y_sort_enabled ( )

If true, child nodes with the lowest Y position are drawn before those with a higher Y position. If false, Y-sorting is disabled. Y-sorting only affects children that inherit from CanvasItem.

You can nest nodes with Y-sorting. Child Y-sorted nodes are sorted in the same space as the parent Y-sort. This feature allows you to organize a scene better or divide it into multiple ones without changing your scene tree.


bool z_as_relative = true

  • void set_z_as_relative ( bool value )

  • bool is_z_relative ( )

If true, the node's Z index is relative to its parent's Z index. If this node's Z index is 2 and its parent's effective Z index is 3, then this node's effective Z index will be 2 + 3 = 5.


int z_index = 0

  • void set_z_index ( int value )

  • int get_z_index ( )

Z index. Controls the order in which the nodes render. A node with a higher Z index will display in front of others. Must be between RenderingServer.CANVAS_ITEM_Z_MIN and RenderingServer.CANVAS_ITEM_Z_MAX (inclusive).

Note: Changing the Z index of a Control only affects the drawing order, not the order in which input events are handled. This can be useful to implement certain UI animations, e.g. a menu where hovered items are scaled and should overlap others.


Method Descriptions

void _draw ( ) virtual

Called when CanvasItem has been requested to redraw (after queue_redraw is called, either manually or by the engine).

Corresponds to the NOTIFICATION_DRAW notification in Object._notification.


void draw_animation_slice ( float animation_length, float slice_begin, float slice_end, float offset=0.0 )

Subsequent drawing commands will be ignored unless they fall within the specified animation slice. This is a faster way to implement animations that loop on background rather than redrawing constantly.


void draw_arc ( Vector2 center, float radius, float start_angle, float end_angle, int point_count, Color color, float width=1.0, bool antialiased=false )

Draws a unfilled arc between the given angles. The larger the value of point_count, the smoother the curve. See also draw_circle.


void draw_char ( Font font, Vector2 pos, String char, int font_size=16, Color modulate=Color(1, 1, 1, 1) ) const

Draws a string first character using a custom font.


void draw_char_outline ( Font font, Vector2 pos, String char, int font_size=16, int size=-1, Color modulate=Color(1, 1, 1, 1) ) const

Draws a string first character outline using a custom font.


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

Draws a colored, filled circle. See also draw_arc, draw_polyline and draw_polygon.


void draw_colored_polygon ( PackedVector2Array points, Color color, PackedVector2Array uvs=PackedVector2Array(), Texture2D texture=null )

Draws a colored polygon of any number of points, convex or concave. Unlike draw_polygon, a single color must be specified for the whole polygon.


void draw_dashed_line ( Vector2 from, Vector2 to, Color color, float width=1.0, float dash=2.0 )

Draws a dashed line from a 2D point to another, with a given color and width. See also draw_multiline and draw_polyline.


void draw_end_animation ( )

After submitting all animations slices via draw_animation_slice, this function can be used to revert drawing to its default state (all subsequent drawing commands will be visible). If you don't care about this particular use case, usage of this function after submitting the slices is not required.


void draw_lcd_texture_rect_region ( Texture2D texture, Rect2 rect, Rect2 src_rect, Color modulate=Color(1, 1, 1, 1) )

Draws a textured rectangle region of the font texture with LCD subpixel anti-aliasing at a given position, optionally modulated by a color.

Texture is drawn using the following blend operation, blend mode of the CanvasItemMaterial is ignored:

dst.r = texture.r * modulate.r * modulate.a + dst.r * (1.0 - texture.r * modulate.a);
dst.g = texture.g * modulate.g * modulate.a