CanvasItem

Inherits: Node < Object Inherited By: Control, Node2D Base class of anything 2D.

Description

CanvasItem is extended by Control for anything GUI-related, and by Node2D for anything related to the 2D engine. CanvasItem can draw. For this, update must be called, then NOTIFICATIONDRAW 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 `drawfunctions). However, they can only be used inside the Object._notification, signal or _draw virtual functions.CanvasItemwill be drawn behind everything. This behavior can be changed on a per-item basis.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 @GDScript.deg2rad.

Tutorials

  • Viewport and canvas transforms
  • Custom drawing in 2D
  • Audio Spectrum Demo

    Properties

    Methods

    Signals

  • draw ( ) CanvasItem must redraw. This can only be connected realtime, as deferred will not allow drawing.
  • hide ( ) Emitted when becoming hidden.
  • item_rect_changed ( ) Rect2 boundaries (position or size) have changed, or when an action is taking place that may have impacted these boundaries (e.g. changing Sprite.texture).
  • visibility_changed ( ) Emitted when the visibility (hidden/visible) changes.

    Enumerations

    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 —- Disables 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 = 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.
  • 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

  • int light_mask CanvasItem responds to Light2D nodes.
  • Material material CanvasItem.
  • Color modulate CanvasItem.
  • Color self_modulate CanvasItem. This is not inherited by children CanvasItems.
  • bool show_behind_parent true, the object draws behind its parent.
  • bool show_on_top true, the object draws on top of its parent.
  • bool use_parent_material true, the parent CanvasItem‘s material property is used as this one’s material.
  • bool visible 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.

    Method Descriptions

  • _draw ( ) virtual Overridable function called by the engine (if defined) to draw the canvas item.
  • draw_arc ( Vector2 center, float radius, float start_angle, float end_angle, int point_count, Color color, float width=1.0, bool antialiased=false ) point_count, the smoother the curve. See also draw_circle. Note: Line drawing is not accelerated by batching if antialiased is true. Note: Due to how it works, built-in antialiasing will not look correct for translucent lines and may not work on certain platforms. As a workaround, install the Antialiased Line2D add-on then create an AntialiasedRegularPolygon2D node. That node relies on a texture with custom mipmaps to perform antialiasing. 2D batching is also still supported with those antialiased lines.
  • float draw_char ( Font font, Vector2 position, String char, String next, Color 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.
  • draw_circle ( Vector2 position, float radius, Color color ) draw_arc, draw_polyline and draw_polygon. Note: Built-in antialiasing is not provided for draw_circle. As a workaround, install the Antialiased Line2D add-on then create an AntialiasedRegularPolygon2D node. That node relies on a texture with custom mipmaps to perform antialiasing.
  • draw_colored_polygon ( PoolVector2Array points, Color color, PoolVector2Array uvs=PoolVector2Array( ), Texture texture=null, Texture normal_map=null, bool antialiased=false ) draw_polygon, a single color must be specified for the whole polygon. Note: Due to how it works, built-in antialiasing will not look correct for translucent polygons and may not work on certain platforms. As a workaround, install the Antialiased Line2D add-on then create an AntialiasedPolygon2D node. That node relies on a texture with custom mipmaps to perform antialiasing.
  • draw_line ( Vector2 from, Vector2 to, Color color, float width=1.0, bool antialiased=false ) draw_multiline and draw_polyline. Note: Line drawing is not accelerated by batching if antialiased is true. Note: Due to how it works, built-in antialiasing will not look correct for translucent lines and may not work on certain platforms. As a workaround, install the Antialiased Line2D add-on then create an AntialiasedLine2D node. That node relies on a texture with custom mipmaps to perform antialiasing. 2D batching is also still supported with those antialiased lines.
  • draw_mesh ( Mesh mesh, Texture texture, Texture normal_map=null, Transform2D transform=Transform2D( 1, 0, 0, 1, 0, 0 ), Color modulate=Color( 1, 1, 1, 1 ) ) Mesh in 2D, using the provided texture. See MeshInstance2D for related documentation.
  • draw_multiline ( PoolVector2Array points, Color color, float width=1.0, bool antialiased=false ) color. When drawing large amounts of lines, this is faster than using individual draw_line calls. To draw interconnected lines, use draw_polyline instead. Note: width and antialiased are currently not implemented and have no effect. As a workaround, install the Antialiased Line2D add-on then create an AntialiasedLine2D node. That node relies on a texture with custom mipmaps to perform antialiasing. 2D batching is also still supported with those antialiased lines.
  • draw_multiline_colors ( PoolVector2Array points, PoolColorArray colors, float width=1.0, bool antialiased=false ) width and segment-by-segment coloring. Colors assigned to line segments match by index between points and colors. When drawing large amounts of lines, this is faster than using individual draw_line calls. To draw interconnected lines, use draw_polyline_colors instead. Note: width and antialiased are currently not implemented and have no effect. As a workaround, install the Antialiased Line2D add-on then create an AntialiasedLine2D node. That node relies on a texture with custom mipmaps to perform antialiasing. 2D batching is also still supported with those antialiased lines.
  • draw_multimesh ( MultiMesh multimesh, Texture texture, Texture normal_map=null ) MultiMesh in 2D with the provided texture. See MultiMeshInstance2D for related documentation.
  • draw_polygon ( PoolVector2Array points, PoolColorArray colors, PoolVector2Array uvs=PoolVector2Array( ), Texture texture=null, Texture normal_map=null, bool antialiased=false ) draw_colored_polygon, each point’s color can be changed individually. See also draw_polyline and draw_polyline_colors. Note: Due to how it works, built-in antialiasing will not look correct for translucent polygons and may not work on certain platforms. As a workaround, install the Antialiased Line2D add-on then create an AntialiasedPolygon2D node. That node relies on a texture with custom mipmaps to perform antialiasing.
  • draw_polyline ( PoolVector2Array points, Color color, float width=1.0, bool antialiased=false ) color and width and optional antialiasing. When drawing large amounts of lines, this is faster than using individual draw_line calls. To draw disconnected lines, use draw_multiline instead. See also draw_polygon. Note: Due to how it works, built-in antialiasing will not look correct for translucent polygons and may not work on certain platforms. As a workaround, install the Antialiased Line2D add-on then create an AntialiasedPolygon2D node. That node relies on a texture with custom mipmaps to perform antialiasing.
  • draw_polyline_colors ( PoolVector2Array points, PoolColorArray colors, float width=1.0, bool antialiased=false ) width and segment-by-segment coloring, and optional antialiasing. Colors assigned to line segments match by index between points and colors. When drawing large amounts of lines, this is faster than using individual draw_line calls. To draw disconnected lines, use draw_multiline_colors instead. See also draw_polygon. Note: Due to how it works, built-in antialiasing will not look correct for translucent polygons and may not work on certain platforms. As a workaround, install the Antialiased Line2D add-on then create an AntialiasedPolygon2D node. That node relies on a texture with custom mipmaps to perform antialiasing.
  • draw_primitive ( PoolVector2Array points, PoolColorArray colors, PoolVector2Array uvs, Texture texture=null, float width=1.0, Texture normal_map=null ) draw_line, draw_polyline, draw_polygon, and draw_rect.
  • draw_rect ( Rect2 rect, Color color, bool filled=true, float width=1.0, bool antialiased=false ) filled is true, the rectangle will be filled with the color specified. If filled is false, the rectangle will be drawn as a stroke with the color and width specified. If antialiased is true, the lines will attempt to perform antialiasing using OpenGL line smoothing. Note: width and antialiased are only effective if filled is false. Note: Due to how it works, built-in antialiasing will not look correct for translucent polygons and may not work on certain platforms. As a workaround, install the Antialiased Line2D add-on then create an AntialiasedPolygon2D node. That node relies on a texture with custom mipmaps to perform antialiasing.
  • draw_set_transform ( Vector2 position, float rotation, Vector2 scale ) Sets a custom transform for drawing via components. Anything drawn afterwards will be transformed by this.
  • draw_set_transform_matrix ( Transform2D xform ) Sets a custom transform for drawing via matrix. Anything drawn afterwards will be transformed by this.
  • draw_string ( Font font, Vector2 position, String text, Color modulate=Color( 1, 1, 1, 1 ), int clip_w=-1 ) text using the specified font at the position (bottom-left corner using the baseline of the font). The text will have its color multiplied by modulate. If clip_w is greater than or equal to 0, the text will be clipped if it exceeds the specified width. Example using the default project font:
    1. # If using this method in a script that redraws constantly, move the# `default_font` declaration to a member variable assigned in `_ready()`# so the Control is only created once.var default_font = Control.new().get_font("font")draw_string(default_font, Vector2(64, 64), "Hello world")
    Font.draw.
  • draw_style_box ( StyleBox style_box, Rect2 rect ) Draws a styled rectangle.
  • draw_texture ( Texture texture, Vector2 position, Color modulate=Color( 1, 1, 1, 1 ), Texture normal_map=null ) Draws a texture at a given position.
  • draw_texture_rect ( Texture texture, Rect2 rect, bool tile, Color modulate=Color( 1, 1, 1, 1 ), bool transpose=false, Texture normal_map=null ) transpose is true, the texture will have its X and Y coordinates swapped.
  • draw_texture_rect_region ( Texture texture, Rect2 rect, Rect2 src_rect, Color modulate=Color( 1, 1, 1, 1 ), bool transpose=false, Texture normal_map=null, bool clip_uv=true ) transpose is true, the texture will have its X and Y coordinates swapped.
  • force_update_transform ( ) Forces the transform to update. Transform changes in physics are not instant for performance reasons. Transforms are accumulated and then set. Use this if you need an up-to-date transform when doing physics operations.
  • RID get_canvas ( ) const RID of the World2D canvas where this item is in.
  • RID get_canvas_item ( ) const VisualServer for this item.
  • Transform2D get_canvas_transform ( ) const Returns the transform matrix of this item’s canvas.
  • Vector2 get_global_mouse_position ( ) const CanvasLayer that this CanvasItem is in using the coordinate system of the CanvasLayer.
  • Transform2D get_global_transform ( ) const Returns the global transform matrix of this item.
  • Transform2D get_global_transform_with_canvas ( ) const Returns the global transform matrix of this item in relation to the canvas.
  • Vector2 get_local_mouse_position ( ) const CanvasItem using the local coordinate system of this CanvasItem.
  • Transform2D get_transform ( ) const Returns the transform matrix of this item.
  • Rect2 get_viewport_rect ( ) const Rect2.
  • Transform2D get_viewport_transform ( ) const Returns this item’s transform in relation to the viewport.
  • World2D get_world_2d ( ) const World2D where this item is in.
  • hide ( ) CanvasItem if it’s currently visible. This is equivalent to setting visible to false.
  • bool is_local_transform_notification_enabled ( ) const true if local transform notifications are communicated to children.
  • bool is_set_as_toplevel ( ) const true if the node is set as top-level. See set_as_toplevel.
  • bool is_transform_notification_enabled ( ) const true if global transform notifications are communicated to children.
  • bool is_visible_in_tree ( ) const true if the node is present in the SceneTree, its visible property is true and all its antecedents are also visible. If any antecedent is hidden, this node will not be visible in the scene tree.
  • Vector2 make_canvas_position_local ( Vector2 screen_point ) const screen_point as this node’s new local transform.
  • InputEvent make_input_local ( InputEvent event ) const event‘s inputs are applied in local space instead of global space.
  • set_as_toplevel ( bool enable ) enable is 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 are not set as top-level. The CanvasItem will effectively act as if it was placed as a child of a bare Node. See also is_set_as_toplevel.
  • set_notify_local_transform ( bool enable ) enable is true, this node will receive NOTIFICATION_LOCAL_TRANSFORM_CHANGED when its local transform changes.
  • set_notify_transform ( bool enable ) enable is true, this node will receive NOTIFICATION_TRANSFORM_CHANGED when its global transform changes.
  • show ( ) CanvasItem if it’s currently hidden. This is equivalent to setting visible to true. For controls that inherit Popup, the correct way to make them visible is to call one of the multiple popup*() functions instead.
  • update ( ) CanvasItem for update. NOTIFICATION_DRAW will be called on idle time to request redraw.