SoText2 Class Reference
[Shapes]
Screen-aligned 2D text shape node. More...
#include <Inventor/nodes/SoText2.h>
Public Types | |
| enum | Justification { LEFT = 0x01, CENTER = 0x03, RIGHT = 0x02, INHERITED = 0x04 } |
Public Member Functions | |
| virtual SoType | getTypeId () const |
| SoText2 () | |
Static Public Member Functions | |
| static SoType | getClassTypeId () |
Public Attributes | |
| SoMFString | string |
| SoSFFloat | spacing |
| SoSFEnum | justification |
Friends | |
| class | SoAnnoText3 |
| class | SoFontServer |
Detailed Description
Screen-aligned 2D text shape node.
This node defines one or more strings of 2D text. The text is always horizontal, aligned with the screen and does not change size with distance from the camera. However the position of the text is specified in 3D units and is affected by viewing and modeling transformations. 2D text cannot be rotated, but because it always faces the user, it is often used for annotation, for example labels on axes.
The text position is always at the local origin (0,0,0). Rotations and scales have no effect on the orientation or size of 2D text, just the location.
Note: A transform node, e.g. SoTranslation, must be used to position the text in 3D space.
Text supports both single byte Latin1 (ISO8859-1) characters and multi-byte UNICODE characters. ISO8859-1 is an 8-bit character set which is a superset of the older 7-bit ASCII character set. See the SbString class for more information.
Rendering:
The typeface and size (default = 10) are specified using an SoFont node. Note that for SoText2 the size is interpreted as a value in pixels, not 3D units.
Setting the SoFont renderStyle field to TEXTURE is recommended for best appearance and performance. (antialiasing is applied).
Additional rendering styles can be applied using an SoTextProperty node, including underline, overline, strikethrough, background and background outline.
SoText2 is drawn using the diffuse color of the current material (SoMaterial). Lighting is not applied, regardless of the lighting model. Textures do not affect SoText2 (note this is independent of the fact that textures are used internally to render SoText2). Complexity (SoComplexity) does not affect SoText2. Drawing styles (SoDrawStyle) other than INVISIBLE do not affect SoText2.
Justification:
Horizontal alignment of the text can be specified using the justification field. Both horizontal and vertical alignment can be controlled using an SoTextProperty node, however the justification setting in the SoText2 node overrides the horizontal setting unless it is explicitly set to INHERITED.
Clipping:
If the transformed position (origin point) of the SoText2 is clipped, then the entire string is clipped, even if some part of the string should conceptually be visible. If the origin point is inside the view volume then the string is clipped similar to other geometry.
Bounding box:
Because 2D text is screen-aligned, it has some unusual characteristics. For example, the 3D bounding box surrounding a 2D text string depends on the current camera and the current viewport size, since changing the field of view or the mapping onto the window changes the relative size of the text with respect to the rest of the scene.
When computing the bounding box of a 2D text node (see SoGetBoundingBoxAction), be careful to:
- Initialize the bounding box action with the correct viewport region.
Typically this information is queried from the viewer. - Make sure the action will traverse the camera node.
Apply the action to a node above the camera or create a path to the 2D text node from the root of the scene graph (e.g. using SoSearchAction).
Picking:
Text can be picked (SoRayPickAction) like any other geometry. If a text node has been picked then SoPickedPoint can return an SoTextDetail object. This object contains information about which string (in a multi-string text node) was picked and which character within the string was picked.
Render caching:
If your Open Inventor version is older than 9.2, then SoText2 nodes using CENTER or RIGHT justification cannot be render cached because the bounding box and justification offset depend on the camera. As a result, no SoSeparator above the SoText2 will be able to build a render cache or a bounding box cache and this can reduce performance. If possible put other geometry, that can be cached, under its own SoSeparator. SoText2 nodes using LEFT justification (the default) can be cached. Since Open Inventor 9.2, SoText2 nodes can be render cached in all cases.
Antialiasing:
Shape Antialiasing type is SoShape::TEXT.
Export limitations:
- SoText2 can be exported to PDF3D/U3D (SoToPDFAction), but...
due to limitations of that file format, the text will not be "screen locked".
- SoText2 can be exported to various Hardcopy formats (SoVectorizeAction), but...
native fonts are used, so the requested font name must be available on the rendering device.
FILE FORMAT/DEFAULT
- Text2 {
| string | "" |
| spacing | 1 |
| justification | LEFT |
ACTION BEHAVIOR
- SoGLRenderAction
Draws text based on the current font, at a location based on the current transformation.
SoRayPickAction
Performs a pick on the text. Text will be picked if the picking ray intersects the bounding box of the strings. The string index and character position are available from the SoTextDetail.
SoGetBoundingBoxAction
Computes the bounding box that encloses the text.
SEE ALSO
SoFont, SoFullSceneAntialiasing, SoText3, SoTextDetail, SoTextProperty
- See related examples:
Member Enumeration Documentation
Justification types.
- Enumerator:
LEFT Left edges of all strings are aligned.
CENTER Centers of all strings are aligned.
RIGHT Right edges of all strings are aligned.
INHERITED The text justification is inherited from the current SoTextProperty::alignmentH value.
Constructor & Destructor Documentation
| SoText2::SoText2 | ( | ) |
Creates a 2D text node with default settings.
Member Function Documentation
| static SoType SoText2::getClassTypeId | ( | ) | [static] |
Returns the type identifier for this class.
Reimplemented from SoShape.
| virtual SoType SoText2::getTypeId | ( | ) | const [virtual] |
Returns the type identifier for this specific instance.
Reimplemented from SoShape.
Friends And Related Function Documentation
friend class SoAnnoText3 [friend] |
friend class SoFontServer [friend] |
Member Data Documentation
Specifies horizontal alignment of strings.
With LEFT justification, the left edge of the first line is at the (transformed) origin, and all left edges are aligned. RIGHT justification is similar. CENTER justification places the center of the first string at the (transformed) origin, with the centers of all remaining strings aligned under it. Use enum Justification. Default is LEFT.
Both horizontal and vertical alignment can be specified using an SoTextProperty node. However the justification setting in this node overrides the horizontal setting in SoTextProperty unless this field is set to INHERITED.
Defines the distance (in the negative y direction) between the base points of successive strings, measured with respect to the current font height.
A value of 1 indicates single spacing, a value of 2 indicates double spacing, and so on.
The text string(s) to display.
Each string will appear on its own line.
The documentation for this class was generated from the following file:
- Inventor/nodes/SoText2.h