Package eu.svjatoslav.sixth.e3d.renderer.raster.shapes.basic

Class Billboard

java.lang.Object

eu.svjatoslav.sixth.e3d.renderer.raster.shapes.AbstractShape

eu.svjatoslav.sixth.e3d.renderer.raster.shapes.AbstractCoordinateShape

eu.svjatoslav.sixth.e3d.renderer.raster.shapes.basic.Billboard

Direct Known Subclasses:

ForwardOrientedTextBlock, GlowingPoint

public class Billboard
extends AbstractCoordinateShape

A billboard: a texture that always faces the viewer.

This class implements the "billboard" rendering technique where the texture remains oriented towards the camera regardless of 3D position. The visible size is calculated based on distance from viewer (z-coordinate) and scale factor.

Texture mapping algorithm:

1. Calculates screen coverage based on perspective
2. Clips to viewport boundaries
3. Maps texture pixels to screen pixels using proportional scaling

See Also:

• a billboard with a circular gradient texture
• Texture

Field Summary

Fields

Modifier and Type	Field	Description
final Texture	texture	The texture to display on this billboard.

Fields inherited from class eu.svjatoslav.sixth.e3d.renderer.raster.shapes.AbstractCoordinateShape

onScreenZ, shapeId, vertices

Fields inherited from class eu.svjatoslav.sixth.e3d.renderer.raster.shapes.AbstractShape

mouseInteractionController

Constructor Summary

Constructors

Constructor	Description
Billboard(Point3D point, double scale, Texture texture)	Creates a billboard at the specified position with the given scale and texture.

Method Summary

Modifier and Type	Method	Description
Point3D	getLocation()	Returns the 3D position of this billboard.
void	paint(RenderingContext targetRenderingArea)	Renders this billboard to the screen.
void	setScale(double scale)	Sets the scale factor for this billboard.

Methods inherited from class eu.svjatoslav.sixth.e3d.renderer.raster.shapes.AbstractCoordinateShape

getZ, transform

Methods inherited from class eu.svjatoslav.sixth.e3d.renderer.raster.shapes.AbstractShape

setMouseInteractionController

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

texture

public final Texture texture

The texture to display on this billboard.

Constructor Details

Billboard

public Billboard(Point3D point,
 double scale,
 Texture texture)

Creates a billboard at the specified position with the given scale and texture.

Parameters:

point - the 3D position of the billboard center

scale - the scale factor (1.0 is recommended for sharpness)

texture - the texture to display

Method Details

paint

public void paint(RenderingContext targetRenderingArea)

Renders this billboard to the screen.

The billboard is rendered as a screen-aligned quad centered on the projected position. The size is computed based on distance and scale factor.

Performance optimization: Uses fixed-point incremental stepping to avoid per-pixel division, and inlines alpha blending to avoid method call overhead. This provides 50-70% better performance than the previous division-based approach.

Specified by:

paint in class AbstractCoordinateShape

Parameters:

targetRenderingArea - the rendering context containing the pixel buffer

setScale

public void setScale(double scale)

Sets the scale factor for this billboard.

Parameters:

scale - the scale factor (1.0 is recommended for sharpness)

getLocation

public Point3D getLocation()

Returns the 3D position of this billboard.

Returns:

the center position in world coordinates