javax.media.j3d
Class TexCoordGeneration

java.lang.Object
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  +--javax.media.j3d.SceneGraphObject
        |
        +--javax.media.j3d.NodeComponent
              |
              +--javax.media.j3d.TexCoordGeneration

public class TexCoordGeneration

extends NodeComponent

The TexCoordGeneration object contains all parameters needed for automatic texture coordinate generation. It is included as part of an Appearance component object.

Texture coordinates determine which texel in the texture map is assigned to a given vertex. Texture coordinates are interpolated between vertices, similarly to how colors are interpolated between two vertices of lines and polygons.

Texture coordinates consist of two or three coordinates, depending on whether the texture is 2D or 3D, respectively. These coordinates are referred to as the S, T, and R coordinates. 2D textures use the S and T coordinates. 3D textures use all three coordinates.

Rather than the programmer having to explicitly assign texture coordinates, Java 3D can automatically generate the texture coordinates to achieve texture mapping onto contours. The TexCoordGeneration attributes specify the functions for automatically generating texture coordinates. The texture attributes that can be defined are:

• Texture format - defines whether the texture is 2D or 3D:
  • TEXTURE_COORDINATE_2 - generates 2D texture coordinates (S and T).

  • TEXTURE_COORDINATE_3 - generates 3D texture coordinates (S, T, and R).

• Texture generation mode - defines how the texture coordinates are generated:
  • OBJECT_LINEAR - texture coordinates are generated as a linear function in object coordinates. The function used is:
    g = p1xo + p2yo + p3zo + p4wo

    where
    

    g is the value computed for the coordinate.
    p1, p2, p3, and p4 are the plane equation coefficients (described below).
    x_o, y_o, z_o, and w_o are the object coordinates of the vertex.

  • EYE_LINEAR - texture coordinates are generated as a linear function in eye coordinates. The function used is:
    g = p1'xe + p2'ye + p3'ze + p4'we

    where
    

    xe, ye, ze, and w_e are the eye coordinates of the vertex.
    p1', p2', p3', and p4' are the plane equation coefficients transformed into eye coordinates.

  • SPHERE_MAP - texture coordinates are generated using spherical reflection mapping in eye coordinates. Used to simulate the reflected image of a spherical environment onto a polygon.

• Plane equation coefficients - defines the coefficients for the plane equations used to generate the coordinates in the OBJECT_LINEAR and EYE_LINEAR texture generation modes. The coefficients define a reference plane in either object coordinates or in eye coordinates, depending on the texture generation mode.

  The equation coefficients are set by the setPlaneS, setPlaneT, and setPlaneR methods for each of the S, T, and R coordinate functions, respectively. By default the equation coefficients are set as follows:

  plane S = (1.0, 0.0, 0.0, 0.0)
  plane T = (0.0, 1.0, 0.0, 0.0)
  plane R = (0.0, 0.0, 0.0, 0.0)

Texture coordinate generation is enabled or disabled by the setEnable method. When enabled, the specified texture coordinate is computed according to the generating function associated with the coordinate. When disabled, subsequent vertices take the specified texture coordinate from the current set of texture coordinates.

Field Summary

static int	ALLOW_ENABLE_READ Specifies that this TexCoordGeneration object allows reading its enable flag.
static int	ALLOW_ENABLE_WRITE Specifies that this TexCoordGeneration object allows writing its enable flag.
static int	ALLOW_FORMAT_READ Specifies that this TexCoordGeneration object allows reading its format information.
static int	ALLOW_MODE_READ Specifies that this TexCoordGeneration object allows reading its mode information.
static int	ALLOW_PLANE_READ Specifies that this TexCoordGeneration object allows reading its planeS, planeR, and planeT component information.
static int	EYE_LINEAR Generates texture coordinates as a linear function in eye coordinates.
static int	OBJECT_LINEAR Generates texture coordinates as a linear function in object coordinates.
static int	SPHERE_MAP Generates texture coordinates using a spherical reflection mapping in eye coordinates.
static int	TEXTURE_COORDINATE_2 Generates 2D texture coordinates (S and T).
static int	TEXTURE_COORDINATE_3 Generates 3D texture coordinates (S, T, and R).

Constructor Summary

TexCoordGeneration()
Constructs a TexCoordGeneration object with default parameters.

TexCoordGeneration(int genMode, int format)
Constructs a TexCoordGeneration object with the specified genMode and format.

TexCoordGeneration(int genMode, int format, Vector4f planeS)
Constructs a TexCoordGeneration object with the specified genMode, format, and the S coordinate plane equation.

TexCoordGeneration(int genMode, int format, Vector4f planeS, Vector4f planeT)
Constructs a TexCoordGeneration object with the specified genMode, format, and the S and T coordinate plane equations.

TexCoordGeneration(int genMode, int format, Vector4f planeS, Vector4f planeT, Vector4f planeR)
Constructs a TexCoordGeneration object with the specified genMode, format, and the S, T, and R coordinate plane equations.

Method Summary

NodeComponent	cloneNodeComponent() Deprecated. replaced with cloneNodeComponent(boolean forceDuplicate)
boolean	getEnable() Retrieves the state of the texCoordGeneration enable flag.
int	getFormat() Retrieves the current TexCoordGeneration format.
int	getGenMode() Retrieves the current TexCoordGeneration generation mode.
void	getPlaneR(Vector4f planeR) Retrieves a copy of the plane equation used to generate the R coordinate.
void	getPlaneS(Vector4f planeS) Retrieves a copy of the plane equation used to generate the S coordinate.
void	getPlaneT(Vector4f planeT) Retrieves a copy of the plane equation used to generate the T coordinate.
void	setEnable(boolean state) Enables or disables texture coordinate generation for this appearance component object.
void	setFormat(int format) Sets the TexCoordGeneration format to the specified value.
void	setGenMode(int genMode) Sets the TexCoordGeneration generation mode to the specified value.
void	setPlaneR(Vector4f planeR) Sets the R coordinate plane equation.
void	setPlaneS(Vector4f planeS) Sets the S coordinate plane equation.
void	setPlaneT(Vector4f planeT) Sets the T coordinate plane equation.

Methods inherited from class javax.media.j3d.NodeComponent

cloneNodeComponent, duplicateNodeComponent, duplicateNodeComponent, getDuplicateOnCloneTree, setDuplicateOnCloneTree

Methods inherited from class javax.media.j3d.SceneGraphObject

clearCapability, duplicateSceneGraphObject, getCapability, getUserData, isCompiled, isLive, setCapability, setUserData, updateNodeReferences

Methods inherited from class java.lang.Object

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

Field Detail

ALLOW_ENABLE_READ

public static final int ALLOW_ENABLE_READ

Specifies that this TexCoordGeneration object allows reading its enable flag.

ALLOW_ENABLE_WRITE

public static final int ALLOW_ENABLE_WRITE

Specifies that this TexCoordGeneration object allows writing its enable flag.

ALLOW_FORMAT_READ

public static final int ALLOW_FORMAT_READ

Specifies that this TexCoordGeneration object allows reading its format information.

ALLOW_MODE_READ

public static final int ALLOW_MODE_READ

Specifies that this TexCoordGeneration object allows reading its mode information.

ALLOW_PLANE_READ

public static final int ALLOW_PLANE_READ

Specifies that this TexCoordGeneration object allows reading its planeS, planeR, and planeT component information.

OBJECT_LINEAR

public static final int OBJECT_LINEAR

Generates texture coordinates as a linear function in object coordinates.

EYE_LINEAR

public static final int EYE_LINEAR

Generates texture coordinates as a linear function in eye coordinates.

SPHERE_MAP

public static final int SPHERE_MAP

Generates texture coordinates using a spherical reflection mapping in eye coordinates.

TEXTURE_COORDINATE_2

public static final int TEXTURE_COORDINATE_2

Generates 2D texture coordinates (S and T).

TEXTURE_COORDINATE_3

public static final int TEXTURE_COORDINATE_3

Generates 3D texture coordinates (S, T, and R).

Constructor Detail

TexCoordGeneration

public TexCoordGeneration()

Constructs a TexCoordGeneration object with default parameters. The default values are as follows:

enable flag : true
texture generation mode : OBJECT_LINEAR
format : TEXTURE_COORDINATE_2
plane S : (1,0,0,0)
plane T : (0,1,0,0)
plane R : (0,0,0,0)

TexCoordGeneration

public TexCoordGeneration(int genMode,
                          int format)

Constructs a TexCoordGeneration object with the specified genMode and format. Defaults will be used for the rest of the state variables.

Parameters:

genMode - texture generation mode, one of: OBJECT_LINEAR, EYE_LINEAR, or SPHERE_MAP

format - texture format, one of: TEXTURE_COORDINATE_2 or TEXTURE_COORDINATE_3

TexCoordGeneration

public TexCoordGeneration(int genMode,
                          int format,
                          Vector4f planeS)

Constructs a TexCoordGeneration object with the specified genMode, format, and the S coordinate plane equation. Defaults will be used for the rest of the state variables.

Parameters:

genMode - texture generation mode, one of: OBJECT_LINEAR, EYE_LINEAR, or SPHERE_MAP

format - texture format, one of: TEXTURE_COORDINATE_2 or TEXTURE_COORDINATE_3

planeS - plane equation for the S coordinate

TexCoordGeneration

public TexCoordGeneration(int genMode,
                          int format,
                          Vector4f planeS,
                          Vector4f planeT)

Constructs a TexCoordGeneration object with the specified genMode, format, and the S and T coordinate plane equations. Defaults will be used for the rest of the state variables.

Parameters:

genMode - texture generation mode, one of: OBJECT_LINEAR, EYE_LINEAR, or SPHERE_MAP

format - texture format, one of: TEXTURE_COORDINATE_2 or TEXTURE_COORDINATE_3

planeS - plane equation for the S coordinate

planeT - plane equation for the T coordinate

TexCoordGeneration

public TexCoordGeneration(int genMode,
                          int format,
                          Vector4f planeS,
                          Vector4f planeT,
                          Vector4f planeR)

Constructs a TexCoordGeneration object with the specified genMode, format, and the S, T, and R coordinate plane equations.

Parameters:

genMode - texture generation mode, one of: OBJECT_LINEAR, EYE_LINEAR, or SPHERE_MAP

format - texture format, one of: TEXTURE_COORDINATE_2 or TEXTURE_COORDINATE_3

planeS - plane equation for the S coordinate

planeT - plane equation for the T coordinate

planeR - plane equation for the R coordinate

Method Detail

setEnable

public void setEnable(boolean state)

Enables or disables texture coordinate generation for this appearance component object.

Parameters:

state - true or false to enable or disable texture coordinate generation

Throws:

CapabilityNotSetException - if appropriate capability is not set and this object is part of live or compiled scene graph

getEnable

public boolean getEnable()

Retrieves the state of the texCoordGeneration enable flag.

Returns:

true if texture coordinate generation is enabled, false if texture coordinate generation is disabled

Throws:

CapabilityNotSetException - if appropriate capability is not set and this object is part of live or compiled scene graph

setFormat

public void setFormat(int format)

Sets the TexCoordGeneration format to the specified value.

Parameters:

format - texture format, one of: TEXTURE_COORDINATE_2 or TEXTURE_COORDINATE_3

Throws:

RestrictedAccessException - if the method is called when this object is part of live or compiled scene graph.

getFormat

public int getFormat()

Retrieves the current TexCoordGeneration format.

Returns:

the texture format

Throws:

CapabilityNotSetException - if appropriate capability is not set and this object is part of live or compiled scene graph

setGenMode

public void setGenMode(int genMode)

Sets the TexCoordGeneration generation mode to the specified value.

Parameters:

genMode - texture generation mode, one of: OBJECT_LINEAR, EYE_LINEAR, or SPHERE_MAP

Throws:

RestrictedAccessException - if the method is called when this object is part of live or compiled scene graph.

getGenMode

public int getGenMode()

Retrieves the current TexCoordGeneration generation mode.

Returns:

the texture generation mode

Throws:

CapabilityNotSetException - if appropriate capability is not set and this object is part of live or compiled scene graph

setPlaneS

public void setPlaneS(Vector4f planeS)

Sets the S coordinate plane equation. This plane equation is used to generate the S coordinate in OBJECT_LINEAR and EYE_LINEAR texture generation modes.

Parameters:

planeS - plane equation for the S coordinate

Throws:

RestrictedAccessException - if the method is called when this object is part of live or compiled scene graph.

getPlaneS

public void getPlaneS(Vector4f planeS)

Retrieves a copy of the plane equation used to generate the S coordinate.

Parameters:

planeS - the S coordinate plane equation

Throws:

CapabilityNotSetException - if appropriate capability is not set and this object is part of live or compiled scene graph

setPlaneT

public void setPlaneT(Vector4f planeT)

Sets the T coordinate plane equation. This plane equation is used to generate the T coordinate in OBJECT_LINEAR and EYE_LINEAR texture generation modes.

Parameters:

planeT - plane equation for the T coordinate

Throws:

RestrictedAccessException - if the method is called when this object is part of live or compiled scene graph.

getPlaneT

public void getPlaneT(Vector4f planeT)

Retrieves a copy of the plane equation used to generate the T coordinate.

Parameters:

planeT - the T coordinate plane equation

Throws:

CapabilityNotSetException - if appropriate capability is not set and this object is part of live or compiled scene graph

setPlaneR

public void setPlaneR(Vector4f planeR)

Sets the R coordinate plane equation. This plane equation is used to generate the R coordinate in OBJECT_LINEAR and EYE_LINEAR texture generation modes.

Parameters:

planeR - plane equation for the R coordinate

Throws:

RestrictedAccessException - if the method is called when this object is part of live or compiled scene graph.

getPlaneR

public void getPlaneR(Vector4f planeR)

Retrieves a copy of the plane equation used to generate the R coordinate.

Parameters:

planeR - the R coordinate plane equation

Throws:

CapabilityNotSetException - if appropriate capability is not set and this object is part of live or compiled scene graph

cloneNodeComponent

public NodeComponent cloneNodeComponent()

Deprecated. replaced with cloneNodeComponent(boolean forceDuplicate)

Overrides:

cloneNodeComponent in class NodeComponent