com.badlogic.gdx.graphics.g3d.model

Class MeshPart

java.lang.Object

com.badlogic.gdx.graphics.g3d.model.MeshPart

public class MeshPart
extends Object

A MeshPart is composed of a subset of vertices of a Mesh, along with the primitive type. The vertices subset is described by an offset and size. When the mesh is indexed (which is when Mesh.getNumIndices() > 0), then the offset represents the offset in the indices array and size represents the number of indices. When the mesh isn't indexed, then the offset member represents the offset in the vertices array and the size member represents the number of vertices.

In other words: Regardless whether the mesh is indexed or not, when primitiveType is not a strip, then size equals the number of primitives multiplied by the number of vertices per primitive. So if the MeshPart represents 4 triangles ( primitiveType is GL_TRIANGLES), then the size member is 12 (4 triangles * 3 vertices = 12 vertices total). Likewise, if the part represents 12 lines (primitiveType is GL_LINES), then the size is 24 (12 lines * 2 vertices = 24 vertices total).

Note that some classes might require the mesh (part) to be indexed.

The Mesh referenced by the mesh member must outlive the MeshPart. When the mesh is disposed, the MeshPart is unusable.

Author:

badlogic, Xoppa

Field Summary

Fields

Modifier and Type	Field and Description
Vector3	center The offset to the center of the bounding box of the shape, only valid after the call to update().
Vector3	halfExtents The location, relative to center, of the corner of the axis aligned bounding box of the shape.
String	id Unique id within model, may be null.
Mesh	mesh The Mesh the part references, also stored in Model
int	offset The offset in the mesh to this part.
int	primitiveType The primitive type, OpenGL constant e.g: GL20.GL_TRIANGLES, GL20.GL_POINTS, GL20.GL_LINES, GL20.GL_LINE_STRIP, GL20.GL_TRIANGLE_STRIP
float	radius The radius relative to center of the bounding sphere of the shape, or negative if not calculated yet.
int	size The size (in total number of vertices) of this part in the mesh.

Constructor Summary

Constructors

Constructor and Description
MeshPart() Construct a new MeshPart, with null values.
MeshPart(MeshPart copyFrom) Construct a new MeshPart which is an exact copy of the provided MeshPart.
MeshPart(String id, Mesh mesh, int offset, int size, int type) Construct a new MeshPart and set all its values.

Method Summary

Modifier and Type	Method and Description
boolean	equals(MeshPart other) Compares this MeshPart to the specified MeshPart and returns true if they both reference the same Mesh and the offset, size and primitiveType members are equal.
boolean	equals(Object arg0)
void	render(ShaderProgram shader) Renders the mesh part using the specified shader, must be called in between ShaderProgram.begin() and ShaderProgram.end().
void	render(ShaderProgram shader, boolean autoBind) Renders the mesh part using the specified shader, must be called in between ShaderProgram.begin() and ShaderProgram.end().
MeshPart	set(MeshPart other) Set this MeshPart to be a copy of the other MeshPart
MeshPart	set(String id, Mesh mesh, int offset, int size, int type) Set this MeshPart to given values, does not update() the bounding box values.
void	update() Calculates and updates the center, halfExtents and radius values.

Methods inherited from class java.lang.Object

getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

id

public String id

Unique id within model, may be null. Will be ignored by equals(MeshPart)

primitiveType

public int primitiveType

The primitive type, OpenGL constant e.g: GL20.GL_TRIANGLES, GL20.GL_POINTS, GL20.GL_LINES, GL20.GL_LINE_STRIP, GL20.GL_TRIANGLE_STRIP

offset

public int offset

The offset in the mesh to this part. If the mesh is indexed (Mesh.getNumIndices() > 0), this is the offset in the indices array, otherwise it is the offset in the vertices array.

size

public int size

The size (in total number of vertices) of this part in the mesh. When the mesh is indexed ( Mesh.getNumIndices() > 0), this is the number of indices, otherwise it is the number of vertices.

mesh

public Mesh mesh

The Mesh the part references, also stored in Model

center

public final Vector3 center

The offset to the center of the bounding box of the shape, only valid after the call to update().

halfExtents

public final Vector3 halfExtents

The location, relative to center, of the corner of the axis aligned bounding box of the shape. Or, in other words: half the dimensions of the bounding box of the shape, where Vector3.x is half the width, Vector3.y is half the height and Vector3.z is half the depth. Only valid after the call to update().

radius

public float radius

The radius relative to center of the bounding sphere of the shape, or negative if not calculated yet. This is the same as the length of the halfExtents member. See update().

Constructor Detail

MeshPart

public MeshPart()

Construct a new MeshPart, with null values. The MeshPart is unusable until you set all members.

MeshPart

public MeshPart(String id,
                Mesh mesh,
                int offset,
                int size,
                int type)

Construct a new MeshPart and set all its values.

Parameters:

id - The id of the new part, may be null.

mesh - The mesh which holds all vertices and (optional) indices of this part.

offset - The offset within the mesh to this part.

size - The size (in total number of vertices) of the part.

type - The primitive type of the part (e.g. GL_TRIANGLES, GL_LINE_STRIP, etc.).

MeshPart

public MeshPart(MeshPart copyFrom)

Construct a new MeshPart which is an exact copy of the provided MeshPart.

Parameters:

copyFrom - The MeshPart to copy.

Method Detail

set

public MeshPart set(MeshPart other)

Set this MeshPart to be a copy of the other MeshPart

Parameters:

other - The MeshPart from which to copy the values

Returns:

this MeshPart, for chaining

set

public MeshPart set(String id,
                    Mesh mesh,
                    int offset,
                    int size,
                    int type)

Set this MeshPart to given values, does not update() the bounding box values.

Returns:

this MeshPart, for chaining.

update

public void update()

Calculates and updates the center, halfExtents and radius values. This is considered a costly operation and should not be called frequently. All vertices (points) of the shape are traversed to calculate the maximum and minimum x, y and z coordinate of the shape. Note that MeshPart is not aware of any transformation that might be applied when rendering. It calculates the untransformed (not moved, not scaled, not rotated) values.

equals

public boolean equals(MeshPart other)

Compares this MeshPart to the specified MeshPart and returns true if they both reference the same Mesh and the offset, size and primitiveType members are equal. The id member is ignored.

Parameters:

other - The other MeshPart to compare this MeshPart to.

Returns:

True when this MeshPart equals the other MeshPart (ignoring the id member), false otherwise.

equals

public boolean equals(Object arg0)

Overrides:

equals in class Object

render

public void render(ShaderProgram shader,
                   boolean autoBind)

Renders the mesh part using the specified shader, must be called in between ShaderProgram.begin() and ShaderProgram.end().

Parameters:

shader - the shader to be used

autoBind - overrides the autoBind member of the Mesh

render

public void render(ShaderProgram shader)

Renders the mesh part using the specified shader, must be called in between ShaderProgram.begin() and ShaderProgram.end().

Parameters:

shader - the shader to be used