com.badlogic.gdx.graphics.glutils

Class IndexBufferObject

java.lang.Object

com.badlogic.gdx.graphics.glutils.IndexBufferObject

All Implemented Interfaces:

IndexData, Disposable

public class IndexBufferObject
extends Object
implements IndexData

In IndexBufferObject wraps OpenGL's index buffer functionality to be used in conjunction with VBOs. This class can be seamlessly used with OpenGL ES 1.x and 2.0.

Uses indirect Buffers on Android 1.5/1.6 to fix GC invocation due to leaking PlatformAddress instances.

You can also use this to store indices for vertex arrays. Do not call bind() or unbind() in this case but rather use getBuffer() to use the buffer directly with glDrawElements. You must also create the IndexBufferObject with the second constructor and specify isDirect as true as glDrawElements in conjunction with vertex arrays needs direct buffers.

VertexBufferObjects must be disposed via the dispose() method when no longer needed

Author:

mzechner

Constructor Summary

Constructors

Constructor and Description
IndexBufferObject(boolean isStatic, int maxIndices) Creates a new IndexBufferObject.
IndexBufferObject(int maxIndices) Creates a new IndexBufferObject to be used with vertex arrays.

Method Summary

Methods

Modifier and Type	Method and Description
void	bind() Binds this IndexBufferObject for rendering with glDrawElements.
void	dispose() Disposes this IndexBufferObject and all its associated OpenGL resources.
ShortBuffer	getBuffer() Returns the underlying ShortBuffer.
int	getNumIndices()
int	getNumMaxIndices()
void	invalidate() Invalidates the IndexBufferObject so a new OpenGL buffer handle is created.
void	setIndices(short[] indices, int offset, int count) Sets the indices of this IndexBufferObject, discarding the old indices.
void	setIndices(ShortBuffer indices) Copies the specified indices to the indices of this IndexBufferObject, discarding the old indices.
void	unbind() Unbinds this IndexBufferObject.

Methods inherited from class java.lang.Object

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

Constructor Detail

IndexBufferObject

public IndexBufferObject(boolean isStatic,
                 int maxIndices)

Creates a new IndexBufferObject.

Parameters:

isStatic - whether the index buffer is static

maxIndices - the maximum number of indices this buffer can hold

IndexBufferObject

public IndexBufferObject(int maxIndices)

Creates a new IndexBufferObject to be used with vertex arrays.

Parameters:

maxIndices - the maximum number of indices this buffer can hold

Method Detail

getNumIndices

public int getNumIndices()

Specified by:

getNumIndices in interface IndexData

Returns:

the number of indices currently stored in this buffer

getNumMaxIndices

public int getNumMaxIndices()

Specified by:

getNumMaxIndices in interface IndexData

Returns:

the maximum number of indices this IndexBufferObject can store.

setIndices

public void setIndices(short[] indices,
              int offset,
              int count)

Sets the indices of this IndexBufferObject, discarding the old indices. The count must equal the number of indices to be copied to this IndexBufferObject.

This can be called in between calls to bind() and unbind(). The index data will be updated instantly.

Specified by:

setIndices in interface IndexData

Parameters:

indices - the vertex data

offset - the offset to start copying the data from

count - the number of shorts to copy

setIndices

public void setIndices(ShortBuffer indices)

Description copied from interface: IndexData

Copies the specified indices to the indices of this IndexBufferObject, discarding the old indices. Copying start at the current Buffer.position() of the specified buffer and copied the Buffer.remaining() amount of indices. This can be called in between calls to IndexData.bind() and IndexData.unbind(). The index data will be updated instantly.

Specified by:

setIndices in interface IndexData

Parameters:

indices - the index data to copy

getBuffer

public ShortBuffer getBuffer()

Returns the underlying ShortBuffer. If you modify the buffer contents they wil be uploaded on the call to bind(). If you need immediate uploading use setIndices(short[], int, int).

Specified by:

getBuffer in interface IndexData

Returns:

the underlying short buffer.

bind

public void bind()

Binds this IndexBufferObject for rendering with glDrawElements.

Specified by:

bind in interface IndexData

unbind

public void unbind()

Unbinds this IndexBufferObject.

Specified by:

unbind in interface IndexData

invalidate

public void invalidate()

Invalidates the IndexBufferObject so a new OpenGL buffer handle is created. Use this in case of a context loss.

Specified by:

invalidate in interface IndexData

dispose

public void dispose()

Disposes this IndexBufferObject and all its associated OpenGL resources.

Specified by:

dispose in interface IndexData

Specified by:

dispose in interface Disposable