glGetVertexAttribPointer() is coded incorrectly. Any use of the buffer returned by glGetVertexAttribPointer() results in a JVM crash (SIGSEGV), because LWJGL is returning an offset as a DirectByteBuffer whose address is typically in the first page of memory. glGetVertexAttribPointer() should return a long, not a ByteBuffer.

The spec for glVertexAttribPointer says:

pointer

Specifies a offset of the first component of the first generic vertex attribute in the array in the data store of the buffer currently bound to the GL_ARRAY_BUFFER target. The initial value is 0.

Emphasis mine. This is an offset into the VBO, not a native pointer.

Now look at glGetVertexAttribPointerv, which says:

The pointer returned is a byte offset into the data store of the buffer object that was bound to the GL_ARRAY_BUFFER target (see glBindBuffer) when the desired pointer was previously specified.

Emphasis mine again. The spec clearly intends this to be an offset, not a pointer.

Nested and Inner Type Summary

Modifier and Type	Class and Description
pack-priv static class	Test_glGetVertexAttribPointer_API_bug.Attr
pack-priv static class	Test_glGetVertexAttribPointer_API_bug.AttrGen

Field Summary

Modifier and Type	Field and Description
pack-priv static final Test_glGetVertexAttribPointer_API_bug.Attr[]	attributes
pack-priv static boolean	crashJvm
pack-priv static final int	FLOAT_BYTES
pack-priv static Test_glGetVertexAttribPointer_API_bug.AttrGen	gen
pack-priv static final Test_glGetVertexAttribPointer_API_bug.Attr	normal
pack-priv static final Test_glGetVertexAttribPointer_API_bug.Attr	position
pack-priv static final int	stride
pack-priv static final int	strideBytes
pack-priv static final Test_glGetVertexAttribPointer_API_bug.Attr	textureCoordinates

Access	Constructor and Description
public	Test_glGetVertexAttribPointer_API_bug()

Method Summary

Modifier and Type	Method and Description
pack-priv static long	getBufferAddress(ByteBuffer buf) Hack to call BufferUtils.getBufferAddress()
pack-priv static long	glGetVertexAttribPointer(int index)
public static void	main(String[] args)

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

attributes	back to summary
pack-priv static final Test_glGetVertexAttribPointer_API_bug.Attr[] attributes

crashJvm	back to summary
pack-priv static boolean crashJvm

FLOAT_BYTES	back to summary
pack-priv static final int FLOAT_BYTES

gen	back to summary
pack-priv static Test_glGetVertexAttribPointer_API_bug.AttrGen gen

normal	back to summary
pack-priv static final Test_glGetVertexAttribPointer_API_bug.Attr normal

position	back to summary
pack-priv static final Test_glGetVertexAttribPointer_API_bug.Attr position

stride	back to summary
pack-priv static final int stride

strideBytes	back to summary
pack-priv static final int strideBytes

textureCoordinates	back to summary
pack-priv static final Test_glGetVertexAttribPointer_API_bug.Attr textureCoordinates

Test_glGetVertexAttribPointer_API_bug	back to summary
public Test_glGetVertexAttribPointer_API_bug()

Method Detail

getBufferAddress	back to summary
pack-priv static long getBufferAddress(ByteBuffer buf) throws SecurityException, NoSuchMethodException, IllegalArgumentException, IllegalAccessException, InvocationTargetException Hack to call BufferUtils.getBufferAddress()

glGetVertexAttribPointer	back to summary
pack-priv static long glGetVertexAttribPointer(int index) throws NoSuchMethodException, IllegalAccessException, InvocationTargetException

main	back to summary
public static void main(String[] args) throws LWJGLException, SecurityException, NoSuchMethodException, IllegalArgumentException, IllegalAccessException, InvocationTargetException, PrivilegedActionException

org.lwjgl.test back to summary

pack-priv Class Test_glGetVertexAttribPointer_API_bug.Attr

Class Inheritance

extends Object

java.lang.Object
org.lwjgl.test.Test_glGetVertexAttribPointer_API_bug.Attr

Field Summary

Modifier and Type	Field and Description
pack-priv final int	index
pack-priv final String	name
pack-priv final int	offset
pack-priv final int	size

Constructor Summary

Access	Constructor and Description
pack-priv	Attr(String name, int index, int size, int offset)

Method Summary

Modifier and Type	Method and Description
pack-priv long	getByteOffset()

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

index	back to summary
pack-priv final int index

name	back to summary
pack-priv final String name

offset	back to summary
pack-priv final int offset

size	back to summary
pack-priv final int size

Constructor Detail

Attr	back to summary
pack-priv Attr(String name, int index, int size, int offset)

Method Detail

getByteOffset	back to summary
pack-priv long getByteOffset()

org.lwjgl.test back to summary

pack-priv Class Test_glGetVertexAttribPointer_API_bug.AttrGen

Class Inheritance

extends Object

java.lang.Object
org.lwjgl.test.Test_glGetVertexAttribPointer_API_bug.AttrGen

Field Summary

Modifier and Type	Field and Description
pack-priv int	offset

Constructor Summary

Access	Constructor and Description
pack-priv	AttrGen()

Method Summary

Modifier and Type	Method and Description
pack-priv Test_glGetVertexAttribPointer_API_bug.Attr	allocAttr(String name, int index, int size)

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

offset	back to summary
pack-priv int offset

Constructor Detail

AttrGen	back to summary
pack-priv AttrGen()

Method Detail

allocAttr	back to summary
pack-priv Test_glGetVertexAttribPointer_API_bug.Attr allocAttr(String name, int index, int size)

public Class Test_glGetVertexAttribPointer_API_bug

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

pack-priv Class Test_glGetVertexAttribPointer_API_bug.Attr

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

pack-priv Class Test_glGetVertexAttribPointer_API_bug.AttrGen

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail