diff options
| -rw-r--r-- | demos/NVidia/VertexArrayRange.java | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/demos/NVidia/VertexArrayRange.java b/demos/NVidia/VertexArrayRange.java index f4d0d2f..0da54bf 100644 --- a/demos/NVidia/VertexArrayRange.java +++ b/demos/NVidia/VertexArrayRange.java @@ -632,9 +632,18 @@ public class VertexArrayRange { loX.reset(); hiX.reset(); - // NOTE: we don't make the glVertexPointer/glNormalPointer - // call until this point because the semantics in the - // "fixed" implementation are that they copy data. + // NOTE: these calls are not safe because the OpenGL for + // Java implementation uses the JNI + // GetPrimitiveArrayCritical routine to fetch the arrays' + // storage. If a garbage collection occurs between or during + // the glVertexPointer and glDrawElements calls, the arrays + // may move, leading to incorrect data being drawn or + // possibly a crash. Future applications should always use + // java.nio direct buffers for the storage passed down to + // glVertexPointer and similar routines taking persistent + // pointers, regardless of whether an extension like + // NVidia's vertex array range is used. Direct buffers can + // be created with ByteBuffer.allocateDirect(). gl.glVertexPointer(3, GL_FLOAT, 3 * SIZEOF_FLOAT, v); gl.glNormalPointer(GL_FLOAT, 3 * SIZEOF_FLOAT, n); |