void setProjectionMatrix(Context ctx, double[] projMatrix) {
if (VERBOSE) System.err.println("JoglPipeline.setProjectionMatrix()");
GLContext context = context(ctx);
GL2 gl = context.getGL().getGL2();
gl.glMatrixMode(GL2.GL_PROJECTION);
if (gl.isExtensionAvailable("GL_VERSION_1_3")) {
// Invert the Z value in clipping coordinates because OpenGL uses
// left-handed clipping coordinates, while Java3D defines right-handed
// coordinates everywhere.