[EDIT] Ignore this post, it was a noob's mistake [/EDIT]
I started Android last week (= I'm pretty new to it :) ) and I'm banging my head on a problem: I try to perfom a raycasting to get the objects under a point of the screen. I found out that the GLU.gluUnproject method was what I needed, after a decent amount of failures, I found a solution
I've copied the MatrixGrabber, MatrixStack and MatrixTrackingGL classes in my project, they seem fine.
the method I use goes as follow:
static public Vertex unProject( float x, float y, World world )
{
world.mg = new MatrixGrabber();
world.mg.getCurrentState(world.gl);
float[] pos = new float[4];
GLU.gluUnProject( x, y, 0f,
world.mg.mModelView, 0,
world.mg.mProjecti开发者_运维技巧on, 0,
world.view().get_size(), 0,
pos, 0);
return new Vertex(pos[0], pos[1], pos[2]);
}
Vertex is a dataHolder with x,y,z floats
World extends GLSurfaceView, I do the GLWrapper replacement in the constructor: world.mg is a MatrixGrabber()
public World( Context context )
{
super(context);
[...]
//allows matrix manipulation
setGLWrapper( new GLWrapper()
{
public GL wrap(GL gl)
{
return new MatrixTrackingGL(gl);
}
});
}
and I make sure that all the variables are instanciated when I do my call
but still I can't get this to work: the app crashes badly on the
world.mg.getCurrentState(world.gl);
call. it also crashes it on getCurrentModelView(gl); and getCurrentProjection(gl);
I'm using Android 1.5, but tried with other versions up to 3. same thing. I don't really know which version of OpenGLI'm using ; the GL10 is used everywhere, I don't know if it is important, all I've read concerned the GL10 "Type".
if anyone has a clue, an advice, a workaround or a solution, I'd be happy happy happy
and anyway, thanks for reading :)
private void getMatrix(GL10 gl, int mode, float[] mat) {
MatrixTrackingGL gl2 = new MatrixTrackingGL(gl);
gl2.glMatrixMode(mode);
gl2.getMatrix(mat, 0);
}
replace the casting on the first line of the MatrixGrabber.java
my World class extended GLSurfaceView and was using the MatrixTrackingGL as a wrapper.
the problem was that the Viewport also extended GLSurfaceView and was NOT using the MatrixTrackingGL... stupid.
now the world doesn't extend anything and the Viewport ( extending GLSurfaceView ) implements the Wrapper's change and everything's fine.
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