How do I transform the modelview matrix with a Java matrix?

OpenGL Development JOGL Development
#1

How do I transform the modelview matrix in OpenGL in with a Java matrix using JOGL?

Im trying to master the art of bone animaiton and Im using the javax. vecmath package. It contains the Matrix4f-class.
So when I have the right transformation matrix in the form of a Matrix4f instance, how do I pass it into OpenGL through JOGL?

#2

OpenGL expects matrices to be specified as a one dimensional array of float values in column major order. Jogl gives you the choice of passing this array either as a float/double array or as a Float/DoubleBuffer. In code this translates to

Matrix4f javaMatrix;
float[] openglMatrix = new float[] {
  javaMatrix.m00,   javaMatrix.m10,   javaMatrix.m20,   javaMatrix.m30,
  javaMatrix.m01,   javaMatrix.m11,   javaMatrix.m21,   javaMatrix.m31,
  javaMatrix.m02,   javaMatrix.m12,   javaMatrix.m22,   javaMatrix.m32,
  javaMatrix.m03,   javaMatrix.m13,   javaMatrix.m23,   javaMatrix.m33
};

To pass the matrix to OpenGL you should then call either

glLoadMatrixf(openglMatrix);

or

glMultMatrixf(openglMatrix);

depending on what you’re trying to do.
If you’re not familiar with OpenGL matrix stuff you might also want to check out the documentation on glMatrixMode, glPushMatrix and glPopMatrix.