/**
* Transforms position of a block, so that it get's rendered at correct point. If you wish to draw
* a block at a point, pass it to this method once you have called pushTransformMatrix() and draw
* it at the result instead
*
* @param vec bottom-left corner of the place where you want to draw
* @param result result is stored here: coordinates that you should use so the rotation matrix
* moves it to correct place. Use null to create new vector.
* @return result
*/
public Vector3f transform(Vector3f vec, Vector3f result) {
if (result == null) result = new Vector3f();
result.set(vec.x + .5f, vec.y + .5f, vec.z + .5f);
MathUtils.multiplyPos(invertedRotation, result);
result.set(result.x - .5f, result.y - .5f, result.z - .5f);
return result;
}
/**
* Creates rotation matrix accord to current rotation and pushes it into GlStateManager. Don't
* forget to pop (remove) it once you are done rendering with this rotation.
*/
public void pushTransformMatrix() {
GlStateManager.pushMatrix();
// add operations in reverse order
// first, rotate forward vector to rotForward
float angle1 = Vector3f.angle(forward, rotForward);
MathUtils.cross(forward, rotForward, tmp1);
tmp1.normalise();
// rotate up and rotate up
tmpMatrix.setIdentity();
tmpMatrix.rotate(angle1, tmp1);
MathUtils.multiplyVec(tmpMatrix, up, tmp2);
// L.s("Diff1: " + MathUtils.distanceSquared(up, tmp2));
// L.s("Diff2: " + MathUtils.distanceSquared(rotUp, tmp3));
// second, rotate up to rotUp
float angle2 = Vector3f.angle(tmp2, rotUp);
// L.s("Angle2: " + angle2);
if (Math.abs(angle2) < Math.PI) {
MathUtils.cross(tmp2, rotUp, tmp2);
tmp2.normalise();
} else {
// full 180 degree rotation, use rotForward instead
tmp2.set(rotForward);
}
// L.s("Tmp2: " + tmp2 + ", atan: " + Math.atan2(tmp2.z, tmp2.x) * MathUtils.radToDeg);
GlStateManager.rotate(angle2 * MathUtils.radToDegF, tmp2.x, tmp2.y, tmp2.z); // */
GlStateManager.rotate(angle1 * MathUtils.radToDegF, tmp1.x, tmp1.y, tmp1.z); // */
invertedRotation.setIdentity();
invertedRotation.rotate(angle2, tmp2);
invertedRotation.rotate(angle1, tmp1);
invertedRotation.invert();
}
/**
* spins the camera clockwise, moving the rotUp vector towards the rotRight vector, but the world
* before you seems to spin counter-clockwise, don't be fooled!
*
* @param angle rotation in radians
*/
public void cameraSpin(float angle) {
tmpMatrix.setIdentity();
tmpMatrix.rotate(angle, rotForward);
MathUtils.multiplyPos(tmpMatrix, rotUp);
MathUtils.multiplyPos(tmpMatrix, rotRight);
}
