我正在使用 rajawali 库在 android 中加载 obj 模型，为此我使用包含访客检测器和访客侦听器的相机类，但我需要在此类中进行额外的平移操作：
public class ArcballCamera extends Camera
{
private Context mContext;
private ScaleGestureDetector mScaleDetector;
private View.OnTouchListener mGestureListener;
private GestureDetector mDetector;
private View mView;
private boolean mIsRotating;
private boolean mIsScaling;
private Vector3 mCameraStartPos;
private Vector3 mPrevSphereCoord;
private Vector3 mCurrSphereCoord;
private Vector2 mPrevScreenCoord;
private Vector2 mCurrScreenCoord;
private Quaternion mStartOrientation;
private Quaternion mCurrentOrientation;
private Object3D mEmpty;
private Object3D mTarget;
private Matrix4 mScratchMatrix;
private Vector3 mScratchVector;
private double mStartFOV;
public ArcballCamera(Context context, View view) {
this(context, view, null);
}
public ArcballCamera(Context context, View view, Object3D target) {
super();
mContext = context;
mTarget = target;
mView = view;
initialize();
addListeners();
}
private void initialize() {
mStartFOV = mFieldOfView;
mLookAtEnabled = true;
setLookAt(0, 0, 0);
mEmpty = new Object3D();
mScratchMatrix = new Matrix4();
mScratchVector = new Vector3();
mCameraStartPos = new Vector3();
mPrevSphereCoord = new Vector3();
mCurrSphereCoord = new Vector3();
mPrevScreenCoord = new Vector2();
mCurrScreenCoord = new Vector2();
mStartOrientation = new Quaternion();
mCurrentOrientation = new Quaternion();
}
@Override
public void setProjectionMatrix(int width, int height) {
super.setProjectionMatrix(width, height);
}
private void mapToSphere(final float x, final float y, Vector3 out)
{
float lengthSquared = x * x + y * y;
if (lengthSquared > 1)
{
out.setAll(x, y, 0);
out.normalize();
}
else
{
out.setAll(x, y, Math.sqrt(1 - lengthSquared));
}
}
private void mapToScreen(final float x, final float y, Vector2 out)
{
out.setX((2 * x - mLastWidth) / mLastWidth);
out.setY(-(2 * y - mLastHeight) / mLastHeight);
}
private void startRotation(final float x, final float y)
{
mapToScreen(x, y, mPrevScreenCoord);
mCurrScreenCoord.setAll(mPrevScreenCoord.getX(), mPrevScreenCoord.getY());
mIsRotating = true;
}
private void updateRotation(final float x, final float y)
{
mapToScreen(x, y, mCurrScreenCoord);
applyRotation();
}
private void endRotation()
{
mStartOrientation.multiply(mCurrentOrientation);
}
private void applyRotation()
{
if (mIsRotating)
{
mapToSphere((float) mPrevScreenCoord.getX(), (float) mPrevScreenCoord.getY(), mPrevSphereCoord);
mapToSphere((float) mCurrScreenCoord.getX(), (float) mCurrScreenCoord.getY(), mCurrSphereCoord);
Vector3 rotationAxis = mPrevSphereCoord.clone();
rotationAxis.cross(mCurrSphereCoord);
rotationAxis.normalize();
double rotationAngle = Math.acos(Math.min(1, mPrevSphereCoord.dot(mCurrSphereCoord)));
mCurrentOrientation.fromAngleAxis(rotationAxis, MathUtil.radiansToDegrees(rotationAngle));
mCurrentOrientation.normalize();
Quaternion q = new Quaternion(mStartOrientation);
q.multiply(mCurrentOrientation);
mEmpty.setOrientation(q);
}
}
@Override
public Matrix4 getViewMatrix() {
Matrix4 m = super.getViewMatrix();
if(mTarget != null) { mScratchMatrix.identity();
mScratchMatrix.translate(mTarget.getPosition());
m.multiply(mScratchMatrix);
}
mScratchMatrix.identity();
mScratchMatrix.rotate(mEmpty.getOrientation());
m.multiply(mScratchMatrix);
if(mTarget != null) {
mScratchVector.setAll(mTarget.getPosition());
mScratchVector.inverse();
mScratchMatrix.identity();
mScratchMatrix.translate(mScratchVector);
m.multiply(mScratchMatrix);
}
return m;
}
public void setFieldOfView(double fieldOfView) {
synchronized (mFrustumLock) {
mStartFOV = fieldOfView;
super.setFieldOfView(fieldOfView);
}
}
...在这种方法中定义了访客检测器和听众，所以我需要在这里平移。
所以有人告诉我如何在这里使用平移...
private void addListeners() {
((Activity) mContext).runOnUiThread(new Runnable() {
@Override
public void run() {
mDetector = new GestureDetector(mContext, new GestureListener());
mScaleDetector = new ScaleGestureDetector(mContext, new ScaleListener());
mGestureListener = new View.OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {
mScaleDetector.onTouchEvent(event);
if (!mIsScaling) {
mDetector.onTouchEvent(event);
if (event.getAction() == MotionEvent.ACTION_UP) {
if (mIsRotating) {
endRotation();
mIsRotating = false;
}
}
}
return true;
}
};
mView.setOnTouchListener(mGestureListener);
}
});
}
public void setTarget(Object3D target) {
mTarget = target;
setLookAt(mTarget.getPosition());
}
public Object3D getTarget() {
return mTarget;
}
private class GestureListener extends GestureDetector.SimpleOnGestureListener {
@Override
public boolean onScroll(MotionEvent event1, MotionEvent event2, float distanceX, float distanceY) {
if(!mIsRotating) {
startRotation(event2.getX(), event2.getY());
return false;
}
mIsRotating = true;
updateRotation(event2.getX(), event2.getY());
return false;
}
}
private class ScaleListener
extends ScaleGestureDetector.SimpleOnScaleGestureListener
{
@Override
public boolean onScale(ScaleGestureDetector detector) {
double fov = Math.max(30, Math.min(100, mStartFOV * (1.0 / detector.getScaleFactor())));
setFieldOfView(fov);
return true;
}
@Override
public boolean onScaleBegin (ScaleGestureDetector detector) {
mIsScaling = true;
mIsRotating = false;
return super.onScaleBegin(detector);
}
@Override
public void onScaleEnd (ScaleGestureDetector detector) {
mIsRotating = false;
mIsScaling = false;
}
}
}**