# www.jpct.net

## jPCT-AE - a 3d engine for Android => Support => Topic started by: graydsl on October 15, 2010, 10:26:53 am

Title: CameraMovement
Post by: graydsl on October 15, 2010, 10:26:53 am
Hiho,

I'm developing a top secret app for my bachelor thesis. :D But I have some problems implementing camera movement. It's working, but for very small finger movement, it's not moving at all, because of slowCamMovement. But if i do it without slowCamMovement it's moving much to fast. So my question is, if there is a general strategy to implement this, which is much better than my approach? Thanks guys!

Code: [Select]
` private void moveCamera(float pX, float pY) { if (!mCameraMoving) { mLastX = pX; mLastY = pY; mCameraMoving = true; return; } else { if (mLastX == pX && mLastY == pY) { return; } else if (mLastY > pY) { // downwards Camera cam = mWorld.getCamera(); float speed = (mLastY - pY) / slowCamMovement; // slowCamMovement = 100f; cam.moveCamera(Camera.CAMERA_MOVEDOWN, speed); } else { // upwards Camera cam = mWorld.getCamera(); float speed = (mLastY - pY) / slowCamMovement; cam.moveCamera(Camera.CAMERA_MOVEUP, -speed); } lastX = pX; lastY = pY; } }`
Title: Re: CameraMovement
Post by: paulscode on October 15, 2010, 11:27:55 am
What happens if you make slowCamMovement smaller, like say 5.0f?  Also, make sure all your variables are either floats or type-cast as floats in your "speed=" algorithm (so Java doesn't try to do integer division and round to zero).
Title: Re: CameraMovement
Post by: Thomas. on October 15, 2010, 11:28:45 am
This may help
http://www.jpct.net/wiki/index.php/Main_Page
Title: Re: CameraMovement
Post by: graydsl on October 15, 2010, 11:59:50 am
I figured it out. :) BTW it's an vertical scrolling camera. Works pretty nice right now. But I'm open for suggestions. ^^

onDrawFrame:
Code: [Select]
` public void onDrawFrame(GL10 gl) { if (mCameraSpeed < 0) { mWorld.getCamera().moveCamera(Camera.CAMERA_MOVEUP, -mCameraSpeed); } else { mWorld.getCamera().moveCamera(Camera.CAMERA_MOVEDOWN, mCameraSpeed); } mCameraSpeed *= mCameraSlowing; fb.clear(new RGBColor(220, 220, 220)); mWorld.renderScene(fb); mWorld.draw(fb); fb.display(); }`
moveCamera:
Code: [Select]
` private void moveCamera(float pX, float pY) { if (!mCameraMoving) { lastX = pX; lastY = pY; mCameraMoving = true; return; } else { if (lastX == pX && lastY == pY) { return; } else { mCameraSpeed += (lastY - pY) / 150f; } lastX = pX; lastY = pY; } }`