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--- public:t-gede-13-1:lab4 [2013/02/05 12:47] – hannes
+++ public:t-gede-13-1:lab4 [2024/04/29 13:33] (current) – external edit 127.0.0.1
@@ Line 14: / Line 14: @@
 No special preparation is required - preparing the joypad is explained in the project steps below.
+**NOTE:** To get the joypads to start sending data, you may have to press a **Mode** button in the center of the device. This is true for the joypads handed out in the lab class!
 ===== Lab Project =====
@@ Line 75: / Line 77: @@
 			break;
 		}
-</code> Make sure also to declare each of the ''bool'' variables as member variables in your class! This is a bit verbose here for clarity, but you can also pack these bits into a single byte to save space and use bit masking. Notice that the POV directions don't necessarily map correctly onto the directions in our world. Finally, you can now use these booleans just like the keyboard button presses for moving the character in your class's ''frameStarted'' method. In fact, you can use the OR operator to check to see if a keyboard direction was pressed OR the corresponding walking direction is true, for example: <code>
+</code> Make sure also to declare each of the ''bool'' variables as member variables in your class! This is a bit verbose here for clarity, but you can also pack these bits into a single byte to save space and use bit masking. Notice that the POV directions don't necessarily map correctly onto the directions in our world. You can now use these booleans just like the keyboard button presses for moving the character in your class's ''frameStarted'' method. In fact, you can use the OR operator to check to see if a keyboard direction was pressed OR the corresponding walking direction is true, for example: <code>
                 if(_Keyboard->isKeyDown(OIS::KC_UP) || _WalkingNorth) { ... }
+</code> Finally, you need to capture the joystick input in this ''frameStarted'' method: <code>
+		if( _Joystick )
+			_Joystick->capture();
 </code>
+  - **Rotate Camera with Analog Stick** Now you should try to rotate (or swivel) the camera around the character with the right analog stick on the joypad. You first need to create a new member variable in your MyFrameListener class that stores the current camera angle (e.g. ''float _camangle''). In your constructor, initialize this angle to the value ''-1*Ogre::Math::HALF_PI'' so that this angle corresponds to the initial orientation of the character. As with the POV button, you should examine the values you get from the analog axes of your joypad. Add the following lines to your ''axisMoved'' callback:<code>
+		int value = e.state.mAxes[axis].abs;
+		switch(axis) {
+			case 0:
+				std::cout << "0:" << value << "\n";
+				break;
+		}
+</code> You can add more cases to this to observe values along the other axes. You will notice that they each run from a negative 32768 to a positive 32767, which corresponds to the range of a 16-bit signed integer. For one of these axes, we want this range to map onto a camera angle that runs from 0 to 360 degrees (calculated in radians). The camera angle can therefore be calculated as follows:<code>
+               _camangle = Ogre::Math::TWO_PI * ((float(-1*value) / float(_Joystick->MAX_AXIS) + 1.0f)/2.0f)+Ogre::Math::HALF_PI;
+</code> The ''-1'' in here is to reverse the axis value to let the direction of movement map better onto the perceived camera motion and the HALF_PI offset is just so that we start by facing the ogre model correctly. Finally, in the ''frameStarted'' callback you have to continue to update the camera position and orientation: <code>
+		_Cam->setPosition(_myogrenode->getPosition()+Ogre::Vector3(20.0f*Ogre::Math::Cos(_camangle), 10.0f, 20.0f*Ogre::Math::Sin(_camangle)));
+		_Cam->lookAt(_myogrenode->getPosition());
+</code> Test to see if this works.
+  - **OPTIONAL: Map more axes and buttons** Add more controls to the camera or other things in the environment. For example, zoom the camera in and out with a different axis of movement or let a button start the effect from lab 2.