3D Shooters for Quake - Pro Android Games - page 207

// Character move
void IN_Move (usercmd_t *cmd)
{
// to look
IN_MouseLook(cmd);
// to move
//IN_MouseMove(cmd);
}

When the user drags a finger across the screen, the onTouchEvent in the GL view fires. This event
receives motion event information such as an action: ACTION_DOWN , ACTION_UP , or ACTION_MOVE ,
depending on the type of motion. Because the native engine runs in a separate thread,
onTouchEvent uses the built-in sub queueEvent to process the action safely into the game thread.
When the finger goes down ( ACTION_DOWN ), the XY coordinates of the press are recorded. When
the finger lifts up ( ACTION_UP ), the XY coordinates are reset to 0. When the finger is dragged
( ACTION_MOVE ), the delta coordinates (DX, DY) are calculated, and if they exceed a threshold value
(30 pixels in this case), they are sent to the engine by consumption using JNI. This requires the
native method int mouseMove(int deltaX, int deltaY) in Natives.java and its C counterpart
Java_quake_jni_Natives_mouseMove . The C implementation of mouseMove simply records the
values of delta XY coordinates to be processed by the video driver.

There is one important function in the video driver that processes movement: IN_Move .
Within this function, you use a mouse handler, IN_MouseMove , to control the pitch and yaw of
the character in 3D space. More details on this will be explained in the following sections.

Game Startup Activity
This is the final piece of the puzzle, the main entry point to the app: the game activity
(see Listing 6-9). Its job is to do the following:

Create an instance of the view

QuakeView .
Set a renderer with a set of string arguments that will be sent to the





engine at startup.

 QuakeView as the content that will start the rendering process and
begin the game!

Set

Listing 6-9. Main Startup Activity

public class QuakeActivity extends Activity {

QuakeView mQuakeView;

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);

// setContentView(R.layout.main);
mQuakeView = new QuakeView(this);