1 /* 2 * Copyright (C) 2011 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 package com.example.android.opengl; 17 18 import android.content.Context; 19 import android.opengl.GLSurfaceView; 20 import android.view.MotionEvent; 21 22 /** 23 * A view container where OpenGL ES graphics can be drawn on screen. 24 * This view can also be used to capture touch events, such as a user 25 * interacting with drawn objects. 26 */ 27 public class MyGLSurfaceView extends GLSurfaceView { 28 29 private final MyGLRenderer mRenderer; 30 31 public MyGLSurfaceView(Context context) { 32 super(context); 33 34 // Set the Renderer for drawing on the GLSurfaceView 35 mRenderer = new MyGLRenderer(); 36 setRenderer(mRenderer); 37 38 // Render the view only when there is a change in the drawing data 39 setRenderMode(GLSurfaceView.RENDERMODE_WHEN_DIRTY); 40 } 41 42 private final float TOUCH_SCALE_FACTOR = 180.0f / 320; 43 private float mPreviousX; 44 private float mPreviousY; 45 46 @Override 47 public boolean onTouchEvent(MotionEvent e) { 48 // MotionEvent reports input details from the touch screen 49 // and other input controls. In this case, we are only 50 // interested in events where the touch position changed. 51 52 float x = e.getX(); 53 float y = e.getY(); 54 55 switch (e.getAction()) { 56 case MotionEvent.ACTION_MOVE: 57 58 float dx = x - mPreviousX; 59 float dy = y - mPreviousY; 60 61 // reverse direction of rotation above the mid-line 62 if (y > getHeight() / 2) { 63 dx = dx * -1 ; 64 } 65 66 // reverse direction of rotation to left of the mid-line 67 if (x < getWidth() / 2) { 68 dy = dy * -1 ; 69 } 70 71 mRenderer.setAngle( 72 mRenderer.getAngle() + 73 ((dx + dy) * TOUCH_SCALE_FACTOR)); // = 180.0f / 320 74 requestRender(); 75 } 76 77 mPreviousX = x; 78 mPreviousY = y; 79 return true; 80 } 81 82 } 83
