1 /* 2 * Copyright (C) 2008 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 17 package com.example.android.apis.graphics; 18 19 import android.app.Activity; 20 import android.content.Context; 21 import android.opengl.GLSurfaceView; 22 import android.os.Bundle; 23 import android.view.InputDevice; 24 import android.view.KeyEvent; 25 import android.view.MotionEvent; 26 27 import javax.microedition.khronos.egl.EGLConfig; 28 import javax.microedition.khronos.opengles.GL10; 29 30 /** 31 * Wrapper activity demonstrating the use of {@link GLSurfaceView}, a view 32 * that uses OpenGL drawing into a dedicated surface. 33 * 34 * Shows: 35 * + How to redraw in response to user input. 36 */ 37 public class TouchRotateActivity extends Activity { 38 39 private GLSurfaceView mGLSurfaceView; 40 41 @Override 42 protected void onCreate(Bundle savedInstanceState) { 43 super.onCreate(savedInstanceState); 44 45 // Create our Preview view and set it as the content of our 46 // Activity 47 mGLSurfaceView = new TouchSurfaceView(this); 48 setContentView(mGLSurfaceView); 49 mGLSurfaceView.requestFocus(); 50 mGLSurfaceView.setFocusableInTouchMode(true); 51 } 52 53 @Override 54 protected void onResume() { 55 // Ideally a game should implement onResume() and onPause() 56 // to take appropriate action when the activity looses focus 57 super.onResume(); 58 mGLSurfaceView.onResume(); 59 } 60 61 @Override 62 protected void onPause() { 63 // Ideally a game should implement onResume() and onPause() 64 // to take appropriate action when the activity looses focus 65 super.onPause(); 66 mGLSurfaceView.onPause(); 67 } 68 69 /** 70 * Implement a simple rotation control. 71 * 72 */ 73 private static class TouchSurfaceView extends GLSurfaceView { 74 75 private static final float TOUCH_SCALE_FACTOR = 180.0f / 320; 76 private static final float TRACKBALL_SCALE_FACTOR = 36.0f; 77 private CubeRenderer mRenderer; 78 private float mPreviousX; 79 private float mPreviousY; 80 81 TouchSurfaceView(Context context) { 82 super(context); 83 mRenderer = new CubeRenderer(); 84 setRenderer(mRenderer); 85 setRenderMode(GLSurfaceView.RENDERMODE_WHEN_DIRTY); 86 } 87 88 @Override 89 public boolean onTrackballEvent(MotionEvent e) { 90 updateAngles(e.getX(), e.getY(), TRACKBALL_SCALE_FACTOR); 91 return true; 92 } 93 94 @Override 95 public boolean onTouchEvent(MotionEvent e) { 96 final int action = e.getActionMasked(); 97 if (action == MotionEvent.ACTION_MOVE) { 98 updateAngles(e.getX() - mPreviousX, e.getY() - mPreviousY, TOUCH_SCALE_FACTOR); 99 } else if (action == MotionEvent.ACTION_DOWN) { 100 if (e.isFromSource(InputDevice.SOURCE_MOUSE)) { 101 requestPointerCapture(); 102 } else { 103 releasePointerCapture(); 104 } 105 } 106 mPreviousX = e.getX(); 107 mPreviousY = e.getY(); 108 return true; 109 } 110 111 @Override 112 public boolean onCapturedPointerEvent(MotionEvent e) { 113 if (e.getActionMasked() == MotionEvent.ACTION_DOWN) { 114 releasePointerCapture(); 115 } else { 116 updateAngles(e.getX(), e.getY(), TOUCH_SCALE_FACTOR); 117 } 118 return true; 119 } 120 121 @Override 122 public boolean onKeyDown(int keyCode, KeyEvent event) { 123 // Release pointer capture on any key press. 124 releasePointerCapture(); 125 return super.onKeyDown(keyCode, event); 126 } 127 128 private void updateAngles(float dx, float dy, float scaleFactor) { 129 if (dx != 0 && dy != 0) { 130 mRenderer.mAngleX += dx * scaleFactor; 131 mRenderer.mAngleY += dy * scaleFactor; 132 requestRender(); 133 } 134 } 135 136 /** 137 * Render a cube. 138 */ 139 private static class CubeRenderer implements GLSurfaceView.Renderer { 140 CubeRenderer() { 141 mCube = new Cube(); 142 } 143 144 @Override 145 public void onDrawFrame(GL10 gl) { 146 /* 147 * Usually, the first thing one might want to do is to clear 148 * the screen. The most efficient way of doing this is to use 149 * glClear(). 150 */ 151 152 gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT); 153 154 /* 155 * Now we're ready to draw some 3D objects 156 */ 157 158 gl.glMatrixMode(GL10.GL_MODELVIEW); 159 gl.glLoadIdentity(); 160 gl.glTranslatef(0, 0, -3.0f); 161 gl.glRotatef(mAngleX, 0, 1, 0); 162 gl.glRotatef(mAngleY, 1, 0, 0); 163 164 gl.glEnableClientState(GL10.GL_VERTEX_ARRAY); 165 gl.glEnableClientState(GL10.GL_COLOR_ARRAY); 166 167 mCube.draw(gl); 168 } 169 170 @Override 171 public void onSurfaceChanged(GL10 gl, int width, int height) { 172 gl.glViewport(0, 0, width, height); 173 174 /* 175 * Set our projection matrix. This doesn't have to be done 176 * each time we draw, but usually a new projection needs to 177 * be set when the viewport is resized. 178 */ 179 180 float ratio = (float) width / height; 181 gl.glMatrixMode(GL10.GL_PROJECTION); 182 gl.glLoadIdentity(); 183 gl.glFrustumf(-ratio, ratio, -1, 1, 1, 10); 184 } 185 186 @Override 187 public void onSurfaceCreated(GL10 gl, EGLConfig config) { 188 /* 189 * By default, OpenGL enables features that improve quality 190 * but reduce performance. One might want to tweak that 191 * especially on software renderer. 192 */ 193 gl.glDisable(GL10.GL_DITHER); 194 195 /* 196 * Some one-time OpenGL initialization can be made here 197 * probably based on features of this particular context 198 */ 199 gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, 200 GL10.GL_FASTEST); 201 202 gl.glClearColor(1, 1, 1, 1); 203 gl.glEnable(GL10.GL_CULL_FACE); 204 gl.glShadeModel(GL10.GL_SMOOTH); 205 gl.glEnable(GL10.GL_DEPTH_TEST); 206 } 207 private Cube mCube; 208 float mAngleX; 209 float mAngleY; 210 } 211 } 212 } 213
