android/src/BitmapUtil.java

   1 /* Copyright_License {
   2
   3   XCSoar Glide Computer - http://www.xcsoar.org/
   4   Copyright (C) 2000-2013 The XCSoar Project
   5   A detailed list of copyright holders can be found in the file "AUTHORS".
   6
   7   This program is free software; you can redistribute it and/or
   8   modify it under the terms of the GNU General Public License
   9   as published by the Free Software Foundation; either version 2
  10   of the License, or (at your option) any later version.
  11
  12   This program is distributed in the hope that it will be useful,
  13   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15   GNU General Public License for more details.
  16
  17   You should have received a copy of the GNU General Public License
  18   along with this program; if not, write to the Free Software
  19   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  20 }
  21 */
  22
  23 package org.xcsoar;
  24
  25 import android.util.Log;
  26 import android.graphics.Bitmap;
  27 import static android.opengl.GLES11.*;
  28 import android.opengl.GLUtils;
  29
  30 /**
  31  * Utilities for dealing with #Bitmap objects and OpenGL.
  32  */
  33 final class BitmapUtil {
  34   private static final String TAG = "XCSoar";
  35
  36   public static int validateTextureSize(int i) {
  37     return NativeView.validateTextureSize(i);
  38   }
  39
  40   /**
  41    * Initialize the current texture and load the specified Bitmap into
  42    * it.
  43    */
  44   private static boolean loadTexture(Bitmap bmp) {
  45     int internalFormat, format, type;
  46     int unpackAlignment;
  47
  48     switch (bmp.getConfig()) {
  49     case ARGB_4444:
  50     case ARGB_8888:
  51       internalFormat = format = GL_RGBA;
  52       type = GL_UNSIGNED_BYTE;
  53       unpackAlignment = 4;
  54       break;
  55
  56     case RGB_565:
  57       internalFormat = format = GL_RGB;
  58       type = GL_UNSIGNED_SHORT_5_6_5;
  59       unpackAlignment = 2;
  60       break;
  61
  62     case ALPHA_8:
  63       internalFormat = format = GL_LUMINANCE;
  64       type = GL_UNSIGNED_BYTE;
  65       unpackAlignment = 1;
  66       break;
  67
  68     default:
  69       return false;
  70     }
  71
  72     /* create an empty texture, and load the Bitmap into it */
  73
  74     glTexImage2D(GL_TEXTURE_2D, 0, internalFormat,
  75                  validateTextureSize(bmp.getWidth()),
  76                  validateTextureSize(bmp.getHeight()),
  77                  0, format, type, null);
  78     glPixelStorei(GL_UNPACK_ALIGNMENT, unpackAlignment);
  79     GLUtils.texSubImage2D(GL_TEXTURE_2D, 0, 0, 0, bmp, format, type);
  80     return true;
  81   }
  82
  83   /**
  84    * Loads an Android Bitmap as OpenGL texture.
  85    *
  86    * @param result an array of 3 integers: texture id, width, height
  87    * (all output)
  88    * @return true on success
  89    */
  90   public static boolean bitmapToOpenGL(Bitmap bmp, int[] result) {
  91     if (bmp == null)
  92       return false;
  93
  94     result[1] = bmp.getWidth();
  95     result[2] = bmp.getHeight();
  96
  97     if (bmp.getConfig() == null) {
  98       /* convert to a format compatible with OpenGL */
  99       Bitmap tmp = bmp.copy(Bitmap.Config.RGB_565, false);
 100       bmp.recycle();
 101
 102       if (tmp == null)
 103         return false;
 104
 105       bmp = tmp;
 106     }
 107
 108     /* create and configure an OpenGL texture */
 109
 110     glGenTextures(1, result, 0);
 111     glBindTexture(GL_TEXTURE_2D, result[0]);
 112     glTexParameterf(GL_TEXTURE_2D,
 113                     GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 114     glTexParameterf(GL_TEXTURE_2D,
 115                     GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 116     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
 117                     GL_NEAREST);
 118     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,
 119                     GL_NEAREST);
 120
 121     try {
 122       if (!loadTexture(bmp)) {
 123         glDeleteTextures(1, result, 0);
 124         return false;
 125       }
 126     } catch (Exception e) {
 127       glDeleteTextures(1, result, 0);
 128       Log.e(TAG, "GLUtils error: " + e);
 129       return false;
 130     } finally {
 131       bmp.recycle();
 132     }
 133
 134     /* done */
 135
 136     return true;
 137   }
 138 }