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      1 /*
      2  * Copyright (C) 2009 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 java.io.IOException;
     20 import java.io.InputStream;
     21 import java.nio.ByteBuffer;
     22 import java.nio.ByteOrder;
     23 import java.nio.CharBuffer;
     24 import java.nio.FloatBuffer;
     25 
     26 import javax.microedition.khronos.egl.EGLConfig;
     27 import javax.microedition.khronos.opengles.GL;
     28 import javax.microedition.khronos.opengles.GL10;
     29 import javax.microedition.khronos.opengles.GL11;
     30 import javax.microedition.khronos.opengles.GL11Ext;
     31 
     32 import android.content.Context;
     33 import android.graphics.Bitmap;
     34 import android.graphics.BitmapFactory;
     35 import android.opengl.GLSurfaceView;
     36 import android.opengl.GLU;
     37 import android.opengl.GLUtils;
     38 import android.os.SystemClock;
     39 
     40 import com.example.android.apis.R;
     41 
     42 public class MatrixPaletteRenderer implements GLSurfaceView.Renderer{
     43     private Context mContext;
     44     private Grid mGrid;
     45     private int mTextureID;
     46 
     47     /** A grid is a topologically rectangular array of vertices.
     48      *
     49      * This grid class is customized for the vertex data required for this
     50      * example.
     51      *
     52      * The vertex and index data are held in VBO objects because on most
     53      * GPUs VBO objects are the fastest way of rendering static vertex
     54      * and index data.
     55      *
     56      */
     57 
     58     private static class Grid {
     59         // Size of vertex data elements in bytes:
     60         final static int FLOAT_SIZE = 4;
     61         final static int CHAR_SIZE = 2;
     62 
     63         // Vertex structure:
     64         // float x, y, z;
     65         // float u, v;
     66         // float weight0, weight1;
     67         // byte palette0, palette1, pad0, pad1;
     68 
     69         final static int VERTEX_SIZE = 8 * FLOAT_SIZE;
     70         final static int VERTEX_TEXTURE_BUFFER_INDEX_OFFSET = 3;
     71         final static int VERTEX_WEIGHT_BUFFER_INDEX_OFFSET = 5;
     72         final static int VERTEX_PALETTE_INDEX_OFFSET = 7 * FLOAT_SIZE;
     73 
     74         private int mVertexBufferObjectId;
     75         private int mElementBufferObjectId;
     76 
     77         // These buffers are used to hold the vertex and index data while
     78         // constructing the grid. Once createBufferObjects() is called
     79         // the buffers are nulled out to save memory.
     80 
     81         private ByteBuffer mVertexByteBuffer;
     82         private FloatBuffer mVertexBuffer;
     83         private CharBuffer mIndexBuffer;
     84 
     85         private int mW;
     86         private int mH;
     87         private int mIndexCount;
     88 
     89         public Grid(int w, int h) {
     90             if (w < 0 || w >= 65536) {
     91                 throw new IllegalArgumentException("w");
     92             }
     93             if (h < 0 || h >= 65536) {
     94                 throw new IllegalArgumentException("h");
     95             }
     96             if (w * h >= 65536) {
     97                 throw new IllegalArgumentException("w * h >= 65536");
     98             }
     99 
    100             mW = w;
    101             mH = h;
    102             int size = w * h;
    103 
    104             mVertexByteBuffer = ByteBuffer.allocateDirect(VERTEX_SIZE * size)
    105                 .order(ByteOrder.nativeOrder());
    106             mVertexBuffer = mVertexByteBuffer.asFloatBuffer();
    107 
    108             int quadW = mW - 1;
    109             int quadH = mH - 1;
    110             int quadCount = quadW * quadH;
    111             int indexCount = quadCount * 6;
    112             mIndexCount = indexCount;
    113             mIndexBuffer = ByteBuffer.allocateDirect(CHAR_SIZE * indexCount)
    114                 .order(ByteOrder.nativeOrder()).asCharBuffer();
    115 
    116             /*
    117              * Initialize triangle list mesh.
    118              *
    119              *     [0]-----[  1] ...
    120              *      |    /   |
    121              *      |   /    |
    122              *      |  /     |
    123              *     [w]-----[w+1] ...
    124              *      |       |
    125              *
    126              */
    127 
    128             {
    129                 int i = 0;
    130                 for (int y = 0; y < quadH; y++) {
    131                     for (int x = 0; x < quadW; x++) {
    132                         char a = (char) (y * mW + x);
    133                         char b = (char) (y * mW + x + 1);
    134                         char c = (char) ((y + 1) * mW + x);
    135                         char d = (char) ((y + 1) * mW + x + 1);
    136 
    137                         mIndexBuffer.put(i++, a);
    138                         mIndexBuffer.put(i++, c);
    139                         mIndexBuffer.put(i++, b);
    140 
    141                         mIndexBuffer.put(i++, b);
    142                         mIndexBuffer.put(i++, c);
    143                         mIndexBuffer.put(i++, d);
    144                     }
    145                 }
    146             }
    147 
    148         }
    149 
    150         public void set(int i, int j, float x, float y, float z,
    151                 float u, float v,
    152                 float w0, float w1,
    153                 int p0, int p1) {
    154             if (i < 0 || i >= mW) {
    155                 throw new IllegalArgumentException("i");
    156             }
    157             if (j < 0 || j >= mH) {
    158                 throw new IllegalArgumentException("j");
    159             }
    160 
    161             if (w0 + w1 != 1.0f) {
    162                 throw new IllegalArgumentException("Weights must add up to 1.0f");
    163             }
    164 
    165             int index = mW * j + i;
    166 
    167             mVertexBuffer.position(index * VERTEX_SIZE / FLOAT_SIZE);
    168             mVertexBuffer.put(x);
    169             mVertexBuffer.put(y);
    170             mVertexBuffer.put(z);
    171             mVertexBuffer.put(u);
    172             mVertexBuffer.put(v);
    173             mVertexBuffer.put(w0);
    174             mVertexBuffer.put(w1);
    175 
    176             mVertexByteBuffer.position(index * VERTEX_SIZE + VERTEX_PALETTE_INDEX_OFFSET);
    177             mVertexByteBuffer.put((byte) p0);
    178             mVertexByteBuffer.put((byte) p1);
    179         }
    180 
    181         public void createBufferObjects(GL gl) {
    182             // Generate a the vertex and element buffer IDs
    183             int[] vboIds = new int[2];
    184             GL11 gl11 = (GL11) gl;
    185             gl11.glGenBuffers(2, vboIds, 0);
    186             mVertexBufferObjectId = vboIds[0];
    187             mElementBufferObjectId = vboIds[1];
    188 
    189             // Upload the vertex data
    190             gl11.glBindBuffer(GL11.GL_ARRAY_BUFFER, mVertexBufferObjectId);
    191             mVertexByteBuffer.position(0);
    192             gl11.glBufferData(GL11.GL_ARRAY_BUFFER, mVertexByteBuffer.capacity(), mVertexByteBuffer, GL11.GL_STATIC_DRAW);
    193 
    194             gl11.glBindBuffer(GL11.GL_ELEMENT_ARRAY_BUFFER, mElementBufferObjectId);
    195             mIndexBuffer.position(0);
    196             gl11.glBufferData(GL11.GL_ELEMENT_ARRAY_BUFFER, mIndexBuffer.capacity() * CHAR_SIZE, mIndexBuffer, GL11.GL_STATIC_DRAW);
    197 
    198             // We don't need the in-memory data any more
    199             mVertexBuffer = null;
    200             mVertexByteBuffer = null;
    201             mIndexBuffer = null;
    202         }
    203 
    204         public void draw(GL10 gl) {
    205             GL11 gl11 = (GL11) gl;
    206             GL11Ext gl11Ext = (GL11Ext) gl;
    207 
    208             gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
    209 
    210             gl11.glBindBuffer(GL11.GL_ARRAY_BUFFER, mVertexBufferObjectId);
    211             gl11.glVertexPointer(3, GL10.GL_FLOAT, VERTEX_SIZE, 0);
    212             gl11.glTexCoordPointer(2, GL10.GL_FLOAT, VERTEX_SIZE, VERTEX_TEXTURE_BUFFER_INDEX_OFFSET * FLOAT_SIZE);
    213 
    214             gl.glEnableClientState(GL11Ext.GL_MATRIX_INDEX_ARRAY_OES);
    215             gl.glEnableClientState(GL11Ext.GL_WEIGHT_ARRAY_OES);
    216 
    217             gl11Ext.glWeightPointerOES(2, GL10.GL_FLOAT, VERTEX_SIZE, VERTEX_WEIGHT_BUFFER_INDEX_OFFSET  * FLOAT_SIZE);
    218             gl11Ext.glMatrixIndexPointerOES(2, GL10.GL_UNSIGNED_BYTE, VERTEX_SIZE, VERTEX_PALETTE_INDEX_OFFSET );
    219 
    220             gl11.glBindBuffer(GL11.GL_ELEMENT_ARRAY_BUFFER, mElementBufferObjectId);
    221             gl11.glDrawElements(GL10.GL_TRIANGLES, mIndexCount, GL10.GL_UNSIGNED_SHORT, 0);
    222             gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);
    223             gl.glDisableClientState(GL11Ext.GL_MATRIX_INDEX_ARRAY_OES);
    224             gl.glDisableClientState(GL11Ext.GL_WEIGHT_ARRAY_OES);
    225             gl11.glBindBuffer(GL11.GL_ARRAY_BUFFER, 0);
    226             gl11.glBindBuffer(GL11.GL_ELEMENT_ARRAY_BUFFER, 0);
    227         }
    228     }
    229 
    230     public MatrixPaletteRenderer(Context context) {
    231         mContext = context;
    232     }
    233 
    234     public void onSurfaceCreated(GL10 gl, EGLConfig config) {
    235         /*
    236          * By default, OpenGL enables features that improve quality
    237          * but reduce performance. One might want to tweak that
    238          * especially on software renderer.
    239          */
    240         gl.glDisable(GL10.GL_DITHER);
    241 
    242         /*
    243          * Some one-time OpenGL initialization can be made here
    244          * probably based on features of this particular context
    245          */
    246         gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT,
    247                 GL10.GL_FASTEST);
    248 
    249         gl.glClearColor(.5f, .5f, .5f, 1);
    250         gl.glShadeModel(GL10.GL_SMOOTH);
    251         gl.glEnable(GL10.GL_DEPTH_TEST);
    252         gl.glEnable(GL10.GL_TEXTURE_2D);
    253 
    254         /*
    255          * Create our texture. This has to be done each time the
    256          * surface is created.
    257          */
    258 
    259         int[] textures = new int[1];
    260         gl.glGenTextures(1, textures, 0);
    261 
    262         mTextureID = textures[0];
    263         gl.glBindTexture(GL10.GL_TEXTURE_2D, mTextureID);
    264 
    265         gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER,
    266                 GL10.GL_NEAREST);
    267         gl.glTexParameterf(GL10.GL_TEXTURE_2D,
    268                 GL10.GL_TEXTURE_MAG_FILTER,
    269                 GL10.GL_LINEAR);
    270 
    271         gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_S,
    272                 GL10.GL_CLAMP_TO_EDGE);
    273         gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_T,
    274                 GL10.GL_CLAMP_TO_EDGE);
    275 
    276         gl.glTexEnvf(GL10.GL_TEXTURE_ENV, GL10.GL_TEXTURE_ENV_MODE,
    277                 GL10.GL_REPLACE);
    278 
    279         InputStream is = mContext.getResources()
    280                 .openRawResource(R.raw.robot);
    281         Bitmap bitmap;
    282         try {
    283             bitmap = BitmapFactory.decodeStream(is);
    284         } finally {
    285             try {
    286                 is.close();
    287             } catch(IOException e) {
    288                 // Ignore.
    289             }
    290         }
    291 
    292         GLUtils.texImage2D(GL10.GL_TEXTURE_2D, 0, bitmap, 0);
    293         bitmap.recycle();
    294 
    295         mGrid = generateWeightedGrid(gl);
    296     }
    297 
    298     public void onDrawFrame(GL10 gl) {
    299         /*
    300          * By default, OpenGL enables features that improve quality
    301          * but reduce performance. One might want to tweak that
    302          * especially on software renderer.
    303          */
    304         gl.glDisable(GL10.GL_DITHER);
    305 
    306         gl.glTexEnvx(GL10.GL_TEXTURE_ENV, GL10.GL_TEXTURE_ENV_MODE,
    307                 GL10.GL_MODULATE);
    308 
    309         /*
    310          * Usually, the first thing one might want to do is to clear
    311          * the screen. The most efficient way of doing this is to use
    312          * glClear().
    313          */
    314 
    315         gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
    316 
    317         gl.glEnable(GL10.GL_DEPTH_TEST);
    318 
    319         gl.glEnable(GL10.GL_CULL_FACE);
    320 
    321         /*
    322          * Now we're ready to draw some 3D objects
    323          */
    324 
    325         gl.glMatrixMode(GL10.GL_MODELVIEW);
    326         gl.glLoadIdentity();
    327 
    328         GLU.gluLookAt(gl, 0, 0, -5, 0f, 0f, 0f, 0f, 1.0f, 0.0f);
    329 
    330         gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
    331         gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
    332 
    333         gl.glActiveTexture(GL10.GL_TEXTURE0);
    334         gl.glBindTexture(GL10.GL_TEXTURE_2D, mTextureID);
    335         gl.glTexParameterx(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_S,
    336                 GL10.GL_REPEAT);
    337         gl.glTexParameterx(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_T,
    338                 GL10.GL_REPEAT);
    339 
    340         long time = SystemClock.uptimeMillis() % 4000L;
    341 
    342         // Rock back and forth
    343         double animationUnit = ((double) time) / 4000;
    344         float unitAngle = (float) Math.cos(animationUnit * 2 * Math.PI);
    345         float angle = unitAngle * 135f;
    346 
    347         gl.glEnable(GL11Ext.GL_MATRIX_PALETTE_OES);
    348         gl.glMatrixMode(GL11Ext.GL_MATRIX_PALETTE_OES);
    349 
    350         GL11Ext gl11Ext = (GL11Ext) gl;
    351 
    352         // matrix 0: no transformation
    353         gl11Ext.glCurrentPaletteMatrixOES(0);
    354         gl11Ext.glLoadPaletteFromModelViewMatrixOES();
    355 
    356 
    357         // matrix 1: rotate by "angle"
    358         gl.glRotatef(angle, 0, 0, 1.0f);
    359 
    360         gl11Ext.glCurrentPaletteMatrixOES(1);
    361         gl11Ext.glLoadPaletteFromModelViewMatrixOES();
    362 
    363         mGrid.draw(gl);
    364 
    365         gl.glDisable(GL11Ext.GL_MATRIX_PALETTE_OES);
    366     }
    367 
    368     public void onSurfaceChanged(GL10 gl, int w, int h) {
    369         gl.glViewport(0, 0, w, h);
    370 
    371         /*
    372         * Set our projection matrix. This doesn't have to be done
    373         * each time we draw, but usually a new projection needs to
    374         * be set when the viewport is resized.
    375         */
    376 
    377         float ratio = (float) w / h;
    378         gl.glMatrixMode(GL10.GL_PROJECTION);
    379         gl.glLoadIdentity();
    380         gl.glFrustumf(-ratio, ratio, -1, 1, 3, 7);
    381     }
    382 
    383     private Grid generateWeightedGrid(GL gl) {
    384         final int uSteps = 20;
    385         final int vSteps = 20;
    386 
    387         float radius = 0.25f;
    388         float height = 2.0f;
    389         Grid grid = new Grid(uSteps + 1, vSteps + 1);
    390 
    391         for (int j = 0; j <= vSteps; j++) {
    392             for (int i = 0; i <= uSteps; i++) {
    393                 double angle = Math.PI * 2 * i / uSteps;
    394                 float x = radius * (float) Math.cos(angle);
    395                 float y = height * ((float) j / vSteps - 0.5f);
    396                 float z = radius * (float) Math.sin(angle);
    397                 float u = -4.0f * (float) i / uSteps;
    398                 float v = -4.0f * (float) j / vSteps;
    399                 float w0 = (float) j / vSteps;
    400                 float w1 = 1.0f - w0;
    401                 grid.set(i, j, x, y, z, u, v, w0, w1, 0, 1);
    402             }
    403         }
    404 
    405         grid.createBufferObjects(gl);
    406         return grid;
    407     }
    408 }
    409