Android example source code file (MatrixPaletteRenderer.java)

This example Android source code file (MatrixPaletteRenderer.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" ^TM.

Java - Android tags/keywords

android, char_size, charbuffer, context, drawing, eglconfig, float_size, gl11ext, graphics, grid, illegalargumentexception, io, matrixpaletterenderer, nio, opengl, vertex_palette_index_offset, vertex_size, vertex_texture_buffer_index_offset, vertex_weight_buffer_index_offset, weights

The MatrixPaletteRenderer.java Android example source code

/*
 * Copyright (C) 2009 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.example.android.apis.graphics;

import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.CharBuffer;
import java.nio.FloatBuffer;

import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.opengles.GL;
import javax.microedition.khronos.opengles.GL10;
import javax.microedition.khronos.opengles.GL11;
import javax.microedition.khronos.opengles.GL11Ext;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.opengl.GLSurfaceView;
import android.opengl.GLU;
import android.opengl.GLUtils;
import android.os.SystemClock;

import com.example.android.apis.R;

public class MatrixPaletteRenderer implements GLSurfaceView.Renderer{
    private Context mContext;
    private Grid mGrid;
    private int mTextureID;

    /** A grid is a topologically rectangular array of vertices.
     *
     * This grid class is customized for the vertex data required for this
     * example.
     *
     * The vertex and index data are held in VBO objects because on most
     * GPUs VBO objects are the fastest way of rendering static vertex
     * and index data.
     *
     */

    private static class Grid {
        // Size of vertex data elements in bytes:
        final static int FLOAT_SIZE = 4;
        final static int CHAR_SIZE = 2;

        // Vertex structure:
        // float x, y, z;
        // float u, v;
        // float weight0, weight1;
        // byte palette0, palette1, pad0, pad1;

        final static int VERTEX_SIZE = 8 * FLOAT_SIZE;
        final static int VERTEX_TEXTURE_BUFFER_INDEX_OFFSET = 3;
        final static int VERTEX_WEIGHT_BUFFER_INDEX_OFFSET = 5;
        final static int VERTEX_PALETTE_INDEX_OFFSET = 7 * FLOAT_SIZE;

        private int mVertexBufferObjectId;
        private int mElementBufferObjectId;

        // These buffers are used to hold the vertex and index data while
        // constructing the grid. Once createBufferObjects() is called
        // the buffers are nulled out to save memory.

        private ByteBuffer mVertexByteBuffer;
        private FloatBuffer mVertexBuffer;
        private CharBuffer mIndexBuffer;

        private int mW;
        private int mH;
        private int mIndexCount;

        public Grid(int w, int h) {
            if (w < 0 || w >= 65536) {
                throw new IllegalArgumentException("w");
            }
            if (h < 0 || h >= 65536) {
                throw new IllegalArgumentException("h");
            }
            if (w * h >= 65536) {
                throw new IllegalArgumentException("w * h >= 65536");
            }

            mW = w;
            mH = h;
            int size = w * h;

            mVertexByteBuffer = ByteBuffer.allocateDirect(VERTEX_SIZE * size)
                .order(ByteOrder.nativeOrder());
            mVertexBuffer = mVertexByteBuffer.asFloatBuffer();

            int quadW = mW - 1;
            int quadH = mH - 1;
            int quadCount = quadW * quadH;
            int indexCount = quadCount * 6;
            mIndexCount = indexCount;
            mIndexBuffer = ByteBuffer.allocateDirect(CHAR_SIZE * indexCount)
                .order(ByteOrder.nativeOrder()).asCharBuffer();

            /*
             * Initialize triangle list mesh.
             *
             *     [0]-----[  1] ...
             *      |    /   |
             *      |   /    |
             *      |  /     |
             *     [w]-----[w+1] ...
             *      |       |
             *
             */

            {
                int i = 0;
                for (int y = 0; y < quadH; y++) {
                    for (int x = 0; x < quadW; x++) {
                        char a = (char) (y * mW + x);
                        char b = (char) (y * mW + x + 1);
                        char c = (char) ((y + 1) * mW + x);
                        char d = (char) ((y + 1) * mW + x + 1);

                        mIndexBuffer.put(i++, a);
                        mIndexBuffer.put(i++, c);
                        mIndexBuffer.put(i++, b);

                        mIndexBuffer.put(i++, b);
                        mIndexBuffer.put(i++, c);
                        mIndexBuffer.put(i++, d);
                    }
                }
            }

        }

        public void set(int i, int j, float x, float y, float z,
                float u, float v,
                float w0, float w1,
                int p0, int p1) {
            if (i < 0 || i >= mW) {
                throw new IllegalArgumentException("i");
            }
            if (j < 0 || j >= mH) {
                throw new IllegalArgumentException("j");
            }

            if (w0 + w1 != 1.0f) {
                throw new IllegalArgumentException("Weights must add up to 1.0f");
            }

            int index = mW * j + i;

            mVertexBuffer.position(index * VERTEX_SIZE / FLOAT_SIZE);
            mVertexBuffer.put(x);
            mVertexBuffer.put(y);
            mVertexBuffer.put(z);
            mVertexBuffer.put(u);
            mVertexBuffer.put(v);
            mVertexBuffer.put(w0);
            mVertexBuffer.put(w1);

            mVertexByteBuffer.position(index * VERTEX_SIZE + VERTEX_PALETTE_INDEX_OFFSET);
            mVertexByteBuffer.put((byte) p0);
            mVertexByteBuffer.put((byte) p1);
        }

        public void createBufferObjects(GL gl) {
            // Generate a the vertex and element buffer IDs
            int[] vboIds = new int[2];
            GL11 gl11 = (GL11) gl;
            gl11.glGenBuffers(2, vboIds, 0);
            mVertexBufferObjectId = vboIds[0];
            mElementBufferObjectId = vboIds[1];

            // Upload the vertex data
            gl11.glBindBuffer(GL11.GL_ARRAY_BUFFER, mVertexBufferObjectId);
            mVertexByteBuffer.position(0);
            gl11.glBufferData(GL11.GL_ARRAY_BUFFER, mVertexByteBuffer.capacity(), mVertexByteBuffer, GL11.GL_STATIC_DRAW);

            gl11.glBindBuffer(GL11.GL_ELEMENT_ARRAY_BUFFER, mElementBufferObjectId);
            mIndexBuffer.position(0);
            gl11.glBufferData(GL11.GL_ELEMENT_ARRAY_BUFFER, mIndexBuffer.capacity() * CHAR_SIZE, mIndexBuffer, GL11.GL_STATIC_DRAW);

            // We don't need the in-memory data any more
            mVertexBuffer = null;
            mVertexByteBuffer = null;
            mIndexBuffer = null;
        }

        public void draw(GL10 gl) {
            GL11 gl11 = (GL11) gl;
            GL11Ext gl11Ext = (GL11Ext) gl;

            gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);

            gl11.glBindBuffer(GL11.GL_ARRAY_BUFFER, mVertexBufferObjectId);
            gl11.glVertexPointer(3, GL10.GL_FLOAT, VERTEX_SIZE, 0);
            gl11.glTexCoordPointer(2, GL10.GL_FLOAT, VERTEX_SIZE, VERTEX_TEXTURE_BUFFER_INDEX_OFFSET * FLOAT_SIZE);

            gl.glEnableClientState(GL11Ext.GL_MATRIX_INDEX_ARRAY_OES);
            gl.glEnableClientState(GL11Ext.GL_WEIGHT_ARRAY_OES);

            gl11Ext.glWeightPointerOES(2, GL10.GL_FLOAT, VERTEX_SIZE, VERTEX_WEIGHT_BUFFER_INDEX_OFFSET  * FLOAT_SIZE);
            gl11Ext.glMatrixIndexPointerOES(2, GL10.GL_UNSIGNED_BYTE, VERTEX_SIZE, VERTEX_PALETTE_INDEX_OFFSET );

            gl11.glBindBuffer(GL11.GL_ELEMENT_ARRAY_BUFFER, mElementBufferObjectId);
            gl11.glDrawElements(GL10.GL_TRIANGLES, mIndexCount, GL10.GL_UNSIGNED_SHORT, 0);
            gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);
            gl.glDisableClientState(GL11Ext.GL_MATRIX_INDEX_ARRAY_OES);
            gl.glDisableClientState(GL11Ext.GL_WEIGHT_ARRAY_OES);
            gl11.glBindBuffer(GL11.GL_ARRAY_BUFFER, 0);
            gl11.glBindBuffer(GL11.GL_ELEMENT_ARRAY_BUFFER, 0);
        }
    }

    public MatrixPaletteRenderer(Context context) {
        mContext = context;
    }

    public void onSurfaceCreated(GL10 gl, EGLConfig config) {
        /*
         * By default, OpenGL enables features that improve quality
         * but reduce performance. One might want to tweak that
         * especially on software renderer.
         */
        gl.glDisable(GL10.GL_DITHER);

        /*
         * Some one-time OpenGL initialization can be made here
         * probably based on features of this particular context
         */
        gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT,
                GL10.GL_FASTEST);

        gl.glClearColor(.5f, .5f, .5f, 1);
        gl.glShadeModel(GL10.GL_SMOOTH);
        gl.glEnable(GL10.GL_DEPTH_TEST);
        gl.glEnable(GL10.GL_TEXTURE_2D);

        /*
         * Create our texture. This has to be done each time the
         * surface is created.
         */

        int[] textures = new int[1];
        gl.glGenTextures(1, textures, 0);

        mTextureID = textures[0];
        gl.glBindTexture(GL10.GL_TEXTURE_2D, mTextureID);

        gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER,
                GL10.GL_NEAREST);
        gl.glTexParameterf(GL10.GL_TEXTURE_2D,
                GL10.GL_TEXTURE_MAG_FILTER,
                GL10.GL_LINEAR);

        gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_S,
                GL10.GL_CLAMP_TO_EDGE);
        gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_T,
                GL10.GL_CLAMP_TO_EDGE);

        gl.glTexEnvf(GL10.GL_TEXTURE_ENV, GL10.GL_TEXTURE_ENV_MODE,
                GL10.GL_REPLACE);

        InputStream is = mContext.getResources()
                .openRawResource(R.raw.robot);
        Bitmap bitmap;
        try {
            bitmap = BitmapFactory.decodeStream(is);
        } finally {
            try {
                is.close();
            } catch(IOException e) {
                // Ignore.
            }
        }

        GLUtils.texImage2D(GL10.GL_TEXTURE_2D, 0, bitmap, 0);
        bitmap.recycle();

        mGrid = generateWeightedGrid(gl);
    }

    public void onDrawFrame(GL10 gl) {
        /*
         * By default, OpenGL enables features that improve quality
         * but reduce performance. One might want to tweak that
         * especially on software renderer.
         */
        gl.glDisable(GL10.GL_DITHER);

        gl.glTexEnvx(GL10.GL_TEXTURE_ENV, GL10.GL_TEXTURE_ENV_MODE,
                GL10.GL_MODULATE);

        /*
         * Usually, the first thing one might want to do is to clear
         * the screen. The most efficient way of doing this is to use
         * glClear().
         */

        gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);

        gl.glEnable(GL10.GL_DEPTH_TEST);

        gl.glEnable(GL10.GL_CULL_FACE);

        /*
         * Now we're ready to draw some 3D objects
         */

        gl.glMatrixMode(GL10.GL_MODELVIEW);
        gl.glLoadIdentity();

        GLU.gluLookAt(gl, 0, 0, -5, 0f, 0f, 0f, 0f, 1.0f, 0.0f);

        gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
        gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY);

        gl.glActiveTexture(GL10.GL_TEXTURE0);
        gl.glBindTexture(GL10.GL_TEXTURE_2D, mTextureID);
        gl.glTexParameterx(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_S,
                GL10.GL_REPEAT);
        gl.glTexParameterx(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_T,
                GL10.GL_REPEAT);

        long time = SystemClock.uptimeMillis() % 4000L;

        // Rock back and forth
        double animationUnit = ((double) time) / 4000;
        float unitAngle = (float) Math.cos(animationUnit * 2 * Math.PI);
        float angle = unitAngle * 135f;

        gl.glEnable(GL11Ext.GL_MATRIX_PALETTE_OES);
        gl.glMatrixMode(GL11Ext.GL_MATRIX_PALETTE_OES);

        GL11Ext gl11Ext = (GL11Ext) gl;

        // matrix 0: no transformation
        gl11Ext.glCurrentPaletteMatrixOES(0);
        gl11Ext.glLoadPaletteFromModelViewMatrixOES();


        // matrix 1: rotate by "angle"
        gl.glRotatef(angle, 0, 0, 1.0f);

        gl11Ext.glCurrentPaletteMatrixOES(1);
        gl11Ext.glLoadPaletteFromModelViewMatrixOES();

        mGrid.draw(gl);

        gl.glDisable(GL11Ext.GL_MATRIX_PALETTE_OES);
    }

    public void onSurfaceChanged(GL10 gl, int w, int h) {
        gl.glViewport(0, 0, w, h);

        /*
        * Set our projection matrix. This doesn't have to be done
        * each time we draw, but usually a new projection needs to
        * be set when the viewport is resized.
        */

        float ratio = (float) w / h;
        gl.glMatrixMode(GL10.GL_PROJECTION);
        gl.glLoadIdentity();
        gl.glFrustumf(-ratio, ratio, -1, 1, 3, 7);
    }

    private Grid generateWeightedGrid(GL gl) {
        final int uSteps = 20;
        final int vSteps = 20;

        float radius = 0.25f;
        float height = 2.0f;
        Grid grid = new Grid(uSteps + 1, vSteps + 1);

        for (int j = 0; j <= vSteps; j++) {
            for (int i = 0; i <= uSteps; i++) {
                double angle = Math.PI * 2 * i / uSteps;
                float x = radius * (float) Math.cos(angle);
                float y = height * ((float) j / vSteps - 0.5f);
                float z = radius * (float) Math.sin(angle);
                float u = -4.0f * (float) i / uSteps;
                float v = -4.0f * (float) j / vSteps;
                float w0 = (float) j / vSteps;
                float w1 = 1.0f - w0;
                grid.set(i, j, x, y, z, u, v, w0, w1, 0, 1);
            }
        }

        grid.createBufferObjects(gl);
        return grid;
    }
}