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Android example source code file (SimpleGLRenderer.java)

This example Android source code file (SimpleGLRenderer.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, bitmap, content, context, drawing, gl10, glerror, glsprite, graphics, grid, inputstream, io, ioexception, load, opengl, paint, simpleglrenderer, spritemethodtest, texture, ui

The SimpleGLRenderer.java Android example source code

/*
 * Copyright (C) 2008 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.android.spritemethodtest;

import java.io.IOException;
import java.io.InputStream;

import javax.microedition.khronos.egl.EGL10;
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.GLUtils;
import android.util.Log;

/**
 * An OpenGL ES renderer based on the GLSurfaceView rendering framework.  This
 * class is responsible for drawing a list of renderables to the screen every
 * frame.  It also manages loading of textures and (when VBOs are used) the
 * allocation of vertex buffer objects.
 */
public class SimpleGLRenderer implements GLSurfaceView.Renderer {
    // Specifies the format our textures should be converted to upon load.
    private static BitmapFactory.Options sBitmapOptions
        = new BitmapFactory.Options();
    // An array of things to draw every frame.
    private GLSprite[] mSprites;
    // Pre-allocated arrays to use at runtime so that allocation during the
    // test can be avoided.
    private int[] mTextureNameWorkspace;
    private int[] mCropWorkspace;
    // A reference to the application context.
    private Context mContext;
    // Determines the use of vertex arrays.
    private boolean mUseVerts;
    // Determines the use of vertex buffer objects.
    private boolean mUseHardwareBuffers;
    
    public SimpleGLRenderer(Context context) {
        // Pre-allocate and store these objects so we can use them at runtime
        // without allocating memory mid-frame.
        mTextureNameWorkspace = new int[1];
        mCropWorkspace = new int[4];
        
        // Set our bitmaps to 16-bit, 565 format.
        sBitmapOptions.inPreferredConfig = Bitmap.Config.RGB_565;
        
        mContext = context;
    }
    
    public int[] getConfigSpec() {
        // We don't need a depth buffer, and don't care about our
        // color depth.
        int[] configSpec = { EGL10.EGL_DEPTH_SIZE, 0, EGL10.EGL_NONE };
        return configSpec;
    }
    
    public void setSprites(GLSprite[] sprites) {
        mSprites = sprites;
    }
    
    /** 
     * Changes the vertex mode used for drawing.  
     * @param useVerts  Specifies whether to use a vertex array.  If false, the
     *     DrawTexture extension is used.
     * @param useHardwareBuffers  Specifies whether to store vertex arrays in
     *     main memory or on the graphics card.  Ignored if useVerts is false.
     */
    public void setVertMode(boolean useVerts, boolean useHardwareBuffers) {
        mUseVerts = useVerts;
        mUseHardwareBuffers = useVerts ? useHardwareBuffers : false;
    }

    /** Draws the sprites. */
    public void drawFrame(GL10 gl) {
        if (mSprites != null) {

            gl.glMatrixMode(GL10.GL_MODELVIEW);
          
            if (mUseVerts) {
                Grid.beginDrawing(gl, true, false);
            }
            
            for (int x = 0; x < mSprites.length; x++) {
                mSprites[x].draw(gl);
            }
            
            if (mUseVerts) {
                Grid.endDrawing(gl);
            }
            
           
        }
    }

    /* Called when the size of the window changes. */
    public void sizeChanged(GL10 gl, int width, int height) {
        gl.glViewport(0, 0, width, height);

        /*
         * 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.
         */
        gl.glMatrixMode(GL10.GL_PROJECTION);
        gl.glLoadIdentity();
        gl.glOrthof(0.0f, width, 0.0f, height, 0.0f, 1.0f);
        
        gl.glShadeModel(GL10.GL_FLAT);
        gl.glEnable(GL10.GL_BLEND);
        gl.glBlendFunc(GL10.GL_SRC_ALPHA, GL10.GL_ONE_MINUS_SRC_ALPHA);
        gl.glColor4x(0x10000, 0x10000, 0x10000, 0x10000);
        gl.glEnable(GL10.GL_TEXTURE_2D);
    }

    /**
     * Called whenever the surface is created.  This happens at startup, and
     * may be called again at runtime if the device context is lost (the screen
     * goes to sleep, etc).  This function must fill the contents of vram with
     * texture data and (when using VBOs) hardware vertex arrays.
     */
    public void surfaceCreated(GL10 gl) {
         /*
         * 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(0.5f, 0.5f, 0.5f, 1);
        gl.glShadeModel(GL10.GL_FLAT);
        gl.glDisable(GL10.GL_DEPTH_TEST);
        gl.glEnable(GL10.GL_TEXTURE_2D);
        /*
         * 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.glDisable(GL10.GL_LIGHTING);

        gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
        
        if (mSprites != null) {
            
            // If we are using hardware buffers and the screen lost context
            // then the buffer indexes that we recorded previously are now
            // invalid.  Forget them here and recreate them below.
            if (mUseHardwareBuffers) {
                for (int x = 0; x < mSprites.length; x++) {
                    // Ditch old buffer indexes.
                    mSprites[x].getGrid().invalidateHardwareBuffers();
                }
            }
            
            // Load our texture and set its texture name on all sprites.
            
            // To keep this sample simple we will assume that sprites that share
            // the same texture are grouped together in our sprite list. A real
            // app would probably have another level of texture management, 
            // like a texture hash.
            
            int lastLoadedResource = -1;
            int lastTextureId = -1;
            
            for (int x = 0; x < mSprites.length; x++) {
                int resource = mSprites[x].getResourceId();
                if (resource != lastLoadedResource) {
                    lastTextureId = loadBitmap(mContext, gl, resource);
                    lastLoadedResource = resource;
                }
                mSprites[x].setTextureName(lastTextureId);
                if (mUseHardwareBuffers) {
                    Grid currentGrid = mSprites[x].getGrid();
                    if (!currentGrid.usingHardwareBuffers()) {
                        currentGrid.generateHardwareBuffers(gl);
                    }
                    //mSprites[x].getGrid().generateHardwareBuffers(gl);
                }
            }
        }
    }
    
    /**
     * Called when the rendering thread shuts down.  This is a good place to
     * release OpenGL ES resources.
     * @param gl
     */
    public void shutdown(GL10 gl) {
        if (mSprites != null) {

            int lastFreedResource = -1;
            int[] textureToDelete = new int[1];
            
            for (int x = 0; x < mSprites.length; x++) {
                int resource = mSprites[x].getResourceId();
                if (resource != lastFreedResource) {
                    textureToDelete[0] = mSprites[x].getTextureName();
                    gl.glDeleteTextures(1, textureToDelete, 0);
                    mSprites[x].setTextureName(0);
                }
                if (mUseHardwareBuffers) {
                    mSprites[x].getGrid().releaseHardwareBuffers(gl);
                }
            }
        }
    }
 
    /** 
     * Loads a bitmap into OpenGL and sets up the common parameters for 
     * 2D texture maps. 
     */
    protected int loadBitmap(Context context, GL10 gl, int resourceId) {
        int textureName = -1;
        if (context != null && gl != null) {
            gl.glGenTextures(1, mTextureNameWorkspace, 0);

            textureName = mTextureNameWorkspace[0];
            gl.glBindTexture(GL10.GL_TEXTURE_2D, textureName);

            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 = context.getResources().openRawResource(resourceId);
            Bitmap bitmap;
            try {
                bitmap = BitmapFactory.decodeStream(is, null, sBitmapOptions);
            } finally {
                try {
                    is.close();
                } catch (IOException e) {
                    // Ignore.
                }
            }

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

            mCropWorkspace[0] = 0;
            mCropWorkspace[1] = bitmap.getHeight();
            mCropWorkspace[2] = bitmap.getWidth();
            mCropWorkspace[3] = -bitmap.getHeight();
            
            bitmap.recycle();

            ((GL11) gl).glTexParameteriv(GL10.GL_TEXTURE_2D, 
                    GL11Ext.GL_TEXTURE_CROP_RECT_OES, mCropWorkspace, 0);

            
            int error = gl.glGetError();
            if (error != GL10.GL_NO_ERROR) {
                Log.e("SpriteMethodTest", "Texture Load GLError: " + error);
            }
        
        }

        return textureName;
    }

}

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