Develop Reference

OpenGL ES 2.0: Square not being displayed (only black screen)

I am new to OpenGL ES and I am trying to display a square in my android app but it is showing only black screen (no square) when I am running the app. Can anyone tell me where am I doing wrong and please solve the issue ?
MainActivity.java
public class MainActivity extends AppCompatActivity {
private GLSurfaceView myGLSurfaceView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
myGLSurfaceView = new GLSurfaceView(this);
// Check if the system supports OpenGL ES 2.0.
final ActivityManager activityManager = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);
final ConfigurationInfo configurationInfo = activityManager.getDeviceConfigurationInfo();
final boolean supportsEs2 = configurationInfo.reqGlEsVersion >= 0x20000;
if (supportsEs2)
{
// Request an OpenGL ES 2.0 compatible context.
myGLSurfaceView.setEGLContextClientVersion(2);
// Set the renderer to our demo renderer, defined below.
myGLSurfaceView.setRenderer(new MyRenderer());
}
else
{
// This is where you could create an OpenGL ES 1.x compatible
// renderer if you wanted to support both ES 1 and ES 2.
return;
}
setContentView(myGLSurfaceView);
}
#Override
protected void onPause() {
super.onPause();
}
#Override
protected void onResume() {
super.onResume();
}
}
MyRenderer.java
class MyRenderer implements GLSurfaceView.Renderer {
private Square mySq;
#Override
public void onSurfaceCreated(GL10 gl, EGLConfig config) {
GLES20.glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
mySq = new Square();
}
#Override
public void onSurfaceChanged(GL10 gl, int width, int height) {
GLES20.glViewport(0, 0, width, height);
}
#Override
public void onDrawFrame(GL10 gl) {
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
mySq.draw();
}
public static int loadShader(int type, String shaderCode){
// create a vertex shader type (GLES20.GL_VERTEX_SHADER)
// or a fragment shader type (GLES20.GL_FRAGMENT_SHADER)
int shader = GLES20.glCreateShader(type);
// add the source code to the shader and compile it
GLES20.glShaderSource(shader, shaderCode);
GLES20.glCompileShader(shader);
return shader;
}
}
Square.java
public class Square {
private FloatBuffer vertexBuffer;
private ShortBuffer drawListBuffer;
private final int mProgram;
private int mPositionHandle;
private int mColorHandle;
// private final int vertexCount = squareCoords.length;
private final int vertexCount =4;
private final int vertexStride = Coords_per_vertex * 4;
static final int Coords_per_vertex = 3;
static float squareCoords[] = {
-0.5f, 0.5f, 0.0f, // top left
-0.5f, -0.5f, 0.0f, // bottom left
0.5f, -0.5f, 0.0f, // bottom right
0.5f, 0.5f, 0.0f }; // top right
float color[] = { 0.63671875f, 0.76953125f, 0.22265625f, 1.0f };
private short drawOrder[]={0,1,2,0,2,3};
private static final String vertexShaderCode = "attribute vec4 vPosition;" +
"void main() {" +
"gl_Position = vPosition;" +
"}";
private final String fragmentShaderCode = "precision mediump float;" +
"uniform vec4 vColor;" +
"void main() {" +
"gl_Color = vColor;" +
"}";
public Square(){
// initialize vertex byte buffer for shape coordinates
ByteBuffer bb = ByteBuffer.allocateDirect(
// (# of coordinate values * 4 bytes per float)
squareCoords.length * 4);
bb.order(ByteOrder.nativeOrder());
vertexBuffer = bb.asFloatBuffer();
vertexBuffer.put(squareCoords);
vertexBuffer.position(0);
// initialize byte buffer for the draw list
ByteBuffer dlb = ByteBuffer.allocateDirect(
// (# of coordinate values * 2 bytes per short)
drawOrder.length * 2);
dlb.order(ByteOrder.nativeOrder());
drawListBuffer = dlb.asShortBuffer();
drawListBuffer.put(drawOrder);
drawListBuffer.position(0);
int vertexShader = MyRenderer.loadShader(GLES20.GL_VERTEX_SHADER,vertexShaderCode);
int fragmentShader = MyRenderer.loadShader(GLES20.GL_FRAGMENT_SHADER,fragmentShaderCode);
// create empty OpenGL ES Program
mProgram = GLES20.glCreateProgram();
// add the vertex shader to program
GLES20.glAttachShader(mProgram, vertexShader);
// add the fragment shader to program
GLES20.glAttachShader(mProgram, fragmentShader);
// creates OpenGL ES program executables
GLES20.glLinkProgram(mProgram);
GLES20.glUseProgram(mProgram);
}
public void draw(){
MyRenderer myR = new MyRenderer();
mPositionHandle = GLES20.glGetAttribLocation(mProgram,"vPosition");
GLES20.glEnableVertexAttribArray(mPositionHandle);
GLES20.glVertexAttribPointer(mPositionHandle,Coords_per_vertex,GLES20.GL_FLOAT,false,vertexStride,vertexBuffer);
mColorHandle = GLES20.glGetUniformLocation(mProgram, "vColor");
GLES20.glUniform4fv(mColorHandle,1,color,0);
GLES20.glDrawArrays(GLES20.GL_TRIANGLES,0,vertexCount);
// Disable vertex array
// GLES20.glDisableVertexAttribArray(mPositionHandle);
}
}

Load Images into Google Cardboard

I'm trying to build a 3D picture viewer as the same in google cardboard demo. It reads in an image from disk and display it a bit differently for each eye to achieve a 3D effect.
I'm in the first step of trying to get the same image to show up for both eyes. Due to other limitations, I'm using google cardboard android SDK instead of unity SDK.
I modified code based on a wonderful cardboard camera see-through project (
https://github.com/Sveder/CardboardPassthrough
How to show 2 camera preview side by side?[For cardboard apps]
), which streams camera data to cardboard.
Anyway, after modifying the code. I can't get the images to show up, though opengl and android doesn't show any error. My basic idea is follows:
use android BitmapFactory read in an image stored in res/ to a bitmap.
For each frame, use GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, img, 0) to bind that image to current opengl active texture GLES20.GL_TEXTURE0
display such image
So in function onDrawEye, I set current active texture to be GL_TEXTURE0, and then bind my image texture to GL_TEXTURE_2D.
onDrawEye Code:
public void onDrawEye(EyeTransform transform) {
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT | GLES20.GL_DEPTH_BUFFER_BIT);
GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
// Bind the texture to this unit.
bindBitmap2D(texture);
checkGLError("bind bit map 2d");
mPositionHandle = GLES20.glGetAttribLocation(mProgram, "position");
GLES20.glEnableVertexAttribArray(mPositionHandle);
GLES20.glVertexAttribPointer(mPositionHandle, COORDS_PER_VERTEX, GLES20.GL_FLOAT,
false, vertexStride, vertexBuffer);
mTextureCoordHandle = GLES20.glGetAttribLocation(mProgram, "inputTextureCoordinate");
GLES20.glEnableVertexAttribArray(mTextureCoordHandle);
GLES20.glVertexAttribPointer(mTextureCoordHandle, COORDS_PER_VERTEX, GLES20.GL_FLOAT,
false, vertexStride, textureVerticesBuffer);
mColorHandle = GLES20.glGetAttribLocation(mProgram, "s_texture");
}
function bindBitmap2D:
public void bindBitmap2D(int texture) {
//must be GL_TEXTUREi
GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
checkGLError("glActiveTexture");
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, texture);
checkGLError("glbindtexture");
// Set filtering
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D,
GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_NEAREST);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D,
GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_NEAREST);
Bitmap img = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);
//convert bitmap to texture and bind the texture to GL_TEXTURE_2D
GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, img, 0);
}
My fragment shader:
private final String fragmentShaderCode2D =
"precision mediump float;\n" +
"varying vec2 textureCoordinate; \n" +
"uniform sampler2D s_texture; \n" +
"void main(void) {" +
" gl_FragColor = texture2D( s_texture, textureCoordinate );\n" +
"}";
Below is my full code:
package com.sveder.cardboardpassthrough;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.SurfaceTexture;
import android.graphics.SurfaceTexture.OnFrameAvailableListener;
import android.opengl.GLES20;
import android.opengl.GLUtils;
import android.os.Bundle;
import android.util.Log;
import com.google.vrtoolkit.cardboard.*;
import javax.microedition.khronos.egl.EGLConfig;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
import java.nio.ShortBuffer;
public class MainActivity extends CardboardActivity
implements CardboardView.StereoRenderer, OnFrameAvailableListener {
private static final String TAG = "MainActivity";
private final String vertexShaderCode =
"attribute vec4 position;" +
"attribute vec2 inputTextureCoordinate;" +
"varying vec2 textureCoordinate;" +
"void main()" +
"{" +
"gl_Position = position;" +
"textureCoordinate = inputTextureCoordinate;" +
"}";
//TODO vec4 maybe? sampler 2d?
// pandora box
private final String fragmentShaderCode2D =
"precision mediump float;\n" +
"varying vec2 textureCoordinate; \n" +
"uniform sampler2D s_texture; \n" +
"void main(void) {" +
" gl_FragColor = texture2D( s_texture, textureCoordinate );\n" +
"}";
private FloatBuffer vertexBuffer, textureVerticesBuffer, vertexBuffer2;
private ShortBuffer drawListBuffer, buf2;
private int mProgram;
private int mPositionHandle, mPositionHandle2;
private int mColorHandle;
private int mTextureCoordHandle;
// number of coordinates per vertex in this array
static final int COORDS_PER_VERTEX = 2;
static float squareVertices[] = { // in counterclockwise order:
-1.0f, -1.0f, // 0.left - mid
1.0f, -1.0f, // 1. right - mid
-1.0f, 1.0f, // 2. left - top
1.0f, 1.0f, // 3. right - top
};
private short drawOrder[] = {0, 2, 1, 1, 2, 3}; // order to draw vertices
static float textureVertices[] = {
0.0f, 1.0f, // A. left-bottom
1.0f, 1.0f, // B. right-bottom
0.0f, 0.0f, // C. left-top
1.0f, 0.0f // D. right-top
};
private final int vertexStride = COORDS_PER_VERTEX * 4; // 4 bytes per vertex
private ByteBuffer indexBuffer; // Buffer for index-array
private int texture;
private CardboardOverlayView mOverlayView;
private CardboardView cardboardView;
private SurfaceTexture surface;
private float[] mView;
public void bindBitmap2D(int texture) {
//must be GL_TEXTUREi
GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
checkGLError("glActiveTexture");
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, texture);
checkGLError("glbindtexture");
// Set filtering
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D,
GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_NEAREST);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D,
GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_NEAREST);
Bitmap img = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);
//convert bitmap to texture and bind the texture to GL_TEXTURE_2D
GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, img, 0);
}
private int createTexture2D() {
int[] texture = new int[1];
GLES20.glGenTextures(1, texture, 0);
return texture[0];
}
/**
* Converts a raw text file, saved as a resource, into an OpenGL ES shader
*
* #param type The type of shader we will be creating.
* #param resId The resource ID of the raw text file about to be turned into a shader.
* #return
*/
private int loadGLShader(int type, String code) {
int shader = GLES20.glCreateShader(type);
GLES20.glShaderSource(shader, code);
GLES20.glCompileShader(shader);
// Get the compilation status.
final int[] compileStatus = new int[1];
GLES20.glGetShaderiv(shader, GLES20.GL_COMPILE_STATUS, compileStatus, 0);
// If the compilation failed, delete the shader.
if (compileStatus[0] == 0) {
Log.e(TAG, "Error compiling shader: " + GLES20.glGetShaderInfoLog(shader));
GLES20.glDeleteShader(shader);
shader = 0;
}
if (shader == 0) {
throw new RuntimeException("Error creating shader.");
}
return shader;
}
private static void checkGLError(String func) {
int error;
while ((error = GLES20.glGetError()) != GLES20.GL_NO_ERROR) {
Log.e(TAG, func + ": glError " + error);
throw new RuntimeException(func + ": glError " + error);
}
}
/**
* Sets the view to our CardboardView and initializes the transformation matrices we will use
* to render our scene.
*
* #param savedInstanceState
*/
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.common_ui);
cardboardView = (CardboardView) findViewById(R.id.cardboard_view);
cardboardView.setRenderer(this);
setCardboardView(cardboardView);
mView = new float[16];
mOverlayView = (CardboardOverlayView) findViewById(R.id.overlay);
mOverlayView.show3DToast("test");
}
#Override
public void onRendererShutdown() {
Log.i(TAG, "onRendererShutdown");
}
#Override
public void onSurfaceChanged(int width, int height) {
Log.i(TAG, "onSurfaceChanged");
}
/**
* Creates the buffers we use to store information about the 3D world. OpenGL doesn't use Java
* arrays, but rather needs data in a format it can understand. Hence we use ByteBuffers.
*
* #param config The EGL configuration used when creating the surface.
*/
#Override
public void onSurfaceCreated(EGLConfig config) {
Log.i(TAG, "onSurfaceCreated");
GLES20.glClearColor(0.1f, 0.1f, 0.1f, 0.5f); // Dark background so text shows up well
ByteBuffer bb = ByteBuffer.allocateDirect(squareVertices.length * 4);
bb.order(ByteOrder.nativeOrder());
vertexBuffer = bb.asFloatBuffer();
vertexBuffer.put(squareVertices);
vertexBuffer.position(0);
ByteBuffer dlb = ByteBuffer.allocateDirect(drawOrder.length * 2);
dlb.order(ByteOrder.nativeOrder());
drawListBuffer = dlb.asShortBuffer();
drawListBuffer.put(drawOrder);
drawListBuffer.position(0);
ByteBuffer bb2 = ByteBuffer.allocateDirect(textureVertices.length * 4);
bb2.order(ByteOrder.nativeOrder());
textureVerticesBuffer = bb2.asFloatBuffer();
textureVerticesBuffer.put(textureVertices);
textureVerticesBuffer.position(0);
// use shader to process and load images
int vertexShader = loadGLShader(GLES20.GL_VERTEX_SHADER, vertexShaderCode);
int fragmentShader = loadGLShader(GLES20.GL_FRAGMENT_SHADER, fragmentShaderCode2D);
mProgram = GLES20.glCreateProgram(); // create empty OpenGL ES Program
GLES20.glAttachShader(mProgram, vertexShader); // add the vertex shader to program
GLES20.glAttachShader(mProgram, fragmentShader); // add the fragment shader to program
GLES20.glLinkProgram(mProgram);
Log.d(TAG, "start binding picture");
texture = createTexture2D();
System.out.println("texture id: " + texture);
bindBitmap2D(texture);
checkGLError("onsurfacecreated");
}
/**
* Prepares OpenGL ES before we draw a frame.
*
* #param headTransform The head transformation in the new frame.
*/
#Override
public void onNewFrame(HeadTransform headTransform) {
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT | GLES20.GL_DEPTH_BUFFER_BIT);
bindBitmap2D(texture);
GLES20.glUseProgram(mProgram);
}
#Override
public void onFrameAvailable(SurfaceTexture arg0) {
this.cardboardView.requestRender();
}
/**
* Draws a frame for an eye. The transformation for that eye (from the camera) is passed in as
* a parameter.
*
* #param transform The transformations to apply to render this eye.
*/
#Override
public void onDrawEye(EyeTransform transform) {
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT | GLES20.GL_DEPTH_BUFFER_BIT);
GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
// Bind the texture to this unit.
bindBitmap2D(texture);
checkGLError("bind bit map 2d");
mPositionHandle = GLES20.glGetAttribLocation(mProgram, "position");
GLES20.glEnableVertexAttribArray(mPositionHandle);
GLES20.glVertexAttribPointer(mPositionHandle, COORDS_PER_VERTEX, GLES20.GL_FLOAT,
false, vertexStride, vertexBuffer);
mTextureCoordHandle = GLES20.glGetAttribLocation(mProgram, "inputTextureCoordinate");
GLES20.glEnableVertexAttribArray(mTextureCoordHandle);
GLES20.glVertexAttribPointer(mTextureCoordHandle, COORDS_PER_VERTEX, GLES20.GL_FLOAT,
false, vertexStride, textureVerticesBuffer);
mColorHandle = GLES20.glGetAttribLocation(mProgram, "s_texture");
}
#Override
public void onFinishFrame(Viewport viewport) {
}
}
Again, I'm not seeing any errors. The screen is just black without showing anything.

Android OpenGL Camera Preview Issue

I'm working on an Android camera app that modifies the camera feed and displays it live on the screen. I have it working and doing what I want perfectly on my DROID RAZR MAXX running 4.3, and it works perfect on other phones, but unfortunately I have ran into a problem on several phones and am unable to track down the issue.
I've attached a screenshot showing what the issue is.
It's very hard to tell what the green "artifacts" are, but it almost looks like it's blocks from the camera feed from when it first turned on. The colors flicker, but the shapes inside the blocks don't really change.
I've stripped out everything that isn't needed and cleaned up the code as best I can, but I honestly have zero clue as to why this is happening, especially since it seems to work on some phones fine, while other phones it doesn't.
If I need to give more information just comment and I will add it!
CameraActivity.java
public class CameraActivity extends Activity
{
private MyGLSurfaceView glSurfaceView;
private MyCamera mCamera;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
mCamera = new MyCamera();
glSurfaceView = new MyGLSurfaceView(this, mCamera);
setContentView(glSurfaceView);
}
#Override
protected void onPause()
{
super.onPause();
mCamera.stop();
}
}
MyCamera.java
public class MyCamera
{
private final static String LOG_TAG = "MyCamera";
private Camera mCamera;
private Parameters mCameraParams;
private Boolean running = false;
void start(SurfaceTexture surface)
{
Log.v(LOG_TAG, "Starting Camera");
mCamera = Camera.open(0);
mCameraParams = mCamera.getParameters();
Log.v(LOG_TAG, mCameraParams.getPreviewSize().width + " x " + mCameraParams.getPreviewSize().height);
try {
mCamera.setPreviewTexture(surface);
mCamera.startPreview();
running = true;
} catch (IOException e) {
e.printStackTrace();
}
}
void stop()
{
if (running) {
Log.v(LOG_TAG, "Stopping Camera");
mCamera.stopPreview();
mCamera.release();
running = false;
}
}
}
MyGLSurfaceView.java
class MyGLSurfaceView extends GLSurfaceView implements Renderer
{
private final static String LOG_TAG = "MyGLSurfaceView";
private MyCamera mCamera;
private SurfaceTexture mSurface;
private DirectVideo mDirectVideo;
public MyGLSurfaceView(Context context, MyCamera camera)
{
super(context);
mCamera = camera;
setEGLContextClientVersion(2);
setRenderer(this);
}
#Override
public void onDrawFrame(GL10 gl)
{
float[] mtx = new float[16];
mSurface.updateTexImage();
mSurface.getTransformMatrix(mtx);
mDirectVideo.draw();
}
#Override
public void onSurfaceChanged(GL10 gl, int width, int height)
{
Log.v(LOG_TAG, "Surface Changed");
GLES20.glViewport(0, 0, width, height);
}
#Override
public void onSurfaceCreated(GL10 gl, EGLConfig config)
{
Log.v(LOG_TAG, "Surface Created");
int texture = createTexture();
mDirectVideo = new DirectVideo(texture);
mSurface = new SurfaceTexture(texture);
mCamera.start(mSurface);
}
private int createTexture()
{
int[] textures = new int[1];
// generate one texture pointer and bind it as an external texture.
GLES20.glGenTextures(1, textures, 0);
GLES20.glBindTexture(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, textures[0]);
// No mip-mapping with camera source.
GLES20.glTexParameterf(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GL10.GL_TEXTURE_MIN_FILTER, GL10.GL_LINEAR);
GLES20.glTexParameterf(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GL10.GL_TEXTURE_MAG_FILTER, GL10.GL_LINEAR);
// Clamp to edge is only option.
GLES20.glTexParameteri(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GL10.GL_TEXTURE_WRAP_S, GL10.GL_CLAMP_TO_EDGE);
GLES20.glTexParameteri(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GL10.GL_TEXTURE_WRAP_T, GL10.GL_CLAMP_TO_EDGE);
return textures[0];
}
public static int loadShader(int type, String shaderCode){
// create a vertex shader type (GLES20.GL_VERTEX_SHADER)
// or a fragment shader type (GLES20.GL_FRAGMENT_SHADER)
int shader = GLES20.glCreateShader(type);
// add the source code to the shader and compile it
GLES20.glShaderSource(shader, shaderCode);
GLES20.glCompileShader(shader);
return shader;
}
}
DirectVideo.java
public class DirectVideo
{
private final String vertexShaderCode =
"attribute vec4 vPosition;" +
"attribute vec2 inputTextureCoordinate;" +
"varying vec2 textureCoordinate;" +
"void main()" +
"{"+
"gl_Position = vPosition;"+
"textureCoordinate = inputTextureCoordinate;" +
"}";
private final String fragmentShaderCode =
"#extension GL_OES_EGL_image_external : require\n"+
"precision mediump float;" +
"varying vec2 textureCoordinate;\n" +
"uniform samplerExternalOES s_texture;\n" +
"void main() {" +
" gl_FragColor = texture2D( s_texture, textureCoordinate );\n" +
"}";
private FloatBuffer vertexBuffer, textureVerticesBuffer;
private ShortBuffer drawListBuffer;
private final int mProgram;
private int mPositionHandle;
private int mTextureCoordHandle;
private short drawOrder[] = { 0, 1, 2, 0, 2, 3 }; // order to draw vertices
// number of coordinates per vertex in this array
private static final int COORDS_PER_VERTEX = 2;
private final int vertexStride = COORDS_PER_VERTEX * 4; // 4 bytes per vertex
static float squareCoords[] = {
-1.0f, 1.0f,
-1.0f, -1.0f,
1.0f, -1.0f,
1.0f, 1.0f,
};
static float textureVertices[] = {
0.0f, 1.0f,
1.0f, 1.0f,
1.0f, 0.0f,
0.0f, 0.0f,
};
private int texture;
public DirectVideo(int texture)
{
this.texture = texture;
// initialize vertex byte buffer for shape coordinates
ByteBuffer bb = ByteBuffer.allocateDirect(squareCoords.length * 4);
bb.order(ByteOrder.nativeOrder());
vertexBuffer = bb.asFloatBuffer();
vertexBuffer.put(squareCoords);
vertexBuffer.position(0);
// initialize byte buffer for the draw list
ByteBuffer dlb = ByteBuffer.allocateDirect(drawOrder.length * 2);
dlb.order(ByteOrder.nativeOrder());
drawListBuffer = dlb.asShortBuffer();
drawListBuffer.put(drawOrder);
drawListBuffer.position(0);
ByteBuffer bb2 = ByteBuffer.allocateDirect(textureVertices.length * 4);
bb2.order(ByteOrder.nativeOrder());
textureVerticesBuffer = bb2.asFloatBuffer();
textureVerticesBuffer.put(textureVertices);
textureVerticesBuffer.position(0);
int vertexShader = MyGLSurfaceView.loadShader(GLES20.GL_VERTEX_SHADER, vertexShaderCode);
int fragmentShader = MyGLSurfaceView.loadShader(GLES20.GL_FRAGMENT_SHADER, fragmentShaderCode);
mProgram = GLES20.glCreateProgram(); // create empty OpenGL ES Program
GLES20.glAttachShader(mProgram, vertexShader); // add the vertex shader to program
GLES20.glAttachShader(mProgram, fragmentShader); // add the fragment shader to program
GLES20.glLinkProgram(mProgram); // creates OpenGL ES program executables
}
public void draw()
{
GLES20.glUseProgram(mProgram);
GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
GLES20.glBindTexture(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, texture);
// get handle to vertex shader's vPosition member
mPositionHandle = GLES20.glGetAttribLocation(mProgram, "vPosition");
// Enable a handle to the triangle vertices
GLES20.glEnableVertexAttribArray(mPositionHandle);
// Prepare the <insert shape here> coordinate data
GLES20.glVertexAttribPointer(mPositionHandle, COORDS_PER_VERTEX, GLES20.GL_FLOAT, false, vertexStride, vertexBuffer);
mTextureCoordHandle = GLES20.glGetAttribLocation(mProgram, "inputTextureCoordinate");
GLES20.glEnableVertexAttribArray(mTextureCoordHandle);
GLES20.glVertexAttribPointer(mTextureCoordHandle, COORDS_PER_VERTEX, GLES20.GL_FLOAT, false, vertexStride, textureVerticesBuffer);
GLES20.glDrawElements(GLES20.GL_TRIANGLES, drawOrder.length, GLES20.GL_UNSIGNED_SHORT, drawListBuffer);
// Disable vertex array
GLES20.glDisableVertexAttribArray(mPositionHandle);
GLES20.glDisableVertexAttribArray(mTextureCoordHandle);
}
}

In the onDrawFrame method you get a transformation matrix, but you don't use it.
This matrix should be used to transform texture coordinates.
For details see the documentation of the SurfaceTexture class.
Here is the fix:
pass the matrix to the the draw method:
#Override
public void onDrawFrame(GL10 gl)
{
float[] mtx = new float[16];
mSurface.updateTexImage();
mSurface.getTransformMatrix(mtx);
mDirectVideo.draw(mtx);
}
Add the following method to the DirectVideo class:
private float[] transformTextureCoordinates( float[] coords, float[] matrix)
{
float[] result = new float[ coords.length ];
float[] vt = new float[4];
for ( int i = 0 ; i < coords.length ; i += 2 ) {
float[] v = { coords[i], coords[i+1], 0 , 1 };
Matrix.multiplyMV(vt, 0, matrix, 0, v, 0);
result[i] = vt[0];
result[i+1] = vt[1];
}
return result;
}
In the draw method Convert the textureVertices list before adding to the buffer ( you should do this conversion at every paint since the matrix can change):
textureVerticesBuffer.clear();
textureVerticesBuffer.put( transformTextureCoordinates( textureVertices, mtx ));
textureVerticesBuffer.position(0);
An alternative solution is if you pass the matrix to the shader.

implements SurfaceTexture.OnFrameAvailableListener
#Override
public void onFrameAvailable(SurfaceTexture surfaceTexture) {
// TODO Auto-generated method stub
}
setOnFrameAvailableListener(this);

Android OpenGL|ES 2.0 Texturing

I am using OpenGL|ES 2.0 to create a simple 2D square. I am struggling to get the textures working. Please help me in this regard. I have attached the code below:
GFXUtils:
public class GFXUtils {
public static final String TAG = "GFXUtils";
public static final int COORDS_PER_VERTEX = 3;
public static final int COORDS_PER_TEXTURE = 2;
public static int vertexStride = COORDS_PER_VERTEX * 4; // bytes per vertex
public static int textureStride = COORDS_PER_TEXTURE * 4; // bytes per vertex
public static Context Context = null;
public static SparseIntArray textures = new SparseIntArray();
public static int loadShader(int type, String shaderCode){
// create a vertex shader type (GLES20.GL_VERTEX_SHADER)
// or a fragment shader type (GLES20.GL_FRAGMENT_SHADER)
int shader = GLES20.glCreateShader(type);
// add the source code to the shader and compile it
GLES20.glShaderSource(shader, shaderCode);
GLES20.glCompileShader(shader);
return shader;
}
public static void checkGlError(String glOperation) {
int error;
while ((error = GLES20.glGetError()) != GLES20.GL_NO_ERROR) {
Log.e(TAG, glOperation + ": glError " + error);
throw new RuntimeException(glOperation + ": glError " + error);
}
}
public static void loadTexture(final int resourceId)
{
final int[] textureHandle = new int[1];
GLES20.glGenTextures(1, textureHandle, 0);
if (textureHandle[0] != 0)
{
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inScaled = false; // No pre-scaling
// Read in the resource
final Bitmap bitmap = BitmapFactory.decodeResource(Context.getResources(), resourceId, options);
// Bind to the texture in OpenGL
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureHandle[0]);
// Set filtering
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_NEAREST);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_NEAREST);
GLES20.glTexParameterf(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_S, GLES20.GL_CLAMP_TO_EDGE);
GLES20.glTexParameterf(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_T, GLES20.GL_CLAMP_TO_EDGE);
// Load the bitmap into the bound texture.
GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, bitmap, 0);
// Recycle the bitmap, since its data has been loaded into OpenGL.
bitmap.recycle();
}
if (textureHandle[0] == 0)
{
throw new RuntimeException("Error loading texture.");
}
textures.append(resourceId, textureHandle[0]);
}
}
Vertex:
public class Vertex
{
public FloatBuffer floatBuffer; // buffer holding the vertices
public ShortBuffer indexBuffer;
public int numVertices;
public int numIndeces;
//public float vertex[];
public Vertex (float[] vertex, int coordsPerVertex)
{
//this.vertex = vertex;
this.setVertices(vertex, coordsPerVertex);
}
public Vertex (float[] vertex, short[] indices, int coordsPerVertex)
{
//this.vertex = vertex;
this.setVertices(vertex, coordsPerVertex);
this.setIndices(indices);
}
private void setVertices(float vertex[], int coordsPerVertex)
{
// a float has 4 bytes so we allocate for each coordinate 4 bytes
ByteBuffer factory = ByteBuffer.allocateDirect (vertex.length * 4);
factory.order (ByteOrder.nativeOrder ());
// allocates the memory from the byte buffer
floatBuffer = factory.asFloatBuffer ();
// fill the vertexBuffer with the vertices
floatBuffer.put (vertex);
// set the cursor position to the beginning of the buffer
floatBuffer.position (0);
numVertices = vertex.length / coordsPerVertex;
}
protected void setIndices(short[] indices) {
ByteBuffer ibb = ByteBuffer.allocateDirect(indices.length * 2);
ibb.order(ByteOrder.nativeOrder());
indexBuffer = ibb.asShortBuffer();
indexBuffer.put(indices);
indexBuffer.position(0);
numIndeces = indices.length;
}
}
UPDATE Square:
public class Square{
private static final String TAG = "Square";
public float[] rotation = {0.0f,0.0f,45.0f};
public float[] scale = {100.0f,100f,100f};
public float[] position = {0.0f,0.0f,100f};
public float[] color = { 0.0f, 0.0f, 1.0f, 1.0f };
private int textureRef = -1;
private int mMVPMatrixHandle;
protected int DRAW_MODE = GLES20.GL_TRIANGLES;
protected int mProgram;
protected int mPositionHandle;
protected Vertex vertices;
protected Vertex texture;
private int mColorHandle;
private int vsTextureCoord;
private int fsTexture;
protected float[] result_matrix = new float[16];
private final String vertexShaderCode =
"uniform mat4 uMVPMatrix;" +
"attribute vec4 vPosition;" +
"attribute vec2 TexCoordIn;" +
"varying vec2 TexCoordOut;" +
"void main() {" +
//the matrix must be included as a modifier of gl_Position
" gl_Position = uMVPMatrix * vPosition;" +
" TexCoordOut = TexCoordIn;" +
"}";
private final String fragmentShaderCode =
"precision mediump float;" +
"uniform vec4 vColor;" +
"uniform sampler2D Texture;" +
"varying lowp vec2 TexCoordOut;" +
"void main() {" +
" gl_FragColor = vColor;" +
"}";
//I am fully aware that I am not using the texture by assigning the colour, but until I can actually SEND the texture through, there would be no point.
static float squareCoords[] = { -0.5f, 0.5f, 0.0f, // top left
-0.5f, -0.5f, 0.0f, // bottom left
0.5f, -0.5f, 0.0f, // bottom right
0.5f, 0.5f, 0.0f }; // top right
private short drawOrder[] = { 0, 1, 2, 0, 2, 3 }; // order to draw vertices
public Square(int textureResourceId) {
int vertexShader = GFXUtils.loadShader(GLES20.GL_VERTEX_SHADER, vertexShaderCode);
int fragmentShader = GFXUtils.loadShader(GLES20.GL_FRAGMENT_SHADER, fragmentShaderCode);
mProgram = GLES20.glCreateProgram(); // create empty OpenGL ES Program
GLES20.glAttachShader(mProgram, vertexShader); // add the vertex shader to program
GLES20.glAttachShader(mProgram, fragmentShader); // add the fragment shader to program
GLES20.glLinkProgram(mProgram); // creates OpenGL ES program executables
textureRef = GFXUtils.textures.get(textureResourceId);
// initialize vertex byte buffer for shape coordinates
vertices = new Vertex(squareCoords, drawOrder, GFXUtils.COORDS_PER_VERTEX);
texture = new Vertex (new float[]
{
1.0f, 0.0f,
0.0f, 0.0f,
1.0f, 1.0f,
0.0f, 1.0f,
}, GFXUtils.COORDS_PER_TEXTURE);
DRAW_MODE = GLES20.GL_TRIANGLE_FAN;
}
private void getHandles()
{
//get handle to vertex shader's vPosition member
mPositionHandle = GLES20.glGetAttribLocation(mProgram, "vPosition");
if (mPositionHandle == -1) Log.e(TAG, "vPosition not found");
//get handle to fragment shader's vColor member
mColorHandle = GLES20.glGetUniformLocation(mProgram, "vColor");
if (mColorHandle == -1) Log.e(TAG, "vColor not found");
//get handle to shape's transformation matrix
mMVPMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uMVPMatrix");
if (mMVPMatrixHandle == -1) Log.e(TAG, "uMVPMatrix not found");
//get handle to texture coordinate variable
vsTextureCoord = GLES20.glGetAttribLocation(mProgram, "TexCoordIn");
if (vsTextureCoord == -1) Log.e(TAG, "TexCoordIn not found");
//get handle to shape's texture reference
fsTexture = GLES20.glGetUniformLocation(mProgram, "Texture");
if (fsTexture == -1) Log.e(TAG, "Texture not found");
}
private void translateRotateScale(float[] matrix, float[] perspectiveMatrix)
{
for (int i= 0; i < perspectiveMatrix.length;i++)
matrix[i] = perspectiveMatrix[i];
Matrix.translateM(matrix, 0, position[0], position[1], position[2]);
Matrix.rotateM(matrix, 0, rotation[0], 1.0f, 0.0f, 0.0f);
Matrix.rotateM(matrix, 0, rotation[1], 0.0f, 1.0f, 0.0f);
Matrix.rotateM(matrix, 0, rotation[2], 0.0f, 0.0f, 1.0f);
Matrix.scaleM(matrix, 0, scale[0], scale[1], scale[2]);
}
public void draw(float[] mvpMatrix) {
rotation[2]+=0.5;
// Add program to OpenGL ES environment
GLES20.glUseProgram(mProgram);
GFXUtils.checkGlError("using program");
//Housekeeping
getHandles();
translateRotateScale(result_matrix, mvpMatrix);
//end housekeeping
// Set color for drawing the shape
GLES20.glUniform4fv(mColorHandle, 1, color, 0);
// Apply the projection and view transformation
GLES20.glUniformMatrix4fv(mMVPMatrixHandle, 1, false, result_matrix, 0);
GFXUtils.checkGlError("glUniformMatrix4fv");
// Prepare the shape coordinate data
GLES20.glVertexAttribPointer(mPositionHandle, GFXUtils.COORDS_PER_VERTEX,
GLES20.GL_FLOAT, false,
GFXUtils.vertexStride, vertices.floatBuffer);
GFXUtils.checkGlError("load vertex buffer");
GLES20.glVertexAttribPointer(vsTextureCoord, GFXUtils.COORDS_PER_TEXTURE,
GLES20.GL_FLOAT, false,
GFXUtils.textureStride, texture.floatBuffer);
GFXUtils.checkGlError("load texture buffer - " + vsTextureCoord);
// Enable a handle to the shape vertices
GLES20.glEnableVertexAttribArray(mPositionHandle);
GFXUtils.checkGlError("enable position handle");
GLES20.glEnableVertexAttribArray(vsTextureCoord);
GFXUtils.checkGlError("enable texture handle");
GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
GFXUtils.checkGlError("activtexture");
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureRef);
GFXUtils.checkGlError("bindtexture");
GLES20.glUniform1i(fsTexture, 0);
GFXUtils.checkGlError("uniformi");
//Draw the shape
GLES20.glDrawElements(DRAW_MODE, vertices.numIndeces, GLES20.GL_UNSIGNED_SHORT, vertices.indexBuffer);
GFXUtils.checkGlError("glDrawArrays with " + vertices.numVertices + " vertices");
//Disable vertex array
GLES20.glDisableVertexAttribArray(vsTextureCoord);
GLES20.glDisableVertexAttribArray(mPositionHandle);
GFXUtils.checkGlError("glDisableVertexAttribArray for position");
}
}
UPDATE But it now cannot find the 'Texture' sampler2D parameter for fsTexture. The image is here:
I have looked at the following:
Android: OpenGL ES 2.0 - Texture always black
Draw multiple objects with textures
Android OpenGLES 2.0 Texture Mapping Does Not Work
Textures in OpenGL ES 2.0 for Android
http://www.learnopengles.com/android-lesson-six-an-introduction-to-texture-filtering/
http://www.learnopengles.com/android-lesson-four-introducing-basic-texturing/
http://blog.shayanjaved.com/2011/05/13/android-opengl-es-2-0-render-to-texture/
http://www.raywenderlich.com/4404/opengl-es-2-0-for-iphone-tutorial-part-2-textures
http://androgeek.info/?p=167

ok then here is my guess at a solution:
the glVertexAttribPointer() calls seems to be fine
my guess:
vsTextureCoord == -1
glGetAttribLocation() does not generate an error
if the attribute was not found. you have to check if the result is
not -1 to make sure everything went fine.
source for the problem could be that the attribute TexCoordIn in your
shader is a vec4!

floatBuffer should contain the address of the first element in that array. you have errors after glVertexAttribPointer because the last parameter doesn't point to the vertex data. straight forward solution is to make floatbuffer = &vertexdata
my suggestion is to put the vertex data to the gl_array_buffer using glGenBuffer,glBindBuffer,glBufferData. after that, just bind the buffer before glVertexAttribPointer using 0 as the last parameter. this is faster than using the address of the vertex

Android HelloOpenGLES20 example doesn't work

I've been trying to do the android dev-guide on OPENGLES20,
but when I run the code, I get only the background color drawn, and not the triangle (I'm done until the stretched triangle photo).
How can I get the triangle to show up?
(Running the app on Android 2.2 device)
Here's the code:
public class HelloOpenGLES20Renderer implements Renderer {
private FloatBuffer triangleVB;
private final String vertexShaderCode = "attribute vec4 vPosition; \n"
+ "void main(){ \n" + " gl_Position = vPosition; \n"
+ "} \n";
private final String fragmentShaderCode = "precision mediump float; \n"
+ "void main(){ \n"
+ " gl_FragColor = vec4 (0.63671875, 0.76953125, 0.22265625, 1.0); \n"
+ "} \n";
private int mProgram;
private int maPositionHandle;
private int loadShader(int type, String shaderCode) {
// create a vertex shader type (GLES20.GL_VERTEX_SHADER)
// or a fragment shader type (GLES20.GL_FRAGMENT_SHADER)
int shader = GLES20.glCreateShader(type);
// add the source code to the shader and compile it
GLES20.glShaderSource(shader, shaderCode);
GLES20.glCompileShader(shader);
return shader;
}
#Override
public void onDrawFrame(GL10 gl) {
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT | GLES20.GL_DEPTH_BUFFER_BIT);
GLES20.glUseProgram(mProgram);
GLES20.glVertexAttribPointer(maPositionHandle, 3, GLES20.GL_FLOAT,
false, 12, triangleVB);
GLES20.glEnableVertexAttribArray(maPositionHandle);
GLES20.glDrawArrays(GLES20.GL_TRIANGLES, 0, 3);
}
public void onSurfaceChanged(GL10 gl, int width, int height) {
GLES20.glViewport(0, 0, width, height);
}
#Override
public void onSurfaceCreated(GL10 gl, EGLConfig config) {
gl.glClearColor(0.5f, 0.5f, 0.5f, 1.0f);
initShapes();
int vertexShader = loadShader(GLES20.GL_VERTEX_SHADER, vertexShaderCode);
int fragmentShader = loadShader(GLES20.GL_VERTEX_SHADER,
fragmentShaderCode);
mProgram = GLES20.glCreateProgram();
GLES20.glAttachShader(mProgram, vertexShader);
GLES20.glAttachShader(mProgram, fragmentShader);
GLES20.glLinkProgram(mProgram);
maPositionHandle = GLES20.glGetAttribLocation(mProgram, "vPosition");
}
private void initShapes() {
float[] triangleCoords = new float[] {
// X,Y,Z
-0.5f, -0.25f, 0, 0.5f, -0.25f, 0, 0.0f, 0.559016994f, 0 };
ByteBuffer vbb = ByteBuffer.allocateDirect(triangleCoords.length * 4);
vbb.order(ByteOrder.nativeOrder());
triangleVB = vbb.asFloatBuffer();
triangleVB.put(triangleCoords);
triangleVB.position(0);
}
}

I think you haven't followed the tutorial 100% properly. E.g in onSurfaceCreated(...) you call loadShader(GLES20.GL_VERTEX_SHADER..) twice while the latter one should be loadShader(GLES20.GL_FRAGMENT_SHADER..).