I am creating an app that makes use of GL10, it's made up f three classes,
Class A extends Activity. Class B implements Renderer. Class C extends Activity.
Class C contains the data for a 3D cube, Class B is the renderer and Class A displays it.
To display it i am using the following method in class A,
GLCubeRenderer ourSurface = new GLCubeRenderer();
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
GLSurfaceView glSurfaceView =
(GLSurfaceView) findViewById(R.id.ourCube);
glSurfaceView.setRenderer(ourSurface);
setContentView(R.layout.cubelayout);
}
And the XML is:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<com.mastermind.GLCubeRenderer
android:id="@+id/ourCube"
android:layout_width="match_parent"
android:layout_height="match_parent"
/>
</RelativeLayout>
the problem is that in the Java code for class A the line 'glSurfaceView.setRenderer(ourSurface);' returns a null pointer exception.
Class B (Renderer) code:
private GLCube cube = new GLCube();
static Context context;
public static float xAngle;
public static float yAngle;
final float[] ambient = { 0.1f, 1, 1, 1 };
final float[] position = { 45, 20, 0, 1 };
final float[] direction = { 0, -1, 0 };
public GLCubeRenderer() {
cube = new GLCube();
}
@Override
public void onSurfaceCreated(GL10 gl, EGLConfig config) {
// TODO Auto-generated method stub
gl.glDisable(GL10.GL_DITHER);
gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_FASTEST);
gl.glEnable(GL10.GL_LIGHT1);
gl.glLightfv(GL10.GL_LIGHT1, GL10.GL_DIFFUSE, ambient, 0);
gl.glLightfv(GL10.GL_LIGHT1, GL10.GL_POSITION, position, 0);
gl.glLightfv(GL10.GL_LIGHT1, GL10.GL_SPOT_DIRECTION, direction, 0);
gl.glLightf(GL10.GL_LIGHT1, GL10.GL_SPOT_CUTOFF, 30.0f);
gl.glClearColor(.0f, 0, .0f, 0);
gl.glClearDepthf(1f);
}
@Override
public void onDrawFrame(GL10 gl) {
// TODO Auto-generated method stub
gl.glDisable(GL10.GL_DITHER);
gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
gl.glMatrixMode(GL10.GL_MODELVIEW);
gl.glLoadIdentity();
GLU.gluLookAt(gl, 0, 0, -5, 0, 0, 0, 0, 2, 0);
gl.glRotatef(xAngle, 0, xAngle, 0);
// gl.glRotatef(yAngle, yAngle, 0, yAngle);
gl.glActiveTexture(GL10.GL_TEXTURE0);
gl.glTexEnvx(GL10.GL_TEXTURE_ENV, GL10.GL_TEXTURE_ENV_MODE, GL10.GL_MODULATE);
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);
cube.draw(gl);
}
@Override
public void onSurfaceChanged(GL10 gl, int width, int height) {
// TODO Auto-generated method stub
gl.glViewport(0, 0, width, height);
float ratio = (float) width / height;
gl.glMatrixMode(GL10.GL_PROJECTION);
gl.glLoadIdentity();
gl.glFrustumf(-ratio, ratio, -1, 1f, 1, 25);
}
And the class C code:
private float vertices[] = {
1, 1, -1, // p0-top front right
1, -1, -1, // p1-bottom front right
-1, -1, -1, // p2-bottom front left
-1, 1, -1, // p3-front top left
1, 1, 1, // p4-top back right
1, -1, 1, // p5-bottom back right
-1, -1, 1, // p6-bottom back left
-1, 1, 1 // p7-front back left
};
// Buffer for our vertices
private FloatBuffer vertBuff;
// Index for our points e.g. p0 = 0f, 1f, in vert Index
private short[] pIndex = {
3, 4, 0,
0, 4, 1,
3, 0, 1,
3, 7, 4,
7, 6, 4,
7, 3, 6,
3, 1, 2,
1, 6, 2,
6, 3, 2,
1, 4, 5,
5, 6, 1,
6, 5, 4
};
// Buffer for points index
private ShortBuffer pBuff;
// Triangle constructor
public GLCube() {
// Construction of vertices
// byte buffer for vertices
ByteBuffer bBuff = ByteBuffer.allocateDirect(vertices.length * 4);
bBuff.order(ByteOrder.nativeOrder());
vertBuff = bBuff.asFloatBuffer();
vertBuff.put(vertices);
vertBuff.position(0);
// Construction of points
// point byte buffer
ByteBuffer pointByteBuff = ByteBuffer.allocateDirect(pIndex.length * 2);
pointByteBuff.order(ByteOrder.nativeOrder());
pBuff = pointByteBuff.asShortBuffer();
pBuff.put(pIndex);
pBuff.position(0);
}
public void draw(GL10 gl) {
gl.glFrontFace(GL10.GL_CW);
gl.glEnable(GL10.GL_CULL_FACE);
gl.glCullFace(GL10.GL_BACK);
gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
gl.glVertexPointer(3, GL10.GL_FLOAT, 0, vertBuff);
gl.glDrawElements(GL10.GL_TRIANGLES, pIndex.length, GL10.GL_UNSIGNED_SHORT, pBuff);
gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);
gl.glDisable(GL10.GL_CULL_FACE);
}
Pardon the length of the question but does anyone have any solutions?
