CODEWITHSUNDEEP
androidopengl-esrotation
user1148358
user1148358

Reputation:

glRotatef not updating

I want to rotate a Quad along 360 degrees with the code below). I am varying "input" on another procedure (Range = 0 to 1).

Despite "input" changing correctly, I can not seem to update rotation of a quad on screen - It remains stuck at the first angle, e.g. 180 if input is 0.5.

@Override
public void onDrawFrame(GL10 gl) {
    gl.glLoadIdentity();
    GLU.gluOrtho2D(gl, 0, width, height, 0);

    gl.glClearColor(0.f, 0.f, 0.f, 1f);
    gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
    gl.glColor4f(1f, 1f, 1f, 1f);

    gl.glPushMatrix();
      gl.glTranslatef(width/2, height/2, 0.0f);
      gl.glRotatef(360 * input, 0.0f, 0.0f, 1.0f);
    gl.glPopMatrix();

    bgQuad.setX(0);
    bgQuad.setY(0);

    bgQuad.draw(gl);
}

Any suggestions?

Upvotes: 0

Views: 176

Answers (1)

ratchet freak
ratchet freak

Reputation: 48186

move popMatrix to after bgQuad.draw(gl);:

@Override
public void onDrawFrame(GL10 gl) {
    gl.glLoadIdentity();
    GLU.gluOrtho2D(gl, 0, width, height, 0);

    gl.glClearColor(0.f, 0.f, 0.f, 1f);
    gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
    gl.glColor4f(1f, 1f, 1f, 1f);

    gl.glPushMatrix();
      gl.glTranslatef(width/2, height/2, 0.0f);
      gl.glRotatef(360 * input, 0.0f, 0.0f, 1.0f);


      bgQuad.setX(0);
      bgQuad.setY(0);

      bgQuad.draw(gl);
    gl.glPopMatrix();
}

glPopMatrix resets the matrix back to the most recent saved matrix and throws away the current matrix.

Upvotes: 1

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