Android OpenGL ES 2.0 rotation

OpenGL OpenGL: Basic Coding
1

Hey all,

I got a small problem with my Open GL ES 2.0 rotation (I’m developing this for Android).

When I rotate by a positive angle (say +45 degrees for example), it rotates anti-clockwise

Any reason for this?!

Thanks guys & girls!!

My shaders:

   String strVShader =  
              "uniform mat4 uMVPMatrix;" +
              "uniform mat4 uRotate;" +
              "attribute vec4 a_position;
"+
              "attribute vec2 a_texCoords;" +
              "varying vec2 v_texCoords;" +
              "void main()
" +
              "{
" +
                  "gl_Position = uMVPMatrix * a_position;
"+  
                  "v_texCoords = a_texCoords;" +
              "}";

    //Fragment shader

    String strFShader =
        "precision mediump float;" +
        "varying vec2 v_texCoords;" +
        "uniform sampler2D u_baseMap;" +
        "void main()" +
        "{" +
        "gl_FragColor = texture2D(u_baseMap, v_texCoords);" +
        "}";

Then in my onSurfaceChanged:

	float ratio = (float) width / height;
		Matrix.frustumM(mProjMatrix, 0, -ratio, ratio, -1, 1, 3, 7);

In onDrawFrame:

		
	
        // Set the camera position (View matrix) so looking from the front
       	Matrix.setLookAtM(mVMatrix, 0, 0, 0, 3, 0f, 0f, 0f, 0f, 1.0f, 0.0f);
              
        // Calculate the projection and view transformation and store results in mMVPMatrix, 0, mProjMatrix, 0, mVMatrix, 0
       Matrix.multiplyMM(mMVPMatrix, 0, mProjMatrix, 0, mVMatrix, 0);

And also my rotation matrix transformations:

Matrix.setRotateM(mRotationMatrix, 0, angle, 0, 0, 0.1f);
	
	Matrix.translateM(mRotationMatrix, 0, 0, 0, -1f);
	
	// Combine the rotation matrix with the projection and camera view
    Matrix.multiplyMM(mvpMatrix2, 0, mRotationMatrix, 0, mvpMatrix, 0);

My vertices are like so:


float[] vertices = {
			
			-.5f,.5f,0, 0,0,
			.5f,.5f,0, 1,0,
			-.5f,-.5f,0, 0,1,
			.5f,-.5f,0, 1,1
			
}

Thank you all :wink: