iPhone OpenGL ES - How to Pick

Question

I\'m working on an OpenGL ES1 app which displays a 2D grid and allows user to navigate and scale/rotate it. I need to know the exact translation of View Touch coordinates in

Answer 1

Could be possible to do this with GL_MODELVIEW_MATRIX? or GL_MODLVIEW, I´m not modifing the view position, only del modelview. I´m doing this:

            glMatrixMode(GL_MODELVIEW);

// Setup model view matrix
            glLoadIdentity();
            [gAccel GetAccelerometerMatrix:(GLfloat *) matrix headingX:headx headingY: heady headingZ:headz];

            // Finally load matrix
            glLoadMatrixf((GLfloat*)matrix);

            glPushMatrix();
            glRotatef(-90, 1, 0, 0);
            glScalef(0.0005, 0.0005, 0.0005);
            glTranslatef(x, 0.0, z);

thanks