CODEWITHSUNDEEP
openglkeyboard
Gribbles Chan
Gribbles Chan

Reputation: 123

OpenGL Keyboard Events not working

I have the following snippet:

float z, yrot = 0, xrot = 0;
float x = 0.0;
float y = 0.0;

void display()                                                  /* 2. */
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);         /* 3. */

glMatrixMode(GL_MODELVIEW_MATRIX);
glLoadIdentity();

glMatrixMode   (GL_MODELVIEW);
glTranslatef(x, y, -0.5);
glRotatef(rotation, 0, 0, -1);
glColor3f(1.0,1.0,1.0);
glutWireTeapot(0.2);


glutSwapBuffers();                                          /* 4. */
}

void keyPressed(unsigned char key, int x, int y)
{

     float yrotrad = (yrot / (180 * 3.141592654f));
     float xrotrad = (xrot / (180 * 3.141592654f));

     switch (key)
     {

         case 'w':

            x += (float)(sin(yrotrad));
            z -= (float)(cos(yrotrad)) ;
            y -= (float)(sin(xrotrad));
            glutPostRedisplay();
            break;
     }
}

int main(int argc, char **argv)                                 /* 5. */
{
    glutDisplayFunc(display);
    glutKeyboardFunc(keyPressed);
    glutMainLoop();
}

What is supposed to happen when I press the w key is that it's supposed to tilt the camera. But when I press w, nothing happens. What am I doing wrong?

Upvotes: 0

Views: 1168

Answers (1)

Thomas
Thomas

Reputation: 182093

Your x and y parameters are shadowing the globals:

void keyPressed(unsigned char key, int x, int y)

So the increment of those is not doing what you think it does. Turn up your compiler warnings -- you'll probably see some about losing precision.

Ironically, it works correctly for z but you don't seem to be using it anywhere in your rendering code.

(Aside: You may also want to look into GLFW. It's quite similar to GLUT and as easy to get started with, but better in every respect.)

Upvotes: 2

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