void processTriangleClicks(GLint x, GLint y) {

    static GLintPoint triangleFirstPoint;
    static GLintPoint triangleSecondPoint;

     y = gWinHeight - y;     // invert y position
     if (shapeClickCount == 0) {       //first click
         triangleFirstPoint.x = x;
         triangleFirstPoint.y = y;
         shapeClickCount++ ;
     }
     else if (shapeClickCount == 1) {    //second click
         triangleSecondPoint.x = x;
         triangleSecondPoint.y = y;
         printf("First Point: %i %i \n", triangleFirstPoint.x, triangleFirstPoint.y);
         printf("Second Point : %i %i \n", triangleSecondPoint.x, triangleSecondPoint.y);
         shapeClickCount++ ;
    }
    else if (shapeClickCount == 2) {
          shapeClickCount = 0;
          glBegin(GL_TRIANGLES);    // draw line using coords when button last pressed
          glVertex2i(triangleFirstPoint.x, triangleFirstPoint.y);
          glVertex2i(triangleSecondPoint.x, triangleSecondPoint.y);
          glVertex2i(x, y);
          glEnd();
    }
    glFlush();
}