/* this function is called when the mouse buttons are clicked or un-clicked */
void glfw_mouse_click_callback (
GLFWwindow* window, int button, int action, int mods
) {
// Note: could query if window has lost focus here
if (GLFW_PRESS == action) {
double xpos, ypos;
glfwGetCursorPos (g_window, &xpos, &ypos);
// work out ray
vec3 ray_wor = get_ray_from_mouse ((float)xpos, (float)ypos);
// check ray against all spheres in scene
int closest_sphere_clicked = -1;
float closest_intersection = 0.0f;
for (int i = 0; i < NUM_SPHERES; i++) {
float t_dist = 0.0f;
if (ray_sphere (
cam_pos, ray_wor, sphere_pos_wor[i], sphere_radius, &t_dist
)) {
// if more than one sphere is in path of ray, only use the closest one
if (-1 == closest_sphere_clicked || t_dist < closest_intersection) {
closest_sphere_clicked = i;
closest_intersection = t_dist;
}
}
} // endfor
g_selected_sphere = closest_sphere_clicked;
printf ("sphere %i was clicked\n", closest_sphere_clicked);
}
}
BOOL linesegment_sphere(const LLVector3 &point_a, const LLVector3 &point_b,
const LLVector3 &sphere_center, F32 sphere_radius,
LLVector3 &intersection, LLVector3 &intersection_normal)
{
LLVector3 ray_direction = point_b - point_a;
F32 segment_length = ray_direction.normVec();
if (ray_sphere(point_a, ray_direction, sphere_center, sphere_radius, intersection, intersection_normal))
{
if (segment_length >= (point_a - intersection).magVec())
{
return TRUE;
}
}
return FALSE;
}
