#include "../graphics.c"

f64 view_x = 0.;
f64 view_y = 0.;
f64 view_s = 1.;
f64 cx     = -.771;
f64 cy     = .1005;
f64 radius = 2.;
i64 limit  = 1024;
i64 time_0;

void update_and_render_frame(void) {
  i32 num_events = p_handle_events();

  i64 time_elapsed = p_time() - time_0;
  time_0 += time_elapsed;

  b8 left  = g_platform.key_down[KEY_LEFT];
  b8 right = g_platform.key_down[KEY_RIGHT];
  b8 up    = g_platform.key_down[KEY_UP];
  b8 down  = g_platform.key_down[KEY_DOWN];

  if (!left && !right && !up && !down && num_events == 0) {
    p_sleep_for(1);
    return;
  }

  if (g_platform.key_pressed[KEY_ESCAPE]) {
    view_x = 0.;
    view_y = 0.;
    view_s = 1.;
  }

  f64 d = (g_platform.key_down[MOD_CTRL] ? .00005 : .001) * view_s * time_elapsed;

  if (left)  { cx -= d; cy -= d; }
  if (right) { cx += d; cy += d; }
  if (up)    { cx += d; cy -= d; }
  if (down)  { cx -= d; cy += d; }

  if (g_platform.key_down[BUTTON_LEFT]) {
    view_x += g_platform.cursor_dx * view_s;
    view_y += g_platform.cursor_dy * view_s;
  }

  if (g_platform.wheel_dy != 0.) {
    f64 dx  = (g_platform.cursor_x * 1. - g_platform.real_width  * .5);
    f64 dy  = (g_platform.cursor_y * 1. - g_platform.real_height * .5);
    view_x -= view_s * dx;
    view_y -= view_s * dy;
    view_s += view_s * g_platform.wheel_dy * .1;
    view_x += view_s * dx;
    view_y += view_s * dy;
  }

  for (i32 j = 0; j < g_platform.frame_height; ++j)
    for (i32 i = 0; i < g_platform.frame_width; ++i) {
      f64 kx = ((f64) g_platform.real_width)  / g_platform.frame_width;
      f64 ky = ((f64) g_platform.real_height) / g_platform.frame_height;

      f64 x = .003 * ((i - (g_platform.frame_width - 1)  * .5) * kx * view_s - view_x);
      f64 y = .003 * ((j - (g_platform.frame_height - 1) * .5) * ky * view_s - view_y);

      i64 n = 0;

      for (; x * x + y * y < radius * radius && n < limit; ++n) {
        f64 z = x * x - y * y;
        y     = 2. * x * y  + cy;
        x     = z + cx;
      }

      u32 c;

      if (n == limit)
        c = 0;
      else
        c = 0xffffff - n * 8 - n * 256 * 4;

      g_platform.pixels[j * g_platform.frame_width + i] = vec4_from_vec3_f32(rgb_f32_from_u32(c), 1.f);
    }

  p_render_frame();
}

i32 main(i32 argc, c8 **argv) {
  (void) argc;
  (void) argv;

  g_platform = (Platform) {
    .title = "Julia Set",
  };

  time_0 = p_time();

  p_event_loop();

  return 0;
}