#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <math.h>

#include "SDL.h"

#include "SDL_opengl.h"

/* Undefine this if you want a flat cube instead of a rainbow cube */
#define SHADED_CUBE

/* Define this to be the name of the logo image to use with -logo */
#define LOGO_FILE	"icon.bmp"

static SDL_Surface *global_image = NULL;
static GLuint global_texture = 0;

#include "entity.h"

/**********************************************************************/

void
HotKey_ToggleFullScreen (void)
{
  SDL_Surface *screen;

  screen = SDL_GetVideoSurface ();
  if (SDL_WM_ToggleFullScreen (screen))
    {
      printf ("Toggled fullscreen mode - now %s\n",
	      (screen->flags & SDL_FULLSCREEN) ? "fullscreen" : "windowed");
    }
  else
    {
      printf ("Unable to toggle fullscreen mode\n");
    }
}

void
HotKey_ToggleGrab (void)
{
  SDL_GrabMode mode;

  printf ("Ctrl-G: toggling input grab!\n");
  mode = SDL_WM_GrabInput (SDL_GRAB_QUERY);
  if (mode == SDL_GRAB_ON)
    {
      printf ("Grab was on\n");
    }
  else
    {
      printf ("Grab was off\n");
    }

  mode = SDL_WM_GrabInput (mode ? SDL_GRAB_OFF : SDL_GRAB_ON);
  if (mode == SDL_GRAB_ON)
    {
      printf ("Grab is now on\n");
    }
  else
    {
      printf ("Grab is now off\n");
    }
}

void
HotKey_Iconify (void)
{
  printf ("Ctrl-Z: iconifying window!\n");
  SDL_WM_IconifyWindow ();
}

int
HandleEvent (SDL_Event * event)
{
  int done;

  done = 0;
  switch (event->type)
    {
    case SDL_ACTIVEEVENT:
      /* See what happened */
      printf ("app %s ", event->active.gain ? "gained" : "lost");
      if (event->active.state & SDL_APPACTIVE)
	{
	  printf ("active ");
	}
      else if (event->active.state & SDL_APPMOUSEFOCUS)
	{
	  printf ("mouse ");
	}
      else if (event->active.state & SDL_APPINPUTFOCUS)
	{
	  printf ("input ");
	}

      printf ("focus\n");
      break;

    case SDL_KEYDOWN:
      if (event->key.keysym.sym == SDLK_ESCAPE)
	{
	  done = 1;
	}

      if ((event->key.keysym.sym == SDLK_g) &&
	  (event->key.keysym.mod & KMOD_CTRL))
	{
	  HotKey_ToggleGrab ();
	}

      if ((event->key.keysym.sym == SDLK_z) &&
	  (event->key.keysym.mod & KMOD_CTRL))
	{
	  HotKey_Iconify ();
	}

      if ((event->key.keysym.sym == SDLK_RETURN) &&
	  (event->key.keysym.mod & KMOD_ALT))
	{
	  HotKey_ToggleFullScreen ();
	}

      printf ("key '%s' pressed\n", SDL_GetKeyName (event->key.keysym.sym));
      break;

    case SDL_QUIT:
      done = 1;
      break;
    }

  return (done);
}

void
SDL_GL_Enter2DMode ()
{
  SDL_Surface *screen = SDL_GetVideoSurface ();

  /* Note, there may be other things you need to change,
     depending on how you have your OpenGL state set up.
   */
  glPushAttrib (GL_ENABLE_BIT);
  glDisable (GL_DEPTH_TEST);
  glDisable (GL_CULL_FACE);
  glEnable (GL_TEXTURE_2D);

  /* This allows alpha blending of 2D textures with the scene */
  glEnable (GL_BLEND);
  glBlendFunc (GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

  glViewport (0, 0, screen->w, screen->h);

  glMatrixMode (GL_PROJECTION);
  glPushMatrix ();
  glLoadIdentity ();

  glOrtho (0.0, (GLdouble) screen->w, (GLdouble) screen->h, 0.0, 0.0, 1.0);

  glMatrixMode (GL_MODELVIEW);
  glPushMatrix ();
  glLoadIdentity ();

  glTexEnvf (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
}

void
SDL_GL_Leave2DMode ()
{
  glMatrixMode (GL_MODELVIEW);
  glPopMatrix ();

  glMatrixMode (GL_PROJECTION);
  glPopMatrix ();

  glPopAttrib ();
}

/* Quick utility function for texture creation */
static int
power_of_two (int input)
{
  int value = 1;

  while (value < input)
    {
      value <<= 1;
    }
  return value;
}

GLuint
SDL_GL_LoadTexture (SDL_Surface * surface, GLfloat * texcoord)
{
  GLuint texture;
  int w, h;
  SDL_Surface *image;
  SDL_Rect area;
  Uint32 saved_flags;
  Uint8 saved_alpha;

  /* Use the surface width and height expanded to powers of 2 */
  w = power_of_two (surface->w);
  h = power_of_two (surface->h);
  texcoord[0] = 0.0f;		/* Min X */
  texcoord[1] = 0.0f;		/* Min Y */
  texcoord[2] = (GLfloat) surface->w / w;	/* Max X */
  texcoord[3] = (GLfloat) surface->h / h;	/* Max Y */

  image = SDL_CreateRGBSurface (SDL_SWSURFACE, w, h, 32,
#if SDL_BYTEORDER == SDL_LIL_ENDIAN	/* OpenGL RGBA masks */
				0x000000FF, 0x0000FF00, 0x00FF0000, 0xFF000000
#else
				0xFF000000, 0x00FF0000, 0x0000FF00, 0x000000FF
#endif
    );
  if (image == NULL)
    {
      return 0;
    }

  /* Save the alpha blending attributes */
  saved_flags = surface->flags & (SDL_SRCALPHA | SDL_RLEACCELOK);
  saved_alpha = surface->format->alpha;
  if ((saved_flags & SDL_SRCALPHA) == SDL_SRCALPHA)
    {
      SDL_SetAlpha (surface, 0, 0);
    }

  /* Copy the surface into the GL texture image */
  area.x = 0;
  area.y = 0;
  area.w = surface->w;
  area.h = surface->h;
  SDL_BlitSurface (surface, &area, image, &area);

  /* Restore the alpha blending attributes */
  if ((saved_flags & SDL_SRCALPHA) == SDL_SRCALPHA)
    {
      SDL_SetAlpha (surface, saved_flags, saved_alpha);
    }

  /* Create an OpenGL texture for the image */
  glGenTextures (1, &texture);
  glBindTexture (GL_TEXTURE_2D, texture);
  glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
  glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
  glTexImage2D (GL_TEXTURE_2D,
		0,
		GL_RGBA, w, h, 0, GL_RGBA, GL_UNSIGNED_BYTE, image->pixels);
  SDL_FreeSurface (image);	/* No longer needed */

  return texture;
}

int
RunGLTest (int argc, char *argv[],
	   int logo, int slowly, int bpp, float gamma, int noframe, int fsaa)
{
  int i;
  int rgb_size[3];
  int w = 640;
  int h = 480;
  int done = 0;
  int frames;
  Uint32 start_time, this_time;
  Uint32 video_flags;
  int value;

  if (SDL_Init (SDL_INIT_VIDEO) < 0)
    {
      fprintf (stderr, "Couldn't initialize SDL: %s\n", SDL_GetError ());
      exit (1);
    }

  /* See if we should detect the display depth */
  if (bpp == 0)
    {
      if (SDL_GetVideoInfo ()->vfmt->BitsPerPixel <= 8)
	bpp = 8;
      else
	bpp = 16;		/* More doesn't seem to work */
    }

  video_flags = SDL_OPENGL;

  for (i = 1; argv[i]; ++i)
    if (strcmp (argv[1], "-fullscreen") == 0)
      video_flags |= SDL_FULLSCREEN;

  if (noframe)
    video_flags |= SDL_NOFRAME;

  /* Initialize the display */
  switch (bpp)
    {
    case 8:
      rgb_size[0] = 3;
      rgb_size[1] = 3;
      rgb_size[2] = 2;
      break;

    case 15:
    case 16:
      rgb_size[0] = 5;
      rgb_size[1] = 5;
      rgb_size[2] = 5;
      break;

    default:
      rgb_size[0] = 8;
      rgb_size[1] = 8;
      rgb_size[2] = 8;
      break;
    }
  SDL_GL_SetAttribute (SDL_GL_RED_SIZE, rgb_size[0]);
  SDL_GL_SetAttribute (SDL_GL_GREEN_SIZE, rgb_size[1]);
  SDL_GL_SetAttribute (SDL_GL_BLUE_SIZE, rgb_size[2]);
  SDL_GL_SetAttribute (SDL_GL_DEPTH_SIZE, 16);
  SDL_GL_SetAttribute (SDL_GL_DOUBLEBUFFER, 1);

  if (fsaa)
    {
      SDL_GL_SetAttribute (SDL_GL_MULTISAMPLEBUFFERS, 1);
      SDL_GL_SetAttribute (SDL_GL_MULTISAMPLESAMPLES, fsaa);
    }

  if (SDL_SetVideoMode (w, h, bpp, video_flags) == NULL)
    {
      fprintf (stderr, "Couldn't set GL mode: %s\n", SDL_GetError ());
      SDL_Quit ();
      exit (1);
    }

  printf ("Screen BPP: %d\n", SDL_GetVideoSurface ()->format->BitsPerPixel);
  printf ("\n");
  printf ("Vendor     : %s\n", glGetString (GL_VENDOR));
  printf ("Renderer   : %s\n", glGetString (GL_RENDERER));
  printf ("Version    : %s\n", glGetString (GL_VERSION));
  printf ("Extensions : %s\n", glGetString (GL_EXTENSIONS));
  printf ("\n");

  SDL_GL_GetAttribute (SDL_GL_RED_SIZE, &value);
  printf ("SDL_GL_RED_SIZE: requested %d, got %d\n", rgb_size[0], value);
  SDL_GL_GetAttribute (SDL_GL_GREEN_SIZE, &value);
  printf ("SDL_GL_GREEN_SIZE: requested %d, got %d\n", rgb_size[1], value);
  SDL_GL_GetAttribute (SDL_GL_BLUE_SIZE, &value);
  printf ("SDL_GL_BLUE_SIZE: requested %d, got %d\n", rgb_size[2], value);
  SDL_GL_GetAttribute (SDL_GL_DEPTH_SIZE, &value);
  printf ("SDL_GL_DEPTH_SIZE: requested %d, got %d\n", bpp, value);
  SDL_GL_GetAttribute (SDL_GL_DOUBLEBUFFER, &value);
  printf ("SDL_GL_DOUBLEBUFFER: requested 1, got %d\n", value);

  if (fsaa)
    {
      SDL_GL_GetAttribute (SDL_GL_MULTISAMPLEBUFFERS, &value);
      printf ("SDL_GL_MULTISAMPLEBUFFERS: requested 1, got %d\n", value);
      SDL_GL_GetAttribute (SDL_GL_MULTISAMPLESAMPLES, &value);
      printf ("SDL_GL_MULTISAMPLESAMPLES: requested %d, got %d\n", fsaa,
	      value);
    }

  /* Set the window manager title bar */
  SDL_WM_SetCaption ("SDL GL test", "testgl");

  /* Set the gamma for the window */
  if (gamma != 0.0)
    SDL_SetGamma (gamma, gamma, gamma);

  view v;
  v.p = point (0, 0, 0);
  v.d = vec3 (0, 0, -1);
  v.u = vec3 (0, 1, 0);
  v.w = w; v.h = h;
  v.fov = 90;

  glMatrixMode (GL_MODELVIEW);
  glLoadIdentity ();

  glEnable (GL_DEPTH_TEST);

  glDepthFunc (GL_LESS);

  glShadeModel (GL_SMOOTH);
  GLfloat ambient[4] = { 1, 1, 1, 1 };
  glEnable (GL_LIGHTING);
  glEnable (GL_COLOR_MATERIAL);
  glLightModelfv (GL_LIGHT_MODEL_AMBIENT, ambient);

  /* Loop until done. */
  start_time = SDL_GetTicks ();
  frames = 0;
  while (!done)
    {
      GLenum gl_error;
      char *sdl_error;
      SDL_Event event;

      /* Do our drawing, too. */
      glClearColor (0.0, 0.0, 0.0, 1.0);
      glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

      static GLfloat ry;
      ry += 0.1;
      v.d.x = cos (ry);
      v.d.z = sin (ry);

      draw_context c;
      v.draw (c);

      SDL_GL_SwapBuffers ();

      /* Check for error conditions. */
      gl_error = glGetError ();

      if (gl_error != GL_NO_ERROR)
	fprintf (stderr, "testgl: OpenGL error: %d\n", gl_error);

      sdl_error = SDL_GetError ();

      if (sdl_error[0] != '\0')
	{
	  fprintf (stderr, "testgl: SDL error '%s'\n", sdl_error);
	  SDL_ClearError ();
	}

      /* Allow the user to see what's happening */
      SDL_Delay (20);

      /* Check if there's a pending event. */
      while (SDL_PollEvent (&event))
	{
	  done = HandleEvent (&event);
	}
      ++frames;
    }

  /* Print out the frames per second */
  this_time = SDL_GetTicks ();
  if (this_time != start_time)
    {
      printf ("%2.2f FPS\n",
	      ((float) frames / (this_time - start_time)) * 1000.0);
    }

  if (global_image)
    {
      SDL_FreeSurface (global_image);
      global_image = NULL;
    }
  if (global_texture)
    {
      glDeleteTextures (1, &global_texture);
      global_texture = 0;
    }

  /* Destroy our GL context, etc. */
  SDL_Quit ();
  return (0);
}

int
main (int argc, char *argv[])
{
  int i, logo;
  int numtests;
  int bpp = 0;
  int slowly;
  float gamma = 0.0;
  int noframe = 0;
  int fsaa = 0;

  logo = 0;
  slowly = 0;
  numtests = 1;
  for (i = 1; argv[i]; ++i)
    {
      if (strcmp (argv[i], "-twice") == 0)
	{
	  ++numtests;
	}
      if (strcmp (argv[i], "-slow") == 0)
	{
	  slowly = 1;
	}
      if (strcmp (argv[i], "-bpp") == 0)
	{
	  bpp = atoi (argv[++i]);
	}
      if (strcmp (argv[i], "-gamma") == 0)
	{
	  gamma = (float) atof (argv[++i]);
	}
      if (strcmp (argv[i], "-noframe") == 0)
	{
	  noframe = 1;
	}
      if (strcmp (argv[i], "-fsaa") == 0)
	{
	  ++fsaa;
	}
      if (strncmp (argv[i], "-h", 2) == 0)
	{
	  printf
	    ("Usage: %s [-twice] [-logo] [-slow] [-bpp n] [-gamma n] [-noframe] [-fsaa]\n",
	     argv[0]);
	  exit (0);
	}
    }
  for (i = 0; i < numtests; ++i)
    {
      RunGLTest (argc, argv, logo, slowly, bpp, gamma, noframe, fsaa);
    }
  return 0;
}