/* This stores the common OpenGL initialization stuff for all instances */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

/* gcc -ansi -pedantic on GNU/Linux causes warnings and errors
 * unless this is defined:
 * warning: #warning "Files using this header must be compiled with _SVID_SOURCE or _XOPEN_SOURCE"
 */
#ifndef _XOPEN_SOURCE
#  define _XOPEN_SOURCE 1
#endif

#include <X11/Xlib.h>
#include <GL/glx.h>
#include <GL/gl.h>
#include <GL/glu.h>
#include "gstglsink.h"
#include <string.h> /* strncmp */

/* attributes for a single buffered visual in RGBA format with at least
 * 4 bits per color and a 16 bit depth buffer */
static int attrListSgl[] = 
{
  GLX_RGBA, GLX_RED_SIZE, 4, 
  GLX_GREEN_SIZE, 4, 
  GLX_BLUE_SIZE, 4, 
  GLX_DEPTH_SIZE, 16,
  None
};

/* attributes for a double buffered visual in RGBA format with at least
 * 4 bits per color and a 16 bit depth buffer */
static int attrListDbl[] = 
  { 
    GLX_RGBA, GLX_DOUBLEBUFFER, 
    GLX_RED_SIZE, 4, 
    GLX_GREEN_SIZE, 4, 
    GLX_BLUE_SIZE, 4, 
    GLX_DEPTH_SIZE, 16,
    None 
  };


GLfloat LightAmbient[] = { 0.1, 0.1, 0.1, 1.0 };  /* reddish ambient light  */
GLfloat LightDiffuse[] = { 0.6, 0.6, 0.6, 1.0 };  /* bluish  diffuse light. */
GLfloat LightPosition[] = { 1.5, 1.5, 1.5, 0.0 };    /* position */


void
gst_glxwindow_unhook_context(GstImageInfo *info)
{
  GstGLImageInfo *window = (GstGLImageInfo *) info;

  if (window->ctx)
    {
      if (!glXMakeCurrent(window->dpy, None, NULL))
        {
	  printf("Could not release drawing context.\n");
        }
      else
	  printf("Released drawing context.\n");
    }
}

void
gst_glxwindow_hook_context(GstImageInfo *info)
{
  GstGLImageInfo *window = (GstGLImageInfo *) info;

  if (window->ctx && window->win && window->ctx)
    {
      if (!glXMakeCurrent(window->dpy, window->win, window->ctx))
        {
	  printf("Could not acquire GLX drawing context.\n");
        }
      else
	  printf("Acquired drawing context.\n");
    }
}

static void
gst_glxwindow_free (GstImageInfo *info)
{
  GstGLImageInfo *window = (GstGLImageInfo *) info;
  
  g_signal_handler_disconnect (window->sink, window->handler_id);

  if (window->ctx)
    {
      if (!glXMakeCurrent(window->dpy, None, NULL))
        {
	  printf("Could not release drawing context.\n");
        }
      glXDestroyContext(window->dpy, window->ctx);
      window->ctx = NULL;
    }
#if 0 
    /* switch back to original desktop resolution if we were in fs */
    if (GLWin.fs)
    {
        XF86VidModeSwitchToMode(GLWin.dpy, GLWin.screen, &GLWin.deskMode);
        XF86VidModeSetViewPort(GLWin.dpy, GLWin.screen, 0, 0);
    }
#endif
  XCloseDisplay (window->dpy);
  g_free (window);
}

static void
gst_glxwindow_callback(GObject *object, GParamSpec *pspec, GstGLImageInfo *data)
{
  XWindowAttributes attr; 
  XGetWindowAttributes(data->dpy, data->win, &attr); 

  if (strncmp (pspec->name, "width", 5) == 0 || strncmp (pspec->name, "height", 6) == 0)
  {
    gint w = 0;
    gint h = 0;
    g_object_get (object, "width", &w, NULL);
    g_object_get (object, "height", &h, NULL);
    if (w != attr.width || h != attr.height)
    {
      attr.width = w;
      attr.height = h;
      XResizeWindow (data->dpy, data->win, attr.width, attr.height);
      XMapRaised (data->dpy, data->win);

      // resize OpenGL
      g_warning("resizing in OpenGL");
      glViewport(0, 0, (GLint) w, (GLint) h);
      glMatrixMode(GL_PROJECTION);
      glLoadIdentity();
      
      GLfloat aspect = (GLfloat) h / (GLfloat) w;
      glFrustum(-1.0, 1.0, -aspect, aspect, 5.0, 500.0);
    }
  }
  if (attr.width != data->width || attr.height != data->height)
  {
    data->width = attr.width;
    data->height = attr.height;
  }

}

void
gst_glxwindow_new (GstElement *sink)
{
  //XGCValues values;
  GstGLImageInfo *new;
  int glxMajorVersion, glxMinorVersion;
  //XSetWindowAttributes attrib;
  XVisualInfo *vi;
  Atom wmDelete;
  Window winDummy;
  unsigned int borderDummy;
  Colormap cmap;
  char* title = "GLSink (experimental)";

  new = g_new0 (GstGLImageInfo, 1);

  if (sink == NULL)
  {
    sink = gst_element_factory_make ("glsink", "glsink");
    g_assert (sink != NULL);
  }
  
  /* fill in the ImageInfo */
  new->info.id = GST_MAKE_FOURCC ('X', 'l', 'i', 'b');
  new->info.free_info = gst_glxwindow_free;
  
  new->dpy = XOpenDisplay (NULL);
  if (!new->dpy) {
    g_warning ("open display failed!\n");
    g_free (new);
    return;
  }
  new->screen = DefaultScreen(new->dpy);
  /* get an appropriate visual */
  vi = glXChooseVisual(new->dpy, new->screen, attrListDbl);
  if (vi == NULL)
    {
      vi = glXChooseVisual(new->dpy, new->screen, attrListSgl);
      GST_DEBUG("Only Singlebuffered Visual!\n");
    }
  else
    {
      GST_DEBUG("Got Doublebuffered Visual!\n");
    }
  glXQueryVersion(new->dpy, &glxMajorVersion, &glxMinorVersion);
  GST_DEBUG("glX-Version %d.%d\n", glxMajorVersion, glxMinorVersion);
  
  /* create a GLX context */
  new->ctx = glXCreateContext(new->dpy, vi, 0, GL_TRUE);
  /* create a color map */
  cmap = XCreateColormap(new->dpy, RootWindow(new->dpy, vi->screen),
			 vi->visual, AllocNone);
  new->attr.colormap = cmap;
  new->attr.border_pixel = 0;

  /* set sizes */
  new->x = 0;
  new->y = 0;
  new->width = 10;
  new->height = 10;

  new->rotX = 0; 
  new->rotY = 0; 
  new->zoom = 1;
  new->zoomdir = 0.01;

  {
        /* create a window in window mode*/
    new->attr.event_mask = ExposureMask | KeyPressMask | ButtonPressMask |
      StructureNotifyMask;
    new->win = XCreateWindow(new->dpy, RootWindow(new->dpy, vi->screen),
			      new->x, new->y, new->width, new->height, 0, vi->depth, InputOutput, vi->visual,
			      CWBorderPixel | CWColormap | CWEventMask, &new->attr);
    if (!new->win) 
      {
	g_warning ("create window failed\n");
	g_free (new);
	return;
      }
    /* only set window title and handle wm_delete_events if in windowed mode */
    wmDelete = XInternAtom(new->dpy, "WM_DELETE_WINDOW", True);
    XSetWMProtocols(new->dpy, new->win, &wmDelete, 1);
    XSetStandardProperties(new->dpy, new->win, title,
			   title, None, NULL, 0, NULL);
    XMapRaised(new->dpy, new->win);
  }       
  /* connect the glx-context to the window */
  glXMakeCurrent(new->dpy, new->win, new->ctx);
  XGetGeometry(new->dpy, new->win, &winDummy, &new->x, &new->y,
	       &new->width, &new->height, &borderDummy, &new->depth);
  printf("Depth %d\n", new->depth);
  if (glXIsDirect(new->dpy, new->ctx)) 
      GST_DEBUG ("Congrats, you have Direct Rendering!\n");
  else
    GST_DEBUG ("Sorry, no Direct Rendering possible!\n");

  g_warning("Initializing OpenGL parameters\n");
  /* initialize OpenGL drawing */
  glEnable(GL_DEPTH_TEST);
  //glShadeModel(GL_SMOOTH);

  glEnable(GL_TEXTURE_2D);
  glDisable(GL_CULL_FACE);
  glClearDepth(1.0f);
  glClearColor(0, 0, 0, 0);

  glLightfv(GL_LIGHT0, GL_AMBIENT, LightAmbient);  /*  add lighting. (ambient) */
  glLightfv(GL_LIGHT0, GL_DIFFUSE, LightDiffuse);  /*  add lighting. (diffuse). */
  glLightfv(GL_LIGHT0, GL_POSITION,LightPosition); /*  set light position. */ 
 
  //glEnable(GL_LIGHT0);					// Quick And Dirty Lighting (Assumes Light0 Is Set Up)
  //glEnable(GL_LIGHTING);					// Enable Lighting
  glDisable(GL_COLOR_MATERIAL);				// Enable Material Coloring
  glEnable(GL_AUTO_NORMAL); // let OpenGL generate the Normals

  glDisable(GL_BLEND);

  glPolygonMode(GL_FRONT, GL_FILL);
  glPolygonMode(GL_BACK, GL_FILL);

  glShadeModel(GL_SMOOTH);
  glHint(GL_PERSPECTIVE_CORRECTION_HINT,GL_NICEST);

  XSelectInput (new->dpy, new->win, ExposureMask | StructureNotifyMask);

  g_object_set (sink, "hook", new, NULL);
  new->sink = sink;
  new->handler_id = g_signal_connect (sink, "notify", G_CALLBACK (gst_glxwindow_callback), new);
}