/*
 * GStreamer
 * Copyright (C) 2008 Filippo Argiolas <filippo.argiolas@gmail.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

/**
 * SECTION:element-glpixbufoverlay
 *
 * Overlay GL video texture with a gdkpixbuf.
 *
 * <refsect2>
 * <title>Examples</title>
 * |[
 * gst-launch  videotestsrc ! "video/x-raw-rgb" ! glupload ! glpixbufoverlay location=imagefile ! glimagesink
 * ]|
 * FBO (Frame Buffer Object) is required.
 * </refsect2>
 */

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

#include <gstglfilter.h>
#include <gstgleffectssources.h>
#include <gdk-pixbuf/gdk-pixbuf.h>

#define GST_TYPE_GL_PIXBUFOVERLAY            (gst_gl_pixbufoverlay_get_type())
#define GST_GL_PIXBUFOVERLAY(obj)            (G_TYPE_CHECK_INSTANCE_CAST((obj), GST_TYPE_GL_PIXBUFOVERLAY,GstGLPixbufOverlay))
#define GST_IS_GL_PIXBUFOVERLAY(obj)         (G_TYPE_CHECK_INSTANCE_TYPE((obj), GST_TYPE_GL_PIXBUFOVERLAY))
#define GST_GL_PIXBUFOVERLAY_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST((klass) , GST_TYPE_GL_PIXBUFOVERLAY,GstGLPixbufOverlayClass))
#define GST_IS_GL_PIXBUFOVERLAY_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass) , GST_TYPE_GL_PIXBUFOVERLAY))
#define GST_GL_PIXBUFOVERLAY_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS((obj) , GST_TYPE_GL_PIXBUFOVERLAY,GstGLPixbufOverlayClass))

struct _GstGLPixbufOverlay
{
  GstGLFilter filter;

  gchar *location;
  gboolean pbuf_has_changed;

  GdkPixbuf *pixbuf;
  gfloat width, height;
  GLuint pbuftexture;

//  gboolean stretch;
};

struct _GstGLPixbufOverlayClass
{
  GstGLFilterClass filter_class;
};

typedef struct _GstGLPixbufOverlay GstGLPixbufOverlay;
typedef struct _GstGLPixbufOverlayClass GstGLPixbufOverlayClass;

#define GST_CAT_DEFAULT gst_gl_pixbufoverlay_debug
GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);

#define DEBUG_INIT(bla)							\
  GST_DEBUG_CATEGORY_INIT (gst_gl_pixbufoverlay_debug, "glpixbufoverlay", 0, "glpixbufoverlay element");

GST_BOILERPLATE_FULL (GstGLPixbufOverlay, gst_gl_pixbufoverlay, GstGLFilter,
    GST_TYPE_GL_FILTER, DEBUG_INIT);

static void gst_gl_pixbufoverlay_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec);
static void gst_gl_pixbufoverlay_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec);

static void gst_gl_pixbufoverlay_init_resources (GstGLFilter * filter);
static void gst_gl_pixbufoverlay_reset_resources (GstGLFilter * filter);

static gboolean gst_gl_pixbufoverlay_filter (GstGLFilter * filter,
    GstGLBuffer * inbuf, GstGLBuffer * outbuf);

static const GstElementDetails element_details =
GST_ELEMENT_DETAILS ("Gstreamer OpenGL PixbufOverlay",
    "Filter/Effect",
    "Overlay GL video texture with a gdkpixbuf",
    "Filippo Argiolas <filippo.argiolas@gmail.com>");

enum
{
  PROP_0,
  PROP_LOCATION,
//  PROP_STRETCH,
  /* future properties? */
  /* PROP_WIDTH, */
  /* PROP_HEIGHT, */
  /* PROP_XPOS, */
  /* PROP_YPOS */
};


/* init resources that need a gl context */
static void
gst_gl_pixbufoverlay_init_gl_resources (GstGLFilter * filter)
{
//  GstGLPixbufOverlay *pixbufoverlay = GST_GL_PIXBUFOVERLAY (filter);
}

/* free resources that need a gl context */
static void
gst_gl_pixbufoverlay_reset_gl_resources (GstGLFilter * filter)
{
  GstGLPixbufOverlay *pixbufoverlay = GST_GL_PIXBUFOVERLAY (filter);

  glDeleteTextures (1, &pixbufoverlay->pbuftexture);
}

static void
gst_gl_pixbufoverlay_base_init (gpointer klass)
{
  GstElementClass *element_class = GST_ELEMENT_CLASS (klass);

  gst_element_class_set_details (element_class, &element_details);
}

static void
gst_gl_pixbufoverlay_class_init (GstGLPixbufOverlayClass * klass)
{
  GObjectClass *gobject_class;

  gobject_class = (GObjectClass *) klass;
  gobject_class->set_property = gst_gl_pixbufoverlay_set_property;
  gobject_class->get_property = gst_gl_pixbufoverlay_get_property;

  GST_GL_FILTER_CLASS (klass)->filter = gst_gl_pixbufoverlay_filter;
  GST_GL_FILTER_CLASS (klass)->display_init_cb =
      gst_gl_pixbufoverlay_init_gl_resources;
  GST_GL_FILTER_CLASS (klass)->display_reset_cb =
      gst_gl_pixbufoverlay_reset_gl_resources;
  GST_GL_FILTER_CLASS (klass)->onStart = gst_gl_pixbufoverlay_init_resources;
  GST_GL_FILTER_CLASS (klass)->onStop = gst_gl_pixbufoverlay_reset_resources;

  g_object_class_install_property (gobject_class,
      PROP_LOCATION,
      g_param_spec_string ("location",
          "Location of the image",
          "Location of the image", NULL, G_PARAM_READWRITE));
  /*
     g_object_class_install_property (gobject_class,
     PROP_STRETCH,
     g_param_spec_boolean ("stretch",
     "Stretch the image to texture size", 
     "Stretch the image to fit video texture size", 
     TRUE, G_PARAM_READWRITE));
   */
}

void
gst_gl_pixbufoverlay_draw_texture (GstGLPixbufOverlay * pixbufoverlay,
    GLuint tex)
{
  GstGLFilter *filter = GST_GL_FILTER (pixbufoverlay);

  gfloat width = (gfloat) filter->width;
  gfloat height = (gfloat) filter->height;

  glActiveTexture (GL_TEXTURE0);
  glEnable (GL_TEXTURE_RECTANGLE_ARB);
  glBindTexture (GL_TEXTURE_RECTANGLE_ARB, tex);

  glBegin (GL_QUADS);

  glTexCoord2f (0.0, 0.0);
  glVertex2f (-1.0, -1.0);
  glTexCoord2f (width, 0.0);
  glVertex2f (1.0, -1.0);
  glTexCoord2f (width, height);
  glVertex2f (1.0, 1.0);
  glTexCoord2f (0.0, height);
  glVertex2f (-1.0, 1.0);

  glEnd ();

  if (pixbufoverlay->pbuftexture == 0)
    return;

//  if (pixbufoverlay->stretch) {
  width = pixbufoverlay->width;
  height = pixbufoverlay->height;
//  }

  glBlendFunc (GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
  glEnable (GL_BLEND);

  glEnable (GL_TEXTURE_RECTANGLE_ARB);
  glBindTexture (GL_TEXTURE_RECTANGLE_ARB, pixbufoverlay->pbuftexture);

  glBegin (GL_QUADS);

  glTexCoord2f (0.0, 0.0);
  glVertex2f (-1.0, -1.0);
  glTexCoord2f (width, 0.0);
  glVertex2f (1.0, -1.0);
  glTexCoord2f (width, height);
  glVertex2f (1.0, 1.0);
  glTexCoord2f (0.0, height);
  glVertex2f (-1.0, 1.0);

  glEnd ();


  glFlush ();
}

static void
gst_gl_pixbufoverlay_init (GstGLPixbufOverlay * pixbufoverlay,
    GstGLPixbufOverlayClass * klass)
{
  pixbufoverlay->location = NULL;
  pixbufoverlay->pixbuf = NULL;
  pixbufoverlay->pbuftexture = 0;
  pixbufoverlay->pbuftexture = 0;
  pixbufoverlay->width = 0;
  pixbufoverlay->height = 0;
//  pixbufoverlay->stretch = TRUE;
  pixbufoverlay->pbuf_has_changed = FALSE;
}

static void
gst_gl_pixbufoverlay_reset_resources (GstGLFilter * filter)
{
//  GstGLPixbufOverlay* pixbufoverlay = GST_GL_PIXBUFOVERLAY(filter);
}

static void
gst_gl_pixbufoverlay_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec)
{
  GstGLPixbufOverlay *pixbufoverlay = GST_GL_PIXBUFOVERLAY (object);

  switch (prop_id) {
    case PROP_LOCATION:
      if (pixbufoverlay->location != NULL)
        g_free (pixbufoverlay->location);
      pixbufoverlay->pbuf_has_changed = TRUE;
      pixbufoverlay->location = g_value_dup_string (value);
      break;
/*  case PROP_STRETCH:
    pixbufoverlay->stretch = g_value_get_boolean (value);
    break;
*/
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static void
gst_gl_pixbufoverlay_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec)
{
  GstGLPixbufOverlay *pixbufoverlay = GST_GL_PIXBUFOVERLAY (object);

  switch (prop_id) {
    case PROP_LOCATION:
      g_value_set_string (value, pixbufoverlay->location);
      break;
/*  case PROP_STRETCH:
    g_value_set_boolean (value, pixbufoverlay->stretch);
    break;
*/
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static void
gst_gl_pixbufoverlay_init_resources (GstGLFilter * filter)
{
//  GstGLPixbufOverlay *pixbufoverlay = GST_GL_PIXBUFOVERLAY (filter);
}

static void
gst_gl_pixbufoverlay_callback (gint width, gint height, guint texture,
    gpointer stuff)
{
  GstGLPixbufOverlay *pixbufoverlay = GST_GL_PIXBUFOVERLAY (stuff);

  glMatrixMode (GL_PROJECTION);
  glLoadIdentity ();

  gst_gl_pixbufoverlay_draw_texture (pixbufoverlay, texture);
}

static void
init_pixbuf_texture (GstGLDisplay * display, gpointer data)
{
  GstGLPixbufOverlay *pixbufoverlay = GST_GL_PIXBUFOVERLAY (data);

  glDeleteTextures (1, &pixbufoverlay->pbuftexture);
  glGenTextures (1, &pixbufoverlay->pbuftexture);
  glBindTexture (GL_TEXTURE_RECTANGLE_ARB, pixbufoverlay->pbuftexture);
  glTexImage2D (GL_TEXTURE_RECTANGLE_ARB, 0, GL_RGBA,
      (gint) pixbufoverlay->width, (gint) pixbufoverlay->height, 0,
      gdk_pixbuf_get_has_alpha (pixbufoverlay->pixbuf) ? GL_RGBA : GL_RGB,
      GL_UNSIGNED_BYTE, gdk_pixbuf_get_pixels (pixbufoverlay->pixbuf));
}

static gboolean
gst_gl_pixbufoverlay_filter (GstGLFilter * filter, GstGLBuffer * inbuf,
    GstGLBuffer * outbuf)
{
  GstGLPixbufOverlay *pixbufoverlay = GST_GL_PIXBUFOVERLAY (filter);
  GError *error = NULL;

  if (pixbufoverlay->pbuf_has_changed && (pixbufoverlay->location != NULL)) {
    pixbufoverlay->pixbuf =
        gdk_pixbuf_new_from_file (pixbufoverlay->location, &error);
    if (pixbufoverlay->pixbuf != NULL) {
      pixbufoverlay->width =
          (gfloat) gdk_pixbuf_get_width (pixbufoverlay->pixbuf);
      pixbufoverlay->height =
          (gfloat) gdk_pixbuf_get_height (pixbufoverlay->pixbuf);
      gst_gl_display_thread_add (filter->display, init_pixbuf_texture,
          pixbufoverlay);
      gdk_pixbuf_unref (pixbufoverlay->pixbuf);
    } else {
      if (error != NULL && error->message != NULL)
        g_warning ("unable to load %s: %s", pixbufoverlay->location,
            error->message);
    }
    pixbufoverlay->pbuf_has_changed = FALSE;
  }

  gst_gl_filter_render_to_target (filter, inbuf->texture, outbuf->texture,
      gst_gl_pixbufoverlay_callback, pixbufoverlay);

  return TRUE;
}