/* 
 * GStreamer
 * Copyright (C) 2008 Julien Isorce <julien.isorce@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., 51 Franklin St, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

/**
 * SECTION:element-glfilterapp
 *
 * The resize and redraw callbacks can be set from a client code.
 *
 * <refsect2>
 * <title>CLient callbacks</title>
 * <para>
 * The graphic scene can be written from a client code through the 
 * two glfilterapp properties.
 * </para>
 * </refsect2>
 * <refsect2>
 * <title>Examples</title>
 * see gst-plugins-gl/tests/examples/generic/recordgraphic
 * </refsect2>
 */

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

#include "gstglfilterapp.h"

#define GST_CAT_DEFAULT gst_gl_filter_app_debug
GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);

enum
{
  SIGNAL_0,
  CLIENT_DRAW_SIGNAL,
  LAST_SIGNAL
};

static guint gst_gl_filter_app_signals[LAST_SIGNAL] = { 0 };

#define DEBUG_INIT \
  GST_DEBUG_CATEGORY_INIT (gst_gl_filter_app_debug, "glfilterapp", 0, "glfilterapp element");

G_DEFINE_TYPE_WITH_CODE (GstGLFilterApp, gst_gl_filter_app,
    GST_TYPE_GL_FILTER, DEBUG_INIT);

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

static gboolean gst_gl_filter_app_set_caps (GstGLFilter * filter,
    GstCaps * incaps, GstCaps * outcaps);
static gboolean gst_gl_filter_app_filter_texture (GstGLFilter * filter,
    guint in_tex, guint out_tex);
static void gst_gl_filter_app_callback (gint width, gint height, guint texture,
    gpointer stuff);


static void
gst_gl_filter_app_class_init (GstGLFilterAppClass * klass)
{
  GObjectClass *gobject_class;
  GstElementClass *element_class;

  gobject_class = (GObjectClass *) klass;
  element_class = GST_ELEMENT_CLASS (klass);

  gobject_class->set_property = gst_gl_filter_app_set_property;
  gobject_class->get_property = gst_gl_filter_app_get_property;

  GST_GL_FILTER_CLASS (klass)->set_caps = gst_gl_filter_app_set_caps;
  GST_GL_FILTER_CLASS (klass)->filter_texture =
      gst_gl_filter_app_filter_texture;

  /**
   * GstGLFilterApp::client-draw:
   * @object: the #GstGLImageSink
   * @texture: the #guint id of the texture.
   * @width: the #guint width of the texture.
   * @height: the #guint height of the texture.
   *
   * Will be emitted before to draw the texture.  The client should
   * redraw the surface/contents with the @texture, @width and @height.
   *
   * Returns: whether the texture was redrawn by the signal.  If not, a
   *          default redraw will occur.
   */
  gst_gl_filter_app_signals[CLIENT_DRAW_SIGNAL] =
      g_signal_new ("client-draw", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_LAST, 0, NULL, NULL, g_cclosure_marshal_generic,
      G_TYPE_BOOLEAN, 3, G_TYPE_UINT, G_TYPE_UINT, G_TYPE_UINT);

  gst_element_class_set_metadata (element_class,
      "OpenGL application filter", "Filter/Effect",
      "Use client callbacks to define the scene",
      "Julien Isorce <julien.isorce@gmail.com>");

  GST_GL_BASE_FILTER_CLASS (klass)->supported_gl_api =
      GST_GL_API_OPENGL | GST_GL_API_GLES2 | GST_GL_API_OPENGL3;
}

static void
gst_gl_filter_app_init (GstGLFilterApp * filter)
{
}

static void
gst_gl_filter_app_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec)
{
  switch (prop_id) {
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static void
gst_gl_filter_app_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec)
{
  switch (prop_id) {
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static gboolean
gst_gl_filter_app_set_caps (GstGLFilter * filter, GstCaps * incaps,
    GstCaps * outcaps)
{
  //GstGLFilterApp* app_filter = GST_GL_FILTER_APP(filter);

  return TRUE;
}

static void
_emit_draw_signal (guint tex, gint width, gint height, gpointer data)
{
  GstGLFilterApp *app_filter = GST_GL_FILTER_APP (data);
  gboolean drawn;

  g_signal_emit (app_filter, gst_gl_filter_app_signals[CLIENT_DRAW_SIGNAL], 0,
      tex, width, height, &drawn);

  app_filter->default_draw = !drawn;
}

struct glcb2
{
  GLCB func;
  gpointer data;
  guint texture;
  guint width;
  guint height;
};

/* convenience functions to simplify filter development */
static void
_glcb2 (gpointer data)
{
  struct glcb2 *cb = data;

  cb->func (cb->width, cb->height, cb->texture, cb->data);
}

static gboolean
gst_gl_filter_app_filter_texture (GstGLFilter * filter, guint in_tex,
    guint out_tex)
{
  GstGLFilterApp *app_filter = GST_GL_FILTER_APP (filter);
  struct glcb2 cb;

  cb.func = (GLCB) _emit_draw_signal;
  cb.data = filter;
  cb.texture = in_tex;
  cb.width = GST_VIDEO_INFO_WIDTH (&filter->in_info);
  cb.height = GST_VIDEO_INFO_HEIGHT (&filter->in_info);

  //blocking call, use a FBO
  gst_gl_context_use_fbo_v2 (GST_GL_BASE_FILTER (filter)->context,
      GST_VIDEO_INFO_WIDTH (&filter->out_info),
      GST_VIDEO_INFO_HEIGHT (&filter->out_info),
      filter->fbo, filter->depthbuffer, out_tex, _glcb2, &cb);

  if (app_filter->default_draw) {
    gst_gl_filter_render_to_target (filter, TRUE, in_tex, out_tex,
        gst_gl_filter_app_callback, filter);
  }

  return TRUE;
}

//opengl scene, params: input texture (not the output filter->texture)
static void
gst_gl_filter_app_callback (gint width, gint height, guint texture,
    gpointer stuff)
{
  GstGLFilter *filter = GST_GL_FILTER (stuff);

#if GST_GL_HAVE_OPENGL
  if (gst_gl_context_get_gl_api (GST_GL_BASE_FILTER (filter)->context) &
      GST_GL_API_OPENGL) {
    GstGLFuncs *gl = GST_GL_BASE_FILTER (filter)->context->gl_vtable;

    gl->MatrixMode (GL_PROJECTION);
    gl->LoadIdentity ();
  }
#endif

  gst_gl_filter_draw_texture (filter, texture, width, height);
}