/*
 * 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., 51 Franklin St, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "../gstgleffects.h"

#define USING_OPENGL(context) (gst_gl_context_check_gl_version (context, GST_GL_API_OPENGL, 1, 0))
#define USING_OPENGL3(context) (gst_gl_context_check_gl_version (context, GST_GL_API_OPENGL3, 3, 1))
#define USING_GLES(context) (gst_gl_context_check_gl_version (context, GST_GL_API_GLES, 1, 0))
#define USING_GLES2(context) (gst_gl_context_check_gl_version (context, GST_GL_API_GLES2, 2, 0))
#define USING_GLES3(context) (gst_gl_context_check_gl_version (context, GST_GL_API_GLES2, 3, 0))

static void
gst_gl_effects_mirror_callback (gint width, gint height, guint texture,
    gpointer data)
{
  GstGLShader *shader;
  GstGLFilter *filter = GST_GL_FILTER (data);
  GstGLEffects *effects = GST_GL_EFFECTS (filter);
  GstGLContext *context = filter->context;
  GstGLFuncs *gl = context->gl_vtable;

  shader = g_hash_table_lookup (effects->shaderstable, "mirror0");

  if (!shader) {
    shader = gst_gl_shader_new (context);
    g_hash_table_insert (effects->shaderstable, (gchar *) "mirror0", shader);

#if GST_GL_HAVE_GLES2
    if (USING_GLES2 (context)) {
      if (!gst_gl_shader_compile_with_default_v_and_check (shader,
              mirror_fragment_source_gles2, &filter->draw_attr_position_loc,
              &filter->draw_attr_texture_loc)) {
        /* gst gl context error is already set */
        GST_ELEMENT_ERROR (effects, RESOURCE, NOT_FOUND,
            ("Failed to initialize squeeze shader, %s",
                gst_gl_context_get_error ()), (NULL));
        return;
      }
    }
#endif
#if GST_GL_HAVE_OPENGL
    if (USING_OPENGL (context)) {
      if (!gst_gl_shader_compile_and_check (shader,
              mirror_fragment_source_opengl, GST_GL_SHADER_FRAGMENT_SOURCE)) {
        gst_gl_context_set_error (context,
            "Failed to initialize mirror shader");
        GST_ELEMENT_ERROR (effects, RESOURCE, NOT_FOUND,
            ("%s", gst_gl_context_get_error ()), (NULL));
        return;
      }

    }
#endif
  }
#if GST_GL_HAVE_OPENGL
  if (USING_OPENGL (context)) {
    gl->MatrixMode (GL_PROJECTION);
    gl->LoadIdentity ();
  }
#endif

  gst_gl_shader_use (shader);

  gl->ActiveTexture (GL_TEXTURE0);
  gl->Enable (GL_TEXTURE_2D);
  gl->BindTexture (GL_TEXTURE_2D, texture);

  gst_gl_shader_set_uniform_1i (shader, "tex", 0);

#if GST_GL_HAVE_OPENGL
  if (USING_OPENGL (filter->context)) {
    gst_gl_shader_set_uniform_1f (shader, "width", (gfloat) width / 2.0f);
    gst_gl_shader_set_uniform_1f (shader, "height", (gfloat) height / 2.0f);
  }
#endif

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

void
gst_gl_effects_mirror (GstGLEffects * effects)
{
  GstGLFilter *filter = GST_GL_FILTER (effects);

  gst_gl_filter_render_to_target (filter, TRUE, effects->intexture,
      effects->outtexture, gst_gl_effects_mirror_callback, effects);
}