/*

 * GStreamer

 * Copyright (C) 2015 Matthew Waters <matthew@centricular.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:gstglformat

 * @title: GstGLFormat

 * @short_description: utilities for dealing with OpenGL formats

 * @see_also: #GstGLBaseMemory, #GstGLMemory, #GstGLFramebuffer, #GstGLBuffer

 *

 * Some useful utilities for converting between various formats and OpenGL

 * formats.

 */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include "gstglformat.h"

#include "gstglcontext.h"

#include "gstglfuncs.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))

#ifndef GL_TEXTURE_RECTANGLE

#define GL_TEXTURE_RECTANGLE 0x84F5

#endif

#ifndef GL_TEXTURE_EXTERNAL_OES

#define GL_TEXTURE_EXTERNAL_OES 0x8D65

#endif

static inline guint

_gl_format_n_components (guint format)

{

  switch (format) {

    case GST_VIDEO_GL_TEXTURE_TYPE_RGBA:

    case GST_GL_RGBA:

      return 4;

    case GST_VIDEO_GL_TEXTURE_TYPE_RGB:

    case GST_VIDEO_GL_TEXTURE_TYPE_RGB16:

    case GST_GL_RGB:

    case GST_GL_RGB565:

      return 3;

    case GST_VIDEO_GL_TEXTURE_TYPE_LUMINANCE_ALPHA:

    case GST_VIDEO_GL_TEXTURE_TYPE_RG:

    case GST_GL_LUMINANCE_ALPHA:

    case GST_GL_RG:

      return 2;

    case GST_VIDEO_GL_TEXTURE_TYPE_LUMINANCE:

    case GST_VIDEO_GL_TEXTURE_TYPE_R:

    case GST_GL_LUMINANCE:

    case GST_GL_RED:

      return 1;

    default:

      return 0;

  }

}

static inline guint

_gl_type_n_components (guint type)

{

  switch (type) {

    case GL_UNSIGNED_BYTE:

      return 1;

    case GL_UNSIGNED_SHORT_5_6_5:

      return 3;

    default:

      g_assert_not_reached ();

      return 0;

  }

}

static inline guint

_gl_type_n_bytes (guint type)

{

  switch (type) {

    case GL_UNSIGNED_BYTE:

      return 1;

    case GL_UNSIGNED_SHORT_5_6_5:

      return 2;

    default:

      g_assert_not_reached ();

      return 0;

  }

}

/**

 * gst_gl_format_type_n_bytes:

 * @format: the OpenGL format, %GL_RGBA, %GL_LUMINANCE, etc

 * @type: the OpenGL type, %GL_UNSIGNED_BYTE, %GL_FLOAT, etc

 *

 * Returns: the number of bytes the specified @format, @type combination takes

 * per pixel

 */

guint

gst_gl_format_type_n_bytes (guint format, guint type)

{

  return _gl_format_n_components (format) / _gl_type_n_components (type) *

      _gl_type_n_bytes (type);

}

/**

 * gst_gl_format_from_video_info:

 * @context: a #GstGLContext

 * @vinfo: a #GstVideoInfo

 * @plane: the plane number in @vinfo

 *

 * Returns: the #GstGLFormat necessary for holding the data in @plane of @vinfo

 */

GstGLFormat

gst_gl_format_from_video_info (GstGLContext * context, GstVideoInfo * vinfo,

    guint plane)

{

  gboolean texture_rg =

      gst_gl_context_check_feature (context, "GL_EXT_texture_rg")

      || gst_gl_context_check_gl_version (context, GST_GL_API_GLES2, 3, 0)

      || gst_gl_context_check_feature (context, "GL_ARB_texture_rg")

      || gst_gl_context_check_gl_version (context, GST_GL_API_OPENGL3, 3, 0);

  GstVideoFormat v_format = GST_VIDEO_INFO_FORMAT (vinfo);

  guint n_plane_components;

  switch (v_format) {

    case GST_VIDEO_FORMAT_RGBx:

    case GST_VIDEO_FORMAT_BGRx:

    case GST_VIDEO_FORMAT_xRGB:

    case GST_VIDEO_FORMAT_xBGR:

    case GST_VIDEO_FORMAT_RGBA:

    case GST_VIDEO_FORMAT_BGRA:

    case GST_VIDEO_FORMAT_ARGB:

    case GST_VIDEO_FORMAT_ABGR:

    case GST_VIDEO_FORMAT_AYUV:

      n_plane_components = 4;

      break;

    case GST_VIDEO_FORMAT_RGB:

    case GST_VIDEO_FORMAT_BGR:

      n_plane_components = 3;

      break;

    case GST_VIDEO_FORMAT_RGB16:

    case GST_VIDEO_FORMAT_BGR16:

      return GST_GL_RGB565;

    case GST_VIDEO_FORMAT_GRAY16_BE:

    case GST_VIDEO_FORMAT_GRAY16_LE:

    case GST_VIDEO_FORMAT_YUY2:

    case GST_VIDEO_FORMAT_UYVY:

      n_plane_components = 2;

      break;

    case GST_VIDEO_FORMAT_NV12:

    case GST_VIDEO_FORMAT_NV21:

      n_plane_components = plane == 0 ? 1 : 2;

      break;

    case GST_VIDEO_FORMAT_GRAY8:

    case GST_VIDEO_FORMAT_Y444:

    case GST_VIDEO_FORMAT_Y42B:

    case GST_VIDEO_FORMAT_Y41B:

    case GST_VIDEO_FORMAT_I420:

    case GST_VIDEO_FORMAT_YV12:

      n_plane_components = 1;

      break;

    default:

      n_plane_components = 4;

      g_assert_not_reached ();

      break;

  }

  switch (n_plane_components) {

    case 4:

      return GST_GL_RGBA;

      break;

    case 3:

      return GST_GL_RGB;

      break;

    case 2:

      return texture_rg ? GST_GL_RG : GST_GL_LUMINANCE_ALPHA;

      break;

    case 1:

      return texture_rg ? GST_GL_RED : GST_GL_LUMINANCE;

      break;

    default:

      g_assert_not_reached ();

      break;

  }

  return GST_GL_RGBA;

}

/**

 * gst_gl_sized_gl_format_from_gl_format_type:

 * @context: a #GstGLContext

 * @format: an OpenGL format, %GL_RGBA, %GL_LUMINANCE, etc

 * @type: an OpenGL type, %GL_UNSIGNED_BYTE, %GL_FLOAT, etc

 *

 * Returns: the sized internal format specified by @format and @type that can

 *          be used in @context

 */

guint

gst_gl_sized_gl_format_from_gl_format_type (GstGLContext * context,

    guint format, guint type)

{

  gboolean ext_texture_rg =

      gst_gl_context_check_feature (context, "GL_EXT_texture_rg");

  switch (format) {

    case GST_GL_RGBA:

      switch (type) {

        case GL_UNSIGNED_BYTE:

          return USING_GLES2 (context)

              && !USING_GLES3 (context) ? GST_GL_RGBA : GST_GL_RGBA8;

          break;

      }

      break;

    case GST_GL_RGB:

      switch (type) {

        case GL_UNSIGNED_BYTE:

          return USING_GLES2 (context)

              && !USING_GLES3 (context) ? GST_GL_RGB : GST_GL_RGB8;

          break;

        case GL_UNSIGNED_SHORT_5_6_5:

          return GST_GL_RGB565;

          break;

      }

      break;

    case GST_GL_RG:

      switch (type) {

        case GL_UNSIGNED_BYTE:

          if (!USING_GLES3 (context) && USING_GLES2 (context) && ext_texture_rg)

            return GST_GL_RG;

          return GST_GL_RG8;

          break;

      }

      break;

    case GST_GL_RED:

      switch (type) {

        case GL_UNSIGNED_BYTE:

          if (!USING_GLES3 (context) && USING_GLES2 (context) && ext_texture_rg)

            return GST_GL_RED;

          return GST_GL_R8;

          break;

      }

      break;

    case GST_GL_RGBA8:

    case GST_GL_RGB8:

    case GST_GL_RGB565:

    case GST_GL_RG8:

    case GST_GL_R8:

    case GST_GL_LUMINANCE:

    case GST_GL_LUMINANCE_ALPHA:

    case GST_GL_ALPHA:

    case GST_GL_DEPTH_COMPONENT16:

    case GST_GL_DEPTH24_STENCIL8:

      return format;

    default:

      break;

  }

  g_assert_not_reached ();

  return 0;

}

/**

 * gst_gl_texture_target_to_string:

 * @target: a #GstGLTextureTarget

 *

 * Returns: the stringified version of @target or %NULL

 */

const gchar *

gst_gl_texture_target_to_string (GstGLTextureTarget target)

{

  switch (target) {

    case GST_GL_TEXTURE_TARGET_2D:

      return GST_GL_TEXTURE_TARGET_2D_STR;

    case GST_GL_TEXTURE_TARGET_RECTANGLE:

      return GST_GL_TEXTURE_TARGET_RECTANGLE_STR;

    case GST_GL_TEXTURE_TARGET_EXTERNAL_OES:

      return GST_GL_TEXTURE_TARGET_EXTERNAL_OES_STR;

    default:

      return NULL;

  }

}

/**

 * gst_gl_texture_target_from_string:

 * @str: a string equivalant to one of the GST_GL_TEXTURE_TARGET_*_STR values

 *

 * Returns: the #GstGLTextureTarget represented by @str or

 *          %GST_GL_TEXTURE_TARGET_NONE

 */

GstGLTextureTarget

gst_gl_texture_target_from_string (const gchar * str)

{

  if (!str)

    return GST_GL_TEXTURE_TARGET_NONE;

  if (g_strcmp0 (str, GST_GL_TEXTURE_TARGET_2D_STR) == 0)

    return GST_GL_TEXTURE_TARGET_2D;

  if (g_strcmp0 (str, GST_GL_TEXTURE_TARGET_RECTANGLE_STR) == 0)

    return GST_GL_TEXTURE_TARGET_RECTANGLE;

  if (g_strcmp0 (str, GST_GL_TEXTURE_TARGET_EXTERNAL_OES_STR) == 0)

    return GST_GL_TEXTURE_TARGET_EXTERNAL_OES;

  return GST_GL_TEXTURE_TARGET_NONE;

}

/**

 * gst_gl_texture_target_to_gl:

 * @target: a #GstGLTextureTarget

 *

 * Returns: the OpenGL value for binding the @target with glBindTexture() and

 *          similar functions or 0

 */

guint

gst_gl_texture_target_to_gl (GstGLTextureTarget target)

{

  switch (target) {

    case GST_GL_TEXTURE_TARGET_2D:

      return GL_TEXTURE_2D;

    case GST_GL_TEXTURE_TARGET_RECTANGLE:

      return GL_TEXTURE_RECTANGLE;

    case GST_GL_TEXTURE_TARGET_EXTERNAL_OES:

      return GL_TEXTURE_EXTERNAL_OES;

    default:

      return 0;

  }

}

/**

 * gst_gl_texture_target_from_gl:

 * @target: an OpenGL texture binding target

 *

 * Returns: the #GstGLTextureTarget that's equiavalant to @target or

 *          %GST_GL_TEXTURE_TARGET_NONE

 */

GstGLTextureTarget

gst_gl_texture_target_from_gl (guint target)

{

  switch (target) {

    case GL_TEXTURE_2D:

      return GST_GL_TEXTURE_TARGET_2D;

    case GL_TEXTURE_RECTANGLE:

      return GST_GL_TEXTURE_TARGET_RECTANGLE;

    case GL_TEXTURE_EXTERNAL_OES:

      return GST_GL_TEXTURE_TARGET_EXTERNAL_OES;

    default:

      return GST_GL_TEXTURE_TARGET_NONE;

  }

}

/**

 * gst_gl_texture_target_to_buffer_pool_option:

 * @target: a #GstGLTextureTarget

 *

 * Returns: a string representing the @GstBufferPoolOption specified by @target

 */

const gchar *

gst_gl_texture_target_to_buffer_pool_option (GstGLTextureTarget target)

{

  switch (target) {

    case GST_GL_TEXTURE_TARGET_2D:

      return GST_BUFFER_POOL_OPTION_GL_TEXTURE_TARGET_2D;

    case GST_GL_TEXTURE_TARGET_RECTANGLE:

      return GST_BUFFER_POOL_OPTION_GL_TEXTURE_TARGET_RECTANGLE;

    case GST_GL_TEXTURE_TARGET_EXTERNAL_OES:

      return GST_BUFFER_POOL_OPTION_GL_TEXTURE_TARGET_EXTERNAL_OES;

    default:

      return NULL;

  }

}