/*
 * Copyright (C) 2000-2014 the xine project
 *
 * This file is part of xine, a free video player.
 *
 * xine is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * xine 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
 *
 * Contains common code to calculate video scaling parameters.
 * In short, it will map frame dimensions to screen/window size.
 * Takes into account aspect ratio correction and zooming.
 */

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

#include <stdio.h>
#include <string.h>
#include <math.h>

#define LOG_MODULE "vo_scale"
#define LOG_VERBOSE
/*
#define LOG
*/

#include <xine/xine_internal.h>
#include <xine/vo_scale.h>

/*
 * convert delivered height/width to ideal width/height
 * taking into account aspect ratio and zoom factor
 */

void _x_vo_scale_compute_ideal_size (vo_scale_t *this) {

  double image_ratio, desired_ratio;

  if (this->scaling_disabled & ~1) {

    this->video_pixel_aspect = this->gui_pixel_aspect;

  } else {

    /*
     * aspect ratio
     */

    image_ratio = (double) (this->delivered_width - (this->crop_left + this->crop_right)) /
                  (double) (this->delivered_height - (this->crop_top + this->crop_bottom));

    switch (this->user_ratio) {
    case XINE_VO_ASPECT_AUTO:
      desired_ratio = this->delivered_ratio;
      break;
    case XINE_VO_ASPECT_ANAMORPHIC:
      desired_ratio = 16.0 / 9.0;
      break;
    case XINE_VO_ASPECT_DVB:
      desired_ratio = 2.0 / 1.0;
      break;
    case XINE_VO_ASPECT_SQUARE:
      desired_ratio = image_ratio;
      break;
    case XINE_VO_ASPECT_4_3:
    default:
      desired_ratio = 4.0 / 3.0;
    }

    this->video_pixel_aspect = desired_ratio / image_ratio;

    _x_assert(this->gui_pixel_aspect != 0.0);

    if (fabs (this->video_pixel_aspect / this->gui_pixel_aspect - 1.0)
	< 0.01) {
      this->video_pixel_aspect = this->gui_pixel_aspect;
    }

#if 0

    /* onefield_xv divide by 2 the number of lines */
    if (this->deinterlace_enabled
	&& (this->deinterlace_method == DEINTERLACE_ONEFIELDXV)
	&& (this->cur_frame->format == XINE_IMGFMT_YV12)) {
      this->displayed_height  = this->displayed_height / 2;
      this->displayed_yoffset = this->displayed_yoffset / 2;
    }
#endif
  }
}


/*
 * make ideal width/height "fit" into the gui
 */

void _x_vo_scale_compute_output_size (vo_scale_t *this) {

  int    cropped_width, cropped_height;
  double x_factor, y_factor, aspect;

  cropped_width  = this->delivered_width - (this->crop_left + this->crop_right);
  cropped_height = this->delivered_height - (this->crop_top + this->crop_bottom);

  aspect   = this->video_pixel_aspect;
  if ( !( this->scaling_disabled & 1 ) )
    aspect /= this->gui_pixel_aspect;
  x_factor = (double) this->gui_width  / (double) (cropped_width * aspect);
  y_factor = (double) (this->gui_height * aspect) / (double) cropped_height;

  if (this->scaling_disabled & ~1) {

    this->output_width   = cropped_width;
    this->output_height  = cropped_height;
    this->displayed_width = cropped_width;
    this->displayed_height = cropped_height;

  } else {

    if ( this->support_zoom ) {

      /* zoom behaviour:
       * - window size never changes due zooming
       * - output image shall be increased whenever there are
       *   black borders to use.
       * - exceding zoom shall be accounted by reducing displayed image.
       */
      if (((double)this->gui_width - (double)cropped_width * y_factor) < ((double)this->gui_height - (double)cropped_height * x_factor)) {
        this->output_width = this->gui_width;
        this->displayed_width = (double)cropped_width / this->zoom_factor_x + 0.5;

        this->output_height = (double)cropped_height * x_factor + 0.5;
        if( this->output_height * this->zoom_factor_y <= this->gui_height ) {
          this->displayed_height = cropped_height;
          this->output_height = (double)this->output_height * this->zoom_factor_y + 0.5;
        } else {
          this->displayed_height = (double)cropped_height *
            this->gui_height / this->output_height / this->zoom_factor_y + 0.5;
          this->output_height = this->gui_height;
        }
      } else {
        this->output_height = this->gui_height;
        this->displayed_height = (double)cropped_height / this->zoom_factor_y + 0.5;

        this->output_width = (double)cropped_width * y_factor + 0.5;
        if( this->output_width * this->zoom_factor_x <= this->gui_width ) {
          this->displayed_width = cropped_width;
          this->output_width = (double)this->output_width * this->zoom_factor_x + 0.5;
        } else {
          this->displayed_width = (double)cropped_width *
            this->gui_width / this->output_width / this->zoom_factor_x + 0.5;
          this->output_width = this->gui_width;
        }
      }

    } else {
      if (((double)this->gui_width - (double)cropped_width * y_factor) < ((double)this->gui_height - (double)cropped_height * x_factor)) {
        this->output_width   = (double) this->gui_width;
        this->output_height  = (double) cropped_height * x_factor + 0.5;
      } else {
        this->output_width   = (double) cropped_width  * y_factor + 0.5;
        this->output_height  = (double) this->gui_height;
      }
      this->displayed_width = cropped_width;
      this->displayed_height = cropped_height;
    }
  }

  /* make sure displayed values are sane, that is, we are not trying to display
   * something outside the delivered image. may happen when zoom < 100%.
   */
  if( this->displayed_width > this->delivered_width ) {
    this->output_width = (double) this->output_width *
                         this->delivered_width / this->displayed_width + 0.5;
    this->displayed_width = this->delivered_width;
  }
  if( this->displayed_height > this->delivered_height ) {
    this->output_height = (double) this->output_height *
                          this->delivered_height / this->displayed_height + 0.5;
    this->displayed_height = this->delivered_height;
  }

  this->output_xoffset =
    (this->gui_width - this->output_width) * this->output_horizontal_position + this->gui_x;
  this->output_yoffset =
    (this->gui_height - this->output_height) * this->output_vertical_position + this->gui_y;

  this->displayed_xoffset = ((cropped_width -  this->displayed_width) / 2) + this->crop_left;
  this->displayed_yoffset = ((cropped_height - this->displayed_height) / 2) + this->crop_top;

  lprintf ("frame source %d x %d (%d x %d) => screen output %d x %d\n",
	   this->delivered_width, this->delivered_height,
	   this->displayed_width, this->displayed_height,
	   this->output_width, this->output_height);

  /* calculate borders */
  if (this->output_height < this->gui_height) {
    /* top */
    this->border[0].x = 0;
    this->border[0].y = 0;
    this->border[0].w = this->gui_width;
    this->border[0].h = this->output_yoffset;
    /* bottom */
    this->border[1].x = 0;
    this->border[1].y = this->output_yoffset + this->output_height;
    this->border[1].w = this->gui_width;
    this->border[1].h = this->gui_height - this->border[1].y;
  } else {
    /* no top/bottom borders */
    this->border[0].w = this->border[0].h = 0;
    this->border[1].w = this->border[1].h = 0;
  }

  if (this->output_width < this->gui_width) {
    /* left */
    this->border[2].x = 0;
    this->border[2].y = 0;
    this->border[2].w = this->output_xoffset;
    this->border[2].h = this->gui_height;
    /* right */
    this->border[3].x = this->output_xoffset + this->output_width;
    this->border[3].y = 0;
    this->border[3].w = this->gui_width - this->border[3].x;
    this->border[3].h = this->gui_height;
  } else {
    /* no left/right borders */
    this->border[2].w = this->border[2].h = 0;
    this->border[3].w = this->border[3].h = 0;
  }
}

/*
 * return true if a redraw is needed due resizing, zooming,
 * aspect ratio changing, etc.
 */

int _x_vo_scale_redraw_needed (vo_scale_t *this) {
  int gui_x, gui_y, gui_width, gui_height, gui_win_x, gui_win_y;
  double gui_pixel_aspect, video_pixel_aspect;
  int ret = 0;

  _x_assert(this->frame_output_cb);
  if ( ! this->frame_output_cb )
    return 0;

  video_pixel_aspect = this->video_pixel_aspect;
  /* Nasty: tweaking GUI into different output window size will work from 2nd attempt on only... */
  if ( this->scaling_disabled & 1 )
    video_pixel_aspect *= this->gui_pixel_aspect;

  this->frame_output_cb (this->user_data,
			 this->delivered_width - (this->crop_left + this->crop_right),
			 this->delivered_height - (this->crop_top + this->crop_bottom),
			 video_pixel_aspect,
			 &gui_x, &gui_y, &gui_width, &gui_height,
			 &gui_pixel_aspect, &gui_win_x, &gui_win_y );

  if ( (gui_x != this->gui_x) || (gui_y != this->gui_y)
      || (gui_width != this->gui_width) || (gui_height != this->gui_height)
      || (gui_pixel_aspect != this->gui_pixel_aspect)
      || (gui_win_x != this->gui_win_x) || (gui_win_y != this->gui_win_y) ) {

    this->gui_x      = gui_x;
    this->gui_y      = gui_y;
    this->gui_width  = gui_width;
    this->gui_height = gui_height;
    this->gui_win_x  = gui_win_x;
    this->gui_win_y  = gui_win_y;
    this->gui_pixel_aspect = gui_pixel_aspect;

    ret = 1;
  }
  else
    ret = this->force_redraw;

  this->force_redraw = 0;
  return ret;
}

/*
 *
 */

void _x_vo_scale_translate_gui2video(vo_scale_t *this,
				 int x, int y,
				 int *vid_x, int *vid_y) {

  if (this->output_width > 0 && this->output_height > 0) {
    /*
     * 1.
     * the driver may center a small output area inside a larger
     * gui area.  This is the case in fullscreen mode, where we often
     * have black borders on the top/bottom/left/right side.
     */
    x -= this->output_xoffset;
    y -= this->output_yoffset;

    /*
     * 2.
     * the driver scales the delivered area into an output area.
     * translate output area coordianates into the delivered area
     * coordiantes.
     */

    x = x * this->displayed_width  / this->output_width  + this->displayed_xoffset;
    y = y * this->displayed_height / this->output_height + this->displayed_yoffset;
  }

  *vid_x = x;
  *vid_y = y;
}

/*/
 * @brief Table for description of a given ratio code.
 *
 * @note changing the size of the elements of the array will break
 * ABI, so please don't do that unless you absolutely can't continue
 * with the current size.
 */
const char _x_vo_scale_aspect_ratio_name_table[][8] = {
  "auto",   /* XINE_VO_ASPECT_AUTO */
  "square", /* XINE_VO_ASPECT_SQUARE */
  "4:3",    /* XINE_VO_ASPECT_4_3 */
  "16:9",   /* XINE_VO_ASPECT_ANAMORPHIC */
  "2:1",    /* XINE_VO_ASPECT_DVB */
  "unknown" /* All the rest */
};

/*
 * config callbacks
 */
static void vo_scale_horizontal_pos_changed(void *data, xine_cfg_entry_t *entry) {
  vo_scale_t *this = (vo_scale_t *)data;

  this->output_horizontal_position = entry->num_value / 100.0;
  this->force_redraw = 1;
}

static void vo_scale_vertical_pos_changed(void *data, xine_cfg_entry_t *entry) {
  vo_scale_t *this = (vo_scale_t *)data;

  this->output_vertical_position = entry->num_value / 100.0;
  this->force_redraw = 1;
}

static void vo_scale_disable_scaling_changed(void *data, xine_cfg_entry_t *entry) {
  vo_scale_t *this = (vo_scale_t *)data;

  this->scaling_disabled &= ~2;
  this->scaling_disabled |= (entry->num_value & 1) << 1;
  this->force_redraw = 1;
}

static void vo_scale_square_pixels_changed(void *data, xine_cfg_entry_t *entry) {
  vo_scale_t *this = (vo_scale_t *)data;

  this->scaling_disabled &= ~1;
  this->scaling_disabled |= entry->num_value & 1;
  this->force_redraw = 1;
}

/*
 * initialize rescaling struct
 */

void _x_vo_scale_init(vo_scale_t *this, int support_zoom, int scaling_disabled,
                   config_values_t *config ) {

  memset( this, 0, sizeof(vo_scale_t) );
  this->support_zoom = support_zoom;
  this->force_redraw = 1;
  this->zoom_factor_x = 1.0;
  this->zoom_factor_y = 1.0;
  this->gui_pixel_aspect = 1.0;
  this->user_ratio = XINE_VO_ASPECT_AUTO;
  this->delivered_ratio = 0.0;

  this->crop_left   = 0;
  this->crop_right  = 0;
  this->crop_top    = 0;
  this->crop_bottom = 0;

  this->output_horizontal_position =
    config->register_range(config, "video.output.horizontal_position", 50, 0, 100,
      _("horizontal image position in the output window"),
      _("If the video window's horizontal size is bigger than the actual image "
	"to show, you can adjust the position where the image will be placed.\n"
	"The position is given as a percentage, so a value of 50 means \"in the "
	"middle\", while 0 means \"at the very left\" and 100 \"at the very right\"."),
      10, vo_scale_horizontal_pos_changed, this) / 100.0;
  this->output_vertical_position =
    config->register_range(config, "video.output.vertical_position", 50, 0, 100,
      _("vertical image position in the output window"),
      _("If the video window's vertical size is bigger than the actual image "
	"to show, you can adjust the position where the image will be placed.\n"
	"The position is given as a percentage, so a value of 50 means \"in the "
	"middle\", while 0 means \"at the top\" and 100 \"at the bottom\"."),
      10, vo_scale_vertical_pos_changed, this) / 100.0;
  this->scaling_disabled = scaling_disabled << 2;
  this->scaling_disabled |=
    config->register_bool(config, "video.output.disable_scaling", 0,
      _("disable all video scaling"),
      _("If you want the video image to be always shown at its original resolution, "
	"you can disable all image scaling here.\n"
	"This of course means that the image will no longer adapt to the size of the "
	"video window and that videos with a pixel aspect ratio other than 1:1, like "
	"anamorphic DVDs, will be shown distorted. But on the other hand, with some "
	"video output drivers like XShm, where the image scaling is not hardware "
	"accelerated, this can dramatically reduce CPU usage."),
      10, vo_scale_disable_scaling_changed, this) << 1;
  this->scaling_disabled |=
    config->register_bool(config, "video.output.square_pixels", 0,
      _("treat screen pixels as exactly square"),
      _("Many screens have \"only\" almost square pixels, like 94x93 dpi.\n"
	"This little deviation is important for true size graphics applications.\n"
	"For video, however, it often just means unnecessary black bars and less "
	"sharpness.\n"),
      10, vo_scale_square_pixels_changed, this);
}