/* The GIMP -- an image manipulation program
 * Copyright (C) 1995 Spencer Kimball and Peter Mattis
 *
 * This program 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.
 *
 * This program 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#include "config.h"

#include <glib.h>

#ifdef GIMP_VERSION
#include "apptypes.h"
#endif

#include "appenv.h"
#include "drawable.h"
#include "gdisplay.h"
#include "gimage_mask.h"
#include "info_dialog.h"
#include "rotate_tool.h"
#include "selection.h"
#include "transform_tool.h"
#include "undo.h"

#include "tile_manager_pvt.h"

#include "lib/size_entry.h"
#include "lib/intl.h"
#include "lib/rint.h"
#include "lib/helpui.h"

/*  index into trans_info array  */
#define ANGLE        0
#define REAL_ANGLE   1
#define CENTER_X     2
#define CENTER_Y     3

#define EPSILON      0.018  /*  ~ 1 degree  */
#define FIFTEEN_DEG  (G_PI / 12.0)

/*  variables local to this file  */
static gdouble    angle_val;
static gdouble    center_vals[2];

/*  needed for size update  */
static GtkWidget *sizeentry;

/*  forward function declarations  */
static void   rotate_tool_recalc  (Tool *, void *);
static void   rotate_tool_motion  (Tool *, void *);
static void   rotate_info_update  (Tool *);

/*  callback functions for the info dialog sizeentries  */
static void   rotate_angle_changed  (GtkWidget *entry, gpointer data);
static void   rotate_center_changed (GtkWidget *entry, gpointer data);

TileManager *
rotate_tool_transform (Tool           *tool,
		       gpointer        gdisp_ptr,
		       TransformState  state)
{
  TransformCore *transform_core;
  GDisplay      *gdisp;
  GtkWidget     *widget;
  GtkWidget     *spinbutton2;

  transform_core = (TransformCore *) tool->private;
  gdisp = (GDisplay *) gdisp_ptr;

  switch (state)
    {
    case INIT:
      angle_val = 0.0;
      center_vals[0] = transform_core->cx;
      center_vals[1] = transform_core->cy;

      if (!transform_info)
	{
	  transform_info = info_dialog_new (_("Rotation Information"),
					    gimp_standard_help_func,
					    "tools/transform.html#TOOLS-TRANSFORM-ROTATION"
					    );

	  widget =
	    info_dialog_add_spinbutton (transform_info, _("Angle:"),
					&angle_val,
					-180, 180, 1, 15, 1, 1, 2,
					(GtkSignalFunc) rotate_angle_changed,
					tool);
	  gtk_spin_button_set_wrap (GTK_SPIN_BUTTON (widget), TRUE);

	  /*  this looks strange (-180, 181), but it works  */
	  widget = info_dialog_add_scale (transform_info, "", &angle_val,
					  -180, 181, 0.01, 0.1, 1, -1,
					  (GtkSignalFunc) rotate_angle_changed,
					  tool);
	  gtk_widget_set_usize (widget, 180, 0);

	  spinbutton2 =
	    info_dialog_add_spinbutton (transform_info, _("Center X:"), NULL,
					-1, 1, 1, 10, 1, 1, 2, NULL, NULL);
	  sizeentry =
	    info_dialog_add_sizeentry (transform_info, _("Y:"),
				       center_vals, 1,
				       gdisp->gimage->unit, "%a",
				       TRUE, TRUE, FALSE,
				       GIMP_SIZE_ENTRY_UPDATE_SIZE,
				       rotate_center_changed, tool);

	  gimp_size_entry_add_field (GIMP_SIZE_ENTRY (sizeentry),
				     GTK_SPIN_BUTTON (spinbutton2), NULL);

	  gtk_table_set_row_spacing (GTK_TABLE (transform_info->info_table),
				     1, 6);
	  gtk_table_set_row_spacing (GTK_TABLE (transform_info->info_table),
				     2, 0);
	}

      gtk_signal_handler_block_by_data (GTK_OBJECT (sizeentry), tool);

      gimp_size_entry_set_unit (GIMP_SIZE_ENTRY (sizeentry),
				gdisp->gimage->unit);
      if (gdisp->dot_for_dot)
	gimp_size_entry_set_unit (GIMP_SIZE_ENTRY (sizeentry), GIMP_UNIT_PIXEL);

      gimp_size_entry_set_resolution (GIMP_SIZE_ENTRY (sizeentry), 0,
				      gdisp->gimage->xresolution, FALSE);
      gimp_size_entry_set_resolution (GIMP_SIZE_ENTRY (sizeentry), 1,
				      gdisp->gimage->yresolution, FALSE);

      gimp_size_entry_set_refval_boundaries (GIMP_SIZE_ENTRY (sizeentry), 0,
					     -65536,
					     65536 + gdisp->gimage->width);
      gimp_size_entry_set_refval_boundaries (GIMP_SIZE_ENTRY (sizeentry), 1,
					     -65536,
					     65536 + gdisp->gimage->height);

      gimp_size_entry_set_size (GIMP_SIZE_ENTRY (sizeentry), 0,
				transform_core->x1, transform_core->x2);
      gimp_size_entry_set_size (GIMP_SIZE_ENTRY (sizeentry), 1,
				transform_core->y1, transform_core->y2);

      gimp_size_entry_set_refval (GIMP_SIZE_ENTRY (sizeentry), 0,
				  center_vals[0]);
      gimp_size_entry_set_refval (GIMP_SIZE_ENTRY (sizeentry), 1,
				  center_vals[1]);

      gtk_widget_set_sensitive (transform_info->shell, TRUE);

      gtk_signal_handler_unblock_by_data (GTK_OBJECT (sizeentry), tool);

      transform_core->trans_info[ANGLE] = angle_val;
      transform_core->trans_info[REAL_ANGLE] = angle_val;
      transform_core->trans_info[CENTER_X] = center_vals[0];
      transform_core->trans_info[CENTER_Y] = center_vals[1];

      return NULL;
      break;

    case MOTION:
      rotate_tool_motion (tool, gdisp_ptr);
      rotate_tool_recalc (tool, gdisp_ptr);
      break;

    case RECALC:
      rotate_tool_recalc (tool, gdisp_ptr);
      break;

    case FINISH:
      gtk_widget_set_sensitive (GTK_WIDGET (transform_info->shell), FALSE);
      return rotate_tool_rotate (gdisp->gimage,
				 gimage_active_drawable (gdisp->gimage),
				 gdisp,
				 transform_core->trans_info[ANGLE],
				 transform_core->original,
				 transform_tool_smoothing (),
				 transform_core->transform);
      break;
    }

  return NULL;
}

Tool *
tools_new_rotate_tool (void)
{
  Tool          *tool;
  TransformCore *private;

  tool = transform_core_new (ROTATE, TRUE);

  private = tool->private;

  /*  set the rotation specific transformation attributes  */
  private->trans_func = rotate_tool_transform;
  private->trans_info[ANGLE]      = 0.0;
  private->trans_info[REAL_ANGLE] = 0.0;
  private->trans_info[CENTER_X]   = 0.0;
  private->trans_info[CENTER_Y]   = 0.0;

  /*  assemble the transformation matrix  */
  gimp_matrix3_identity (private->transform);

  return tool;
}

void
tools_free_rotate_tool (Tool *tool)
{
  transform_core_free (tool);
}

static void
rotate_info_update (Tool *tool)
{
  TransformCore *transform_core;

  transform_core = (TransformCore *) tool->private;

  angle_val      = gimp_rad_to_deg (transform_core->trans_info[ANGLE]);
  center_vals[0] = transform_core->cx;
  center_vals[1] = transform_core->cy;

  info_dialog_update (transform_info);
  info_dialog_popup (transform_info);
}

static void
rotate_angle_changed (GtkWidget *widget,
		      gpointer   data)
{
  Tool          *tool;
  GDisplay      *gdisp;
  TransformCore *transform_core;
  gdouble        value;

  tool = (Tool *) data;

  if (tool)
    {
      gdisp = (GDisplay *) tool->gdisp_ptr;
      transform_core = (TransformCore *) tool->private;

      value = gimp_deg_to_rad (GTK_ADJUSTMENT (widget)->value);

      if (value != transform_core->trans_info[ANGLE])
	{
	  draw_core_pause (transform_core->core, tool);      
	  transform_core->trans_info[ANGLE] = value;
	  rotate_tool_recalc (tool, gdisp);
	  draw_core_resume (transform_core->core, tool);
	}
    }
}

static void
rotate_center_changed (GtkWidget *widget,
		       gpointer   data)
{
  Tool          *tool;
  GDisplay      *gdisp;
  TransformCore *transform_core;
  gint           cx;
  gint           cy;

  tool = (Tool *) data;

  if (tool)
    {
      gdisp = (GDisplay *) tool->gdisp_ptr;
      transform_core = (TransformCore *) tool->private;

      cx = RINT (gimp_size_entry_get_refval (GIMP_SIZE_ENTRY (widget), 0));
      cy = RINT (gimp_size_entry_get_refval (GIMP_SIZE_ENTRY (widget), 1));

      if ((cx != transform_core->cx) ||
	  (cy != transform_core->cy))
	{
	  draw_core_pause (transform_core->core, tool);      
	  transform_core->cx = cx;
	  transform_core->cy = cy;
	  rotate_tool_recalc (tool, gdisp);
	  draw_core_resume (transform_core->core, tool);
	}
    }
}

static void
rotate_tool_motion (Tool *tool,
		    void *gdisp_ptr)
{
  TransformCore *transform_core;
  gdouble        angle1, angle2, angle;
  gdouble        cx, cy;
  gdouble        x1, y1, x2, y2;

  transform_core = (TransformCore *) tool->private;

  if (transform_core->function == HANDLE_CENTER)
    {
      transform_core->cx = transform_core->curx;
      transform_core->cy = transform_core->cury;

      return;
    }

  cx = transform_core->cx;
  cy = transform_core->cy;

  x1 = transform_core->curx - cx;
  x2 = transform_core->lastx - cx;
  y1 = cy - transform_core->cury;
  y2 = cy - transform_core->lasty;

  /*  find the first angle  */
  angle1 = atan2 (y1, x1);

  /*  find the angle  */
  angle2 = atan2 (y2, x2);

  angle = angle2 - angle1;

  if (angle > G_PI || angle < -G_PI)
    angle = angle2 - ((angle1 < 0) ? 2.0 * G_PI + angle1 : angle1 - 2.0 * G_PI);

  /*  increment the transform tool's angle  */
  transform_core->trans_info[REAL_ANGLE] += angle;

  /*  limit the angle to between 0 and 360 degrees  */
  if (transform_core->trans_info[REAL_ANGLE] < - G_PI)
    transform_core->trans_info[REAL_ANGLE] =
      2.0 * G_PI - transform_core->trans_info[REAL_ANGLE];
  else if (transform_core->trans_info[REAL_ANGLE] > G_PI)
    transform_core->trans_info[REAL_ANGLE] =
      transform_core->trans_info[REAL_ANGLE] - 2.0 * G_PI;

  /*  constrain the angle to 15-degree multiples if ctrl is held down  */
  if (transform_core->state & GDK_CONTROL_MASK)
    transform_core->trans_info[ANGLE] =
      FIFTEEN_DEG * (int) ((transform_core->trans_info[REAL_ANGLE] +
			    FIFTEEN_DEG / 2.0) /
			   FIFTEEN_DEG);
  else
    transform_core->trans_info[ANGLE] = transform_core->trans_info[REAL_ANGLE];
}

static void
rotate_tool_recalc (Tool *tool,
		    void *gdisp_ptr)
{
  TransformCore *transform_core;
  GDisplay      *gdisp;
  gdouble        cx, cy;

  gdisp = (GDisplay *) tool->gdisp_ptr;
  transform_core = (TransformCore *) tool->private;

  cx = transform_core->cx;
  cy = transform_core->cy;

  /*  assemble the transformation matrix  */
  gimp_matrix3_identity  (transform_core->transform);
  gimp_matrix3_translate (transform_core->transform, -cx, -cy);
  gimp_matrix3_rotate    (transform_core->transform,
			  transform_core->trans_info[ANGLE]);
  gimp_matrix3_translate (transform_core->transform, +cx, +cy);

  /*  transform the bounding box  */
  transform_core_transform_bounding_box (tool);

  /*  update the information dialog  */
  rotate_info_update (tool);
}

TileManager *
rotate_tool_rotate (GImage       *gimage,
		    GimpDrawable *drawable,
		    GDisplay     *gdisp,
		    gdouble       angle,
		    TileManager  *float_tiles,
		    gboolean      interpolation,
		    GimpMatrix3   matrix)
{
  gimp_progress *progress;
  TileManager   *ret;

  progress = progress_start (gdisp, _("Rotating..."), FALSE, NULL, NULL);

  ret = transform_core_do (gimage, drawable, float_tiles,
			   interpolation, matrix,
			   progress ? progress_update_and_flush :
			   (progress_func_t) NULL,
			   progress);

  if (progress)
    progress_end (progress);

  return ret;
}

/* from tools_cmds.c: */

static Argument *
rotate_invoker (Argument *args)
{
  gboolean success = TRUE;
  Argument *return_args;
  GimpDrawable *drawable;
  gboolean interpolation;
  gdouble angle;
  GimpImage *gimage;
  TileManager *float_tiles, *new_tiles;
  gboolean new_layer;
  double cx, cy;
  GimpMatrix3 matrix;

  drawable = gimp_drawable_get_ID (args[0].value.pdb_int);
  if (drawable == NULL)
    success = FALSE;

  interpolation = args[1].value.pdb_int ? TRUE : FALSE;

  angle = args[2].value.pdb_float;

  if (success)
    {
      if (GIMP_IS_LAYER (drawable) &&
	  layer_get_mask (GIMP_LAYER (drawable)))
	{
	  g_message (_("Transformations do not work on\n"
		       "layers that contain layer masks."));
	  success = FALSE;
	}
    }
    
    if (success)
    {
      gimage = drawable_gimage (GIMP_DRAWABLE (drawable));
    
      /* Start a transform undo group */
      undo_push_group_start (gimage, TRANSFORM_CORE_UNDO);
    
      /* Cut/Copy from the specified drawable */
      float_tiles = transform_core_cut (gimage, drawable, &new_layer);
    
      cx = float_tiles->x + float_tiles->width / 2.0;
      cy = float_tiles->y + float_tiles->height / 2.0;
    
      /* Assemble the transformation matrix */
      gimp_matrix3_identity  (matrix);
      gimp_matrix3_translate (matrix, -cx, -cy);
      gimp_matrix3_rotate    (matrix, angle);
      gimp_matrix3_translate (matrix, +cx, +cy);
    
      /* Rotate the buffer */
      new_tiles = rotate_tool_rotate (gimage, drawable, NULL, angle,
				      float_tiles, interpolation, matrix);
    
      /* Free the cut/copied buffer */
      tile_manager_destroy (float_tiles);
    
      if (new_tiles)
	success = transform_core_paste (gimage, drawable, new_tiles, new_layer);
      else
	success = FALSE;
    
      /* Push the undo group end */
      undo_push_group_end (gimage);
    }

  return_args = procedural_db_return_args (&rotate_proc, success);

  if (success)
    return_args[1].value.pdb_int = drawable_ID (GIMP_DRAWABLE (drawable));

  return return_args;
}

static ProcArg rotate_inargs[] =
{
  {
    PDB_DRAWABLE,
    "drawable",
    "The affected drawable"
  },
  {
    PDB_INT32,
    "interpolation",
    "Whether to use interpolation"
  },
  {
    PDB_FLOAT,
    "angle",
    "The angle of rotation (radians)"
  }
};

static ProcArg rotate_outargs[] =
{
  {
    PDB_DRAWABLE,
    "drawable",
    "The rotated drawable"
  }
};

static ProcRecord rotate_proc =
{
  "gimp_rotate",
  "Rotate the specified drawable about its center through the specified angle.",
  "This tool rotates the specified drawable if no selection exists. If a selection exists, the portion of the drawable which lies under the selection is cut from the drawable and made into a floating selection which is then rotated by the specified amount. The interpolation parameter can be set to TRUE to indicate that either linear or cubic interpolation should be used to smooth the resulting rotated drawable. The return value is the ID of the rotated drawable. If there was no selection, this will be equal to the drawable ID supplied as input. Otherwise, this will be the newly created and rotated drawable.",
  "Spencer Kimball & Peter Mattis",
  "Spencer Kimball & Peter Mattis",
  "1995-1996",
  PDB_INTERNAL,
  3,
  rotate_inargs,
  1,
  rotate_outargs,
  { { rotate_invoker } }
};
