/* vim:expandtab:ts=2 sw=2:
*/
/*  Grafx2 - The Ultimate 256-color bitmap paint program

    Copyright 2009 Yves Rizoud
    Copyright 2007 Adrien Destugues
    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)

    Grafx2 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; version 2
    of the License.

    Grafx2 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 Grafx2; if not, see <http://www.gnu.org/licenses/>
*/
#include "const.h"
#include "struct.h"
#include "global.h"
#include "windows.h"
#include "engine.h"
#include "pages.h"

void Layer_activate(short layer, short side)
{
  word old_layers;

  if (layer >= Main_backups->Pages->Nb_layers)
    return;
  
  // Keep a copy of which layers were visible
  old_layers = Main_layers_visible;
  
  #ifndef NOLAYERS
  
  if (side == RIGHT_SIDE)
  {
    // Right-click on current layer
    if (Main_current_layer == layer)
    {
      if (Main_layers_visible == (dword)(1<<layer))
      {
        // Set all layers visible
        Main_layers_visible = 0xFFFFFFFF;
      }
      else
      {
        // Set only this one visible
        Main_layers_visible = 1<<layer;
      }
    }
    else
    {
      // Right-click on an other layer : toggle its visibility
      Main_layers_visible ^= 1<<layer;
    }
  }
  else
  {
    // Left-click on any layer
    Main_current_layer = layer;
    Main_layers_visible |= 1<<layer;
  }
  #else
  // Handler for limited layers support: only allow one visible at a time
  if (side == LEFT_SIDE)
  {
    Main_current_layer = layer;
    Main_layers_visible = 1<<layer;
    
    Update_screen_targets();
  }
  #endif

  Hide_cursor();
  if (Main_layers_visible != old_layers)
    Redraw_layered_image();
  else
    Update_depth_buffer(); // Only need the depth buffer
  //Download_infos_page_main(Main_backups->Pages);
  //Download_infos_backup(Main_backups);
  Display_all_screen();
  Display_layerbar();
  Display_cursor();
}

void Button_Layer_add(void)
{
  Hide_cursor();

  if (Main_backups->Pages->Nb_layers < 32)
  {
    // Backup with unchanged layers
    Backup_layers(0);
    if (!Add_layer(Main_backups,Main_current_layer+1))
    {
      Update_depth_buffer();
      Display_all_screen();
      Display_layerbar();
      End_of_modification();
    }
  }

  Unselect_button(BUTTON_LAYER_ADD);
  Display_cursor();
}

void Button_Layer_remove(void)
{
  Hide_cursor();

  if (Main_backups->Pages->Nb_layers > 1)
  {
    // Backup with unchanged layers
    Backup_layers(0);
    if (!Delete_layer(Main_backups,Main_current_layer))
    {
      Update_screen_targets();
      Redraw_layered_image();
      
      Display_all_screen();
      Display_layerbar();
      End_of_modification();
    }
  }
  Unselect_button(BUTTON_LAYER_REMOVE);
  Display_cursor();
}

void Button_Layer_select(void)
{
  word layer;
  // Determine which button is clicked according to mouse position
  layer = (Mouse_X/Menu_factor_X - Menu_bars[MENUBAR_LAYERS].Skin_width)
    / Layer_button_width;
  
  Layer_activate(layer, LEFT_SIDE);
}

void Button_Layer_toggle(void)
{
  word layer;
  // Determine which button is clicked according to mouse position
  layer = (Mouse_X/Menu_factor_X - Menu_bars[MENUBAR_LAYERS].Skin_width)
    / Layer_button_width;
  
  Layer_activate(layer, RIGHT_SIDE);
}

void Button_Layer_menu(void)
{
  Hide_cursor();
  Unselect_button(BUTTON_LAYER_MENU);
  Display_cursor();
}

void Button_Layer_set_transparent(void)
{
  Hide_cursor();

  if (Main_backups->Pages->Transparent_color != Back_color)
  {
    Backup_layers(-1);
    Main_backups->Pages->Transparent_color = Back_color;
    
    Redraw_layered_image();
    Display_all_screen();
    End_of_modification();
  }

  Unselect_button(BUTTON_LAYER_COLOR);
  Display_cursor();
}

void Button_Layer_get_transparent(void)
{
  Hide_cursor();

  if (Main_backups->Pages->Transparent_color != Back_color)
  {
    Set_back_color(Main_backups->Pages->Transparent_color);
  }

  Unselect_button(BUTTON_LAYER_COLOR);
  Display_cursor();
}

void Button_Layer_merge(void)
{
  Hide_cursor();

  if (Main_current_layer>0)
  {
    // Backup layer below the current
    Backup_layers(1<<(Main_current_layer-1));
  
    Merge_layer();
    
    Update_screen_targets();
    Redraw_layered_image();
    Display_all_screen();
    Display_layerbar();
    End_of_modification();
  }
  
  Unselect_button(BUTTON_LAYER_MERGE);
  Display_cursor();
}

void Button_Layer_up(void)
{
  Hide_cursor();

  if (Main_current_layer < (Main_backups->Pages->Nb_layers-1))
  {
    byte * tmp;
    dword layer_flags;
    
    // Backup with unchanged layers
    Backup_layers(0);
    
    // swap
    tmp = Main_backups->Pages->Image[Main_current_layer];
    Main_backups->Pages->Image[Main_current_layer] = Main_backups->Pages->Image[Main_current_layer+1];
    Main_backups->Pages->Image[Main_current_layer+1] = tmp;
    
    // Swap visibility indicators
    layer_flags = (Main_layers_visible >> Main_current_layer) & 3;
    // Only needed if they are different.
    if (layer_flags == 1 || layer_flags == 2)
    {
      // One is on, the other is off. Negating them will
      // perform the swap.
      Main_layers_visible ^= (3 << Main_current_layer);
    }
    Main_current_layer++;
    
    Update_screen_targets();
    Redraw_layered_image();
    Display_all_screen();
    Display_layerbar();
    End_of_modification();
  }
  
  Unselect_button(BUTTON_LAYER_UP);
  Display_cursor();
}

void Button_Layer_down(void)
{
  Hide_cursor();
  
  if (Main_current_layer > 0)
  {
    byte * tmp;
    dword layer_flags;
  
    // Backup with unchanged layers
    Backup_layers(0);
    
    // swap
    tmp = Main_backups->Pages->Image[Main_current_layer];
    Main_backups->Pages->Image[Main_current_layer] = Main_backups->Pages->Image[Main_current_layer-1];
    Main_backups->Pages->Image[Main_current_layer-1] = tmp;
    
    // Swap visibility indicators
    layer_flags = (Main_layers_visible >> (Main_current_layer-1)) & 3;
    // Only needed if they are different.
    if (layer_flags == 1 || layer_flags == 2)
    {
      // Only needed if they are different.
      // One is on, the other is off. Negating them will
      // perform the swap.
      Main_layers_visible ^= (3 << (Main_current_layer-1));
    }
    Main_current_layer--;
    Update_screen_targets();
    Redraw_layered_image();
    Display_layerbar();
    Display_all_screen();
    End_of_modification();
  }
  
  Unselect_button(BUTTON_LAYER_DOWN);
  Display_cursor();
}