/* The GIMP -- an image manipulation program
 * Copyright (C) 1995 Spencer Kimball and Peter Mattis
 * color2bw plugin (C) Regis Rampnoux 2001
 *
 * This program is free software; you can redistribute it and/or modify
 * it.
 *
 * 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.
 *
 */
/*
 * todo list:
 * - add preview
 * - add spinbuttons for % values
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/uio.h>
#include <unistd.h>
#include <gtk/gtk.h>
#include <libgimp/gimp.h>
#include <libgimp/gimpui.h>
/*
    def pour The Gimp
*/

static void query (void);

static void run   (gchar   *name,
		   gint     nparams,
		   GimpParam  *param,
		   gint    *nreturn_vals,
		   GimpParam **return_vals);

#define PLUGIN_NAME "plug_in_color2bw"

GimpPlugInInfo PLUG_IN_INFO =
{
  NULL,  /* init_proc  */
  NULL,  /* quit_proc  */
  query, /* query_proc */
  run,   /* run_proc   */
};
//
// definitions pour le plug in
//
#define DECAL_HORIZONTAL 0
#define DA_WIDTH         300
#define DA_HEIGHT        20
#define RED_PIX          0
#define GREEN_PIX        1
#define BLUE_PIX         2
#define ALPHA_PIX        3

gint color2bw_delete_event( GtkWidget *widget,  GdkEvent  *event,  gpointer   data );
void color2bw_aff_bar(GtkWidget *widget, gpointer *bidon );
void color2bw_expo(GtkWidget *widget);
void color2bw_draw_triangle(GtkWidget *widget, gint value, gint hauteur, gint bas);
void color2bw_choice_triangle(GtkWidget *widget,gpointer *none);
void color2bw_aff_value(GtkWidget *widget, gpointer *bidon);
void color2bw_maj_triangle(GtkWidget *widget,gpointer *none);
void color2bw_cre_boutons(GtkWidget *vbox);
void color2bw_destroy( GtkWidget *widget,  gpointer   *data );
void color2bw_apply_on_image ( void ) ;

static gint color2bw_pcr = 100;
static gint color2bw_pcg = 100;
static gboolean color2bw_pcur = FALSE;

static GtkWidget *lib_valeurs ;
static gint32 id_image, id_drawable;


MAIN ()
static void
query (void)
{
    static GimpParamDef args[] =
  {
    { GIMP_PDB_INT32, "run_mode", "Interactive" },
    { GIMP_PDB_IMAGE, "image", "Input image" },
    { GIMP_PDB_DRAWABLE, "drawable", "Input drawable" },
  };
  static gint nargs = sizeof(args) / sizeof(args[0]);

    gimp_install_procedure(PLUGIN_NAME,
    "Convert color pictures to black and white",
    "grayscale conversion for photos with % of colors",
    "Regis Rampnoux <regisr@regix.com>",
    "(C) regis rampnoux",
    "Version 0.1 dec 2001",
    "<Image>/Filters/Misc/color2bw",
    "RGB*", GIMP_PLUGIN, nargs, 0, args, NULL);
}



static void
run (gchar   *name,
     gint     nparams,
     GimpParam  *param,
     gint    *nreturn_vals,
     GimpParam **return_vals)
{

    GtkWidget *window;
    GtkWidget *box;
    GtkWidget *vbox, *frame, *box2;
    GtkWidget *rv;

  static GimpParam values[1];

  GimpRunModeType run_mode;
  GimpPDBStatusType status = GIMP_PDB_SUCCESS;

  run_mode = param[0].data.d_int32;
  id_image = param[1].data.d_image;
  id_drawable = param[2].data.d_int32;

  values[0].type = GIMP_PDB_STATUS;
  values[0].data.d_status = status;
  
  *nreturn_vals = 1;
  *return_vals = values;
  
    gimp_ui_init("color2bw",TRUE);

    window = gtk_window_new (GTK_WINDOW_TOPLEVEL);

    gtk_window_set_title (GTK_WINDOW (window), "Color to B&W Convert");
    gtk_signal_connect (GTK_OBJECT (window), "delete_event",
                        GTK_SIGNAL_FUNC (color2bw_delete_event), NULL);
    gtk_container_set_border_width (GTK_CONTAINER (window), 10);

    vbox = gtk_vbox_new(FALSE, 0);
    box = gtk_hbox_new(FALSE, 0);

  gtk_container_add (GTK_CONTAINER (window), vbox);
  gtk_box_pack_start (GTK_BOX (vbox), box, FALSE, FALSE, 0);
  frame = gtk_aspect_frame_new (NULL,0.0,0.0,0.0,TRUE);
  gtk_frame_set_shadow_type (GTK_FRAME (frame), GTK_SHADOW_ETCHED_IN);
  gtk_box_pack_start (GTK_BOX (box), frame, FALSE, FALSE, 0);


  
    rv=gtk_preview_new (GTK_PREVIEW_COLOR);
      gtk_preview_size (GTK_PREVIEW (rv),DA_WIDTH+ 2 * DECAL_HORIZONTAL, DA_HEIGHT);
  
    gtk_container_add (GTK_CONTAINER (frame), rv);
 
    gtk_signal_connect (GTK_OBJECT (rv), "expose_event",
                      (GtkSignalFunc) color2bw_aff_bar, NULL);
   
    gtk_signal_connect (GTK_OBJECT (rv), "button_press_event",
                      (GtkSignalFunc) color2bw_choice_triangle, NULL);
       
   gtk_signal_connect (GTK_OBJECT (rv), "motion_notify_event",
                      (GtkSignalFunc) color2bw_maj_triangle, NULL);
   
   gtk_widget_show (rv);
   gtk_widget_show (frame);
    gtk_widget_show (box);
    box2 = gtk_hbox_new(FALSE, 0);
    lib_valeurs = gtk_label_new("");
    gtk_box_pack_start (GTK_BOX (vbox), box2, FALSE, FALSE, 5);
    gtk_box_pack_start (GTK_BOX (box2),lib_valeurs , FALSE, FALSE, 5);

  color2bw_aff_value(lib_valeurs, (gpointer *)NULL);
  gtk_widget_show_all(box2);
  color2bw_cre_boutons(vbox); 
   gtk_widget_show(vbox);
    gtk_widget_show  (window);
    gtk_main ();

}

void color2bw_choice_triangle(GtkWidget *widget,gpointer *none)
{
  gint pos_x, pos_y;

  gtk_widget_get_pointer(widget,&pos_x, &pos_y);
  color2bw_pcur = (abs(pos_x - color2bw_pcr) <  abs(pos_x - color2bw_pcr - color2bw_pcg)) ? FALSE: TRUE;
  if (color2bw_pcg == 0 && color2bw_pcr == DA_WIDTH) color2bw_pcur = FALSE;
  else if (color2bw_pcr == 0 && color2bw_pcg == 0) color2bw_pcur = TRUE; 
  gtk_widget_add_events(widget,GDK_BUTTON1_MOTION_MASK | GDK_BUTTON_RELEASE_MASK );
}


void color2bw_maj_triangle(GtkWidget *widget,gpointer *none)
{
  gint pos_x, pos_y;

  gtk_widget_get_pointer(widget,&pos_x, &pos_y);

  // on reste dans les limites!
  if (pos_x < 0) pos_x = 0;
  else if (pos_x > DA_WIDTH) pos_x = DA_WIDTH;

  // si la zone verte est vide on choisi le triangle en fonction du sens
  // du déplacement de la souris (les deux repères sont superposés)
  if ( !color2bw_pcg ) color2bw_pcur = (pos_x < color2bw_pcr)?FALSE:TRUE;
  if (color2bw_pcur) color2bw_pcg = pos_x - color2bw_pcr; 
  else {
    color2bw_pcg = color2bw_pcg - pos_x + color2bw_pcr;
    color2bw_pcr = pos_x;
  }

  if (color2bw_pcg < 0 ) color2bw_pcg = 0;
  else if (color2bw_pcg + color2bw_pcr > DA_WIDTH) color2bw_pcg = DA_WIDTH - color2bw_pcr;  
 
  if (color2bw_pcg + color2bw_pcr > DA_WIDTH) {
  if (color2bw_pcur) color2bw_pcr = DA_WIDTH  - color2bw_pcg;
  else color2bw_pcg = DA_WIDTH - color2bw_pcr;
  }
  color2bw_aff_bar(widget, (gpointer *)NULL);
  color2bw_expo(widget);
  color2bw_aff_value(lib_valeurs, (gpointer *)NULL);

}

void color2bw_draw_triangle(GtkWidget *widget, gint value, gint hauteur, gint bas)
{
  GdkPoint points[3];
  GdkColor color;
  GdkColormap *colormap;
  GdkGC *gc;

  points[0].x = value - hauteur/2;
  points[0].y = hauteur+bas;
  points[1].x = value;
  points[1].y = 0+bas;
  points[2].x = value + hauteur/2;
  points[2].y = hauteur+bas;
  colormap = gdk_window_get_colormap(widget->window);
  gc = gdk_gc_new(widget->window);
  color.red = 0;
  color.green = 0;
  color.blue =  0;
  gdk_color_alloc(colormap,&color);
  gdk_gc_set_foreground(gc, &color);
  gdk_draw_polygon( widget->window, gc, TRUE,points,3);
  gdk_gc_destroy(gc); 

}

void color2bw_aff_value(GtkWidget *widget, gpointer *bidon) 
{
    gchar *format_valeur = "Red: %3d%% - Green: %3d%% - Blue: %3d%%";
    gchar *lib;

    lib = g_strdup_printf(format_valeur,(int) color2bw_pcr/3,(int) color2bw_pcg/3,100-(int) color2bw_pcg/3 - (int) color2bw_pcr/3);
    gtk_label_set_text(GTK_LABEL(widget),lib);
    gtk_widget_show_all(widget);
    g_free(lib);
    

}

void color2bw_aff_bar(GtkWidget *widget, gpointer *bidon)
{
  GdkColor color;
  GdkColormap *colormap;
  GdkGC *gc;


 gdk_window_clear(widget->window);
  // creation de la colormap
 colormap = gdk_window_get_colormap(widget->window);
 gc = gdk_gc_new(widget->window);
 

  color.red = 65535;
  color.green = 0;
  color.blue =  0;
  gdk_color_alloc(colormap,&color);
  gdk_gc_set_foreground(gc, &color);
  gdk_draw_rectangle( widget->window, gc, TRUE,DECAL_HORIZONTAL,0, color2bw_pcr,DA_HEIGHT);
  color.red = 0;
  color.green = 65535;
  color.blue =  0;
  gdk_color_alloc(colormap,&color);
  gdk_gc_set_foreground(gc, &color);
  gdk_draw_rectangle( widget->window, gc, TRUE,color2bw_pcr+DECAL_HORIZONTAL,0, color2bw_pcg,DA_HEIGHT);
  color.red = 0;
  color.green = 0;
  color.blue =  65535;
  gdk_color_alloc(colormap,&color);
  gdk_gc_set_foreground(gc, &color);
 gdk_draw_rectangle( widget->window, gc, TRUE,color2bw_pcr+color2bw_pcg+DECAL_HORIZONTAL,0, DA_WIDTH - color2bw_pcg -color2bw_pcr,DA_HEIGHT);
  gdk_gc_destroy(gc); 
  color2bw_draw_triangle(widget,color2bw_pcr+DECAL_HORIZONTAL,DA_HEIGHT-4,4);
  color2bw_draw_triangle(widget,color2bw_pcr+color2bw_pcg+DECAL_HORIZONTAL,DA_HEIGHT-4,4);
  gtk_widget_add_events(widget,GDK_BUTTON_PRESS_MASK);

}

void color2bw_expo(GtkWidget *widget)
{ 
 gtk_widget_queue_draw(GTK_WIDGET (widget));
}


void color2bw_destroy( GtkWidget *widget,  gpointer   *data )
{
    gtk_main_quit();
}

gint color2bw_delete_event( GtkWidget *widget,  GdkEvent  *event,  gpointer   data )
{
    gtk_main_quit();
    return(FALSE);
}
void color2bw_cre_boutons(GtkWidget *vbox)
{
    GtkWidget *box;
    GtkWidget *button;

    box = gtk_hbox_new(FALSE, 0);

    gtk_box_pack_start (GTK_BOX (vbox), box, FALSE, FALSE, 5);
    button = gtk_button_new_with_label ("  OK  ");
    gtk_signal_connect (GTK_OBJECT (button), "clicked",
                        GTK_SIGNAL_FUNC (color2bw_apply_on_image), (gpointer) NULL);
    gtk_box_pack_start(GTK_BOX(box), button, FALSE, FALSE, 5);
    gtk_widget_show(button);

    button = gtk_button_new_with_label ("  Quit   ");
    gtk_signal_connect (GTK_OBJECT (button), "clicked",
                        GTK_SIGNAL_FUNC (color2bw_destroy), (gpointer) "quit");
    gtk_box_pack_start(GTK_BOX(box), button, FALSE, FALSE, 5);

    gtk_widget_show(button);
 
    gtk_widget_show(box);
}


void color2bw_apply_on_image(void) 
{
gint32 w0, w, h0, h, h_pr, col, val;
GimpPixelRgn srcPR, dstPR;
gpointer *pr;
guchar *src, *dst, *src_pix, *dst_pix;
GimpDrawable *drawable; 
gboolean alpha;

 alpha = gimp_drawable_has_alpha(id_drawable);
 gimp_drawable_mask_bounds(id_drawable,&w0, &h0, &w, &h);
 drawable = gimp_drawable_get (id_drawable);
 gimp_pixel_rgn_init (&srcPR, drawable,w0,h0,w-w0,h-h0,FALSE,FALSE); 
 gimp_pixel_rgn_init (&dstPR, drawable,w0,h0,w-w0,h-h0,TRUE,TRUE);

 for (pr=gimp_pixel_rgns_register(2,&srcPR,&dstPR); pr != NULL;
      pr = gimp_pixel_rgns_process(pr)) {
   src = srcPR.data;
   dst = dstPR.data;
   h_pr = srcPR.h;

   while (h_pr--) {
     src_pix = src;
     dst_pix = dst;
     for (col = 0; col < srcPR.w; col++) { 
       val = src_pix[RED_PIX]*color2bw_pcr + src_pix[GREEN_PIX]*color2bw_pcg +
	 src_pix[BLUE_PIX]*(300-color2bw_pcr-color2bw_pcg);
       dst_pix[RED_PIX]=(unsigned char) (val/300);
       dst_pix[GREEN_PIX]=(unsigned char) (val/300);
       dst_pix[BLUE_PIX]=(unsigned char) (val/300);
       if (alpha) dst_pix[ALPHA_PIX] = src_pix[ALPHA_PIX];

       src_pix += srcPR.bpp;
       dst_pix += dstPR.bpp;  
     }
     src += srcPR.rowstride;
     dst += dstPR.rowstride;
   }
 }
 gimp_drawable_merge_shadow (id_drawable,TRUE);
 gimp_drawable_update(id_drawable,0,0,w,h);

 gimp_displays_flush();
 gtk_main_quit();
}