more work on the gamma correction stuff

-Yosh

ChangeLog

@@ -1,3 +1,7 @@
+Fri Aug 27 18:15:33 PDT 1999 Manish Singh <yosh@gimp.org>
+
+	* app/gdisplay_color.c: more work on the gamma correction stuff
+
 1999-08-28  Tor Lillqvist  <tml@iki.fi>
 
 	* app/gimpbrushpipe.c: Implement the selection of brush based on

app/display/gimpdisplayshell-filter.c

@@ -18,6 +18,9 @@
 
 #include "gdisplay_color.h"
 #include "gimpimageP.h"
+#include "libgimp/parasite.h"
+#include "libgimp/gimpintl.h"
+#include <gtk/gtk.h>
 
 typedef struct _ColorDisplayInfo ColorDisplayInfo;
 
@@ -29,6 +32,54 @@ struct _ColorDisplayInfo {
 
 static GHashTable *color_display_table = NULL;
 
+typedef struct _GammaContext GammaContext;
+
+struct _GammaContext
+{
+  double gamma;
+  guchar *lookup;
+
+  GtkWidget *shell;
+  GtkWidget *spinner;
+};
+
+static gpointer   gamma_new                       (int           type);
+static void       gamma_create_lookup_table       (GammaContext *context);
+static void       gamma_destroy                   (gpointer      cd_ID);
+static void       gamma_convert                   (gpointer      cd_ID,
+						   guchar       *buf,
+						   int           width,
+						   int           height,
+						   int           bpp);
+static void       gamma_load                      (gpointer      cd_ID,
+						   Parasite     *state);
+static Parasite * gamma_save                      (gpointer      cd_ID);
+static void       gamma_configure_ok_callback     (GtkWidget    *widget,
+						   gpointer      data);
+static void       gamma_configure_cancel_callback (GtkWidget    *widget,
+						   gpointer      data);
+static gint       gamma_configure_delete_callback (GtkWidget    *widget,
+						   GdkEvent     *event,
+						   gpointer      data);
+static void       gamma_configure                 (gpointer      cd_ID);
+
+void
+gdisplay_color_init (void)
+{
+  GimpColorDisplayMethods methods = {
+    NULL,
+    gamma_new,
+    gamma_convert,
+    gamma_destroy,
+    NULL,
+    gamma_load,
+    gamma_save,
+    gamma_configure
+  };
+
+  gimp_color_display_register ("Gamma", &methods);
+}
+
 gboolean
 gimp_color_display_register (const char              *name,
     			     GimpColorDisplayMethods *methods)
@@ -122,16 +173,10 @@ gdisplay_color_detach (GDisplay *gdisp)
     }  
 }
 
-typedef struct _GammaContext GammaContext;
+/* The Gamma Color Display */
 
-struct _GammaContext
+static gpointer
-{
+gamma_new (int type)
-  double gamma;
-  guchar *lookup;
-};
-
-static
-gpointer gamma_new (int type)
 {
   int i;
   GammaContext *context = NULL;
@@ -139,6 +184,8 @@ gpointer gamma_new (int type)
   context = g_new (GammaContext, 1);
   context->gamma = 1.0;
   context->lookup = g_new (guchar, 256);
+  context->shell = NULL;
+  context->spinner = NULL;
 
   for (i = 0; i < 256; i++)
     context->lookup[i] = i;
@@ -146,21 +193,43 @@ gpointer gamma_new (int type)
   return context;
 }
 
-static
+static void
-void gamma_destroy (gpointer cd_ID)
+gamma_create_lookup_table (GammaContext *context)
+{
+  double one_over_gamma;
+  double ind;
+  int i;
+
+  if (context->gamma == 0.0)
+    context->gamma = 1.0;
+
+  one_over_gamma = 1.0 / context->gamma;
+
+  for (i = 0; i < 256; i++)
+    {
+      ind = (double) i / 255.0;
+      context->lookup[i] = (guchar) (int) (255 * pow (ind, one_over_gamma));
+    }
+}
+
+static void
+gamma_destroy (gpointer cd_ID)
 {
   GammaContext *context = (GammaContext *) cd_ID;
 
+  if (context->shell)
+    gtk_widget_destroy (context->shell);
+
   g_free (context->lookup);
   g_free (context);
 }
 
-static
+static void
-void gamma_convert (gpointer  cd_ID,
+gamma_convert (gpointer  cd_ID,
-    		    guchar   *buf,
+    	       guchar   *buf,
-		    int       width,
+	       int       width,
-		    int       height,
+	       int       height,
-		    int       bpp)
+	       int       bpp)
 {
   int i;
   guchar *lookup = ((GammaContext *) cd_ID)->lookup;
@@ -169,7 +238,133 @@ void gamma_convert (gpointer  cd_ID,
     *buf++ = lookup[*buf];
 }
 
-void
+static void
-gdisplay_color_init (void)
+gamma_load (gpointer  cd_ID,
+            Parasite *state)
 {
+  GammaContext *context = (GammaContext *) cd_ID;
+
+#if G_BYTE_ORDER == G_BIG_ENDIAN
+  memcpy (&context->gamma, parasite_data (state), sizeof (double));
+#else
+  guint32 buf[2], *data = parasite_data (state);
+
+  buf[0] = g_ntohl (data[1]);
+  buf[1] = g_ntohl (data[0]);
+
+  memcpy (&context->gamma, buf, sizeof (double));
+#endif
+
+  gamma_create_lookup_table (context);
+}
+
+static Parasite *
+gamma_save (gpointer cd_ID)
+{
+  GammaContext *context = (GammaContext *) cd_ID;
+  guint32 buf[2];
+
+  memcpy (buf, &context->gamma, sizeof (double));
+
+#if G_BYTE_ORDER == G_LITTLE_ENDIAN
+  {
+    guint32 tmp = g_htonl (buf[0]);
+    buf[0] = g_htonl (buf[1]);
+    buf[1] = tmp;
+  }
+#endif
+
+  return parasite_new ("Display/Gamma", PARASITE_PERSISTENT,
+		       sizeof (double), &buf);
+}
+
+static void
+gamma_configure_ok_callback (GtkWidget *widget,
+				 gpointer   data)
+{
+  GammaContext *context = (GammaContext *) data;
+
+  context->gamma = gtk_spin_button_get_value_as_float (context->spinner);
+  gamma_create_lookup_table (context);
+
+  gtk_widget_hide (widget);
+}
+
+static void
+gamma_configure_cancel_callback (GtkWidget *widget,
+				 gpointer   data)
+{
+  gtk_widget_hide (widget);
+}
+
+static gint
+gamma_configure_delete_callback (GtkWidget *widget,
+				 GdkEvent  *event,
+				 gpointer   data)
+{
+  gamma_configure_cancel_callback (widget, data);
+  return TRUE;
+}
+
+static void
+gamma_configure (gpointer cd_ID)
+{
+  GammaContext *context = (GammaContext *) cd_ID;
+  GtkWidget *vbox;
+  GtkWidget *hbox;
+  GtkWidget *label;
+  GtkWidget *entry;
+  GtkWidget *hbbox;
+  GtkWidget *button;
+  GtkObject *adjustment;
+
+  if (!context->shell)
+    {
+      context->shell = gtk_dialog_new ();
+      gtk_window_set_wmclass (GTK_WINDOW (context->shell), "gamma", "Gimp");
+      gtk_window_set_title (GTK_WINDOW (context->shell), _("Gamma"));
+
+      gtk_signal_connect (GTK_OBJECT (context->shell), "delete_event",
+			  GTK_SIGNAL_FUNC (gamma_configure_delete_callback),
+			  NULL);
+
+      hbox = gtk_hbox_new (TRUE, 2);
+      gtk_box_pack_start (GTK_BOX (GTK_DIALOG (context->shell)->vbox),
+			  hbox, FALSE, FALSE, 0);
+
+      label = gtk_label_new (_("Gamma:"));
+      gtk_misc_set_alignment (GTK_MISC (label), 1.0, 0.5);
+      gtk_box_pack_start (GTK_BOX (hbox), label, TRUE, FALSE, 0);
+
+      adjustment = gtk_adjustment_new (1.0, 0.01, 10.0, 0.01, 0.1, 0.0);
+      context->spinner = gtk_spin_button_new (GTK_ADJUSTMENT (adjustment),
+					      0.1, 3);
+      gtk_widget_set_usize (context->spinner, 100, 0);
+      gtk_box_pack_start (GTK_BOX (hbox), label, TRUE, FALSE, 0);
+ 
+      gtk_widget_show_all (hbox);
+
+      hbbox = gtk_hbutton_box_new ();
+      gtk_button_box_set_spacing (GTK_BUTTON_BOX (hbbox), 4);
+      gtk_box_pack_end (GTK_BOX (GTK_DIALOG (context->shell)->action_area),
+			hbbox, FALSE, FALSE, 0);  
+
+      button = gtk_button_new_with_label (_("OK"));
+      GTK_WIDGET_SET_FLAGS (button, GTK_CAN_DEFAULT);
+      gtk_box_pack_start (GTK_BOX (hbbox), button, FALSE, FALSE, 0);
+      gtk_signal_connect (GTK_OBJECT (button), "clicked",
+			  GTK_SIGNAL_FUNC (gamma_configure_ok_callback),
+			  cd_ID);
+
+      button = gtk_button_new_with_label (_("Cancel"));
+      GTK_WIDGET_SET_FLAGS (button, GTK_CAN_DEFAULT);
+      gtk_box_pack_start (GTK_BOX (hbbox), button, FALSE, FALSE, 0);
+      gtk_signal_connect (GTK_OBJECT (button), "clicked",
+			  GTK_SIGNAL_FUNC (gamma_configure_cancel_callback),
+			  cd_ID);
+
+      gtk_widget_show_all (hbbox);
+    }
+
+  gtk_widget_show (context->shell);
 }

app/gdisplay_color.c

@@ -18,6 +18,9 @@
 
 #include "gdisplay_color.h"
 #include "gimpimageP.h"
+#include "libgimp/parasite.h"
+#include "libgimp/gimpintl.h"
+#include <gtk/gtk.h>
 
 typedef struct _ColorDisplayInfo ColorDisplayInfo;
 
@@ -29,6 +32,54 @@ struct _ColorDisplayInfo {
 
 static GHashTable *color_display_table = NULL;
 
+typedef struct _GammaContext GammaContext;
+
+struct _GammaContext
+{
+  double gamma;
+  guchar *lookup;
+
+  GtkWidget *shell;
+  GtkWidget *spinner;
+};
+
+static gpointer   gamma_new                       (int           type);
+static void       gamma_create_lookup_table       (GammaContext *context);
+static void       gamma_destroy                   (gpointer      cd_ID);
+static void       gamma_convert                   (gpointer      cd_ID,
+						   guchar       *buf,
+						   int           width,
+						   int           height,
+						   int           bpp);
+static void       gamma_load                      (gpointer      cd_ID,
+						   Parasite     *state);
+static Parasite * gamma_save                      (gpointer      cd_ID);
+static void       gamma_configure_ok_callback     (GtkWidget    *widget,
+						   gpointer      data);
+static void       gamma_configure_cancel_callback (GtkWidget    *widget,
+						   gpointer      data);
+static gint       gamma_configure_delete_callback (GtkWidget    *widget,
+						   GdkEvent     *event,
+						   gpointer      data);
+static void       gamma_configure                 (gpointer      cd_ID);
+
+void
+gdisplay_color_init (void)
+{
+  GimpColorDisplayMethods methods = {
+    NULL,
+    gamma_new,
+    gamma_convert,
+    gamma_destroy,
+    NULL,
+    gamma_load,
+    gamma_save,
+    gamma_configure
+  };
+
+  gimp_color_display_register ("Gamma", &methods);
+}
+
 gboolean
 gimp_color_display_register (const char              *name,
     			     GimpColorDisplayMethods *methods)
@@ -122,16 +173,10 @@ gdisplay_color_detach (GDisplay *gdisp)
     }  
 }
 
-typedef struct _GammaContext GammaContext;
+/* The Gamma Color Display */
 
-struct _GammaContext
+static gpointer
-{
+gamma_new (int type)
-  double gamma;
-  guchar *lookup;
-};
-
-static
-gpointer gamma_new (int type)
 {
   int i;
   GammaContext *context = NULL;
@@ -139,6 +184,8 @@ gpointer gamma_new (int type)
   context = g_new (GammaContext, 1);
   context->gamma = 1.0;
   context->lookup = g_new (guchar, 256);
+  context->shell = NULL;
+  context->spinner = NULL;
 
   for (i = 0; i < 256; i++)
     context->lookup[i] = i;
@@ -146,21 +193,43 @@ gpointer gamma_new (int type)
   return context;
 }
 
-static
+static void
-void gamma_destroy (gpointer cd_ID)
+gamma_create_lookup_table (GammaContext *context)
+{
+  double one_over_gamma;
+  double ind;
+  int i;
+
+  if (context->gamma == 0.0)
+    context->gamma = 1.0;
+
+  one_over_gamma = 1.0 / context->gamma;
+
+  for (i = 0; i < 256; i++)
+    {
+      ind = (double) i / 255.0;
+      context->lookup[i] = (guchar) (int) (255 * pow (ind, one_over_gamma));
+    }
+}
+
+static void
+gamma_destroy (gpointer cd_ID)
 {
   GammaContext *context = (GammaContext *) cd_ID;
 
+  if (context->shell)
+    gtk_widget_destroy (context->shell);
+
   g_free (context->lookup);
   g_free (context);
 }
 
-static
+static void
-void gamma_convert (gpointer  cd_ID,
+gamma_convert (gpointer  cd_ID,
-    		    guchar   *buf,
+    	       guchar   *buf,
-		    int       width,
+	       int       width,
-		    int       height,
+	       int       height,
-		    int       bpp)
+	       int       bpp)
 {
   int i;
   guchar *lookup = ((GammaContext *) cd_ID)->lookup;
@@ -169,7 +238,133 @@ void gamma_convert (gpointer  cd_ID,
     *buf++ = lookup[*buf];
 }
 
-void
+static void
-gdisplay_color_init (void)
+gamma_load (gpointer  cd_ID,
+            Parasite *state)
 {
+  GammaContext *context = (GammaContext *) cd_ID;
+
+#if G_BYTE_ORDER == G_BIG_ENDIAN
+  memcpy (&context->gamma, parasite_data (state), sizeof (double));
+#else
+  guint32 buf[2], *data = parasite_data (state);
+
+  buf[0] = g_ntohl (data[1]);
+  buf[1] = g_ntohl (data[0]);
+
+  memcpy (&context->gamma, buf, sizeof (double));
+#endif
+
+  gamma_create_lookup_table (context);
+}
+
+static Parasite *
+gamma_save (gpointer cd_ID)
+{
+  GammaContext *context = (GammaContext *) cd_ID;
+  guint32 buf[2];
+
+  memcpy (buf, &context->gamma, sizeof (double));
+
+#if G_BYTE_ORDER == G_LITTLE_ENDIAN
+  {
+    guint32 tmp = g_htonl (buf[0]);
+    buf[0] = g_htonl (buf[1]);
+    buf[1] = tmp;
+  }
+#endif
+
+  return parasite_new ("Display/Gamma", PARASITE_PERSISTENT,
+		       sizeof (double), &buf);
+}
+
+static void
+gamma_configure_ok_callback (GtkWidget *widget,
+				 gpointer   data)
+{
+  GammaContext *context = (GammaContext *) data;
+
+  context->gamma = gtk_spin_button_get_value_as_float (context->spinner);
+  gamma_create_lookup_table (context);
+
+  gtk_widget_hide (widget);
+}
+
+static void
+gamma_configure_cancel_callback (GtkWidget *widget,
+				 gpointer   data)
+{
+  gtk_widget_hide (widget);
+}
+
+static gint
+gamma_configure_delete_callback (GtkWidget *widget,
+				 GdkEvent  *event,
+				 gpointer   data)
+{
+  gamma_configure_cancel_callback (widget, data);
+  return TRUE;
+}
+
+static void
+gamma_configure (gpointer cd_ID)
+{
+  GammaContext *context = (GammaContext *) cd_ID;
+  GtkWidget *vbox;
+  GtkWidget *hbox;
+  GtkWidget *label;
+  GtkWidget *entry;
+  GtkWidget *hbbox;
+  GtkWidget *button;
+  GtkObject *adjustment;
+
+  if (!context->shell)
+    {
+      context->shell = gtk_dialog_new ();
+      gtk_window_set_wmclass (GTK_WINDOW (context->shell), "gamma", "Gimp");
+      gtk_window_set_title (GTK_WINDOW (context->shell), _("Gamma"));
+
+      gtk_signal_connect (GTK_OBJECT (context->shell), "delete_event",
+			  GTK_SIGNAL_FUNC (gamma_configure_delete_callback),
+			  NULL);
+
+      hbox = gtk_hbox_new (TRUE, 2);
+      gtk_box_pack_start (GTK_BOX (GTK_DIALOG (context->shell)->vbox),
+			  hbox, FALSE, FALSE, 0);
+
+      label = gtk_label_new (_("Gamma:"));
+      gtk_misc_set_alignment (GTK_MISC (label), 1.0, 0.5);
+      gtk_box_pack_start (GTK_BOX (hbox), label, TRUE, FALSE, 0);
+
+      adjustment = gtk_adjustment_new (1.0, 0.01, 10.0, 0.01, 0.1, 0.0);
+      context->spinner = gtk_spin_button_new (GTK_ADJUSTMENT (adjustment),
+					      0.1, 3);
+      gtk_widget_set_usize (context->spinner, 100, 0);
+      gtk_box_pack_start (GTK_BOX (hbox), label, TRUE, FALSE, 0);
+ 
+      gtk_widget_show_all (hbox);
+
+      hbbox = gtk_hbutton_box_new ();
+      gtk_button_box_set_spacing (GTK_BUTTON_BOX (hbbox), 4);
+      gtk_box_pack_end (GTK_BOX (GTK_DIALOG (context->shell)->action_area),
+			hbbox, FALSE, FALSE, 0);  
+
+      button = gtk_button_new_with_label (_("OK"));
+      GTK_WIDGET_SET_FLAGS (button, GTK_CAN_DEFAULT);
+      gtk_box_pack_start (GTK_BOX (hbbox), button, FALSE, FALSE, 0);
+      gtk_signal_connect (GTK_OBJECT (button), "clicked",
+			  GTK_SIGNAL_FUNC (gamma_configure_ok_callback),
+			  cd_ID);
+
+      button = gtk_button_new_with_label (_("Cancel"));
+      GTK_WIDGET_SET_FLAGS (button, GTK_CAN_DEFAULT);
+      gtk_box_pack_start (GTK_BOX (hbbox), button, FALSE, FALSE, 0);
+      gtk_signal_connect (GTK_OBJECT (button), "clicked",
+			  GTK_SIGNAL_FUNC (gamma_configure_cancel_callback),
+			  cd_ID);
+
+      gtk_widget_show_all (hbbox);
+    }
+
+  gtk_widget_show (context->shell);
 }