GtkGamma/Curve enhancement

[Vidar Madsen <vidar vidar prosalg no>]

Hi all.

I've just put together a trivial patch to allow GtkCurve and GtkGamma to
accept negative gamma-values, much the same way xv's color editor does it. 
Negative values simply causes the curve to be drawn "backwards", a pretty
useful feature if you ask me. 

Another thing. Is there a new deadline set for v1.0 now?

Thanks,
Vidar


--- gtkcurve.c-orig	Fri Mar 27 13:15:54 1998
+++ gtkcurve.c	Fri Mar 27 13:18:10 1998
@@ -639,6 +639,7 @@
   gfloat x, one_over_gamma, height, one_over_width;
   GtkCurveType old_type;
   gint i;
+  gint neg = 0;
 
   if (c->num_points < 2)
     return;
@@ -646,18 +647,27 @@
   old_type = c->curve_type;
   c->curve_type = GTK_CURVE_TYPE_FREE;
 
-  if (gamma <= 0)
+  if (gamma < 0) {
+    neg = 1;
+    gamma = -gamma;
+  }
+  if(gamma == 0)
     one_over_gamma = 1.0;
   else
     one_over_gamma = 1.0 / gamma;
+
   one_over_width = 1.0 / (c->num_points - 1);
   height = c->height;
   for (i = 0; i < c->num_points; ++i)
     {
       x = (gfloat) i / (c->num_points - 1);
       c->point[i].x = RADIUS + i;
-      c->point[i].y =
-	RADIUS + (height * (1.0 - pow (x, one_over_gamma)) + 0.5);
+      if(!neg) 
+	c->point[i].y =
+	  RADIUS + (height * (1.0 - pow (x, one_over_gamma)) + 0.5);
+      else
+	c->point[c->num_points-1-i].y =
+	  RADIUS + (height * (1.0 - pow (x, one_over_gamma)) + 0.5);
     }
 
   if (old_type != GTK_CURVE_TYPE_FREE)
--- gtkgamma.c-orig	Fri Mar 27 13:14:40 1998
+++ gtkgamma.c	Fri Mar 27 13:15:48 1998
@@ -357,7 +357,7 @@
   if (start)
     {
       v = strtod (start, &end);
-      if (end > start && v > 0.0)
+      if (end > start)
 	c->gamma = v;
     }
   gtk_curve_set_gamma (GTK_CURVE (c->curve), c->gamma);