app: various fixes in GimpToolFocus

app/display/gimptoolfocus.c

@@ -44,6 +44,8 @@
 #define HANDLE_SIZE   12.0
 #define SNAP_DISTANCE 12.0
 
+#define EPSILON       1e-6
+
 
 enum
 {
@@ -610,6 +612,20 @@ gimp_tool_focus_motion (GimpToolWidget   *widget,
             y = cy;
           }
 
+        if (fabs (fabs (priv->aspect_ratio) - 1.0) <= EPSILON)
+          {
+            if (priv->radius <= EPSILON)
+              {
+                g_object_set (focus,
+                              "aspect-ratio", 0.0,
+                              NULL);
+              }
+            else
+              {
+                break;
+              }
+          }
+
         radius = gimp_canvas_limit_boundary_radius (GIMP_CANVAS_LIMIT (limit),
                                                     x, y);
 
@@ -634,39 +650,63 @@ gimp_tool_focus_motion (GimpToolWidget   *widget,
               inner_radius = radius;
 
               if (extend)
+                {
+                  if (priv->inner_limit > EPSILON)
                     outer_radius = inner_radius / priv->inner_limit;
                   else
+                    inner_radius = 0.0;
+                }
+              else
+                {
                   inner_radius = MIN (inner_radius, outer_radius);
                 }
+            }
             break;
 
           case LIMIT_MIDDLE:
             {
               if (extend)
+                {
+                  if (priv->inner_limit > EPSILON || priv->midpoint > EPSILON)
                     {
                       outer_radius = radius / (priv->inner_limit         +
                                                (1.0 - priv->inner_limit) *
                                                priv->midpoint);
                       inner_radius = priv->inner_limit * outer_radius;
                     }
+                  else
+                    {
+                      radius = 0.0;
+                    }
+                }
               else
                 {
                   radius = CLAMP (radius, inner_radius, outer_radius);
                 }
 
+              if (outer_radius > inner_radius)
+                {
                   g_object_set (focus,
-                            "midpoint",    (radius       - inner_radius) /
+                                "midpoint", MAX ((radius       - inner_radius) /
                                                  (outer_radius - inner_radius),
+                                                 0.0),
                                 NULL);
                 }
+            }
             break;
           }
 
         g_object_set (focus,
                       "radius", outer_radius,
+                      NULL);
+
+        if (outer_radius > EPSILON)
+          {
+            g_object_set (focus,
                           "inner-limit", inner_radius / outer_radius,
                           NULL);
           }
+      }
       break;
 
     case HOVER_HANDLE:
@@ -705,6 +745,25 @@ gimp_tool_focus_motion (GimpToolWidget   *widget,
 
         gimp_vector2_mul (&p, r);
 
+        if (extend)
+          {
+            if (handle->orientation == GTK_ORIENTATION_HORIZONTAL)
+              {
+                if (rx <= EPSILON && ry > EPSILON)
+                  break;
+
+                ry = r * (1.0 - priv->aspect_ratio);
+              }
+            else
+              {
+                if (ry <= EPSILON && rx > EPSILON)
+                  break;
+
+                rx = r * (1.0 + priv->aspect_ratio);
+              }
+          }
+        else
+          {
             if (gimp_canvas_item_transform_distance (
                   priv->limits[priv->hover_limit].item,
                   s.x, s.y,
@@ -715,13 +774,6 @@ gimp_tool_focus_motion (GimpToolWidget   *widget,
                 else
                   r = rx;
               }
-
-        if (extend)
-          {
-            if (handle->orientation == GTK_ORIENTATION_HORIZONTAL)
-              ry *= r / rx;
-            else
-              rx *= r / ry;
           }
 
         if (handle->orientation == GTK_ORIENTATION_HORIZONTAL)
@@ -736,8 +788,23 @@ gimp_tool_focus_motion (GimpToolWidget   *widget,
 
         g_object_set (focus,
                       "radius", r,
-                      "aspect-ratio", rx >= ry ? 1.0 - ry / rx : rx / ry - 1.0,
                       NULL);
+
+        if (! extend)
+          {
+            gdouble aspect_ratio;
+
+            if (fabs (rx - ry) <= EPSILON)
+              aspect_ratio = 0.0;
+            else if (rx > ry)
+              aspect_ratio = 1.0 - ry / rx;
+            else
+              aspect_ratio = rx / ry - 1.0;
+
+            g_object_set (focus,
+                          "aspect-ratio", aspect_ratio,
+                          NULL);
+          }
       }
       break;