[gimp/gimp-2-10] tools: in performance-log-viewer.py, handle infinities in sample graph

[Ell <ell src gnome org>]

commit c44015a84e5ca2f397ff9dc2b0d50707f8fe1470
Author: Ell <ell_se yahoo com>
Date:   Sat Sep 29 15:37:55 2018 -0400

    tools: in performance-log-viewer.py, handle infinities in sample graph
    
    Don't take infinite values into account when calculating the
    vertical scale of sample graphs, and rather display infinite values
    as dashed lines at the top of the graph.
    
    (cherry picked from commit 46e5e4d478cde2eafdc62f9d51bc5266886dc6a5)

 tools/performance-log-viewer.py | 64 +++++++++++++++++++++++++++++++++++------
 1 file changed, 55 insertions(+), 9 deletions(-)
---
diff --git a/tools/performance-log-viewer.py b/tools/performance-log-viewer.py
index dba9d4aa81..a27bf8a118 100755
--- a/tools/performance-log-viewer.py
+++ b/tools/performance-log-viewer.py
@@ -813,10 +813,14 @@ class SampleGraph (Gtk.DrawingArea):
             var_active = row[self.model.ACTIVE]
 
             if var_active:
-                self.max_value = max (
-                    self.max_value,
-                    max (sample.vars[var_name].value or 0 for sample in samples)
-                )
+                values = (sample.vars[var_name].value for sample in samples)
+                values = filter (lambda x: x is not None, values)
+                values = filter (math.isfinite,           values)
+
+                try:
+                    self.max_value = max (self.max_value, max (values))
+                except:
+                    pass
 
         self.queue_draw ()
 
@@ -1030,7 +1034,8 @@ class SampleGraph (Gtk.DrawingArea):
         Gtk.render_background (style, cr, 0, 0, width, height)
 
         if self.model:
-            vscale = (height - 4) / self.max_value
+            max_value = self.max_value
+            vscale    = (height - 4) / max_value
 
             cr.save ()
 
@@ -1038,6 +1043,7 @@ class SampleGraph (Gtk.DrawingArea):
             cr.scale (1, -1)
 
             first_sample = True
+            has_infinite = False
 
             for row in self.model:
                 var_name   = row[self.model.NAME]
@@ -1051,8 +1057,15 @@ class SampleGraph (Gtk.DrawingArea):
                         value = samples[i].vars[var_name].value
 
                         if value is not None:
-                            if is_boolean:
-                                value *= self.max_value
+                            first_sample = False
+
+                            if math.isinf (value):
+                                first_sample = True
+                                has_infinite = True
+
+                                value = max_value
+                            elif is_boolean:
+                                value *= max_value
 
                             y = value * vscale
 
@@ -1072,8 +1085,6 @@ class SampleGraph (Gtk.DrawingArea):
                                     cr.line_to (x0, y)
 
                                 cr.line_to (x1, y)
-
-                            first_sample = False
                         else:
                             first_sample = True
 
@@ -1083,6 +1094,41 @@ class SampleGraph (Gtk.DrawingArea):
                     cr.set_line_width (2)
                     cr.stroke ()
 
+                    if has_infinite:
+                        cr.save ()
+
+                        for i in range (len (samples)):
+                            value = samples[i].vars[var_name].value
+
+                            if value is not None and math.isinf (value):
+                                first_sample = False
+
+                                y = max_value * vscale
+
+                                if is_continuous:
+                                    x = self.sample_to_x (i)
+
+                                    if first_sample:
+                                        cr.move_to (x, y)
+                                    else:
+                                        cr.line_to (x, y)
+                                else:
+                                    (x0, x1) = self.sample_to_range (i)
+
+                                    if first_sample:
+                                        cr.move_to (x0, y)
+                                    else:
+                                        cr.line_to (x0, y)
+
+                                    cr.line_to (x1, y)
+                            else:
+                                first_sample = True
+
+                        cr.set_dash ([6, 6], 0)
+                        cr.stroke ()
+
+                        cr.restore ()
+
             cr.restore ()
 
             cr.set_line_width (1)