From a35e3dfc775f8a86b8a95623059f581c02cf8e00 Mon Sep 17 00:00:00 2001
From: Michiharu Ariza <ariza@adobe.com>
Date: Sun, 17 Mar 2019 17:48:10 -0700
Subject: [PATCH] fix infer_delta

code cleanup
---
 src/hb-ot-glyf-table.hh     | 22 ++++++++++++++--------
 src/hb-ot-var-gvar-table.hh |  9 +++++++--
 2 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/src/hb-ot-glyf-table.hh b/src/hb-ot-glyf-table.hh
index 8f79e2aa3..cd7dc46e6 100644
--- a/src/hb-ot-glyf-table.hh
+++ b/src/hb-ot-glyf-table.hh
@@ -513,9 +513,9 @@ struct glyf
       return true;
     }
 
-    struct bounds_t
+    struct contour_bounds_t
     {
-      bounds_t () { min.x = min.y = FLT_MAX; max.x = max.y = FLT_MIN; }
+      contour_bounds_t () { min.x = min.y = FLT_MAX; max.x = max.y = FLT_MIN; }
 
       void add (const contour_point_t &p)
       {
@@ -525,8 +525,14 @@ struct glyf
       	max.y = MAX (max.y, p.y);
       }
 
-      void _union (const bounds_t &b)
-      { add (b.min); add (b.max); }
+      void merge (const contour_bounds_t &b)
+      {
+	if (empty ()) { *this = b; return; }
+	add (b.min);
+	add (b.max);
+      }
+
+      bool empty () const { return (min.x >= max.x) || (min.y >= max.y); }
 
       contour_point_t	min;
       contour_point_t	max;
@@ -535,7 +541,7 @@ struct glyf
     /* Note: Recursively calls itself. Who's checking recursively nested composite glyph BTW? */
     bool get_bounds_var (hb_codepoint_t glyph,
 			 const int *coords, unsigned int coord_count,
-			 bounds_t &bounds) const
+			 contour_bounds_t &bounds) const
     {
       hb_vector_t<contour_point_t>	points;
       hb_vector_t<unsigned int>		end_points;
@@ -555,12 +561,12 @@ struct glyf
       /* composite glyph */
       do
       {
-	bounds_t	comp_bounds;
+	contour_bounds_t	comp_bounds;
 	if (unlikely (!get_bounds_var (composite.current->glyphIndex, coords, coord_count, comp_bounds))) return false;
 
 	composite.current->transform_point (comp_bounds.min.x, comp_bounds.min.y);
 	composite.current->transform_point (comp_bounds.max.x, comp_bounds.max.y);
-	bounds._union (comp_bounds);
+	bounds.merge (comp_bounds);
       } while (composite.move_to_next());
 
       /* Shift bounds by the updated left side bearing (vertically too?) */
@@ -577,7 +583,7 @@ struct glyf
 			  const int *coords, unsigned int coord_count,
 			  hb_glyph_extents_t *extents) const
     {
-      bounds_t	bounds;
+      contour_bounds_t	bounds;
       if (unlikely (!get_bounds_var (glyph, coords, coord_count, bounds))) return false;
 
       if (bounds.min.x >= bounds.max.x)
diff --git a/src/hb-ot-var-gvar-table.hh b/src/hb-ot-var-gvar-table.hh
index 738c1e731..fbcd55408 100644
--- a/src/hb-ot-var-gvar-table.hh
+++ b/src/hb-ot-var-gvar-table.hh
@@ -575,6 +575,11 @@ struct gvar
       } while (iterator.move_to_next ());
 
       /* infer deltas for unreferenced points */
+      hb_vector_t<contour_point_t> orig_points;
+      orig_points.resize (points.length);
+      for (unsigned int i = 0; i < orig_points.length; i++)
+      	orig_points[i] = points[i];
+
       unsigned int start_point = 0;
       for (unsigned int c = 0; c < end_points.length; c++)
       {
@@ -597,8 +602,8 @@ struct gvar
 	    if (next == i || deltas[next].flag) break;
 	  }
 	  assert (next != i);
-	  deltas[i].x = infer_delta (points[i].x, points[prev].x, points[next].x, deltas[prev].x, deltas[next].x);
-	  deltas[i].y = infer_delta (points[i].y, points[prev].y, points[next].y, deltas[prev].y, deltas[next].y);
+	  deltas[i].x = infer_delta<x_getter> (orig_points.as_array (), deltas.as_array (), i, prev, next);
+	  deltas[i].y = infer_delta<y_getter> (orig_points.as_array (), deltas.as_array (), i, prev, next);
 	}
 	start_point = end_point + 1;
       }