Fix null reference exception when drawing empty geometries (null Box).

awulkiew · awulkiew · commit a815b73deba4 · 2020-01-26T19:18:49.000+01:00
diff --git a/Visual_Studio_2017/GraphicalDebugging/ExpressionDrawer.cs b/Visual_Studio_2017/GraphicalDebugging/ExpressionDrawer.cs
@@ -73,13 +73,12 @@ private static Geometry.Interval RelativeEnvelopeLon(Geometry.IRandomAccessRange
 
             if (points.Count < 1)
             {
-                result = new Geometry.Interval();
-                Geometry.AssignInverse(result);
+                result = Geometry.InversedInterval();
                 return result;
             }
 
             double x0 = points[0][0];
-            result = new Geometry.Interval(x0);
+            result = new Geometry.Interval(x0, x0);
 
             int count = points.Count + (closed ? 1 : 0);
             for (int ii = 1; ii < count; ++ii)
@@ -582,7 +581,7 @@ public Geometry.Box Aabb(Geometry.Traits traits, bool calculateEnvelope)
                 }
 
                 if (box == null)
-                    Geometry.AssignInverse(box);
+                    box = Geometry.InversedBox();
 
                 return box;
             }
@@ -623,7 +622,7 @@ public Geometry.Box Aabb(Geometry.Traits traits, bool calculateEnvelope)
                 }
 
                 if (box == null)
-                    Geometry.AssignInverse(box);
+                    box = Geometry.InversedBox();
 
                 return box;
             }
@@ -664,7 +663,7 @@ public Geometry.Box Aabb(Geometry.Traits traits, bool calculateEnvelope)
                 }
 
                 if (box == null)
-                    Geometry.AssignInverse(box);
+                    box = Geometry.InversedBox();
 
                 return box;
             }
@@ -706,7 +705,7 @@ public Geometry.Box Aabb(Geometry.Traits traits, bool calculateEnvelope)
                 }
 
                 if (result == null)
-                    Geometry.AssignInverse(result);
+                    result = Geometry.InversedBox();
 
                 return result;
             }
@@ -854,8 +853,7 @@ public Geometry.Box Aabb(Geometry.Traits traits, bool calculateEnvelope)
             {
                 // NOTE: traits == null
 
-                Geometry.Box box = new Geometry.Box();
-                Geometry.AssignInverse(box);
+                Geometry.Box box = Geometry.InversedBox();
 
                 if (values.Count > 0)
                     Geometry.Expand(box, new Point(0.0, 0.0));
@@ -955,8 +953,7 @@ public Geometry.Box Aabb(Geometry.Traits traits, bool calculateEnvelope)
                 // NOTE: traits == null
                 // so don't return points.Aabb(traits, calculateEnvelope)
 
-                Geometry.Box box = new Geometry.Box();
-                Geometry.AssignInverse(box);
+                Geometry.Box box = Geometry.InversedBox();
 
                 for (int i = 0; i < points.Count; ++i)
                     Geometry.Expand(box, points[i]);
@@ -1075,8 +1072,7 @@ public void Draw(Geometry.Box box, Graphics graphics, Settings settings, Geometr
 
             public Geometry.Box Aabb(Geometry.Traits traits, bool calculateEnvelope)
             {
-                Geometry.Box box = new Geometry.Box();
-                Geometry.AssignInverse(box);
+                Geometry.Box box = Geometry.InversedBox();
 
                 for (int i = 0; i < turns.Count; ++i)
                 {
@@ -1210,8 +1206,7 @@ static Geometry.Box Draw(Graphics graphics, bool ignoreTraits,
             if (drawables.Length != traits.Length || drawables.Length != settings.Length)
                 throw new ArgumentOutOfRangeException("drawables.Length, traits.Length, settings.Length");
 
-            Geometry.Box box = new Geometry.Box();
-            Geometry.AssignInverse(box);
+            Geometry.Box box = Geometry.InversedBox();
 
             int drawnCount = 0;
             int count = drawables.Length;
diff --git a/Visual_Studio_2017/GraphicalDebugging/Geometry.cs b/Visual_Studio_2017/GraphicalDebugging/Geometry.cs
@@ -112,12 +112,6 @@ public class Interval
             public Interval()
             { }
 
-            public Interval(double v)
-            {
-                Min = v;
-                Max = v;
-            }
-
             public Interval(double mi, double ma)
             {
                 Min = mi;
@@ -302,6 +296,20 @@ public static void AssignInverse(Interval i)
             i.Max = double.MinValue;
         }
 
+        public static Box InversedBox()
+        {
+            Box result = new Box();
+            AssignInverse(result);
+            return result;
+        }
+
+        public static Interval InversedInterval()
+        {
+            Interval result = new Interval();
+            AssignInverse(result);
+            return result;
+        }
+
         public static Box Aabb(Point p1, Point p2, Unit unit)
         {
             if (unit == Unit.None)
@@ -327,24 +335,20 @@ public static Box AabbAngle(Point p1, Point p2, Unit unit)
 
         public static Box Aabb(IRandomAccessRange<Point> points, bool closed, Unit unit)
         {
-            Box result = new Box();
-
             if (points.Count < 1)
             {
-                AssignInverse(result);
-                return result;
+                return InversedBox();
             }
 
             Point p1 = points[0];
             if (points.Count < 2)
             {
                 // NOTE: unsafe, if this Box is modified then the original points will be modified as well
-                result = new Box(p1, p1);
-                return result;
+                return new Box(p1, p1);
             }
             Point p2 = points[1];
 
-            result = Aabb(p1, p2, unit);
+            Box result = Aabb(p1, p2, unit);
             int count = points.Count + (closed ? 1 : 0);
             for (int i = 2; i < count; ++i)
             {
@@ -535,9 +539,7 @@ public static Box Envelope(IRandomAccessRange<Point> range, bool closed, Traits
         {
             if (range.Count <= 0)
             {
-                Box result = new Box();
-                AssignInverse(result);
-                return result;
+                return InversedBox();
             }
             else if (range.Count <= 1)
             {
diff --git a/Visual_Studio_2017/GraphicalDebugging/GeometryWatchControl.xaml.cs b/Visual_Studio_2017/GraphicalDebugging/GeometryWatchControl.xaml.cs
@@ -313,6 +313,13 @@ private void UpdateItems(bool load, int modified_index = -1)
                                 {
                                     try
                                     {
+                                        // TODO: Unify the loading of empty geometries.
+                                        //   For empty linestring the coordinate system name is drawn
+                                        //   however for empty multilinestring it is not. The reason
+                                        //   is that in the latter case null drawable and traits are
+                                        //   returned becasue traits are loaded from an element
+                                        //   (linestring) but there are no elements since the
+                                        //   multi-geometry is empty.
                                         ExpressionDrawer.IDrawable d = null;
                                         Geometry.Traits t = null;
                                         ExpressionLoader.Load(names[i], ExpressionLoader.OnlyGeometries, out t, out d);

Original file line number	Diff line number	Diff line change
`@@ -73,13 +73,12 @@ private static Geometry.Interval RelativeEnvelopeLon(Geometry.IRandomAccessRange`
`73`	`73`
`74`	`74`	`if (points.Count < 1)`
`75`	`75`	`{`
`76`		`- result = new Geometry.Interval();`
`77`		`- Geometry.AssignInverse(result);`
	`76`	`+ result = Geometry.InversedInterval();`
`78`	`77`	`return result;`
`79`	`78`	`}`
`80`	`79`
`81`	`80`	`double x0 = points[0][0];`
`82`		`- result = new Geometry.Interval(x0);`
	`81`	`+ result = new Geometry.Interval(x0, x0);`
`83`	`82`
`84`	`83`	`int count = points.Count + (closed ? 1 : 0);`
`85`	`84`	`for (int ii = 1; ii < count; ++ii)`
`@@ -582,7 +581,7 @@ public Geometry.Box Aabb(Geometry.Traits traits, bool calculateEnvelope)`
`582`	`581`	`}`
`583`	`582`
`584`	`583`	`if (box == null)`
`585`		`- Geometry.AssignInverse(box);`
	`584`	`+ box = Geometry.InversedBox();`
`586`	`585`
`587`	`586`	`return box;`
`588`	`587`	`}`
`@@ -623,7 +622,7 @@ public Geometry.Box Aabb(Geometry.Traits traits, bool calculateEnvelope)`
`623`	`622`	`}`
`624`	`623`
`625`	`624`	`if (box == null)`
`626`		`- Geometry.AssignInverse(box);`
	`625`	`+ box = Geometry.InversedBox();`
`627`	`626`
`628`	`627`	`return box;`
`629`	`628`	`}`
`@@ -664,7 +663,7 @@ public Geometry.Box Aabb(Geometry.Traits traits, bool calculateEnvelope)`
`664`	`663`	`}`
`665`	`664`
`666`	`665`	`if (box == null)`
`667`		`- Geometry.AssignInverse(box);`
	`666`	`+ box = Geometry.InversedBox();`
`668`	`667`
`669`	`668`	`return box;`
`670`	`669`	`}`
`@@ -706,7 +705,7 @@ public Geometry.Box Aabb(Geometry.Traits traits, bool calculateEnvelope)`
`706`	`705`	`}`
`707`	`706`
`708`	`707`	`if (result == null)`
`709`		`- Geometry.AssignInverse(result);`
	`708`	`+ result = Geometry.InversedBox();`
`710`	`709`
`711`	`710`	`return result;`
`712`	`711`	`}`
`@@ -854,8 +853,7 @@ public Geometry.Box Aabb(Geometry.Traits traits, bool calculateEnvelope)`
`854`	`853`	`{`
`855`	`854`	`// NOTE: traits == null`
`856`	`855`
`857`		`- Geometry.Box box = new Geometry.Box();`
`858`		`- Geometry.AssignInverse(box);`
	`856`	`+ Geometry.Box box = Geometry.InversedBox();`
`859`	`857`
`860`	`858`	`if (values.Count > 0)`
`861`	`859`	`Geometry.Expand(box, new Point(0.0, 0.0));`
`@@ -955,8 +953,7 @@ public Geometry.Box Aabb(Geometry.Traits traits, bool calculateEnvelope)`
`955`	`953`	`// NOTE: traits == null`
`956`	`954`	`// so don't return points.Aabb(traits, calculateEnvelope)`
`957`	`955`
`958`		`- Geometry.Box box = new Geometry.Box();`
`959`		`- Geometry.AssignInverse(box);`
	`956`	`+ Geometry.Box box = Geometry.InversedBox();`
`960`	`957`
`961`	`958`	`for (int i = 0; i < points.Count; ++i)`
`962`	`959`	`Geometry.Expand(box, points[i]);`
`@@ -1075,8 +1072,7 @@ public void Draw(Geometry.Box box, Graphics graphics, Settings settings, Geometr`
`1075`	`1072`
`1076`	`1073`	`public Geometry.Box Aabb(Geometry.Traits traits, bool calculateEnvelope)`
`1077`	`1074`	`{`
`1078`		`- Geometry.Box box = new Geometry.Box();`
`1079`		`- Geometry.AssignInverse(box);`
	`1075`	`+ Geometry.Box box = Geometry.InversedBox();`
`1080`	`1076`
`1081`	`1077`	`for (int i = 0; i < turns.Count; ++i)`
`1082`	`1078`	`{`
`@@ -1210,8 +1206,7 @@ static Geometry.Box Draw(Graphics graphics, bool ignoreTraits,`
`1210`	`1206`	`if (drawables.Length != traits.Length \|\| drawables.Length != settings.Length)`
`1211`	`1207`	`throw new ArgumentOutOfRangeException("drawables.Length, traits.Length, settings.Length");`
`1212`	`1208`
`1213`		`- Geometry.Box box = new Geometry.Box();`
`1214`		`- Geometry.AssignInverse(box);`
	`1209`	`+ Geometry.Box box = Geometry.InversedBox();`
`1215`	`1210`
`1216`	`1211`	`int drawnCount = 0;`
`1217`	`1212`	`int count = drawables.Length;`
Original file line number	Diff line number	Diff line change
`@@ -112,12 +112,6 @@ public class Interval`
`112`	`112`	`public Interval()`
`113`	`113`	`{ }`
`114`	`114`
`115`		`- public Interval(double v)`
`116`		`- {`
`117`		`- Min = v;`
`118`		`- Max = v;`
`119`		`- }`
`120`		`-`
`121`	`115`	`public Interval(double mi, double ma)`
`122`	`116`	`{`
`123`	`117`	`Min = mi;`
`@@ -302,6 +296,20 @@ public static void AssignInverse(Interval i)`
`302`	`296`	`i.Max = double.MinValue;`
`303`	`297`	`}`
`304`	`298`
	`299`	`+ public static Box InversedBox()`
	`300`	`+ {`
	`301`	`+ Box result = new Box();`
	`302`	`+ AssignInverse(result);`
	`303`	`+ return result;`
	`304`	`+ }`
	`305`	`+`
	`306`	`+ public static Interval InversedInterval()`
	`307`	`+ {`
	`308`	`+ Interval result = new Interval();`
	`309`	`+ AssignInverse(result);`
	`310`	`+ return result;`
	`311`	`+ }`
	`312`	`+`
`305`	`313`	`public static Box Aabb(Point p1, Point p2, Unit unit)`
`306`	`314`	`{`
`307`	`315`	`if (unit == Unit.None)`
`@@ -327,24 +335,20 @@ public static Box AabbAngle(Point p1, Point p2, Unit unit)`
`327`	`335`
`328`	`336`	`public static Box Aabb(IRandomAccessRange<Point> points, bool closed, Unit unit)`
`329`	`337`	`{`
`330`		`- Box result = new Box();`
`331`		`-`
`332`	`338`	`if (points.Count < 1)`
`333`	`339`	`{`
`334`		`- AssignInverse(result);`
`335`		`- return result;`
	`340`	`+ return InversedBox();`
`336`	`341`	`}`
`337`	`342`
`338`	`343`	`Point p1 = points[0];`
`339`	`344`	`if (points.Count < 2)`
`340`	`345`	`{`
`341`	`346`	`// NOTE: unsafe, if this Box is modified then the original points will be modified as well`
`342`		`- result = new Box(p1, p1);`
`343`		`- return result;`
	`347`	`+ return new Box(p1, p1);`
`344`	`348`	`}`
`345`	`349`	`Point p2 = points[1];`
`346`	`350`
`347`		`- result = Aabb(p1, p2, unit);`
	`351`	`+ Box result = Aabb(p1, p2, unit);`
`348`	`352`	`int count = points.Count + (closed ? 1 : 0);`
`349`	`353`	`for (int i = 2; i < count; ++i)`
`350`	`354`	`{`
`@@ -535,9 +539,7 @@ public static Box Envelope(IRandomAccessRange<Point> range, bool closed, Traits`
`535`	`539`	`{`
`536`	`540`	`if (range.Count <= 0)`
`537`	`541`	`{`
`538`		`- Box result = new Box();`
`539`		`- AssignInverse(result);`
`540`		`- return result;`
	`542`	`+ return InversedBox();`
`541`	`543`	`}`
`542`	`544`	`else if (range.Count <= 1)`
`543`	`545`	`{`
Original file line number	Diff line number	Diff line change
`@@ -313,6 +313,13 @@ private void UpdateItems(bool load, int modified_index = -1)`
`313`	`313`	`{`
`314`	`314`	`try`
`315`	`315`	`{`
	`316`	`+ // TODO: Unify the loading of empty geometries.`
	`317`	`+ // For empty linestring the coordinate system name is drawn`
	`318`	`+ // however for empty multilinestring it is not. The reason`
	`319`	`+ // is that in the latter case null drawable and traits are`
	`320`	`+ // returned becasue traits are loaded from an element`
	`321`	`+ // (linestring) but there are no elements since the`
	`322`	`+ // multi-geometry is empty.`
`316`	`323`	`ExpressionDrawer.IDrawable d = null;`
`317`	`324`	`Geometry.Traits t = null;`
`318`	`325`	`ExpressionLoader.Load(names[i], ExpressionLoader.OnlyGeometries, out t, out d);`