favour pdf level widths over advance widths for truetype. fix image sizes for visual verification tests

src/UglyToad.PdfPig.Tests/Integration/AssertablePositionData.cs

@@ -54,5 +54,10 @@
                 Assert.Equal(Height, letter.GlyphRectangle.Height, 1);
             }
         }
+
+        public override string ToString()
+        {
+            return $"{X} {Y} {Width} {Text} {FontSize} {FontName} {Height}";
+        }
     }
 }

src/UglyToad.PdfPig.Tests/Integration/SinglePageInkscapeTests.cs

@@ -0,0 +1,74 @@
+namespace UglyToad.PdfPig.Tests.Integration
+{
+    using System;
+    using System.Collections.Generic;
+    using System.IO;
+    using System.Linq;
+    using Xunit;
+
+    public class SinglePageInkscapeTests
+    {
+        private static string GetFilename()
+        {
+            var documentFolder = Path.GetFullPath(Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "..", "..", "..", "Integration", "Documents"));
+
+            return Path.Combine(documentFolder, "Single Page Simple - from inkscape.pdf");
+        }
+
+        [Fact]
+        public void LettersHaveCorrectPositionsPdfBox()
+        {
+            using (var document = PdfDocument.Open(GetFilename()))
+            {
+                var page = document.GetPage(1);
+
+                var letters = page.Letters;
+                var positions = GetPdfBoxData();
+
+                for (int i = 0; i < letters.Count; i++)
+                {
+                    var letter = letters[i];
+                    var position = positions[i];
+                    position.AssertWithinTolerance(letter, page, false);
+                }
+            }
+        }
+
+        private static IReadOnlyList<AssertablePositionData> GetPdfBoxData()
+        {
+            const string data = @"100.57143	687.4286	31.616001	W	32.0	KTICVV+DejaVuSans	47.776
+130.74742	687.4286	13.152	r	32.0	KTICVV+DejaVuSans	36.704002
+143.89941	687.4286	8.864	i	32.0	KTICVV+DejaVuSans	49.792004
+152.76341	687.4286	12.544001	t	32.0	KTICVV+DejaVuSans	46.016003
+165.30742	687.4286	19.68	e	32.0	KTICVV+DejaVuSans	37.632
+184.98743	687.4286	10.144	 	32.0	KTICVV+DejaVuSans	0.0
+195.13142	687.4286	16.640001	s	32.0	KTICVV+DejaVuSans	37.632
+211.77142	687.4286	19.552	o	32.0	KTICVV+DejaVuSans	37.632
+231.32343	687.4286	31.168001	m	32.0	KTICVV+DejaVuSans	36.704002
+262.49142	687.4286	19.68	e	32.0	KTICVV+DejaVuSans	37.632
+282.17142	687.4286	12.544001	t	32.0	KTICVV+DejaVuSans	46.016003
+294.71542	687.4286	20.256	h	32.0	KTICVV+DejaVuSans	49.792004
+315.06744	687.4286	8.864	i	32.0	KTICVV+DejaVuSans	49.792004
+323.93146	687.4286	20.256	n	32.0	KTICVV+DejaVuSans	36.704002
+344.18747	687.4286	20.288	g	32.0	KTICVV+DejaVuSans	50.336002
+364.47546	687.4286	10.144	 	32.0	KTICVV+DejaVuSans	0.0
+374.61948	687.4286	8.864	i	32.0	KTICVV+DejaVuSans	49.792004
+383.4835	687.4286	20.256	n	32.0	KTICVV+DejaVuSans	36.704002
+100.57143	647.4286	9.408	I	32.0	KTICVV+DejaVuSans	47.776
+109.97942	647.4286	20.256	n	32.0	KTICVV+DejaVuSans	36.704002
+130.23543	647.4286	18.528002	k	32.0	KTICVV+DejaVuSans	49.792004
+148.76343	647.4286	16.640001	s	32.0	KTICVV+DejaVuSans	37.632
+165.40343	647.4286	17.568	c	32.0	KTICVV+DejaVuSans	37.632
+183.06743	647.4286	19.584002	a	32.0	KTICVV+DejaVuSans	37.632
+202.65143	647.4286	20.288	p	32.0	KTICVV+DejaVuSans	50.336002
+222.93942	647.4286	19.68	e	32.0	KTICVV+DejaVuSans	37.632
+";
+
+            var result = data.Split(new[] { "\r", "\n", "\r\n" }, StringSplitOptions.RemoveEmptyEntries)
+                .Select(AssertablePositionData.Parse)
+                .ToList();
+
+            return result;
+        }
+    }
+}

src/UglyToad.PdfPig.Tests/Integration/VisualVerification/GenerateLetterBoundingBoxImages.cs

@@ -35,7 +35,7 @@
         [Fact]
         public void SinglePageSimpleFromInkscape()
         {
-            Run(SingleInkscapePage);
+            Run(SingleInkscapePage, 841);
         }
 
         [Fact]
@@ -65,7 +65,7 @@
         [Fact]
         public void PigProductionCompactFontFormat()
         {
-            Run(PigProduction);
+            Run(PigProduction, 680);
         }
 
         private static void Run(string file, int imageHeight = 792)

src/UglyToad.PdfPig/Fonts/Simple/TrueTypeSimpleFont.cs

@@ -1,5 +1,6 @@
 namespace UglyToad.PdfPig.Fonts.Simple
 {
+    using System;
     using Cmap;
     using Composite;
     using Core;
@@ -107,18 +108,24 @@
             }
             
             decimal width;
-            if (font == null)
+
+            var index = characterCode - firstCharacter;
+            if (widths != null && index >= 0 && index < widths.Length)
             {
                 fromFont = false;
-                 width = widths[characterCode - firstCharacter];
+                 width = widths[index];
             }
-            else
+            else if (font != null)
             {
                 if (!font.TryGetBoundingAdvancedWidth(characterCode, out width))
                 {
                     width = boundingBoxPreTransform;
                 }
             }
+            else
+            {
+                throw new InvalidOperationException($"Could not retrieve width for character code: {characterCode} in font {Name}.");
+            }
             
             if (fromFont)
             {