improve ascii/binary detection

ixmilia · Sep 13, 2023 · 7602b74 · 7602b74
1 parent 93855a7
commit 7602b74
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Showing 2 changed files with 75 additions and 9 deletions.
diff --git a/src/IxMilia.Stl.Test/StlReaderTests.cs b/src/IxMilia.Stl.Test/StlReaderTests.cs
@@ -173,6 +173,74 @@ public void ReadBinaryStlNoLengthOrPositionStreamTest()
             Assert.Equal(new StlVertex(22.0f, 23.0f, 24.0f), file.Triangles[1].Vertex3);
         }
 
+        [Fact]
+        public void ReadBinaryStlWithAsciiHeaderTest()
+        {
+            var binarySize =
+                80 +                    // header
+                sizeof(int) +           // number of triangles
+                2 *                     // 2 verticies
+                (
+                    sizeof(float) * 3 +     // normal vector
+                    sizeof(float) * 3 +     // vertex 1
+                    sizeof(float) * 3 +     // vertex 2
+                    sizeof(float) * 3 +     // vertex 3
+                    sizeof(short)           // attribute byte count
+                );
+            var binaryList = new List<byte>();
+
+            var headerText = "solid TestSolid";
+            binaryList.AddRange(Encoding.ASCII.GetBytes(headerText));
+            binaryList.AddRange(new byte[80 - headerText.Length]); // header
+            binaryList.AddRange(BitConverter.GetBytes(2)); // 2 triangles
+
+            // first triangle
+            binaryList.AddRange(BitConverter.GetBytes(1.0f)); // normal.X
+            binaryList.AddRange(BitConverter.GetBytes(2.0f)); // normal.Y
+            binaryList.AddRange(BitConverter.GetBytes(3.0f)); // normal.Z
+            binaryList.AddRange(BitConverter.GetBytes(4.0f)); // vertex1.X
+            binaryList.AddRange(BitConverter.GetBytes(5.0f)); // vertex1.Y
+            binaryList.AddRange(BitConverter.GetBytes(6.0f)); // vertex1.Z
+            binaryList.AddRange(BitConverter.GetBytes(7.0f)); // vertex2.X
+            binaryList.AddRange(BitConverter.GetBytes(8.0f)); // vertex2.Y
+            binaryList.AddRange(BitConverter.GetBytes(9.0f)); // vertex2.Z
+            binaryList.AddRange(BitConverter.GetBytes(10.0f)); // vertex3.X
+            binaryList.AddRange(BitConverter.GetBytes(11.0f)); // vertex3.Y
+            binaryList.AddRange(BitConverter.GetBytes(12.0f)); // vertex3.Z
+            binaryList.AddRange(BitConverter.GetBytes((short)0)); // attribute byte count
+
+            // second triangle
+            binaryList.AddRange(BitConverter.GetBytes(13.0f)); // normal.X
+            binaryList.AddRange(BitConverter.GetBytes(14.0f)); // normal.Y
+            binaryList.AddRange(BitConverter.GetBytes(15.0f)); // normal.Z
+            binaryList.AddRange(BitConverter.GetBytes(16.0f)); // vertex1.X
+            binaryList.AddRange(BitConverter.GetBytes(17.0f)); // vertex1.Y
+            binaryList.AddRange(BitConverter.GetBytes(18.0f)); // vertex1.Z
+            binaryList.AddRange(BitConverter.GetBytes(19.0f)); // vertex2.X
+            binaryList.AddRange(BitConverter.GetBytes(20.0f)); // vertex2.Y
+            binaryList.AddRange(BitConverter.GetBytes(21.0f)); // vertex2.Z
+            binaryList.AddRange(BitConverter.GetBytes(22.0f)); // vertex3.X
+            binaryList.AddRange(BitConverter.GetBytes(23.0f)); // vertex3.Y
+            binaryList.AddRange(BitConverter.GetBytes(24.0f)); // vertex3.Z
+            binaryList.AddRange(BitConverter.GetBytes((short)0)); // attribute byte count
+
+            Assert.Equal(binarySize, binaryList.Count);
+
+            var file = FromBytes(binaryList.ToArray());
+            Assert.Equal("TestSolid", file.SolidName);
+            Assert.Equal(2, file.Triangles.Count);
+
+            Assert.Equal(new StlNormal(1.0f, 2.0f, 3.0f), file.Triangles[0].Normal);
+            Assert.Equal(new StlVertex(4.0f, 5.0f, 6.0f), file.Triangles[0].Vertex1);
+            Assert.Equal(new StlVertex(7.0f, 8.0f, 9.0f), file.Triangles[0].Vertex2);
+            Assert.Equal(new StlVertex(10.0f, 11.0f, 12.0f), file.Triangles[0].Vertex3);
+
+            Assert.Equal(new StlNormal(13.0f, 14.0f, 15.0f), file.Triangles[1].Normal);
+            Assert.Equal(new StlVertex(16.0f, 17.0f, 18.0f), file.Triangles[1].Vertex1);
+            Assert.Equal(new StlVertex(19.0f, 20.0f, 21.0f), file.Triangles[1].Vertex2);
+            Assert.Equal(new StlVertex(22.0f, 23.0f, 24.0f), file.Triangles[1].Vertex3);
+        }
+
         [Fact]
         public void ReadAsciiTriangleWithNoNormalTest()
         {

diff --git a/src/IxMilia.Stl/StlReader.cs b/src/IxMilia.Stl/StlReader.cs
@@ -24,18 +24,19 @@ public StlReader(Stream stream)
         public string ReadSolidName()
         {
             int i;
-            bool headerComplete = false;
+            bool headerAsciiComplete = false;
+            bool headerBinaryComplete = false;
             var sb = new StringBuilder();
-            for (i = 0; i < 80 && !headerComplete; i++)
+            for (i = 0; i < 80 && !headerAsciiComplete && !headerBinaryComplete; i++)
             {
                 var b = binReader.ReadByte();
                 if (b == '\n')
                 {
-                    headerComplete = true;
+                    headerAsciiComplete = true;
                 }
                 else if (b == 0)
                 {
-                    headerComplete = true;
+                    headerBinaryComplete = true;
                 }
                 else
                 {
@@ -47,13 +48,10 @@ public string ReadSolidName()
             var match = headerReg.Match(header);
             if (match.Success)
             {
-                isAscii = true;
                 header = match.Groups[1].Value;
             }
-            else
-            {
-                isAscii = false;
-            }
+
+            isAscii = headerAsciiComplete && match.Success;
 
             if (isAscii)
             {