Add initial font metrics and equation rendering.

src/base/core/encoding/UnicodeUtils.cpp

@@ -39,3 +39,53 @@ std::wstring UnicodeUtils::utf8ToUtf16WString(const std::string& input)
     throw std::logic_error("Not implemented");
 #endif
 }
+
+std::vector<uint32_t> UnicodeUtils::utf8ToUtf32(const std::string& input)
+{
+    const auto utf_16 = utf8ToUtf16WString(input);
+
+    std::vector<uint32_t> output;
+    std::size_t pos = 0;
+    while (pos < utf_16.size())
+    {
+        const auto c = utf_16[pos];
+        pos++;
+        if (!isSurrogate(c))
+        {
+            output.push_back(c);
+        }
+        else
+        {
+            if (isHighSurrogate(c) && pos < utf_16.size() && isLowSurrogate(utf_16[pos]))
+            {
+                output.push_back(surrogateToUtf32(c, utf_16[pos]));
+                pos++;
+            }
+            else
+            {
+                throw std::logic_error("Unexpected UTF16 content given for conversion to UTF32");
+            }
+        }
+    }
+    return output;
+}
+
+bool UnicodeUtils::isSurrogate(wchar_t c)
+{ 
+    return (c - 0xd800u) < 2048u; 
+}
+
+bool UnicodeUtils::isHighSurrogate(wchar_t c)
+{
+    return (c & 0xfffffc00) == 0xd800;
+}
+
+bool UnicodeUtils::isLowSurrogate(wchar_t c)
+{
+    return (c & 0xfffffc00) == 0xdc00;
+}
+
+uint32_t UnicodeUtils::surrogateToUtf32(wchar_t high, wchar_t low)
+{
+    return (high << 10) + low - 0x35fdc00;
+}

src/base/core/encoding/UnicodeUtils.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <string>
+#include <vector>
 
 class UnicodeUtils
 {
@@ -8,4 +9,12 @@ public:
 	static std::string utf16ToUtf8String(const std::wstring& input);
 
 	static std::wstring utf8ToUtf16WString(const std::string& input);
+
+	static std::vector<uint32_t> utf8ToUtf32(const std::string& input);
+
+private:
+	static bool isSurrogate(wchar_t c);
+	static bool isHighSurrogate(wchar_t c);
+	static bool isLowSurrogate(wchar_t c);
+	static uint32_t surrogateToUtf32(wchar_t high, wchar_t low);
 };