Add `AsHexPad2` to `utils/str_cat`

Source/CMakeLists.txt

@@ -257,7 +257,6 @@ add_devilutionx_object_library(libdevilutionx_palette_kd_tree
 )
 target_link_dependencies(libdevilutionx_palette_kd_tree PUBLIC
   DevilutionX::SDL
-  fmt::fmt
   libdevilutionx_strings
 )
 
@@ -554,7 +553,6 @@ add_devilutionx_object_library(libdevilutionx_palette_blending
 )
 target_link_dependencies(libdevilutionx_palette_blending PUBLIC
   DevilutionX::SDL
-  fmt::fmt
   libdevilutionx_palette_kd_tree
   libdevilutionx_strings
 )

Source/dvlnet/zerotier_native.cpp

@@ -66,9 +66,13 @@ std::string ComputeAlternateFolderName(std::string_view path)
 	    nullptr, 0);
 
 	if (status != 0)
-		return "";
+		return {};
 
-	return fmt::format("{:02x}", fmt::join(hash, ""));
+	char buf[hashSize * 2];
+	for (size_t i = 0; i < hashSize; ++i) {
+		BufCopy(&buf[i * 2], AsHexPad2(hash[i]));
+	}
+	return std::string(buf, hashSize * 2);
 }
 
 std::string ToZTCompliantPath(std::string_view configPath)

Source/engine/render/text_render.cpp

@@ -34,6 +34,7 @@
 #include "utils/is_of.hpp"
 #include "utils/language.h"
 #include "utils/log.hpp"
+#include "utils/str_cat.hpp"
 #include "utils/utf8.hpp"
 
 namespace devilution {
@@ -139,12 +140,12 @@ bool IsSmallFontTallRow(uint16_t row)
 
 void GetFontPath(GameFontTables size, uint16_t row, std::string_view ext, char *out)
 {
-	*fmt::format_to(out, R"(fonts\{}-{:02x}{})", FontSizes[size], row, ext) = '\0';
+	*BufCopy(out, "fonts\\", FontSizes[size], "-", AsHexPad2(row), ext) = '\0';
 }
 
 void GetFontPath(std::string_view language_code, GameFontTables size, uint16_t row, std::string_view ext, char *out)
 {
-	*fmt::format_to(out, R"(fonts\{}\{}-{:02x}{})", language_code, FontSizes[size], row, ext) = '\0';
+	*BufCopy(out, "fonts\\", language_code, "\\", FontSizes[size], "-", AsHexPad2(row), ext) = '\0';
 }
 
 uint32_t GetFontId(GameFontTables size, uint16_t row)

Source/utils/palette_kd_tree.cpp

@@ -13,8 +13,6 @@
 #include <SDL_pixels.h>
 #endif
 
-#include <fmt/format.h>
-
 #include "utils/static_vector.hpp"
 #include "utils/str_cat.hpp"
 
@@ -197,9 +195,8 @@ void PaletteKdTreeNode<0>::toGraphvizDot(
 	const std::pair<RGB, uint8_t> *const end = values.data() + valuesEndInclusive;
 	for (const std::pair<RGB, uint8_t> *it = values.data() + valuesBegin; it <= end; ++it) {
 		const auto &[rgb, paletteIndex] = *it;
-		char hexColor[6];
-		fmt::format_to(hexColor, "{:02x}{:02x}{:02x}", rgb[0], rgb[1], rgb[2]);
-		StrAppend(dot, R"(<td balign="left" bgcolor="#)", std::string_view(hexColor, 6), "\">");
+		StrAppend(dot, R"(<td balign="left" bgcolor="#)",
+		    AsHexPad2(rgb[0]), AsHexPad2(rgb[1]), AsHexPad2(rgb[2]), "\">");
 		const bool useWhiteText = rgb[0] + rgb[1] + rgb[2] < 350;
 		if (useWhiteText) StrAppend(dot, R"(<font color="white">)");
 		StrAppend(dot,

Source/utils/str_cat.cpp

@@ -1,9 +1,17 @@
 #include "utils/str_cat.hpp"
 
+#include <cstdint>
+
 #include <fmt/format.h>
 
 namespace devilution {
 
+namespace {
+
+[[nodiscard]] char HexDigit(uint8_t v) { return "0123456789abcdef"[v]; }
+
+} // namespace
+
 char *BufCopy(char *out, long long value)
 {
 	const fmt::format_int formatted { value };
@@ -16,6 +24,23 @@ char *BufCopy(char *out, unsigned long long value)
 	std::memcpy(out, formatted.data(), formatted.size());
 	return out + formatted.size();
 }
+char *BufCopy(char *out, AsHexU8Pad2 value)
+{
+	*out++ = HexDigit(value.value >> 4);
+	*out++ = HexDigit(value.value & 0xf);
+	return out;
+}
+char *BufCopy(char *out, AsHexU16Pad2 value)
+{
+	if (value.value > 0xff) {
+		if (value.value > 0xfff) {
+			out = BufCopy(out, AsHexU8Pad2 { static_cast<uint8_t>(value.value >> 8) });
+		} else {
+			*out++ = HexDigit(value.value >> 8);
+		}
+	}
+	return BufCopy(out, AsHexU8Pad2 { static_cast<uint8_t>(value.value & 0xff) });
+}
 
 void StrAppend(std::string &out, long long value)
 {
@@ -27,5 +52,17 @@ void StrAppend(std::string &out, unsigned long long value)
 	const fmt::format_int formatted { value };
 	out.append(formatted.data(), formatted.size());
 }
+void StrAppend(std::string &out, AsHexU8Pad2 value)
+{
+	char hex[2];
+	BufCopy(hex, value);
+	out.append(hex, 2);
+}
+void StrAppend(std::string &out, AsHexU16Pad2 value)
+{
+	char hex[4];
+	const auto len = static_cast<size_t>(BufCopy(hex, value) - hex);
+	out.append(hex, len);
+}
 
 } // namespace devilution

Source/utils/str_cat.hpp

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <cstdint>
 #include <cstring>
 #include <string>
 #include <string_view>
@@ -7,6 +8,24 @@
 
 namespace devilution {
 
+struct AsHexU8Pad2 {
+	uint8_t value;
+};
+
+struct AsHexU16Pad2 {
+	uint16_t value;
+};
+
+/**
+ * @brief Formats the value as a lowercase zero-padded hexadecimal with at least 2 hex digits (0-padded on the left).
+ */
+constexpr AsHexU8Pad2 AsHexPad2(uint8_t value) { return { value }; }
+
+/**
+ * @brief Formats the value as a lowercase zero-padded hexadecimal with at least 2 hex digits (0-padded on the left).
+ */
+constexpr AsHexU16Pad2 AsHexPad2(uint16_t value) { return { value }; }
+
 /**
  * @brief Writes the integer to the given buffer.
  * @return char* end of the buffer
@@ -43,6 +62,9 @@ inline char *BufCopy(char *out, unsigned short value)
 	return BufCopy(out, static_cast<unsigned long long>(value));
 }
 
+char *BufCopy(char *out, AsHexU8Pad2 value);
+char *BufCopy(char *out, AsHexU16Pad2 value);
+
 /**
  * @brief Appends the integer to the given string.
  */
@@ -77,6 +99,9 @@ inline void StrAppend(std::string &out, unsigned short value)
 	StrAppend(out, static_cast<unsigned long long>(value));
 }
 
+void StrAppend(std::string &out, AsHexU8Pad2 value);
+void StrAppend(std::string &out, AsHexU16Pad2 value);
+
 /**
  * @brief Copies the given std::string_view to the given buffer.
  */