Compiler and binary size friendly version of the imgui glyph initiali…

…zers.

build-scripts/get_translation_characters.py

@@ -4,6 +4,7 @@
 # creates ImGui glyph ranges for each locale, so that every locale can
 # have properly rendered text.
 
+import itertools
 import sys
 from cldr_language_helpers import alphabets
 
@@ -14,6 +15,28 @@ def main():
           "el es fr hu id is it ja ko nb nl pl pt ru sr tr uk_UA zh_Hans "
           "zh_Hant > src/cldr/imgui-glyph-ranges.cpp\n")
     print("// NOLINTBEGIN(cata-static-declarations,readability-function-size)")
+    print("")
+    print("#if defined(__GNUC__) or defined(__clang__)")
+    print("#define NOINLINE __attribute__ ((noinline))")
+    print("#else")
+    print("#define NOINLINE __declspec(noinline)")
+    print("#endif")
+    print("#if defined(__GNUC__)")
+    print("#define NOUNROLL #pragma GCC unroll 0")
+    print("#elif defined(__clang__)")
+    print("#define NOUNROLL #pragma clang loop unroll(disable)")
+    print("#else")
+    print("#define NOUNROLL")
+    print("#endif")
+    print("")
+    print("static NOINLINE void AddGlyphs( ImFontGlyphRangesBuilder *b, "
+          "ImWchar const *glyphp, ImWchar const *end) {")
+    print("  NOUNROLL")
+    print("  for( ; glyphp != end; ++glyphp ) {")
+    print("    b->AddChar(*glyphp);")
+    print("  }")
+    print("}")
+    print("")
     try:
         for language in sys.argv[1:]:
             print_func(language)
@@ -25,9 +48,14 @@ def main():
         return 1
 
 
+def chunks(xs, n):
+    n = max(1, n)
+    return (xs[i:i + n] for i in range(0, len(xs), n))
+
+
 def print_func(language):
     print(f"static void AddGlyphRangesFromCLDRFor{language.upper()}("
-          "ImFontGlyphRangesBuilder *b) {{")
+          "ImFontGlyphRangesBuilder *b) {")
     # All of the glyphs used this language
     chars = []
     for c in alphabets.ALPHABETS_BY_LANG_MAP[language]:
@@ -43,31 +71,16 @@ def print_func(language):
         for g in c:
             chars.append(ord(g))
     # Sort and remove duplicates, so we can detect sequences
-    chars = sorted(list(set(chars)))
-
-    # Detect if this character is just one greater than the last character,
-    # and so could be added with a for loop instead
-    last_char = chars[0]
-    output = [[last_char, 1]]
-    for char in chars[1:]:
-        if char - last_char == 1:
-            output[-1][1] += 1
-        else:
-            output.append([char, 1])
-        last_char = char
+    chars = [hex(c) for c in sorted(list(set(chars)))]
 
-    for char, length in output:
-        if length == 1:
-            print(f"    b->AddChar({hex(char)});")
-        # Don't add a for loop if it's neutral or requires more lines
-        elif length < 4:
-            for i in range(length):
-                print(f"    b->AddChar({hex(char + i)});")
-        else:
-            print(f"    for(int i = 0; i < {length}; ++i)" + " {\n" +
-                  f"        b->AddChar({hex(char)} + i);" + "\n" +
-                  "    }")
-    print("}\n")
+    print("  static constexpr ImWchar glyphs[] = {")
+    char_chunks = list(chunks(chars, 16))
+    for cs in itertools.islice(char_chunks, len(char_chunks) - 1):
+        print(", ".join(cs) + ",")
+    print(", ".join(char_chunks[-1]))
+    print("  };")
+    print("  AddGlyphs(b, glyphs, glyphs + std::extent_v<decltype(glyphs)>);")
+    print("}")
 
 
 if __name__ == '__main__':