Fonts: adding ImFontHooks for codepoint remapping.

imgui.h

@@ -177,6 +177,7 @@ struct ImFontBaked;                 // Baked data for a ImFont at a given size.
 struct ImFontConfig;                // Configuration data when adding a font or merging fonts
 struct ImFontGlyph;                 // A single font glyph (code point + coordinates within in ImFontAtlas + offset)
 struct ImFontGlyphRangesBuilder;    // Helper to build glyph ranges from text/string data
+struct ImFontHooks;                 // Opaque interface to font hooks
 struct ImFontLoader;                // Opaque interface to a font loading backend (stb_truetype, FreeType etc.).
 struct ImTextureData;               // Specs and pixel storage for a texture used by Dear ImGui.
 struct ImTextureRect;               // Coordinates of a rectangle within a texture.
@@ -3682,6 +3683,7 @@ struct ImFontAtlas
     const ImFontLoader*         FontLoader;         // Font loader opaque interface (default to stb_truetype, can be changed to use FreeType by defining IMGUI_ENABLE_FREETYPE). Don't set directly!
     const char*                 FontLoaderName;     // Font loader name (for display e.g. in About box) == FontLoader->Name
     void*                       FontLoaderData;     // Font backend opaque storage
+    const ImFontHooks*          FontHooks;          // Shared font hooks for all fonts.
     unsigned int                FontBuilderFlags;   // [FIXME: Should be called FontLoaderFlags] Shared flags (for all fonts) for font loader. THIS IS BUILD IMPLEMENTATION DEPENDENT (e.g. . Per-font override is also available in ImFontConfig.
     int                         RefCount;           // Number of contexts using this atlas
 
@@ -3769,6 +3771,7 @@ struct ImFont
     float                       Scale;              // 4     // in  // Base font scale (~1.0f), multiplied by the per-window font scale which you can adjust with SetWindowFontScale()
     ImU8                        Used8kPagesMap[(IM_UNICODE_CODEPOINT_MAX+1)/8192/8]; // 1 bytes if ImWchar=ImWchar16, 16 bytes if ImWchar==ImWchar32. Store 1-bit for each block of 4K codepoints that has one active glyph. This is mainly used to facilitate iterations across all used codepoints.
     bool                        EllipsisAutoBake;   // 1     //     // Mark when the "..." glyph needs to be generated.
+    const ImFontHooks*          FontHooks;          // 8     // in  // Custom font hooks for the font.
 
     // Methods
     IMGUI_API ImFont();

imgui_draw.cpp

@@ -4365,6 +4365,14 @@ static void ImFontBaked_BuildGrowIndex(ImFontBaked* baked, int new_size)
     baked->IndexLookup.resize(new_size, IM_FONTGLYPH_INDEX_UNUSED);
 }
 
+static void ImFont_FontHookRemapCodepoint(ImFontAtlas* atlas, ImFont* font, ImWchar* c)
+{
+    if (font->FontHooks && font->FontHooks->FontHookRemapCodepoint != NULL)
+        font->FontHooks->FontHookRemapCodepoint(atlas, font, c);
+    else if (atlas->FontHooks && atlas->FontHooks->FontHookRemapCodepoint != NULL)
+        atlas->FontHooks->FontHookRemapCodepoint(atlas, font, c);
+}
+
 static ImFontGlyph* ImFontBaked_BuildLoadGlyph(ImFontBaked* baked, ImWchar codepoint)
 {
     ImFont* font = baked->ContainerFont;
@@ -4377,6 +4385,10 @@ static ImFontGlyph* ImFontBaked_BuildLoadGlyph(ImFontBaked* baked, ImWchar codep
         return NULL;
     }
 
+    // User remapping hooks
+    ImWchar src_codepoint = codepoint;
+    ImFont_FontHookRemapCodepoint(atlas, font, &codepoint);
+
     //char utf8_buf[5];
     //IMGUI_DEBUG_LOG("[font] BuildLoadGlyph U+%04X (%s)\n", (unsigned int)codepoint, ImTextCharToUtf8(utf8_buf, (unsigned int)codepoint));
 
@@ -4398,6 +4410,7 @@ static ImFontGlyph* ImFontBaked_BuildLoadGlyph(ImFontBaked* baked, ImWchar codep
             if (loader->FontBakedLoadGlyph(atlas, src, baked, loader_user_data_p, codepoint, &glyph_buf))
             {
                 // FIXME: Add hooks for e.g. #7962
+                glyph_buf.Codepoint = src_codepoint;
                 glyph_buf.SourceIdx = src_n;
                 return ImFontAtlasBakedAddFontGlyph(atlas, baked, src, &glyph_buf);
             }
@@ -5079,7 +5092,7 @@ void ImFontAtlasBakedSetFontGlyphBitmap(ImFontAtlas* atlas, ImFontBaked* baked,
     ImFontAtlasTextureBlockQueueUpload(atlas, tex, r->x, r->y, r->w, r->h);
 }
 
-// FIXME-NEWATLAS: Implement AddRemapChar() which was removed since transitioning to baked logic.
+// FIXME: Use ImFontHooks::FontHookRemapCodepoint() hooks.
 void ImFont::AddRemapChar(ImWchar from_codepoint, ImWchar to_codepoint, bool overwrite_dst)
 {
     IM_UNUSED(from_codepoint);
@@ -5149,6 +5162,7 @@ bool ImFontBaked::IsGlyphLoaded(ImWchar c)
 bool ImFont::IsGlyphInFont(ImWchar c)
 {
     ImFontAtlas* atlas = ContainerAtlas;
+    ImFont_FontHookRemapCodepoint(atlas, this, &c);
     for (ImFontConfig* src : Sources)
     {
         const ImFontLoader* loader = src->FontLoader ? src->FontLoader : atlas->FontLoader;

imgui_internal.h

@@ -37,7 +37,7 @@ Index of this file:
 // [SECTION] Tab bar, Tab item support
 // [SECTION] Table support
 // [SECTION] ImGui internal API
-// [SECTION] ImFontLoader
+// [SECTION] ImFontLoader, ImFontHooks
 // [SECTION] ImFontAtlas internal API
 // [SECTION] Test Engine specific hooks (imgui_test_engine)
 
@@ -3664,7 +3664,7 @@ namespace ImGui
 
 
 //-----------------------------------------------------------------------------
-// [SECTION] ImFontLoader
+// [SECTION] ImFontLoader, ImFontHooks
 //-----------------------------------------------------------------------------
 
 // Hooks and storage for a given font backend.
@@ -3693,6 +3693,14 @@ struct ImFontLoader
 IMGUI_API const ImFontLoader* ImFontAtlasGetFontLoaderForStbTruetype();
 #endif
 
+// User hooks
+// Conceptually this could be public, but API is still going to be evolve.
+struct ImFontHooks
+{
+    // Modify codepoint to map to another value.
+    void            (*FontHookRemapCodepoint)(ImFontAtlas* atlas, ImFont* font, ImWchar* io_codepoint);
+};
+
 //-----------------------------------------------------------------------------
 // [SECTION] ImFontAtlas internal API
 //-----------------------------------------------------------------------------