From 1d75400a2d50e1eebea14ec009c3ae8e59accd57 Mon Sep 17 00:00:00 2001
From: Patrick Wuttke <mewin@mewin.de>
Date: Wed, 5 Mar 2025 22:02:30 +0100
Subject: [PATCH] Added more options to font loading.

---
 SModule                      |  2 +-
 private/raid/application.cpp | 63 +++++++++++++++++++++++++++---------
 public/raid/raid.hpp         | 23 ++++++++++++-
 3 files changed, 71 insertions(+), 17 deletions(-)

diff --git a/SModule b/SModule
index 2d1be6d..77ef2e8 100644
--- a/SModule
+++ b/SModule
@@ -4,7 +4,7 @@ Import('env')
 public_dir = env.Dir('public')
 env.Append(CPPPATH = [public_dir])
 if env['BUILD_TYPE'] == 'release':
-    cppdefines += ['RAID_RELEASE=1']
+    env.Append(CPPDEFINES = ['RAID_RELEASE'])
 env = env.Module('private/raid/SModule')
 
 LIB_CONFIG = {
diff --git a/private/raid/application.cpp b/private/raid/application.cpp
index dd78e91..0983476 100644
--- a/private/raid/application.cpp
+++ b/private/raid/application.cpp
@@ -7,6 +7,7 @@
 #include <SDL3/SDL.h>
 #include <mijin/debug/assert.hpp>
 #include <mijin/platform/folders.hpp>
+#include <mijin/util/iterators.hpp>
 #include <mijin/util/scope_guard.hpp>
 #include <mijin/virtual_filesystem/mapping.hpp>
 #include <mijin/virtual_filesystem/relative.hpp>
@@ -125,29 +126,55 @@ int Application::run(int argc, char** argv)
     return 0;
 }
 
-bool Application::loadFont(const fs::path& path)
+
+bool Application::loadFonts(std::span<const FontConfig> fonts)
 {
     ImGuiIO& imguiIO = ImGui::GetIO();
 
-    std::unique_ptr<mijin::Stream> fontFile;
-    if (const mijin::StreamError error = mFS.open(path, mijin::FileOpenMode::READ, fontFile);
-            error != mijin::StreamError::SUCCESS)
-    {
-        msgError("Error opening font file {}: {}.", path.generic_string(), mijin::errorName(error));
-        return false;
-    }
+    std::vector<mijin::TypelessBuffer> buffers;
+    buffers.reserve(fonts.size());
 
-    mijin::TypelessBuffer data;
-    if (const mijin::StreamError readError = fontFile->readRest(data); readError != mijin::StreamError::SUCCESS)
+    for (const FontConfig& font : fonts)
     {
-        msgError("Error reading font data from {}: {}.", path.generic_string(), mijin::errorName(readError));
-        return false;
+        std::unique_ptr<mijin::Stream> fontFile;
+        if (const mijin::StreamError error = mFS.open(font.path, mijin::FileOpenMode::READ, fontFile);
+                error != mijin::StreamError::SUCCESS)
+        {
+            msgError("Error opening font file {}: {}.", font.path.generic_string(), mijin::errorName(error));
+            return false;
+        }
+
+        mijin::TypelessBuffer& data = buffers.emplace_back();
+        if (const mijin::StreamError readError = fontFile->readRest(data); readError != mijin::StreamError::SUCCESS)
+        {
+            msgError("Error reading font data from {}: {}.", font.path.generic_string(), mijin::errorName(readError));
+            return false;
+        }
     }
 
     // by default ImGui takes ownership of the data, that's now what we want
     ImFontConfig config;
     config.FontDataOwnedByAtlas = false;
-    imguiIO.Fonts->AddFontFromMemoryTTF(data.data(), static_cast<int>(data.byteSize()), 20, &config);
+    std::vector<ImWchar> glyphRangesConverted;
+    for (const auto& [font, data] : mijin::zip(fonts, buffers))
+    {
+        ImWchar* glyphRanges = nullptr;
+        if (!font.glyphRanges.empty())
+        {
+            glyphRangesConverted.reserve(2 * font.glyphRanges.size() + 1);
+            glyphRangesConverted.clear();
+            for (const std::pair<ImWchar, ImWchar>& range : font.glyphRanges)
+            {
+                glyphRangesConverted.push_back(range.first);
+                glyphRangesConverted.push_back(range.second);
+            }
+            glyphRangesConverted.push_back(0);
+            glyphRanges = glyphRangesConverted.data();
+        }
+        config.PixelSnapH = font.flags.pixelSnapH;
+        imguiIO.Fonts->AddFontFromMemoryTTF(data.data(), static_cast<int>(data.byteSize()), font.size, &config, glyphRanges);
+        config.MergeMode = true; // for any more fonts
+    }
 
     // but in that case Build() has to be run before the data gets deleted
     imguiIO.Fonts->Build();
@@ -209,6 +236,13 @@ void Application::configureImgui()
     imguiIO.ConfigViewportsNoAutoMerge = true;
 }
 
+std::vector<FontConfig> Application::getDefaultFonts()
+{
+    return {{
+        .path = "/data/fonts/NotoSans-Regular.ttf"
+    }};
+}
+
 void Application::handleMessage(const Message& message)
 {
     switch (message.severity)
@@ -452,8 +486,7 @@ bool Application::initImGui()
     // init font
     if (imguiIO.Fonts->Fonts.empty())
     {
-        static const char* const DEFAULT_FONT = "/data/fonts/NotoSans-Regular.ttf";
-        if (!loadFont(DEFAULT_FONT))
+        if (!loadFonts(getDefaultFonts()))
         {
             imguiIO.Fonts->AddFontDefault();
         }
diff --git a/public/raid/raid.hpp b/public/raid/raid.hpp
index 9c8d7ec..f6410ba 100644
--- a/public/raid/raid.hpp
+++ b/public/raid/raid.hpp
@@ -9,6 +9,7 @@
 #include <fmt/format.h>
 #include <imgui.h>
 #include <mijin/async/coroutine.hpp>
+#include <mijin/util/bitflags.hpp>
 #include <mijin/virtual_filesystem/stacked.hpp>
 #include <SDL3/SDL.h>
 
@@ -34,6 +35,19 @@ struct Message
     const char* text;
 };
 
+struct FontFlags : mijin::BitFlags<FontFlags>
+{
+    bool pixelSnapH : 1 = false;
+};
+
+struct FontConfig
+{
+    fs::path path;
+    std::vector<std::pair<ImWchar, ImWchar>> glyphRanges;
+    float size = 20.f;
+    FontFlags flags;
+};
+
 class Application
 {
 private:
@@ -90,7 +104,13 @@ public:
     int run(int argc, char* argv[]);
 
     [[nodiscard]]
-    bool loadFont(const fs::path& path);
+    bool loadFonts(std::span<const FontConfig> fonts);
+
+    [[nodiscard]]
+    bool loadFont(const FontConfig& font)
+    {
+        return loadFonts({&font, 1});
+    }
 
     [[nodiscard]]
     ImTextureID getOrLoadTexture(fs::path path);
@@ -100,6 +120,7 @@ protected:
     virtual std::string getFolderName() = 0;
     virtual std::string getWindowTitle() = 0;
     virtual void configureImgui();
+    virtual std::vector<FontConfig> getDefaultFonts();
     virtual void handleMessage(const Message& message);
     virtual void handleSDLEvent(const SDL_Event& event);