font_loader.cc

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#include "app/platform/font_loader.h"
 
#include <cstring>
#include <filesystem>
#include <fstream>
#include <string>
#include <vector>
 
#include "absl/status/status.h"
#include "absl/strings/str_cat.h"
#include "absl/strings/str_format.h"
#include "app/gui/core/icons.h"
#include "imgui/imgui.h"
#include "util/file_util.h"
#include "util/macro.h"
#include "util/platform_paths.h"
 
namespace yaze {
 
static const char* KARLA_REGULAR = "Karla-Regular.ttf";
static const char* ROBOTO_MEDIUM = "Roboto-Medium.ttf";
static const char* COUSINE_REGULAR = "Cousine-Regular.ttf";
static const char* DROID_SANS = "DroidSans.ttf";
static const char* NOTO_SANS_JP = "NotoSansJP.ttf";
static const char* IBM_PLEX_JP = "IBMPlexSansJP-Bold.ttf";
 
static const float FONT_SIZE_DEFAULT = 16.0F;
static const float FONT_SIZE_DROID_SANS = 18.0F;
static const float ICON_FONT_SIZE = 18.0F;
 
namespace {
 
std::string ResolveRepoFontPath(const std::string& font_path) {
  // Prefer the robust asset search (exe-dir, ~/.yaze, /usr/share, repo-relative)
  // so installed binaries and .desktop/double-click launches (CWD=$HOME or /)
  // still find bundled fonts at startup.
  auto found = util::PlatformPaths::FindAsset("font/" + font_path);
  if (found.ok()) {
    return found->string();
  }
  // Fallback: CWD-relative probes for running directly from the repo/build dir.
  const std::vector<std::filesystem::path> candidates = {
      std::filesystem::path("assets/font") / font_path,
      std::filesystem::path("../assets/font") / font_path,
      std::filesystem::path("../../assets/font") / font_path,
      std::filesystem::path("../../../assets/font") / font_path,
  };
  for (const auto& candidate : candidates) {
    if (std::filesystem::exists(candidate)) {
      return candidate.string();
    }
  }
  return (std::filesystem::path("assets/font") / font_path).string();
}
 
std::string SetFontPath(const std::string& font_path) {
#ifdef __APPLE__
#if TARGET_OS_IOS == 1
  const std::string bundle_root = util::GetBundleResourcePath();
  std::string bundle_path =
      absl::StrCat(bundle_root, "assets/font/", font_path);
  if (std::filesystem::exists(bundle_path)) {
    return bundle_path;
  }
  bundle_path = absl::StrCat(bundle_root, font_path);
  if (std::filesystem::exists(bundle_path)) {
    return bundle_path;
  }
  return ResolveRepoFontPath(font_path);
#else
  std::string bundle_path = absl::StrCat(util::GetBundleResourcePath(),
                                         "Contents/Resources/font/", font_path);
  if (std::filesystem::exists(bundle_path)) {
    return bundle_path;
  }
  return ResolveRepoFontPath(font_path);
#endif
#else
  return ResolveRepoFontPath(font_path);
#endif
}
 
absl::Status LoadFont(const FontConfig& font_config) {
  ImGuiIO& imgui_io = ImGui::GetIO();
  std::string actual_font_path = SetFontPath(font_config.font_path);
  // Check if the file exists with std library first, since ImGui IO will assert
  // if the file does not exist
  if (!std::filesystem::exists(actual_font_path)) {
    return absl::InternalError(
        absl::StrFormat("Font file %s does not exist", actual_font_path));
  }
 
  if (!imgui_io.Fonts->AddFontFromFileTTF(actual_font_path.data(),
                                          font_config.font_size)) {
    return absl::InternalError(
        absl::StrFormat("Failed to load font from %s", actual_font_path));
  }
  return absl::OkStatus();
}
 
absl::Status AddIconFont(const FontConfig& /*config*/) {
  static const ImWchar icons_ranges[] = {ICON_MIN_MD, 0xf900, 0};
  ImFontConfig icons_config{};
  icons_config.MergeMode = true;
  icons_config.GlyphOffset.y = 5.0F;
  icons_config.GlyphMinAdvanceX = 13.0F;
  icons_config.PixelSnapH = true;
  std::string icon_font_path = SetFontPath(FONT_ICON_FILE_NAME_MD);
  ImGuiIO& imgui_io = ImGui::GetIO();
  if (!imgui_io.Fonts->AddFontFromFileTTF(icon_font_path.c_str(),
                                          ICON_FONT_SIZE, &icons_config,
                                          icons_ranges)) {
    return absl::InternalError("Failed to add icon fonts");
  }
  return absl::OkStatus();
}
 
// NotoSansJP.ttf is ~9.5 MB and is merged into every base font; loading it
// from file per merge kept one copy per font. All merges share this buffer.
// ImGui 1.92 reads font source data for the life of the atlas, so the buffer
// is never freed. An empty buffer means the file was missing or unreadable.
std::vector<char>* JapaneseFontData() {
  static std::vector<char>* data = [] {
    auto* buffer = new std::vector<char>();
    std::ifstream file(SetFontPath(NOTO_SANS_JP),
                       std::ios::binary | std::ios::ate);
    if (!file) {
      return buffer;
    }
    const std::streamsize size = file.tellg();
    if (size <= 0) {
      return buffer;
    }
    buffer->resize(static_cast<size_t>(size));
    file.seekg(0);
    if (!file.read(buffer->data(), size)) {
      buffer->clear();
    }
    return buffer;
  }();
  return data;
}
 
absl::Status AddJapaneseFont(const FontConfig& /*config*/) {
  std::vector<char>* font_data = JapaneseFontData();
  if (font_data->empty()) {
    return absl::InternalError("Failed to add Japanese fonts");
  }
  ImFontConfig japanese_font_config{};
  japanese_font_config.FontDataOwnedByAtlas = false;
  japanese_font_config.MergeMode = true;
  japanese_font_config.GlyphOffset.y = 5.0F;
  japanese_font_config.GlyphMinAdvanceX = 13.0F;
  japanese_font_config.PixelSnapH = true;
  std::strncpy(japanese_font_config.Name, NOTO_SANS_JP,
               sizeof(japanese_font_config.Name) - 1);
  ImGuiIO& imgui_io = ImGui::GetIO();
  if (!imgui_io.Fonts->AddFontFromMemoryTTF(
          font_data->data(), static_cast<int>(font_data->size()),
          ICON_FONT_SIZE, &japanese_font_config,
          imgui_io.Fonts->GetGlyphRangesJapanese())) {
    return absl::InternalError("Failed to add Japanese fonts");
  }
  return absl::OkStatus();
}
 
}  // namespace
 
absl::Status LoadPackageFonts() {
  if (font_registry.fonts.empty()) {
    // Initialize the font names and sizes with proper ImFontConfig
    // initialization
    font_registry.fonts = {
        FontConfig{KARLA_REGULAR, FONT_SIZE_DEFAULT, {}, {}},
        FontConfig{ROBOTO_MEDIUM, FONT_SIZE_DEFAULT, {}, {}},
        FontConfig{COUSINE_REGULAR, FONT_SIZE_DEFAULT, {}, {}},
        FontConfig{IBM_PLEX_JP, FONT_SIZE_DEFAULT, {}, {}},
        FontConfig{DROID_SANS, FONT_SIZE_DROID_SANS, {}, {}},
    };
  }
 
  // Load fonts with associated icon and Japanese merges
  for (const auto& font_config : font_registry.fonts) {
    RETURN_IF_ERROR(LoadFont(font_config));
    RETURN_IF_ERROR(AddIconFont(font_config));
    RETURN_IF_ERROR(AddJapaneseFont(font_config));
  }
  return absl::OkStatus();
}
 
void SetActiveFontIndex(int index) {
  ImGuiIO& io = ImGui::GetIO();
  if (io.Fonts == nullptr || io.Fonts->Fonts.Size == 0) {
    return;
  }
  if (index < 0 || index >= io.Fonts->Fonts.Size) {
    index = 0;
  }
  io.FontDefault = io.Fonts->Fonts[index];
}
 
absl::Status ReloadPackageFont(const FontConfig& config) {
  ImGuiIO& imgui_io = ImGui::GetIO();
  std::string actual_font_path = SetFontPath(config.font_path);
  if (!imgui_io.Fonts->AddFontFromFileTTF(actual_font_path.data(),
                                          config.font_size)) {
    return absl::InternalError(
        absl::StrFormat("Failed to load font from %s", actual_font_path));
  }
  RETURN_IF_ERROR(AddIconFont(config));
  RETURN_IF_ERROR(AddJapaneseFont(config));
  return absl::OkStatus();
}
 
absl::Status LoadFontFromMemory(const std::string& name,
                                const std::string& data, float size_pixels) {
  ImGuiIO& imgui_io = ImGui::GetIO();
 
  // ImGui takes ownership of the data and will free it
  void* font_data = ImGui::MemAlloc(data.size());
  if (!font_data) {
    return absl::InternalError("Failed to allocate memory for font data");
  }
  std::memcpy(font_data, data.data(), data.size());
 
  ImFontConfig config;
  std::strncpy(config.Name, name.c_str(), sizeof(config.Name) - 1);
  config.Name[sizeof(config.Name) - 1] = 0;
 
  if (!imgui_io.Fonts->AddFontFromMemoryTTF(
          font_data, static_cast<int>(data.size()), size_pixels, &config)) {
    ImGui::MemFree(font_data);
    return absl::InternalError("Failed to load font from memory");
  }
 
  // We also need to add icons and Japanese characters to this new font
  // Note: This is a simplified version of AddIconFont/AddJapaneseFont that
  // works with the current font being added (since we can't easily merge into
  // a font that's just been added without rebuilding atlas immediately)
  // For now, we'll just load the base font. Merging requires more complex logic.
 
  // Important: We must rebuild the font atlas!
  // This is usually done by the backend, but since we changed fonts at runtime...
  // Ideally, this should be done before NewFrame().
  // If called during a frame, changes won't appear until texture is rebuilt.
 
  return absl::OkStatus();
}
 
#ifdef __linux__
void LoadSystemFonts() {
  // Load Linux System Fonts into ImGui
  // System font loading is now handled by NFD (Native File Dialog)
  // This function is kept for compatibility but does nothing
}
#endif
 
}  // namespace yaze