font_osx.cpp

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/*
 * This file is part of OpenTTD.
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <https://www.gnu.org/licenses/old-licenses/gpl-2.0>.
 */

 
#include "../../stdafx.h"
#include "../../debug.h"
#include "font_osx.h"
#include "../../core/math_func.hpp"
#include "../../blitter/factory.hpp"
#include "../../error_func.h"
#include "../../fileio_func.h"
#include "../../string_func.h"
#include "../../strings_func.h"
#include "../../zoom_func.h"
#include "macos.h"
 
#include "../../table/control_codes.h"
 
#include "../../safeguards.h"
 
CoreTextFontCache::CoreTextFontCache(FontSize fs, CFAutoRelease<CTFontDescriptorRef> &&font, int pixels) : TrueTypeFontCache(fs, pixels), font_desc(std::move(font))
{
  this->SetFontSize(pixels);
}

void CoreTextFontCache::ClearFontCache()
{
  /* GUI scaling might have changed, determine font size anew if it was automatically selected. */
  if (this->font) this->SetFontSize(this->req_size);
 
  this->TrueTypeFontCache::ClearFontCache();
}
 
void CoreTextFontCache::SetFontSize(int pixels)
{
  if (pixels == 0) {
    /* Try to determine a good height based on the height recommended by the font. */
    int scaled_height = ScaleGUITrad(FontCache::GetDefaultFontHeight(this->fs));
    pixels = scaled_height;
 
    CFAutoRelease<CTFontRef> font(CTFontCreateWithFontDescriptor(this->font_desc.get(), 0.0f, nullptr));
    if (font) {
      float min_size = 0.0f;
 
      /* The 'head' TrueType table contains information about the
       * 'smallest readable size in pixels'. Try to read it, if
       * that doesn't work, we use the default OS font size instead.
       *
       * Reference: https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6head.html */
      CFAutoRelease<CFDataRef> data(CTFontCopyTable(font.get(), kCTFontTableHead, kCTFontTableOptionNoOptions));
      if (data) {
        uint16_t lowestRecPPEM; // At offset 46 of the 'head' TrueType table.
        CFDataGetBytes(data.get(), CFRangeMake(46, sizeof(lowestRecPPEM)), (UInt8 *)&lowestRecPPEM);
        min_size = CFSwapInt16BigToHost(lowestRecPPEM); // TrueType data is always big-endian.
      } else {
        CFAutoRelease<CFNumberRef> size((CFNumberRef)CTFontCopyAttribute(font.get(), kCTFontSizeAttribute));
        CFNumberGetValue(size.get(), kCFNumberFloatType, &min_size);
      }
 
      /* Font height is minimum height plus the difference between the default
       * height for this font size and the small size. */
      int diff = scaled_height - ScaleGUITrad(FontCache::GetDefaultFontHeight(FS_SMALL));
      /* Clamp() is not used as scaled_height could be greater than MAX_FONT_SIZE, which is not permitted in Clamp(). */
      pixels = std::min(std::max(std::min<int>(min_size, MAX_FONT_MIN_REC_SIZE) + diff, scaled_height), MAX_FONT_SIZE);
    }
  } else {
    pixels = ScaleGUITrad(pixels);
  }
  this->used_size = pixels;
 
  this->font.reset(CTFontCreateWithFontDescriptor(this->font_desc.get(), pixels, nullptr));
 
  /* Query the font metrics we needed. We generally round all values up to
   * make sure we don't inadvertently cut off a row or column of pixels,
   * except when determining glyph to glyph advances. */
  this->ascender = (int)std::ceil(CTFontGetAscent(this->font.get()));
  this->descender = -(int)std::ceil(CTFontGetDescent(this->font.get()));
  this->height = this->ascender - this->descender;
 
  /* Get real font name. */
  char name[128];
  CFAutoRelease<CFStringRef> font_name((CFStringRef)CTFontCopyAttribute(this->font.get(), kCTFontDisplayNameAttribute));
  CFStringGetCString(font_name.get(), name, lengthof(name), kCFStringEncodingUTF8);
  this->font_name = name;
 
  Debug(fontcache, 2, "Loaded font '{}' with size {}", this->font_name, pixels);
}
 
GlyphID CoreTextFontCache::MapCharToGlyph(char32_t key, bool allow_fallback)
{
  assert(IsPrintable(key));
 
  /* Convert characters outside of the Basic Multilingual Plane into surrogate pairs. */
  UniChar chars[2];
  if (key >= 0x010000U) {
    chars[0] = (UniChar)(((key - 0x010000U) >> 10) + 0xD800);
    chars[1] = (UniChar)(((key - 0x010000U) & 0x3FF) + 0xDC00);
  } else {
    chars[0] = (UniChar)(key & 0xFFFF);
  }
 
  CGGlyph glyph[2] = {0, 0};
  if (CTFontGetGlyphsForCharacters(this->font.get(), chars, glyph, key >= 0x010000U ? 2 : 1)) {
    return glyph[0];
  }
 
  if (allow_fallback && key >= SCC_SPRITE_START && key <= SCC_SPRITE_END) {
    return this->parent->MapCharToGlyph(key);
  }
 
  return 0;
}
 
const Sprite *CoreTextFontCache::InternalGetGlyph(GlyphID key, bool use_aa)
{
  /* Get glyph size. */
  CGGlyph glyph = (CGGlyph)key;
  CGRect bounds = CTFontGetOpticalBoundsForGlyphs(this->font.get(), &glyph, nullptr, 1, 0);
  if (CGRectIsNull(bounds)) UserError("Unable to render font glyph");
 
  uint bb_width = (uint)std::ceil(bounds.size.width) + 1; // Sometimes the glyph bounds are too tight and cut of the last pixel after rounding.
  uint bb_height = (uint)std::ceil(bounds.size.height);
 
  /* Add 1 scaled pixel for the shadow on the medium font. Our sprite must be at least 1x1 pixel. */
  uint shadow = (this->fs == FS_NORMAL) ? ScaleGUITrad(1) : 0;
  uint width = std::max(1U, bb_width + shadow);
  uint height = std::max(1U, bb_height + shadow);
 
  /* Limit glyph size to prevent overflows later on. */
  if (width > MAX_GLYPH_DIM || height > MAX_GLYPH_DIM) UserError("Font glyph is too large");
 
  SpriteLoader::SpriteCollection spritecollection;
  SpriteLoader::Sprite &sprite = spritecollection[ZoomLevel::Min];
  sprite.AllocateData(ZoomLevel::Min, width * height);
  sprite.colours = SpriteComponent::Palette;
  if (use_aa) sprite.colours.Set(SpriteComponent::Alpha);
  sprite.width = width;
  sprite.height = height;
  sprite.x_offs = (int16_t)std::round(CGRectGetMinX(bounds));
  sprite.y_offs = this->ascender - (int16_t)std::ceil(CGRectGetMaxY(bounds));
 
  if (bounds.size.width > 0) {
    /* Glyph is not a white-space glyph. Render it to a bitmap context. */
 
    /* We only need the alpha channel, as we apply our own colour constants to the sprite. */
    int pitch = Align(bb_width, 16);
    CFAutoRelease<CGContextRef> context(CGBitmapContextCreate(nullptr, bb_width, bb_height, 8, pitch, nullptr, kCGImageAlphaOnly));
    const uint8_t *bmp = static_cast<uint8_t *>(CGBitmapContextGetData(context.get()));
    /* Set antialias according to requirements. */
    CGContextSetAllowsAntialiasing(context.get(), use_aa);
    CGContextSetAllowsFontSubpixelPositioning(context.get(), use_aa);
    CGContextSetAllowsFontSubpixelQuantization(context.get(), !use_aa);
    CGContextSetShouldSmoothFonts(context.get(), false);
 
    CGPoint pos{-bounds.origin.x, -bounds.origin.y};
    CTFontDrawGlyphs(this->font.get(), &glyph, &pos, 1, context.get());
 
    /* Draw shadow for medium size. */
    if (this->fs == FS_NORMAL && !use_aa) {
      for (uint y = 0; y < bb_height; y++) {
        for (uint x = 0; x < bb_width; x++) {
          if (bmp[y * pitch + x] > 0) {
            sprite.data[shadow + x + (shadow + y) * sprite.width].m = SHADOW_COLOUR;
            sprite.data[shadow + x + (shadow + y) * sprite.width].a = use_aa ? bmp[x + y * pitch] : 0xFF;
          }
        }
      }
    }
 
    /* Extract pixel data. */
    for (uint y = 0; y < bb_height; y++) {
      for (uint x = 0; x < bb_width; x++) {
        if (bmp[y * pitch + x] > 0) {
          sprite.data[x + y * sprite.width].m = FACE_COLOUR;
          sprite.data[x + y * sprite.width].a = use_aa ? bmp[x + y * pitch] : 0xFF;
        }
      }
    }
  }
 
  UniquePtrSpriteAllocator allocator;
  BlitterFactory::GetCurrentBlitter()->Encode(SpriteType::Font, spritecollection, allocator);
 
  GlyphEntry new_glyph;
  new_glyph.data = std::move(allocator.data);
  new_glyph.width = (uint8_t)std::round(CTFontGetAdvancesForGlyphs(this->font.get(), kCTFontOrientationDefault, &glyph, nullptr, 1));
 
  return this->SetGlyphPtr(key, std::move(new_glyph)).GetSprite();
}
 
class CoreTextFontCacheFactory : public FontCacheFactory {
public:
  CoreTextFontCacheFactory() : FontCacheFactory("coretext", "CoreText font loader") {}

  std::unique_ptr<FontCache> LoadFont(FontSize fs, FontType fonttype) const override
  {
    if (fonttype != FontType::TrueType) return nullptr;
 
    std::string font = GetFontCacheFontName(fs);
    if (font.empty()) return nullptr;
 
    /* Might be a font file name, try load it. */
    CFAutoRelease<CTFontDescriptorRef> font_ref(LoadFontFromFile(font));
    if (!font_ref) {
      ShowInfo("Unable to load file '{}' for {} font, using default OS font selection instead", font, FontSizeToName(fs));
      CFAutoRelease<CFStringRef> name(CFStringCreateWithCString(kCFAllocatorDefault, font.c_str(), kCFStringEncodingUTF8));
 
      /* Simply creating the font using CTFontCreateWithNameAndSize will *always* return
      * something, no matter the name. As such, we can't use it to check for existence.
      * We instead query the list of all font descriptors that match the given name which
      * does not do this stupid name fallback. */
      CFAutoRelease<CTFontDescriptorRef> name_desc(CTFontDescriptorCreateWithNameAndSize(name.get(), 0.0));
      CFAutoRelease<CFSetRef> mandatory_attribs(CFSetCreate(kCFAllocatorDefault, const_cast<const void **>(reinterpret_cast<const void * const *>(&kCTFontNameAttribute)), 1, &kCFTypeSetCallBacks));
      CFAutoRelease<CFArrayRef> descs(CTFontDescriptorCreateMatchingFontDescriptors(name_desc.get(), mandatory_attribs.get()));
 
      /* Assume the first result is the one we want. */
      if (descs && CFArrayGetCount(descs.get()) > 0) {
        font_ref.reset((CTFontDescriptorRef)CFArrayGetValueAtIndex(descs.get(), 0));
        CFRetain(font_ref.get());
      }
    }
 
    if (!font_ref) {
      ShowInfo("Unable to use '{}' for {} font, using sprite font instead", font, FontSizeToName(fs));
      return nullptr;
    }
 
    return std::make_unique<CoreTextFontCache>(fs, std::move(font_ref), GetFontCacheFontSize(fs));
  }
 
  bool FindFallbackFont(FontCacheSettings *settings, const std::string &language_isocode, MissingGlyphSearcher *callback) const override
  {
    /* Determine fallback font using CoreText. This uses the language isocode
     * to find a suitable font. CoreText is available from 10.5 onwards. */
    std::string lang;
    if (language_isocode == "zh_TW") {
      /* Traditional Chinese */
      lang = "zh-Hant";
    } else if (language_isocode == "zh_CN") {
      /* Simplified Chinese */
      lang = "zh-Hans";
    } else {
      /* Just copy the first part of the isocode. */
      lang = language_isocode.substr(0, language_isocode.find('_'));
    }
 
    /* Create a font descriptor matching the wanted language and latin (english) glyphs.
     * Can't use CFAutoRelease here for everything due to the way the dictionary has to be created. */
    CFStringRef lang_codes[2];
    lang_codes[0] = CFStringCreateWithCString(kCFAllocatorDefault, lang.c_str(), kCFStringEncodingUTF8);
    lang_codes[1] = CFSTR("en");
    CFArrayRef lang_arr = CFArrayCreate(kCFAllocatorDefault, (const void **)lang_codes, lengthof(lang_codes), &kCFTypeArrayCallBacks);
    CFAutoRelease<CFDictionaryRef> lang_attribs(CFDictionaryCreate(kCFAllocatorDefault, const_cast<const void **>(reinterpret_cast<const void *const *>(&kCTFontLanguagesAttribute)), (const void **)&lang_arr, 1, &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks));
    CFAutoRelease<CTFontDescriptorRef> lang_desc(CTFontDescriptorCreateWithAttributes(lang_attribs.get()));
    CFRelease(lang_arr);
    CFRelease(lang_codes[0]);
 
    /* Get array of all font descriptors for the wanted language. */
    CFAutoRelease<CFSetRef> mandatory_attribs(CFSetCreate(kCFAllocatorDefault, const_cast<const void **>(reinterpret_cast<const void *const *>(&kCTFontLanguagesAttribute)), 1, &kCFTypeSetCallBacks));
    CFAutoRelease<CFArrayRef> descs(CTFontDescriptorCreateMatchingFontDescriptors(lang_desc.get(), mandatory_attribs.get()));
 
    bool result = false;
    for (int tries = 0; tries < 2; tries++) {
      for (CFIndex i = 0; descs.get() != nullptr && i < CFArrayGetCount(descs.get()); i++) {
        CTFontDescriptorRef font = (CTFontDescriptorRef)CFArrayGetValueAtIndex(descs.get(), i);
 
        /* Get font traits. */
        CFAutoRelease<CFDictionaryRef> traits((CFDictionaryRef)CTFontDescriptorCopyAttribute(font, kCTFontTraitsAttribute));
        CTFontSymbolicTraits symbolic_traits;
        CFNumberGetValue((CFNumberRef)CFDictionaryGetValue(traits.get(), kCTFontSymbolicTrait), kCFNumberIntType, &symbolic_traits);
 
        /* Skip symbol fonts and vertical fonts. */
        if ((symbolic_traits & kCTFontClassMaskTrait) == (CTFontStylisticClass)kCTFontSymbolicClass || (symbolic_traits & kCTFontVerticalTrait)) continue;
        /* Skip bold fonts (especially Arial Bold, which looks worse than regular Arial). */
        if (symbolic_traits & kCTFontBoldTrait) continue;
        /* Select monospaced fonts if asked for. */
        if (((symbolic_traits & kCTFontMonoSpaceTrait) == kCTFontMonoSpaceTrait) != callback->Monospace()) continue;
 
        /* Get font name. */
        char buffer[128];
        CFAutoRelease<CFStringRef> font_name((CFStringRef)CTFontDescriptorCopyAttribute(font, kCTFontDisplayNameAttribute));
        CFStringGetCString(font_name.get(), buffer, std::size(buffer), kCFStringEncodingUTF8);
 
        /* Serif fonts usually look worse on-screen with only small
         * font sizes. As such, we try for a sans-serif font first.
         * If we can't find one in the first try, try all fonts. */
        if (tries == 0 && (symbolic_traits & kCTFontClassMaskTrait) != (CTFontStylisticClass)kCTFontSansSerifClass) continue;
 
        /* There are some special fonts starting with an '.' and the last
         * resort font that aren't usable. Skip them. */
        std::string_view name{buffer};
        if (name.starts_with(".") || name.starts_with("LastResort")) continue;
 
        /* Save result. */
        callback->SetFontNames(settings, name);
        if (!callback->FindMissingGlyphs()) {
          Debug(fontcache, 2, "CT-Font for {}: {}", language_isocode, name);
          result = true;
          break;
        }
      }
    }
 
    if (!result) {
      /* For some OS versions, the font 'Arial Unicode MS' does not report all languages it
       * supports. If we didn't find any other font, just try it, maybe we get lucky. */
      callback->SetFontNames(settings, "Arial Unicode MS");
      result = !callback->FindMissingGlyphs();
    }
 
    callback->FindMissingGlyphs();
    return result;
  }
 
private:
  static CTFontDescriptorRef LoadFontFromFile(const std::string &font_name)
  {
    /* Might be a font file name, try load it. Direct font loading is
     * only supported starting on OSX 10.6. */
    CFAutoRelease<CFStringRef> path;
 
    /* See if this is an absolute path. */
    if (FileExists(font_name)) {
      path.reset(CFStringCreateWithCString(kCFAllocatorDefault, font_name.c_str(), kCFStringEncodingUTF8));
    } else {
      /* Scan the search-paths to see if it can be found. */
      std::string full_font = FioFindFullPath(BASE_DIR, font_name);
      if (!full_font.empty()) {
        path.reset(CFStringCreateWithCString(kCFAllocatorDefault, full_font.c_str(), kCFStringEncodingUTF8));
      }
    }
 
    if (path) {
      /* Try getting a font descriptor to see if the system can use it. */
      CFAutoRelease<CFURLRef> url(CFURLCreateWithFileSystemPath(kCFAllocatorDefault, path.get(), kCFURLPOSIXPathStyle, false));
      CFAutoRelease<CFArrayRef> descs(CTFontManagerCreateFontDescriptorsFromURL(url.get()));
 
      if (descs && CFArrayGetCount(descs.get()) > 0) {
        CTFontDescriptorRef font_ref = (CTFontDescriptorRef)CFArrayGetValueAtIndex(descs.get(), 0);
        CFRetain(font_ref);
        return font_ref;
      }
    }
 
    return nullptr;
  }
 
private:
  static CoreTextFontCacheFactory instance;
};
 
/* static */ CoreTextFontCacheFactory CoreTextFontCacheFactory::instance;