Add: [Win32] GDI engine for font glyph rendering as a replacement for including FreeType.

Building with FreeType is still possible and will take precedence over the GDI renderer, but
the project files don't include FreeType anymore by default. Combining GDI rendering with ICU
text layout is untested.

1 files changed, 273 insertions, 2 deletions

diff --git a/src/fontcache.cpp b/src/fontcache.cpp
index 50600de40..778af3440 100644
--- a/src/fontcache.cpp
+++ b/src/fontcache.cpp
@@ -199,7 +199,7 @@ bool SpriteFontCache::GetDrawGlyphShadow()
 
 /* static */ FontCache *FontCache::caches[FS_END] = { new SpriteFontCache(FS_NORMAL), new SpriteFontCache(FS_SMALL), new SpriteFontCache(FS_LARGE), new SpriteFontCache(FS_MONO) };
 
-#if defined(WITH_FREETYPE)
+#if defined(WITH_FREETYPE) || defined(_WIN32)
 
 FreeTypeSettings _freetype;
 
@@ -710,9 +710,278 @@ const void *FreeTypeFontCache::InternalGetFontTable(uint32 tag, size_t &length)
 	return result;
 }
 
+#elif defined(_WIN32)
+
+#include "os/windows/win32.h"
+#ifndef ANTIALIASED_QUALITY
+#define ANTIALIASED_QUALITY     4
+#endif
+
+/** Font cache for fonts that are based on a Win32 font. */
+class Win32FontCache : public TrueTypeFontCache {
+private:
+	LOGFONT logfont;      ///< Logical font information for selecting the font face.
+	HFONT font = nullptr; ///< The font face associated with this font.
+	HDC dc = nullptr;     ///< Cached GDI device context.
+	HGDIOBJ old_font;     ///< Old font selected into the GDI context.
+	SIZE glyph_size;      ///< Maximum size of regular glyphs.
+
+	void SetFontSize(FontSize fs, int pixels);
+	virtual const void *InternalGetFontTable(uint32 tag, size_t &length);
+	virtual const Sprite *InternalGetGlyph(GlyphID key, bool aa);
+
+public:
+	Win32FontCache(FontSize fs, const LOGFONT &logfont, int pixels);
+	~Win32FontCache();
+	virtual void ClearFontCache();
+	virtual GlyphID MapCharToGlyph(WChar key);
+	virtual const char *GetFontName() { return WIDE_TO_MB(this->logfont.lfFaceName); }
+	virtual bool IsBuiltInFont() { return false; }
+};
+
+
+/**
+ * Create a new Win32FontCache.
+ * @param fs      The font size that is going to be cached.
+ * @param logfont The font that has to be loaded.
+ * @param pixels  The number of pixels this font should be high.
+ */
+Win32FontCache::Win32FontCache(FontSize fs, const LOGFONT &logfont, int pixels) : TrueTypeFontCache(fs, pixels), logfont(logfont)
+{
+	this->dc = CreateCompatibleDC(nullptr);
+	this->SetFontSize(fs, pixels);
+}
+
+Win32FontCache::~Win32FontCache()
+{
+	this->ClearFontCache();
+	DeleteDC(this->dc);
+	DeleteObject(this->font);
+}
+
+void Win32FontCache::SetFontSize(FontSize fs, int pixels)
+{
+	if (pixels == 0) {
+		/* Try to determine a good height based on the minimal height recommended by the font. */
+		int scaled_height = ScaleFontTrad(_default_font_height[this->fs]);
+		pixels = scaled_height;
+
+		HFONT temp = CreateFontIndirect(&this->logfont);
+		if (temp != nullptr) {
+			HGDIOBJ old = SelectObject(this->dc, temp);
+
+			UINT size = GetOutlineTextMetrics(this->dc, 0, nullptr);
+			LPOUTLINETEXTMETRIC otm = (LPOUTLINETEXTMETRIC)AllocaM(BYTE, size);
+			GetOutlineTextMetrics(this->dc, size, otm);
+
+			/* Font height is minimum height plus the difference between the default
+			 * height for this font size and the small size. */
+			int diff = scaled_height - ScaleFontTrad(_default_font_height[FS_SMALL]);
+			pixels = Clamp(min(otm->otmusMinimumPPEM, 20) + diff, scaled_height, MAX_FONT_SIZE);
+
+			SelectObject(dc, old);
+			DeleteObject(temp);
+		}
+	} else {
+		pixels = ScaleFontTrad(pixels);
+	}
+	this->used_size = pixels;
+
+	/* Create GDI font handle. */
+	this->logfont.lfHeight = -pixels;
+	this->logfont.lfWidth  = 0;
+	this->logfont.lfOutPrecision = ANTIALIASED_QUALITY;
+
+	if (this->font != nullptr) {
+		SelectObject(dc, this->old_font);
+		DeleteObject(this->font);
+	}
+	this->font = CreateFontIndirect(&this->logfont);
+	this->old_font = SelectObject(this->dc, this->font);
+
+	/* Query the font metrics we needed. */
+	UINT otmSize = GetOutlineTextMetrics(this->dc, 0, nullptr);
+	POUTLINETEXTMETRIC otm = (POUTLINETEXTMETRIC)AllocaM(BYTE, otmSize);
+	GetOutlineTextMetrics(this->dc, otmSize, otm);
+
+	this->units_per_em = otm->otmEMSquare;
+	this->ascender = otm->otmTextMetrics.tmAscent;
+	this->descender = otm->otmTextMetrics.tmDescent;
+	this->height = this->ascender + this->descender;
+	this->glyph_size.cx = otm->otmTextMetrics.tmMaxCharWidth;
+	this->glyph_size.cy = otm->otmTextMetrics.tmHeight;
+
+	DEBUG(freetype, 2, "Loaded font '%s' with size %d", FS2OTTD((LPTSTR)((BYTE *)otm + (ptrdiff_t)otm->otmpFullName)), pixels);
+}
+
+/**
+ * Reset cached glyphs.
+ */
+void Win32FontCache::ClearFontCache()
+{
+	/* GUI scaling might have changed, determine font size anew if it was automatically selected. */
+	if (this->font != nullptr) this->SetFontSize(this->fs, this->req_size);
+
+	this->TrueTypeFontCache::ClearFontCache();
+}
+
+/* virtual */ const Sprite *Win32FontCache::InternalGetGlyph(GlyphID key, bool aa)
+{
+	GLYPHMETRICS gm;
+	MAT2 mat = { {0, 1}, {0, 0}, {0, 0}, {0, 1} };
+
+	/* Make a guess for the needed memory size. */
+	DWORD size = this->glyph_size.cy * Align(aa ? this->glyph_size.cx : max(this->glyph_size.cx / 8l, 1l), 4); // Bitmap data is DWORD-aligned rows.
+	byte *bmp = AllocaM(byte, size);
+	size = GetGlyphOutline(this->dc, key, GGO_GLYPH_INDEX | (aa ? GGO_GRAY8_BITMAP : GGO_BITMAP), &gm, size, bmp, &mat);
+
+	if (size == GDI_ERROR) {
+		/* No dice with the guess. First query size of needed glyph memory, then allocate the
+		 * memory and query again. This dance is necessary as some glyphs will only render with
+		 * the exact matching size; e.g. the space glyph has no pixels and must be requested
+		 * with size == 0, anything else fails. Unfortunately, a failed call doesn't return any
+		 * info about the size and thus the triple GetGlyphOutline()-call. */
+		size = GetGlyphOutline(this->dc, key, GGO_GLYPH_INDEX | (aa ? GGO_GRAY8_BITMAP : GGO_BITMAP), &gm, 0, nullptr, &mat);
+		if (size == GDI_ERROR) usererror("Unable to render font glyph");
+		bmp = AllocaM(byte, size);
+		GetGlyphOutline(this->dc, key, GGO_GLYPH_INDEX | (aa ? GGO_GRAY8_BITMAP : GGO_BITMAP), &gm, size, bmp, &mat);
+	}
+
+	/* Add 1 pixel for the shadow on the medium font. Our sprite must be at least 1x1 pixel. */
+	uint width = max(1U, (uint)gm.gmBlackBoxX + (this->fs == FS_NORMAL));
+	uint height = max(1U, (uint)gm.gmBlackBoxY + (this->fs == FS_NORMAL));
+
+	/* Limit glyph size to prevent overflows later on. */
+	if (width > 256 || height > 256) usererror("Font glyph is too large");
+
+	/* GDI has rendered the glyph, now we allocate a sprite and copy the image into it. */
+	SpriteLoader::Sprite sprite;
+	sprite.AllocateData(ZOOM_LVL_NORMAL, width * height);
+	sprite.type = ST_FONT;
+	sprite.width = width;
+	sprite.height = height;
+	sprite.x_offs = gm.gmptGlyphOrigin.x;
+	sprite.y_offs = this->ascender - gm.gmptGlyphOrigin.y;
+
+	if (size > 0) {
+		/* All pixel data returned by GDI is in the form of DWORD-aligned rows.
+		 * For a non anti-aliased glyph, the returned bitmap has one bit per pixel.
+		 * For anti-aliased rendering, GDI uses the strange value range of 0 to 64,
+		 * inclusively. To map this to 0 to 255, we shift left by two and then
+		 * subtract one. */
+		uint pitch = Align(aa ? gm.gmBlackBoxX : max(gm.gmBlackBoxX / 8u, 1u), 4);
+
+		/* Draw shadow for medium size. */
+		if (this->fs == FS_NORMAL && !aa) {
+			for (uint y = 0; y < gm.gmBlackBoxY; y++) {
+				for (uint x = 0; x < gm.gmBlackBoxX; x++) {
+					if (aa ? (bmp[x + y * pitch] > 0) : HasBit(bmp[(x / 8) + y * pitch], 7 - (x % 8))) {
+						sprite.data[1 + x + (1 + y) * sprite.width].m = SHADOW_COLOUR;
+						sprite.data[1 + x + (1 + y) * sprite.width].a = aa ? (bmp[x + y * pitch] << 2) - 1 : 0xFF;
+					}
+				}
+			}
+		}
+
+		for (uint y = 0; y < gm.gmBlackBoxY; y++) {
+			for (uint x = 0; x < gm.gmBlackBoxX; x++) {
+				if (aa ? (bmp[x + y * pitch] > 0) : HasBit(bmp[(x / 8) + y * pitch], 7 - (x % 8))) {
+					sprite.data[x + y * sprite.width].m = FACE_COLOUR;
+					sprite.data[x + y * sprite.width].a = aa ? (bmp[x + y * pitch] << 2) - 1 : 0xFF;
+				}
+			}
+		}
+	}
+
+	GlyphEntry new_glyph;
+	new_glyph.sprite = BlitterFactory::GetCurrentBlitter()->Encode(&sprite, AllocateFont);
+	new_glyph.width = gm.gmCellIncX;
+
+	this->SetGlyphPtr(key, &new_glyph);
+
+	return new_glyph.sprite;
+}
+
+/* virtual */ GlyphID Win32FontCache::MapCharToGlyph(WChar key)
+{
+	assert(IsPrintable(key));
+
+	if (key >= SCC_SPRITE_START && key <= SCC_SPRITE_END) {
+		return this->parent->MapCharToGlyph(key);
+	}
+
+	/* Convert characters outside of the BMP into surrogate pairs. */
+	WCHAR chars[2];
+	if (key >= 0x010000U) {
+		chars[0] = (WCHAR)(((key - 0x010000U) >> 10) + 0xD800);
+		chars[1] = (WCHAR)(((key - 0x010000U) & 0x3FF) + 0xDC00);
+	} else {
+		chars[0] = (WCHAR)(key & 0xFFFF);
+	}
+
+	WORD glyphs[2] = {0, 0};
+	GetGlyphIndicesW(this->dc, chars, key >= 0x010000U ? 2 : 1, glyphs, GGI_MARK_NONEXISTING_GLYPHS);
+
+	return glyphs[0] != 0xFFFF ? glyphs[0] : 0;
+}
+
+/* virtual */ const void *Win32FontCache::InternalGetFontTable(uint32 tag, size_t &length)
+{
+	DWORD len = GetFontData(this->dc, tag, 0, nullptr, 0);
+
+	void *result = nullptr;
+	if (len != GDI_ERROR && len > 0) {
+		result = MallocT<BYTE>(len);
+		GetFontData(this->dc, tag, 0, result, len);
+	}
+
+	length = len;
+	return result;
+}
+
+/**
+ * Loads the GDI font.
+ * If a GDI font description is present, e.g. from the automatic font
+ * fallback search, use it. Otherwise, try to resolve it by font name.
+ * @param fs The font size to load.
+ */
+static void LoadWin32Font(FontSize fs)
+{
+	FreeTypeSubSetting *settings = nullptr;
+	switch (fs) {
+		default: NOT_REACHED();
+		case FS_SMALL:  settings = &_freetype.small;  break;
+		case FS_NORMAL: settings = &_freetype.medium; break;
+		case FS_LARGE:  settings = &_freetype.large;  break;
+		case FS_MONO:   settings = &_freetype.mono;   break;
+	}
+
+	if (StrEmpty(settings->font)) return;
+
+	LOGFONT logfont;
+	MemSetT(&logfont, 0);
+
+	logfont.lfWeight = strcasestr(settings->font, " bold") != nullptr ? FW_BOLD : FW_NORMAL; // Poor man's way to allow selecting bold fonts.
+	logfont.lfPitchAndFamily = fs == FS_MONO ? FIXED_PITCH : VARIABLE_PITCH;
+	logfont.lfCharSet = DEFAULT_CHARSET;
+	logfont.lfOutPrecision = OUT_OUTLINE_PRECIS;
+	logfont.lfClipPrecision = CLIP_DEFAULT_PRECIS;
+	convert_to_fs(settings->font, logfont.lfFaceName, lengthof(logfont.lfFaceName), false);
+
+	HFONT font = CreateFontIndirect(&logfont);
+	if (font == nullptr) {
+		static const char *SIZE_TO_NAME[] = { "medium", "small", "large", "mono" };
+		ShowInfoF("Unable to use '%s' for %s font, Win32 reported error 0x%lX, using sprite font instead", settings->font, SIZE_TO_NAME[fs], GetLastError());
+		return;
+	}
+	DeleteObject(font);
+
+	new Win32FontCache(fs, logfont, settings->size);
+}
+
 #endif /* WITH_FREETYPE */
 
-#endif /* defined(WITH_FREETYPE) */
+#endif /* defined(WITH_FREETYPE) || defined(_WIN32) */
 
 /**
  * (Re)initialize the freetype related things, i.e. load the non-sprite fonts.
@@ -728,6 +997,8 @@ void InitFreeType(bool monospace)
 
 #ifdef WITH_FREETYPE
 		LoadFreeTypeFont(fs);
+#elif defined(_WIN32)
+		LoadWin32Font(fs);
 #endif
 	}
 }