Merge branch 'sdf-font-hintingmode' of https://github.com/Labrium/love into sdf-font-hintingmode

src/modules/font/BMFontRasterizer.cpp

@@ -20,6 +20,7 @@
 
 // LOVE
 #include "BMFontRasterizer.h"
+#include "GenericShaper.h"
 #include "filesystem/Filesystem.h"
 #include "image/Image.h"
 
@@ -147,7 +148,7 @@ BMFontRasterizer::BMFontRasterizer(love::filesystem::FileData *fontdef, const st
 	// The parseConfig function will try to load any missing page images.
 	for (int i = 0; i < (int) imagelist.size(); i++)
 	{
-		if (imagelist[i]->getFormat() != PIXELFORMAT_RGBA8)
+		if (imagelist[i]->getFormat() != PIXELFORMAT_RGBA8_UNORM)
 			throw love::Exception("Only 32-bit RGBA images are supported in BMFonts.");
 
 		images[i] = imagelist[i];
@@ -164,6 +165,14 @@ BMFontRasterizer::~BMFontRasterizer()
 
 void BMFontRasterizer::parseConfig(const std::string &configtext)
 {
+	{
+		BMFontCharacter nullchar = {};
+		nullchar.page = -1;
+		nullchar.glyph = 0;
+		characters.push_back(nullchar);
+		characterIndices[0] = (int)characters.size() - 1;
+	}
+
 	std::stringstream ss(configtext);
 	std::string line;
 
@@ -211,7 +220,7 @@ void BMFontRasterizer::parseConfig(const std::string &configtext)
 
 				ImageData *imagedata = imagemodule->newImageData(data.get());
 
-				if (imagedata->getFormat() != PIXELFORMAT_RGBA8)
+				if (imagedata->getFormat() != PIXELFORMAT_RGBA8_UNORM)
 				{
 					imagedata->release();
 					throw love::Exception("Only 32-bit RGBA images are supported in BMFonts.");
@@ -237,7 +246,10 @@ void BMFontRasterizer::parseConfig(const std::string &configtext)
 			c.metrics.bearingY = -cline.getAttributeInt("yoffset");
 			c.metrics.advance  =  cline.getAttributeInt("xadvance");
 
-			characters[id] = c;
+			c.glyph = id;
+
+			characters.push_back(c);
+			characterIndices[id] = (int) characters.size() - 1;
 		}
 		else if (tag == "kerning")
 		{
@@ -257,13 +269,15 @@ void BMFontRasterizer::parseConfig(const std::string &configtext)
 	bool guessheight = lineHeight == 0;
 
 	// Verify the glyph character attributes.
-	for (const auto &cpair : characters)
+	for (const auto &c : characters)
 	{
-		const BMFontCharacter &c = cpair.second;
+		if (c.glyph == 0)
+			continue;
+
 		int width = c.metrics.width;
 		int height = c.metrics.height;
 
-		if (!unicode && cpair.first > 127)
+		if (!unicode && c.glyph > 127)
 			throw love::Exception("Invalid BMFont character id (only unicode and ASCII are supported)");
 
 		if (c.page < 0 || images[c.page].get() == nullptr)
@@ -272,13 +286,13 @@ void BMFontRasterizer::parseConfig(const std::string &configtext)
 		const image::ImageData *id = images[c.page].get();
 
 		if (!id->inside(c.x, c.y))
-			throw love::Exception("Invalid coordinates for BMFont character %u.", cpair.first);
+			throw love::Exception("Invalid coordinates for BMFont character %u.", c.glyph);
 
 		if (width > 0 && !id->inside(c.x + width - 1, c.y))
-			throw love::Exception("Invalid width %d for BMFont character %u.", width, cpair.first);
+			throw love::Exception("Invalid width %d for BMFont character %u.", width, c.glyph);
 
 		if (height > 0 && !id->inside(c.x, c.y + height - 1))
-			throw love::Exception("Invalid height %d for BMFont character %u.", height, cpair.first);
+			throw love::Exception("Invalid height %d for BMFont character %u.", height, c.glyph);
 
 		if (guessheight)
 			lineHeight = std::max(lineHeight, c.metrics.height);
@@ -292,22 +306,37 @@ int BMFontRasterizer::getLineHeight() const
 	return lineHeight;
 }
 
-GlyphData *BMFontRasterizer::getGlyphData(uint32 glyph) const
+int BMFontRasterizer::getGlyphSpacing(uint32 glyph) const
 {
-	auto it = characters.find(glyph);
+	auto it = characterIndices.find(glyph);
+	if (it == characterIndices.end())
+		return 0;
 
+	return characters[it->second].metrics.advance;
+}
+
+int BMFontRasterizer::getGlyphIndex(uint32 glyph) const
+{
+	auto it = characterIndices.find(glyph);
+	if (it == characterIndices.end())
+		return 0;
+	return it->second;
+}
+
+GlyphData *BMFontRasterizer::getGlyphDataForIndex(int index) const
+{
 	// Return an empty GlyphData if we don't have the glyph character.
-	if (it == characters.end())
-		return new GlyphData(glyph, GlyphMetrics(), PIXELFORMAT_RGBA8);
+	if (index < 0 || index >= (int) characters.size())
+		return new GlyphData(0, GlyphMetrics(), PIXELFORMAT_RGBA8_UNORM);
 
-	const BMFontCharacter &c = it->second;
+	const BMFontCharacter& c = characters[index];
 	const auto &imagepair = images.find(c.page);
 
 	if (imagepair == images.end())
-		return new GlyphData(glyph, GlyphMetrics(), PIXELFORMAT_RGBA8);
+		return new GlyphData(c.glyph, GlyphMetrics(), PIXELFORMAT_RGBA8_UNORM);
 
 	image::ImageData *imagedata = imagepair->second.get();
-	GlyphData *g = new GlyphData(glyph, c.metrics, PIXELFORMAT_RGBA8);
+	GlyphData *g = new GlyphData(c.glyph, c.metrics, PIXELFORMAT_RGBA8_UNORM);
 
 	size_t pixelsize = imagedata->getPixelSize();
 
@@ -333,7 +362,7 @@ int BMFontRasterizer::getGlyphCount() const
 
 bool BMFontRasterizer::hasGlyph(uint32 glyph) const
 {
-	return characters.find(glyph) != characters.end();
+	return characterIndices.find(glyph) != characterIndices.end();
 }
 
 float BMFontRasterizer::getKerning(uint32 leftglyph, uint32 rightglyph) const
@@ -352,6 +381,11 @@ Rasterizer::DataType BMFontRasterizer::getDataType() const
 	return DATA_IMAGE;
 }
 
+TextShaper *BMFontRasterizer::newTextShaper()
+{
+	return new GenericShaper(this);
+}
+
 bool BMFontRasterizer::accepts(love::filesystem::FileData *fontdef)
 {
 	const char *data = (const char *) fontdef->getData();

src/modules/font/BMFontRasterizer.h

@@ -47,11 +47,14 @@ public:
 
 	// Implements Rasterizer.
 	int getLineHeight() const override;
-	GlyphData *getGlyphData(uint32 glyph) const override;
+	int getGlyphSpacing(uint32 glyph) const override;
+	int getGlyphIndex(uint32 glyph) const override;
+	GlyphData *getGlyphDataForIndex(int index) const override;
 	int getGlyphCount() const override;
 	bool hasGlyph(uint32 glyph) const override;
 	float getKerning(uint32 leftglyph, uint32 rightglyph) const override;
 	DataType getDataType() const override;
+	TextShaper *newTextShaper() override;
 
 	static bool accepts(love::filesystem::FileData *fontdef);
 
@@ -63,6 +66,7 @@ private:
 		int y;
 		int page;
 		GlyphMetrics metrics;
+		uint32 glyph;
 	};
 
 	void parseConfig(const std::string &config);
@@ -72,8 +76,10 @@ private:
 	// Image pages, indexed by their page id.
 	std::unordered_map<int, StrongRef<image::ImageData>> images;
 
-	// Glyph characters, indexed by their glyph id.
-	std::unordered_map<uint32, BMFontCharacter> characters;
+	std::vector<BMFontCharacter> characters;
+
+	// Glyph character indices, indexed by their glyph id.
+	std::unordered_map<uint32, int> characterIndices;
 
 	// Kerning information, indexed by two (packed) characters.
 	std::unordered_map<uint64, int> kerning;

src/modules/font/Font.cpp

@@ -22,6 +22,7 @@
 #include "Font.h"
 #include "BMFontRasterizer.h"
 #include "ImageRasterizer.h"
+#include "data/DataModule.h"
 
 #include "libraries/utf8/utf8.h"
 
@@ -30,28 +31,28 @@ namespace love
 namespace font
 {
 
-// Default TrueType font.
-#include "Vera.ttf.h"
+// Default TrueType font, gzip-compressed.
+#include "NotoSans-Regular.ttf.gzip.h"
 
-class DefaultFontData : public love::Data
+Font::Font()
 {
-public:
+	auto compressedbytes = (const char *) NotoSans_Regular_ttf_gzip;
+	size_t compressedsize = NotoSans_Regular_ttf_gzip_len;
 
-	Data *clone() const override { return new DefaultFontData(); }
-	void *getData() const override { return Vera_ttf; }
-	size_t getSize() const override { return sizeof(Vera_ttf); }
-};
+	size_t rawsize = 0;
+	char *fontdata = data::decompress(data::Compressor::FORMAT_GZIP, compressedbytes, compressedsize, rawsize);
+
+	defaultFontData.set(new data::ByteData(fontdata, rawsize, true), Acquire::NORETAIN);
+}
 
 Rasterizer *Font::newTrueTypeRasterizer(int size, TrueTypeRasterizer::Hinting hinting)
 {
-	StrongRef<DefaultFontData> data(new DefaultFontData, Acquire::NORETAIN);
-	return newTrueTypeRasterizer(data.get(), size, hinting);
+	return newTrueTypeRasterizer(defaultFontData.get(), size, hinting);
 }
 
 Rasterizer *Font::newTrueTypeRasterizer(int size, float dpiscale, TrueTypeRasterizer::Hinting hinting)
 {
-	StrongRef<DefaultFontData> data(new DefaultFontData, Acquire::NORETAIN);
-	return newTrueTypeRasterizer(data.get(), size, dpiscale, hinting);
+	return newTrueTypeRasterizer(defaultFontData.get(), size, dpiscale, hinting);
 }
 
 Rasterizer *Font::newBMFontRasterizer(love::filesystem::FileData *fontdef, const std::vector<image::ImageData *> &images, float dpiscale)

src/modules/font/Font.h

@@ -43,6 +43,7 @@ class Font : public Module
 
 public:
 
+	Font();
 	virtual ~Font() {}
 
 	virtual Rasterizer *newRasterizer(love::filesystem::FileData *data) = 0;
@@ -64,6 +65,10 @@ public:
 	virtual ModuleType getModuleType() const { return M_FONT; }
 	virtual const char *getName() const = 0;
 
+private:
+
+	StrongRef<Data> defaultFontData;
+
 }; // Font
 
 } // font

src/modules/font/GenericShaper.cpp

@@ -0,0 +1,203 @@
+/**
+ * Copyright (c) 2006-2023 LOVE Development Team
+ *
+ * This software is provided 'as-is', without any express or implied
+ * warranty.  In no event will the authors be held liable for any damages
+ * arising from the use of this software.
+ *
+ * Permission is granted to anyone to use this software for any purpose,
+ * including commercial applications, and to alter it and redistribute it
+ * freely, subject to the following restrictions:
+ *
+ * 1. The origin of this software must not be misrepresented; you must not
+ *    claim that you wrote the original software. If you use this software
+ *    in a product, an acknowledgment in the product documentation would be
+ *    appreciated but is not required.
+ * 2. Altered source versions must be plainly marked as such, and must not be
+ *    misrepresented as being the original software.
+ * 3. This notice may not be removed or altered from any source distribution.
+ **/
+
+// LOVE
+#include "GenericShaper.h"
+#include "Rasterizer.h"
+#include "common/Optional.h"
+
+namespace love
+{
+namespace font
+{
+
+GenericShaper::GenericShaper(Rasterizer *rasterizer)
+	: TextShaper(rasterizer)
+{
+}
+
+GenericShaper::~GenericShaper()
+{
+}
+
+void GenericShaper::computeGlyphPositions(const ColoredCodepoints &codepoints, Range range, Vector2 offset, float extraspacing, std::vector<GlyphPosition> *positions, std::vector<IndexedColor> *colors, TextInfo *info)
+{
+	if (!range.isValid())
+		range = Range(0, codepoints.cps.size());
+
+	if (rasterizers[0]->getDataType() == Rasterizer::DATA_TRUETYPE)
+		offset.y += getBaseline();
+
+	// Spacing counter and newline handling.
+	Vector2 curpos = offset;
+
+	int maxwidth = 0;
+	uint32 prevglyph = 0;
+
+	if (positions)
+		positions->reserve(range.getSize());
+
+	int colorindex = 0;
+	int ncolors = (int) codepoints.colors.size();
+	Optional<Colorf> colorToAdd;
+
+	// Make sure the right color is applied to the start of the glyph list,
+	// when the start isn't 0.
+	if (colors && range.getOffset() > 0 && !codepoints.colors.empty())
+	{
+		for (; colorindex < ncolors; colorindex++)
+		{
+			if (codepoints.colors[colorindex].index >= (int) range.getOffset())
+				break;
+			colorToAdd.set(codepoints.colors[colorindex].color);
+		}
+	}
+
+	for (int i = (int) range.getMin(); i <= (int) range.getMax(); i++)
+	{
+		uint32 g = codepoints.cps[i];
+
+		// Do this before anything else so we don't miss colors corresponding
+		// to newlines. The actual add to the list happens after newline
+		// handling, to make sure the resulting index is valid in the positions
+		// array.
+		if (colors && colorindex < ncolors && codepoints.colors[colorindex].index == i)
+		{
+			colorToAdd.set(codepoints.colors[colorindex].color);
+			colorindex++;
+		}
+
+		if (g == '\n')
+		{
+			if (curpos.x > maxwidth)
+				maxwidth = (int)curpos.x;
+
+			// Wrap newline, but do not output a position for it.
+			curpos.y += floorf(getHeight() * getLineHeight() + 0.5f);
+			curpos.x = offset.x;
+			prevglyph = 0;
+			continue;
+		}
+
+		// Ignore carriage returns
+		if (g == '\r')
+		{
+			prevglyph = g;
+			continue;
+		}
+
+		if (colorToAdd.hasValue && colors && positions)
+		{
+			IndexedColor c = {colorToAdd.value, (int) positions->size()};
+			colors->push_back(c);
+			colorToAdd.clear();
+		}
+
+		// Add kerning to the current horizontal offset.
+		curpos.x += getKerning(prevglyph, g);
+
+		GlyphIndex glyphindex;
+		int advance = getGlyphAdvance(g, &glyphindex);
+
+		if (positions)
+			positions->push_back({ Vector2(curpos.x, curpos.y), glyphindex });
+
+		// Advance the x position for the next glyph.
+		curpos.x += advance;
+
+		// Account for extra spacing given to space characters.
+		if (g == ' ' && extraspacing != 0.0f)
+			curpos.x = floorf(curpos.x + extraspacing);
+
+		prevglyph = g;
+	}
+
+	if (curpos.x > maxwidth)
+		maxwidth = (int)curpos.x;
+
+	if (info != nullptr)
+	{
+		info->width = maxwidth - offset.x;
+		info->height = curpos.y - offset.y;
+		if (curpos.x > offset.x)
+			info->height += floorf(getHeight() * getLineHeight() + 0.5f);
+	}
+}
+
+int GenericShaper::computeWordWrapIndex(const ColoredCodepoints &codepoints, Range range, float wraplimit, float *width)
+{
+	if (!range.isValid())
+		range = Range(0, codepoints.cps.size());
+
+	uint32 prevglyph = 0;
+
+	float w = 0.0f;
+	float outwidth = 0.0f;
+	float widthbeforelastspace = 0.0f;
+	int wrapindex = -1;
+	int lastspaceindex = -1;
+
+	for (int i = (int)range.getMin(); i <= (int)range.getMax(); i++)
+	{
+		uint32 g = codepoints.cps[i];
+
+		if (g == '\r')
+		{
+			prevglyph = g;
+			continue;
+		}
+
+		float newwidth = w + getKerning(prevglyph, g) + getGlyphAdvance(g);
+
+		// Only wrap when there's a non-space character.
+		if (newwidth > wraplimit && !isWhitespace(g))
+		{
+			// Rewind to the last seen space when wrapping.
+			if (lastspaceindex != -1)
+			{
+				wrapindex = lastspaceindex;
+				outwidth = widthbeforelastspace;
+			}
+			break;
+		}
+
+		// Don't count trailing spaces in the output width.
+		if (isWhitespace(g))
+		{
+			lastspaceindex = i;
+			if (!isWhitespace(prevglyph))
+				widthbeforelastspace = w;
+		}
+		else
+			outwidth = newwidth;
+
+		w = newwidth;
+		prevglyph = g;
+		wrapindex = i;
+	}
+
+	if (width)
+		*width = outwidth;
+
+	return wrapindex;
+}
+
+} // font
+} // love

src/modules/font/GenericShaper.h

@@ -0,0 +1,46 @@
+/**
+ * Copyright (c) 2006-2023 LOVE Development Team
+ *
+ * This software is provided 'as-is', without any express or implied
+ * warranty.  In no event will the authors be held liable for any damages
+ * arising from the use of this software.
+ *
+ * Permission is granted to anyone to use this software for any purpose,
+ * including commercial applications, and to alter it and redistribute it
+ * freely, subject to the following restrictions:
+ *
+ * 1. The origin of this software must not be misrepresented; you must not
+ *    claim that you wrote the original software. If you use this software
+ *    in a product, an acknowledgment in the product documentation would be
+ *    appreciated but is not required.
+ * 2. Altered source versions must be plainly marked as such, and must not be
+ *    misrepresented as being the original software.
+ * 3. This notice may not be removed or altered from any source distribution.
+ **/
+
+#pragma once
+
+// LOVE
+#include "TextShaper.h"
+
+namespace love
+{
+namespace font
+{
+
+class GenericShaper : public love::font::TextShaper
+{
+public:
+
+	GenericShaper(Rasterizer *rasterizer);
+	virtual ~GenericShaper();
+
+	void computeGlyphPositions(const ColoredCodepoints &codepoints, Range range, Vector2 offset, float extraspacing, std::vector<GlyphPosition> *positions, std::vector<IndexedColor> *colors, TextInfo *info) override;
+	int computeWordWrapIndex(const ColoredCodepoints &codepoints, Range range, float wraplimit, float *width) override;
+
+private:
+
+}; // GenericShaper
+
+} // font
+} // love

src/modules/font/GlyphData.cpp

@@ -24,10 +24,6 @@
 // UTF-8
 #include "libraries/utf8/utf8.h"
 
-// stdlib
-#include <iostream>
-#include <cstddef>
-
 namespace love
 {
 namespace font
@@ -41,7 +37,7 @@ GlyphData::GlyphData(uint32 glyph, GlyphMetrics glyphMetrics, PixelFormat f)
 	, data(nullptr)
 	, format(f)
 {
-	if (f != PIXELFORMAT_LA8 && f != PIXELFORMAT_RGBA8)
+	if (f != PIXELFORMAT_LA8_UNORM && f != PIXELFORMAT_RGBA8_UNORM)
 		throw love::Exception("Invalid GlyphData pixel format.");
 
 	if (metrics.width > 0 && metrics.height > 0)
@@ -78,7 +74,7 @@ void *GlyphData::getData() const
 
 size_t GlyphData::getPixelSize() const
 {
-	return getPixelFormatSize(format);
+	return getPixelFormatBlockSize(format);
 }
 
 void *GlyphData::getData(int x, int y) const

src/modules/font/ImageRasterizer.cpp

@@ -20,8 +20,9 @@
 
 // LOVE
 #include "ImageRasterizer.h"
-
+#include "GenericShaper.h"
 #include "common/Exception.h"
+
 #include <string.h>
 
 namespace love
@@ -31,18 +32,17 @@ namespace font
 
 static_assert(sizeof(Color32) == 4, "sizeof(Color32) must equal 4 bytes!");
 
-ImageRasterizer::ImageRasterizer(love::image::ImageData *data, uint32 *glyphs, int numglyphs, int extraspacing, float dpiscale)
+ImageRasterizer::ImageRasterizer(love::image::ImageData *data, const uint32 *glyphs, int numglyphs, int extraspacing, float dpiscale)
 	: imageData(data)
-	, glyphs(glyphs)
-	, numglyphs(numglyphs)
+	, numglyphs(numglyphs + 1) // Always have a null glyph at the start of the array.
 	, extraSpacing(extraspacing)
 {
 	this->dpiScale = dpiscale;
 
-	if (data->getFormat() != PIXELFORMAT_RGBA8)
+	if (data->getFormat() != PIXELFORMAT_RGBA8_UNORM)
 		throw love::Exception("Only 32-bit RGBA images are supported in Image Fonts!");
 
-	load();
+	load(glyphs, numglyphs);
 }
 
 ImageRasterizer::~ImageRasterizer()
@@ -54,21 +54,38 @@ int ImageRasterizer::getLineHeight() const
 	return getHeight();
 }
 
-GlyphData *ImageRasterizer::getGlyphData(uint32 glyph) const
+int ImageRasterizer::getGlyphSpacing(uint32 glyph) const
+{
+	auto it = glyphIndices.find(glyph);
+	if (it == glyphIndices.end())
+		return 0;
+	return imageGlyphs[it->second].width + extraSpacing;
+}
+
+int ImageRasterizer::getGlyphIndex(uint32 glyph) const
+{
+	auto it = glyphIndices.find(glyph);
+	if (it == glyphIndices.end())
+		return 0;
+	return it->second;
+}
+
+GlyphData *ImageRasterizer::getGlyphDataForIndex(int index) const
 {
 	GlyphMetrics gm = {};
+	uint32 glyph = 0;
 
 	// Set relevant glyph metrics if the glyph is in this ImageFont
-	std::map<uint32, ImageGlyphData>::const_iterator it = imageGlyphs.find(glyph);
-	if (it != imageGlyphs.end())
+	if (index >= 0 && index < (int) imageGlyphs.size())
 	{
-		gm.width = it->second.width;
-		gm.advance = it->second.width + extraSpacing;
+		gm.width = imageGlyphs[index].width;
+		gm.advance = imageGlyphs[index].width + extraSpacing;
+		glyph = imageGlyphs[index].glyph;
 	}
 
 	gm.height = metrics.height;
 
-	GlyphData *g = new GlyphData(glyph, gm, PIXELFORMAT_RGBA8);
+	GlyphData *g = new GlyphData(glyph, gm, PIXELFORMAT_RGBA8_UNORM);
 
 	if (gm.width == 0)
 		return g;
@@ -82,7 +99,7 @@ GlyphData *ImageRasterizer::getGlyphData(uint32 glyph) const
 	// copy glyph pixels from imagedata to glyphdata
 	for (int i = 0; i < g->getWidth() * g->getHeight(); i++)
 	{
-		Color32 p = imagepixels[it->second.x + (i % gm.width) + (imageData->getWidth() * (i / gm.width))];
+		Color32 p = imagepixels[imageGlyphs[index].x + (i % gm.width) + (imageData->getWidth() * (i / gm.width))];
 
 		// Use transparency instead of the spacer color
 		if (p == spacer)
@@ -94,7 +111,7 @@ GlyphData *ImageRasterizer::getGlyphData(uint32 glyph) const
 	return g;
 }
 
-void ImageRasterizer::load()
+void ImageRasterizer::load(const uint32 *glyphs, int glyphcount)
 {
 	auto pixels = (const Color32 *) imageData->getData();
 
@@ -113,7 +130,16 @@ void ImageRasterizer::load()
 	int start = 0;
 	int end = 0;
 
-	for (int i = 0; i < numglyphs; ++i)
+	{
+		ImageGlyphData nullglyph;
+		nullglyph.x = 0;
+		nullglyph.width = 0;
+		nullglyph.glyph = 0;
+		imageGlyphs.push_back(nullglyph);
+		glyphIndices[0] = (int) imageGlyphs.size() - 1;
+	}
+
+	for (int i = 0; i < glyphcount; ++i)
 	{
 		start = end;
 
@@ -133,8 +159,10 @@ void ImageRasterizer::load()
 		ImageGlyphData imageGlyph;
 		imageGlyph.x = start;
 		imageGlyph.width = end - start;
+		imageGlyph.glyph = glyphs[i];
 
-		imageGlyphs[glyphs[i]] = imageGlyph;
+		imageGlyphs.push_back(imageGlyph);
+		glyphIndices[glyphs[i]] = (int) imageGlyphs.size() - 1;
 	}
 }
 
@@ -145,7 +173,7 @@ int ImageRasterizer::getGlyphCount() const
 
 bool ImageRasterizer::hasGlyph(uint32 glyph) const
 {
-	return imageGlyphs.find(glyph) != imageGlyphs.end();
+	return glyphIndices.find(glyph) != glyphIndices.end();
 }
 
 Rasterizer::DataType ImageRasterizer::getDataType() const
@@ -153,5 +181,10 @@ Rasterizer::DataType ImageRasterizer::getDataType() const
 	return DATA_IMAGE;
 }
 
+TextShaper *ImageRasterizer::newTextShaper()
+{
+	return new GenericShaper(this);
+}
+
 } // font
 } // love

src/modules/font/ImageRasterizer.h

@@ -39,15 +39,18 @@ namespace font
 class ImageRasterizer : public Rasterizer
 {
 public:
-	ImageRasterizer(love::image::ImageData *imageData, uint32 *glyphs, int numglyphs, int extraspacing, float dpiscale);
+	ImageRasterizer(love::image::ImageData *imageData, const uint32 *glyphs, int numglyphs, int extraspacing, float dpiscale);
 	virtual ~ImageRasterizer();
 
 	// Implement Rasterizer
 	int getLineHeight() const override;
-	GlyphData *getGlyphData(uint32 glyph) const override;
+	int getGlyphSpacing(uint32 glyph) const override;
+	int getGlyphIndex(uint32 glyph) const override;
+	GlyphData *getGlyphDataForIndex(int index) const override;
 	int getGlyphCount() const override;
 	bool hasGlyph(uint32 glyph) const override;
 	DataType getDataType() const override;
+	TextShaper *newTextShaper() override;
 
 
 private:
@@ -57,23 +60,23 @@ private:
 	{
 		int x;
 		int width;
+		uint32 glyph;
 	};
 
 	// Load all the glyph positions into memory
-	void load();
+	void load(const uint32 *glyphs, int glyphcount);
 
 	// The image data
 	StrongRef<love::image::ImageData> imageData;
 
-	// The glyphs in the font
-	uint32 *glyphs;
-
 	// Number of glyphs in the font
 	int numglyphs;
 
 	int extraSpacing;
 
-	std::map<uint32, ImageGlyphData> imageGlyphs;
+
+	std::vector<ImageGlyphData> imageGlyphs;
+	std::map<uint32, int> glyphIndices;
 
 	// Color used to identify glyph separation in the source ImageData
 	Color32 spacer;

src/modules/font/Rasterizer.cpp

@@ -55,6 +55,11 @@ int Rasterizer::getDescent() const
 	return metrics.descent;
 }
 
+GlyphData *Rasterizer::getGlyphData(uint32 glyph) const
+{
+	return getGlyphDataForIndex(getGlyphIndex(glyph));
+}
+
 GlyphData *Rasterizer::getGlyphData(const std::string &text) const
 {
 	uint32 codepoint = 0;

src/modules/font/Rasterizer.h

@@ -31,6 +31,8 @@ namespace love
 namespace font
 {
 
+class TextShaper;
+
 /**
  * Holds the specific font metrics.
  **/
@@ -84,17 +86,32 @@ public:
 	 **/
 	virtual int getLineHeight() const = 0;
 
+	/**
+	 * Gets the spacing of the given unicode glyph.
+	 **/
+	virtual int getGlyphSpacing(uint32 glyph) const = 0;
+
+	/**
+	 * Gets a rasterizer-specific index associated with the given glyph.
+	 **/
+	virtual int getGlyphIndex(uint32 glyph) const = 0;
+
 	/**
 	 * Gets a specific glyph.
 	 * @param glyph The (UNICODE) glyph codepoint to get data for.
 	 **/
-	virtual GlyphData *getGlyphData(uint32 glyph) const = 0;
+	GlyphData *getGlyphData(uint32 glyph) const;
 
 	/**
 	 * Gets a specific glyph.
 	 * @param text The (UNICODE) glyph character to get the data for.
 	 **/
-	virtual GlyphData *getGlyphData(const std::string &text) const;
+	GlyphData *getGlyphData(const std::string &text) const;
+
+	/**
+	 * Gets a specific glyph for the given rasterizer glyph index.
+	 **/
+	virtual GlyphData *getGlyphDataForIndex(int index) const = 0;
 
 	/**
 	 * Gets the number of glyphs the rasterizer has data for.
@@ -120,6 +137,10 @@ public:
 
 	virtual DataType getDataType() const = 0;
 
+	virtual ptrdiff_t getHandle() const { return 0; }
+
+	virtual TextShaper *newTextShaper() = 0;
+
 	float getDPIScale() const;
 
 protected:

src/modules/font/TextShaper.cpp

@@ -0,0 +1,381 @@
+/**
+ * Copyright (c) 2006-2023 LOVE Development Team
+ *
+ * This software is provided 'as-is', without any express or implied
+ * warranty.  In no event will the authors be held liable for any damages
+ * arising from the use of this software.
+ *
+ * Permission is granted to anyone to use this software for any purpose,
+ * including commercial applications, and to alter it and redistribute it
+ * freely, subject to the following restrictions:
+ *
+ * 1. The origin of this software must not be misrepresented; you must not
+ *    claim that you wrote the original software. If you use this software
+ *    in a product, an acknowledgment in the product documentation would be
+ *    appreciated but is not required.
+ * 2. Altered source versions must be plainly marked as such, and must not be
+ *    misrepresented as being the original software.
+ * 3. This notice may not be removed or altered from any source distribution.
+ **/
+
+// LOVE
+#include "TextShaper.h"
+#include "Rasterizer.h"
+#include "common/Exception.h"
+
+#include "libraries/utf8/utf8.h"
+
+namespace love
+{
+namespace font
+{
+
+void getCodepointsFromString(const std::string &text, std::vector<uint32> &codepoints)
+{
+	codepoints.reserve(text.size());
+
+	try
+	{
+		utf8::iterator<std::string::const_iterator> i(text.begin(), text.begin(), text.end());
+		utf8::iterator<std::string::const_iterator> end(text.end(), text.begin(), text.end());
+
+		while (i != end)
+		{
+			uint32 g = *i++;
+			codepoints.push_back(g);
+		}
+	}
+	catch (utf8::exception &e)
+	{
+		throw love::Exception("UTF-8 decoding error: %s", e.what());
+	}
+}
+
+void getCodepointsFromString(const std::vector<ColoredString> &strs, ColoredCodepoints &codepoints)
+{
+	if (strs.empty())
+		return;
+
+	codepoints.cps.reserve(strs[0].str.size());
+
+	for (const ColoredString &cstr : strs)
+	{
+		// No need to add the color if the string is empty anyway, and the code
+		// further on assumes no two colors share the same starting position.
+		if (cstr.str.size() == 0)
+			continue;
+
+		IndexedColor c = { cstr.color, (int)codepoints.cps.size() };
+		codepoints.colors.push_back(c);
+
+		getCodepointsFromString(cstr.str, codepoints.cps);
+	}
+
+	if (codepoints.colors.size() == 1)
+	{
+		IndexedColor c = codepoints.colors[0];
+
+		if (c.index == 0 && c.color == Colorf(1.0f, 1.0f, 1.0f, 1.0f))
+			codepoints.colors.pop_back();
+	}
+}
+
+love::Type TextShaper::type("TextShaper", &Object::type);
+
+TextShaper::TextShaper(Rasterizer *rasterizer)
+	: rasterizers{rasterizer}
+	, dpiScales{rasterizer->getDPIScale()}
+	, height(floorf(rasterizer->getHeight() / rasterizer->getDPIScale() + 0.5f))
+	, lineHeight(1)
+	, useSpacesForTab(false)
+{
+	if (!rasterizer->hasGlyph('\t'))
+		useSpacesForTab = true;
+}
+
+TextShaper::~TextShaper()
+{
+}
+
+float TextShaper::getHeight() const
+{
+	return height;
+}
+
+void TextShaper::setLineHeight(float h)
+{
+	lineHeight = h;
+}
+
+float TextShaper::getLineHeight() const
+{
+	return lineHeight;
+}
+
+int TextShaper::getAscent() const
+{
+	return floorf(rasterizers[0]->getAscent() / rasterizers[0]->getDPIScale() + 0.5f);
+}
+
+int TextShaper::getDescent() const
+{
+	return floorf(rasterizers[0]->getDescent() / rasterizers[0]->getDPIScale() + 0.5f);
+}
+
+float TextShaper::getBaseline() const
+{
+	float ascent = getAscent();
+	if (ascent != 0.0f)
+		return ascent;
+	else if (rasterizers[0]->getDataType() == font::Rasterizer::DATA_TRUETYPE)
+		return floorf(getHeight() / 1.25f + 0.5f); // 1.25 is magic line height for true type fonts
+	else
+		return 0.0f;
+}
+
+bool TextShaper::hasGlyph(uint32 glyph) const
+{
+	for (const StrongRef<Rasterizer> &r : rasterizers)
+	{
+		if (r->hasGlyph(glyph))
+			return true;
+	}
+
+	return false;
+}
+
+bool TextShaper::hasGlyphs(const std::string &text) const
+{
+	if (text.size() == 0)
+		return false;
+
+	try
+	{
+		utf8::iterator<std::string::const_iterator> i(text.begin(), text.begin(), text.end());
+		utf8::iterator<std::string::const_iterator> end(text.end(), text.begin(), text.end());
+
+		while (i != end)
+		{
+			uint32 codepoint = *i++;
+
+			if (!hasGlyph(codepoint))
+				return false;
+		}
+	}
+	catch (utf8::exception &e)
+	{
+		throw love::Exception("UTF-8 decoding error: %s", e.what());
+	}
+
+	return true;
+}
+
+float TextShaper::getKerning(uint32 leftglyph, uint32 rightglyph)
+{
+	uint64 packedglyphs = ((uint64)leftglyph << 32) | (uint64)rightglyph;
+
+	const auto it = kerning.find(packedglyphs);
+	if (it != kerning.end())
+		return it->second;
+
+	float k = 0.0f;
+	bool found = false;
+
+	for (const auto &r : rasterizers)
+	{
+		if (r->hasGlyph(leftglyph) && r->hasGlyph(rightglyph))
+		{
+			found = true;
+			k = floorf(r->getKerning(leftglyph, rightglyph) / r->getDPIScale() + 0.5f);
+			break;
+		}
+	}
+
+	if (!found)
+		k = floorf(rasterizers[0]->getKerning(leftglyph, rightglyph) / rasterizers[0]->getDPIScale() + 0.5f);
+
+	kerning[packedglyphs] = k;
+	return k;
+}
+
+float TextShaper::getKerning(const std::string &leftchar, const std::string &rightchar)
+{
+	uint32 left = 0;
+	uint32 right = 0;
+
+	try
+	{
+		left = utf8::peek_next(leftchar.begin(), leftchar.end());
+		right = utf8::peek_next(rightchar.begin(), rightchar.end());
+	}
+	catch (utf8::exception &e)
+	{
+		throw love::Exception("UTF-8 decoding error: %s", e.what());
+	}
+
+	return getKerning(left, right);
+}
+
+int TextShaper::getGlyphAdvance(uint32 glyph, GlyphIndex *glyphindex)
+{
+	const auto it = glyphAdvances.find(glyph);
+	if (it != glyphAdvances.end())
+	{
+		if (glyphindex)
+			*glyphindex = it->second.second;
+		return it->second.first;
+	}
+
+	int rasterizeri = 0;
+	uint32 realglyph = glyph;
+
+	if (glyph == '\t' && isUsingSpacesForTab())
+		realglyph = ' ';
+
+	for (size_t i = 0; i < rasterizers.size(); i++)
+	{
+		if (rasterizers[i]->hasGlyph(realglyph))
+		{
+			rasterizeri = (int) i;
+			break;
+		}
+	}
+
+	const auto &r = rasterizers[rasterizeri];
+	int advance = floorf(r->getGlyphSpacing(realglyph) / r->getDPIScale() + 0.5f);
+
+	if (glyph == '\t' && realglyph == ' ')
+		advance *= SPACES_PER_TAB;
+
+	GlyphIndex glyphi = {r->getGlyphIndex(realglyph), rasterizeri};
+
+	glyphAdvances[glyph] = std::make_pair(advance, glyphi);
+	if (glyphindex)
+		*glyphindex = glyphi;
+	return advance;
+}
+
+int TextShaper::getWidth(const std::string &str)
+{
+	if (str.size() == 0) return 0;
+
+	ColoredCodepoints codepoints;
+	getCodepointsFromString(str, codepoints.cps);
+
+	TextInfo info;
+	computeGlyphPositions(codepoints, Range(), Vector2(0.0f, 0.0f), 0.0f, nullptr, nullptr, &info);
+
+	return info.width;
+}
+
+static size_t findNewline(const ColoredCodepoints &codepoints, size_t start)
+{
+	for (size_t i = start; i < codepoints.cps.size(); i++)
+	{
+		if (codepoints.cps[i] == '\n')
+		{
+			return i;
+		}
+	}
+
+	return codepoints.cps.size();
+}
+
+void TextShaper::getWrap(const ColoredCodepoints &codepoints, float wraplimit, std::vector<Range> &lineranges, std::vector<int> *linewidths)
+{
+	size_t nextnewline = findNewline(codepoints, 0);
+
+	for (size_t i = 0; i < codepoints.cps.size();)
+	{
+		if (nextnewline < i)
+			nextnewline = findNewline(codepoints, i);
+
+		if (nextnewline == i) // Empty line.
+		{
+			lineranges.push_back(Range());
+			if (linewidths)
+				linewidths->push_back(0);
+			i++;
+		}
+		else
+		{
+			Range r(i, nextnewline - i);
+			float width = 0.0f;
+			int wrapindex = computeWordWrapIndex(codepoints, r, wraplimit, &width);
+
+			if (wrapindex >= (int) i)
+			{
+				r = Range(i, (size_t) wrapindex + 1 - i);
+				i = (size_t)wrapindex + 1;
+			}
+			else
+			{
+				r = Range();
+				i++;
+			}
+
+			// We've already handled this line, skip the newline character.
+			if (nextnewline == i)
+				i++;
+
+			lineranges.push_back(r);
+			if (linewidths)
+				linewidths->push_back(width);
+		}
+	}
+}
+
+void TextShaper::getWrap(const std::vector<ColoredString> &text, float wraplimit, std::vector<std::string> &lines, std::vector<int> *linewidths)
+{
+	ColoredCodepoints cps;
+	getCodepointsFromString(text, cps);
+
+	std::vector<Range> codepointranges;
+	getWrap(cps, wraplimit, codepointranges, linewidths);
+
+	std::string line;
+
+	for (const auto &range : codepointranges)
+	{
+		line.clear();
+
+		if (range.isValid())
+		{
+			line.reserve(range.getSize());
+
+			for (size_t i = range.getMin(); i <= range.getMax(); i++)
+			{
+				char character[5] = { '\0' };
+				char *end = utf8::unchecked::append(cps.cps[i], character);
+				line.append(character, end - character);
+			}
+		}
+
+		lines.push_back(line);
+	}
+}
+
+void TextShaper::setFallbacks(const std::vector<Rasterizer*> &fallbacks)
+{
+	for (Rasterizer *r : fallbacks)
+	{
+		if (r->getDataType() != rasterizers[0]->getDataType())
+			throw love::Exception("Font fallbacks must be of the same font type.");
+	}
+
+	// Clear caches.
+	kerning.clear();
+	glyphAdvances.clear();
+
+	rasterizers.resize(1);
+	dpiScales.resize(1);
+
+	for (Rasterizer *r : fallbacks)
+	{
+		rasterizers.push_back(r);
+		dpiScales.push_back(r->getDPIScale());
+	}
+}
+
+} // font
+} // love

src/modules/font/TextShaper.h

@@ -0,0 +1,156 @@
+/**
+ * Copyright (c) 2006-2023 LOVE Development Team
+ *
+ * This software is provided 'as-is', without any express or implied
+ * warranty.  In no event will the authors be held liable for any damages
+ * arising from the use of this software.
+ *
+ * Permission is granted to anyone to use this software for any purpose,
+ * including commercial applications, and to alter it and redistribute it
+ * freely, subject to the following restrictions:
+ *
+ * 1. The origin of this software must not be misrepresented; you must not
+ *    claim that you wrote the original software. If you use this software
+ *    in a product, an acknowledgment in the product documentation would be
+ *    appreciated but is not required.
+ * 2. Altered source versions must be plainly marked as such, and must not be
+ *    misrepresented as being the original software.
+ * 3. This notice may not be removed or altered from any source distribution.
+ **/
+
+#pragma once
+
+// LOVE
+#include "common/Object.h"
+#include "common/Vector.h"
+#include "common/int.h"
+#include "common/Color.h"
+#include "common/Range.h"
+
+#include <vector>
+#include <string>
+#include <unordered_map>
+
+namespace love
+{
+namespace font
+{
+
+class Rasterizer;
+
+struct ColoredString
+{
+	std::string str;
+	Colorf color;
+};
+
+struct IndexedColor
+{
+	Colorf color;
+	int index;
+};
+
+struct ColoredCodepoints
+{
+	std::vector<uint32> cps;
+	std::vector<IndexedColor> colors;
+};
+
+void getCodepointsFromString(const std::string &str, std::vector<uint32> &codepoints);
+void getCodepointsFromString(const std::vector<ColoredString> &strs, ColoredCodepoints &codepoints);
+
+class TextShaper : public Object
+{
+public:
+
+	struct GlyphIndex
+	{
+		int index;
+		int rasterizerIndex;
+	};
+
+	struct GlyphPosition
+	{
+		Vector2 position;
+		GlyphIndex glyphIndex;
+	};
+
+	struct TextInfo
+	{
+		int width;
+		int height;
+	};
+
+	// This will be used if the Rasterizer doesn't have a tab character itself.
+	static const int SPACES_PER_TAB = 4;
+
+	static love::Type type;
+
+	virtual ~TextShaper();
+
+	const std::vector<StrongRef<Rasterizer>> &getRasterizers() const { return rasterizers; }
+	bool isUsingSpacesForTab() const { return useSpacesForTab; }
+
+	float getHeight() const;
+
+	/**
+	 * Sets the line height (which should be a number to multiply the font size by,
+	 * example: line height = 1.2 and size = 12 means that rendered line height = 12*1.2)
+	 * @param height The new line height.
+	 **/
+	void setLineHeight(float height);
+
+	/**
+	 * Returns the line height.
+	 **/
+	float getLineHeight() const;
+
+	// Extra font metrics
+	int getAscent() const;
+	int getDescent() const;
+	float getBaseline() const;
+
+	bool hasGlyph(uint32 glyph) const;
+	bool hasGlyphs(const std::string &text) const;
+
+	float getKerning(uint32 leftglyph, uint32 rightglyph);
+	float getKerning(const std::string &leftchar, const std::string &rightchar);
+
+	int getGlyphAdvance(uint32 glyph, GlyphIndex *glyphindex = nullptr);
+
+	int getWidth(const std::string &str);
+
+	void getWrap(const std::vector<ColoredString> &text, float wraplimit, std::vector<std::string> &lines, std::vector<int> *linewidths = nullptr);
+	void getWrap(const ColoredCodepoints &codepoints, float wraplimit, std::vector<Range> &lineranges, std::vector<int> *linewidths = nullptr);
+
+	virtual void setFallbacks(const std::vector<Rasterizer *> &fallbacks);
+
+	virtual void computeGlyphPositions(const ColoredCodepoints &codepoints, Range range, Vector2 offset, float extraspacing, std::vector<GlyphPosition> *positions, std::vector<IndexedColor> *colors, TextInfo *info) = 0;
+	virtual int computeWordWrapIndex(const ColoredCodepoints &codepoints, Range range, float wraplimit, float *width) = 0;
+
+protected:
+
+	TextShaper(Rasterizer *rasterizer);
+
+	static inline bool isWhitespace(uint32 codepoint) { return codepoint == ' ' || codepoint == '\t'; }
+
+	std::vector<StrongRef<Rasterizer>> rasterizers;
+	std::vector<float> dpiScales;
+
+private:
+
+	int height;
+	float lineHeight;
+
+	bool useSpacesForTab;
+
+	// maps glyphs to advance and glyph+rasterizer index.
+	std::unordered_map<uint32, std::pair<int, GlyphIndex>> glyphAdvances;
+
+	// map of left/right glyph pairs to horizontal kerning.
+	std::unordered_map<uint64, float> kerning;
+
+}; // TextShaper
+
+} // font
+} // love

src/modules/font/freetype/HarfbuzzShaper.cpp

@@ -0,0 +1,415 @@
+/**
+ * Copyright (c) 2006-2023 LOVE Development Team
+ *
+ * This software is provided 'as-is', without any express or implied
+ * warranty.  In no event will the authors be held liable for any damages
+ * arising from the use of this software.
+ *
+ * Permission is granted to anyone to use this software for any purpose,
+ * including commercial applications, and to alter it and redistribute it
+ * freely, subject to the following restrictions:
+ *
+ * 1. The origin of this software must not be misrepresented; you must not
+ *    claim that you wrote the original software. If you use this software
+ *    in a product, an acknowledgment in the product documentation would be
+ *    appreciated but is not required.
+ * 2. Altered source versions must be plainly marked as such, and must not be
+ *    misrepresented as being the original software.
+ * 3. This notice may not be removed or altered from any source distribution.
+ **/
+
+// LOVE
+#include "HarfbuzzShaper.h"
+#include "TrueTypeRasterizer.h"
+#include "common/Optional.h"
+
+// harfbuzz
+#include <hb.h>
+#include <hb-ft.h>
+
+namespace love
+{
+namespace font
+{
+namespace freetype
+{
+
+HarfbuzzShaper::HarfbuzzShaper(TrueTypeRasterizer *rasterizer)
+	: TextShaper(rasterizer)
+	, spaceGlyphIndex()
+	, tabSpacesAdvanceX(0)
+	, tabSpacesAdvanceY(0)
+{
+	hbFonts.push_back(hb_ft_font_create_referenced((FT_Face)rasterizer->getHandle()));
+	hbBuffers.push_back(hb_buffer_create());
+
+	if (hbFonts[0] == nullptr || hbFonts[0] == hb_font_get_empty())
+		throw love::Exception("Could not create Harfbuzz font object.");
+
+	if (hbBuffers[0] == nullptr || hbBuffers[0] == hb_buffer_get_empty())
+		throw love::Exception("Could not create Harfbuzz buffer object.");
+
+	updateSpacesForTabInfo();
+}
+
+HarfbuzzShaper::~HarfbuzzShaper()
+{
+	for (hb_buffer_t *buffer : hbBuffers)
+		hb_buffer_destroy(buffer);
+	for (hb_font_t *font : hbFonts)
+		hb_font_destroy(font);
+}
+
+void HarfbuzzShaper::setFallbacks(const std::vector<Rasterizer*> &fallbacks)
+{
+	for (size_t i = 1; i < rasterizers.size(); i++)
+	{
+		hb_buffer_destroy(hbBuffers[i]);
+		hb_font_destroy(hbFonts[i]);
+	}
+
+	TextShaper::setFallbacks(fallbacks);
+
+	hbFonts.resize(rasterizers.size());
+	hbBuffers.resize(rasterizers.size());
+
+	for (size_t i = 1; i < rasterizers.size(); i++)
+	{
+		hbFonts[i] = hb_ft_font_create_referenced((FT_Face)rasterizers[i]->getHandle());
+		hbBuffers[i] = hb_buffer_create();
+	}
+
+	updateSpacesForTabInfo();
+}
+
+void HarfbuzzShaper::updateSpacesForTabInfo()
+{
+	if (!isUsingSpacesForTab())
+		return;
+
+	hb_codepoint_t glyphid = 0;
+	for (size_t i = 0; i < hbFonts.size(); i++)
+	{
+		hb_font_t *hbfont = hbFonts[i];
+		if (hb_font_get_glyph(hbfont, ' ', 0, &glyphid))
+		{
+			spaceGlyphIndex.index = glyphid;
+			spaceGlyphIndex.rasterizerIndex = i;
+			tabSpacesAdvanceX = hb_font_get_glyph_h_advance(hbfont, glyphid) * SPACES_PER_TAB;
+			tabSpacesAdvanceY = hb_font_get_glyph_v_advance(hbfont, glyphid) * SPACES_PER_TAB;
+			break;
+		}
+	}
+}
+
+bool HarfbuzzShaper::isValidGlyph(uint32 glyphindex, const std::vector<uint32> &codepoints, uint32 codepointindex)
+{
+	if (glyphindex != 0)
+		return true;
+
+	uint32 codepoint = codepoints[codepointindex];
+	if (codepoint == '\n' || codepoint == '\r' || (codepoint == '\t' && isUsingSpacesForTab()))
+		return true;
+
+	return false;
+}
+
+void HarfbuzzShaper::computeBufferRanges(const ColoredCodepoints &codepoints, Range range, std::vector<BufferRange> &bufferranges)
+{
+	bufferranges.clear();
+
+	if (codepoints.cps.size() == 0)
+		return;
+
+	// Less computation for the typical case (no fallback fonts).
+	if (rasterizers.size() == 1)
+	{
+		hb_buffer_reset(hbBuffers[0]);
+		hb_buffer_add_codepoints(hbBuffers[0], codepoints.cps.data(), codepoints.cps.size(), (unsigned int)range.getOffset(), (int)range.getSize());
+
+		// TODO: Expose APIs for direction and script?
+		hb_buffer_guess_segment_properties(hbBuffers[0]);
+
+		hb_shape(hbFonts[0], hbBuffers[0], nullptr, 0);
+
+		bufferranges.push_back({0, (int) range.first, Range(0, hb_buffer_get_length(hbBuffers[0]))});
+		return;
+	}
+
+	std::vector<Range> fallbackranges = { range };
+
+	// For each font, figure out the ranges of valid glyphs in the given string,
+	// and add the rest to a list to be shaped by the next fallback font.
+	// Harfbuzz doesn't have its own fallback API.
+	for (size_t rasti = 0; rasti < rasterizers.size(); rasti++)
+	{
+		hb_buffer_t *hbb = hbBuffers[rasti];
+		hb_buffer_reset(hbb);
+
+		for (Range r : fallbackranges)
+			hb_buffer_add_codepoints(hbb, codepoints.cps.data(), codepoints.cps.size(), (unsigned int)r.getOffset(), (int)r.getSize());
+
+		hb_buffer_guess_segment_properties(hbb);
+
+		hb_shape(hbFonts[rasti], hbb, nullptr, 0);
+
+		int glyphcount = (int)hb_buffer_get_length(hbb);
+		const hb_glyph_info_t *glyphinfos = hb_buffer_get_glyph_infos(hbb, nullptr);
+		hb_direction_t direction = hb_buffer_get_direction(hbb);
+
+		fallbackranges.clear();
+
+		for (int i = 0; i < glyphcount; i++)
+		{
+			if (isValidGlyph(glyphinfos[i].codepoint, codepoints.cps, glyphinfos[i].cluster))
+			{
+				if (bufferranges.empty() || bufferranges.back().index != rasti || bufferranges.back().range.getMax() + 1 != i)
+					bufferranges.push_back({(int)rasti, (int)glyphinfos[i].cluster, Range(i, 1)});
+				else
+					bufferranges.back().range.last++;
+			}
+			else if (rasti == rasterizers.size() - 1)
+			{
+				// Use the first font for remaining invalid glyphs when no
+				// fallback font supports them.
+				if (bufferranges.empty() || bufferranges.back().index != 0 || bufferranges.back().range.getMax() + 1 != i)
+					bufferranges.push_back({0, (int)glyphinfos[i].cluster, Range(i, 1)});
+				else
+					bufferranges.back().range.last++;
+			}
+			else
+			{
+				// Harfbuzz puts RTL text into the buffer in reverse order, so
+				// it'll start with the last cluster (character index).
+				if (fallbackranges.empty() || (direction == HB_DIRECTION_RTL ? fallbackranges.back().getMin() : fallbackranges.back().getMax()) != glyphinfos[i - 1].cluster)
+					fallbackranges.push_back(Range(glyphinfos[i].cluster, 1));
+				else
+					fallbackranges.back().encapsulate(glyphinfos[i].cluster);
+			}
+		}
+	}
+
+	std::sort(bufferranges.begin(), bufferranges.end(), [](const BufferRange &a, const BufferRange &b)
+	{
+		if (a.codepointStart != b.codepointStart)
+			return a.codepointStart < b.codepointStart;
+		if (a.index != b.index)
+			return a.index < b.index;
+		return a.range.first < b.range.first;
+	});
+}
+
+void HarfbuzzShaper::computeGlyphPositions(const ColoredCodepoints &codepoints, Range range, Vector2 offset, float extraspacing, std::vector<GlyphPosition> *positions, std::vector<IndexedColor> *colors, TextInfo *info)
+{
+	if (!range.isValid() && !codepoints.cps.empty())
+		range = Range(0, codepoints.cps.size());
+
+	offset.y += getBaseline();
+	Vector2 curpos = offset;
+
+	int colorindex = 0;
+	int ncolors = (int)codepoints.colors.size();
+	Optional<Colorf> colorToAdd;
+
+	// Make sure the right color is applied to the start of the glyph list,
+	// when the start isn't 0.
+	if (colors && range.getOffset() > 0 && !codepoints.colors.empty())
+	{
+		for (; colorindex < ncolors; colorindex++)
+		{
+			if (codepoints.colors[colorindex].index >= (int) range.getOffset())
+				break;
+			colorToAdd.set(codepoints.colors[colorindex].color);
+		}
+	}
+
+	std::vector<BufferRange> bufferranges;
+	computeBufferRanges(codepoints, range, bufferranges);
+
+	int maxwidth = (int)curpos.x;
+
+	for (const auto &bufferrange : bufferranges)
+	{
+		if (positions)
+			positions->reserve(positions->size() + bufferrange.range.getSize());
+
+		hb_buffer_t *hbbuffer = hbBuffers[bufferrange.index];
+
+		const hb_glyph_info_t *glyphinfos = hb_buffer_get_glyph_infos(hbbuffer, nullptr);
+		hb_glyph_position_t *glyphpositions = hb_buffer_get_glyph_positions(hbbuffer, nullptr);
+		hb_direction_t direction = hb_buffer_get_direction(hbbuffer);
+
+		for (size_t i = bufferrange.range.first; i <= bufferrange.range.last; i++)
+		{
+			const hb_glyph_info_t &info = glyphinfos[i];
+			hb_glyph_position_t &glyphpos = glyphpositions[i];
+
+			// TODO: this doesn't handle situations where the user inserted a color
+			// change in the middle of some characters that get combined into a single
+			// cluster.
+			if (colors && colorindex < ncolors && codepoints.colors[colorindex].index == info.cluster)
+			{
+				colorToAdd.set(codepoints.colors[colorindex].color);
+				colorindex++;
+			}
+
+			uint32 clustercodepoint = codepoints.cps[info.cluster];
+
+			// Harfbuzz doesn't handle newlines itself, but it does leave them in
+			// the glyph list so we can do it manually.
+			if (clustercodepoint == '\n')
+			{
+				if (curpos.x > maxwidth)
+					maxwidth = (int)curpos.x;
+
+				// Wrap newline, but do not output a position for it.
+				curpos.y += floorf(getHeight() * getLineHeight() + 0.5f);
+				curpos.x = offset.x;
+				continue;
+			}
+
+			// Ignore carriage returns
+			if (clustercodepoint == '\r')
+				continue;
+
+			// This is a glyph index at this point, despite the name.
+			GlyphIndex gindex = { (int) info.codepoint, bufferrange.index };
+
+			if (clustercodepoint == '\t' && isUsingSpacesForTab())
+			{
+				gindex = spaceGlyphIndex;
+
+				// This should be safe to overwrite.
+				// TODO: RTL support?
+				glyphpos.x_offset = 0;
+				glyphpos.y_offset = 0;
+				glyphpos.x_advance = HB_DIRECTION_IS_HORIZONTAL(direction) ? tabSpacesAdvanceX : 0;
+				glyphpos.y_advance = HB_DIRECTION_IS_VERTICAL(direction) ? tabSpacesAdvanceY : 0;
+			}
+
+			if (colorToAdd.hasValue && colors && positions)
+			{
+				IndexedColor c = {colorToAdd.value, (int) positions->size()};
+				colors->push_back(c);
+				colorToAdd.clear();
+			}
+
+			if (positions)
+			{
+				GlyphPosition p = { curpos, gindex };
+
+				// Harfbuzz position coordinate systems are based on the given font.
+				// Freetype uses 26.6 fixed point coordinates, so harfbuzz does too.
+				p.position.x += floorf((glyphpos.x_offset >> 6) / dpiScales[0] + 0.5f);
+				p.position.y += floorf((glyphpos.y_offset >> 6) / dpiScales[0] + 0.5f);
+
+				positions->push_back(p);
+			}
+
+			curpos.x += floorf((glyphpos.x_advance >> 6) / dpiScales[0] + 0.5f);
+			curpos.y += floorf((glyphpos.y_advance >> 6) / dpiScales[0] + 0.5f);
+
+			// Account for extra spacing given to space characters.
+			if (clustercodepoint == ' ' && extraspacing != 0.0f)
+				curpos.x = floorf(curpos.x + extraspacing);
+		}
+	}
+
+	if (curpos.x > maxwidth)
+		maxwidth = (int)curpos.x;
+
+	if (info != nullptr)
+	{
+		info->width = maxwidth - offset.x;
+		info->height = curpos.y - offset.y;
+		if (curpos.x > offset.x)
+			info->height += floorf(getHeight() * getLineHeight() + 0.5f);
+	}
+}
+
+int HarfbuzzShaper::computeWordWrapIndex(const ColoredCodepoints &codepoints, Range range, float wraplimit, float *width)
+{
+	if (!range.isValid())
+		range = Range(0, codepoints.cps.size());
+
+	float w = 0.0f;
+	float outwidth = 0.0f;
+	float widthbeforelastspace = 0.0f;
+	int wrapindex = -1;
+	int lastspaceindex = -1;
+
+	uint32 prevcodepoint = 0;
+
+	std::vector<BufferRange> bufferranges;
+	computeBufferRanges(codepoints, range, bufferranges);
+
+	for (const auto &bufferrange : bufferranges)
+	{
+		hb_buffer_t *hbbuffer = hbBuffers[bufferrange.index];
+
+		const hb_glyph_info_t *glyphinfos = hb_buffer_get_glyph_infos(hbbuffer, nullptr);
+		hb_glyph_position_t *glyphpositions = hb_buffer_get_glyph_positions(hbbuffer, nullptr);
+		hb_direction_t direction = hb_buffer_get_direction(hbbuffer);
+
+		for (size_t i = bufferrange.range.first; i <= bufferrange.range.last; i++)
+		{
+			const hb_glyph_info_t &info = glyphinfos[i];
+			hb_glyph_position_t &glyphpos = glyphpositions[i];
+
+			uint32 clustercodepoint = codepoints.cps[info.cluster];
+
+			if (clustercodepoint == '\r')
+			{
+				prevcodepoint = clustercodepoint;
+				continue;
+			}
+
+			if (clustercodepoint == '\t' && isUsingSpacesForTab())
+			{
+				// This should be safe to overwrite.
+				// TODO: RTL support?
+				glyphpos.x_offset = 0;
+				glyphpos.y_offset = 0;
+				glyphpos.x_advance = HB_DIRECTION_IS_HORIZONTAL(direction) ? tabSpacesAdvanceX : 0;
+				glyphpos.y_advance = HB_DIRECTION_IS_VERTICAL(direction) ? tabSpacesAdvanceY : 0;
+			}
+
+			float newwidth = w + floorf((glyphpos.x_advance >> 6) / dpiScales[0] + 0.5f);
+
+			// Only wrap when there's a non-space character.
+			if (newwidth > wraplimit && !isWhitespace(clustercodepoint))
+			{
+				// Rewind to the last seen space when wrapping.
+				if (lastspaceindex != -1)
+				{
+					wrapindex = lastspaceindex;
+					outwidth = widthbeforelastspace;
+				}
+				break;
+			}
+
+			// Don't count trailing spaces in the output width.
+			if (isWhitespace(clustercodepoint))
+			{
+				lastspaceindex = info.cluster;
+				if (!isWhitespace(prevcodepoint))
+					widthbeforelastspace = w;
+			}
+			else
+				outwidth = newwidth;
+
+			w = newwidth;
+			prevcodepoint = clustercodepoint;
+			wrapindex = info.cluster;
+		}
+	}
+
+	if (width)
+		*width = outwidth;
+
+	return wrapindex;
+}
+
+} // freetype
+} // font
+} // love

src/modules/font/freetype/HarfbuzzShaper.h

@@ -0,0 +1,76 @@
+/**
+ * Copyright (c) 2006-2023 LOVE Development Team
+ *
+ * This software is provided 'as-is', without any express or implied
+ * warranty.  In no event will the authors be held liable for any damages
+ * arising from the use of this software.
+ *
+ * Permission is granted to anyone to use this software for any purpose,
+ * including commercial applications, and to alter it and redistribute it
+ * freely, subject to the following restrictions:
+ *
+ * 1. The origin of this software must not be misrepresented; you must not
+ *    claim that you wrote the original software. If you use this software
+ *    in a product, an acknowledgment in the product documentation would be
+ *    appreciated but is not required.
+ * 2. Altered source versions must be plainly marked as such, and must not be
+ *    misrepresented as being the original software.
+ * 3. This notice may not be removed or altered from any source distribution.
+ **/
+
+#pragma once
+
+// LOVE
+#include "font/TextShaper.h"
+
+extern "C"
+{
+typedef struct hb_font_t hb_font_t;
+typedef struct hb_buffer_t hb_buffer_t;
+}
+
+namespace love
+{
+namespace font
+{
+namespace freetype
+{
+
+class TrueTypeRasterizer;
+
+class HarfbuzzShaper : public love::font::TextShaper
+{
+public:
+
+	HarfbuzzShaper(TrueTypeRasterizer *rasterizer);
+	virtual ~HarfbuzzShaper();
+
+	void setFallbacks(const std::vector<Rasterizer *> &fallbacks) override;
+	void computeGlyphPositions(const ColoredCodepoints &codepoints, Range range, Vector2 offset, float extraspacing, std::vector<GlyphPosition> *positions, std::vector<IndexedColor> *colors, TextInfo *info) override;
+	int computeWordWrapIndex(const ColoredCodepoints &codepoints, Range range, float wraplimit, float *width) override;
+
+private:
+
+	struct BufferRange
+	{
+		int index;
+		int codepointStart;
+		Range range;
+	};
+
+	void updateSpacesForTabInfo();
+	bool isValidGlyph(uint32 glyphindex, const std::vector<uint32> &codepoints, uint32 codepointindex);
+	void computeBufferRanges(const ColoredCodepoints &codepoints, Range range, std::vector<BufferRange> &bufferranges);
+
+	std::vector<hb_font_t *> hbFonts;
+	std::vector<hb_buffer_t *> hbBuffers;
+
+	GlyphIndex spaceGlyphIndex;
+	int tabSpacesAdvanceX;
+	int tabSpacesAdvanceY;
+
+}; // HarfbuzzShaper
+
+} // freetype
+} // font
+} // love

src/modules/font/freetype/TrueTypeRasterizer.cpp

@@ -20,6 +20,7 @@
 
 // LOVE
 #include "TrueTypeRasterizer.h"
+#include "HarfbuzzShaper.h"
 #include "common/Exception.h"
 
 // C
@@ -75,7 +76,30 @@ int TrueTypeRasterizer::getLineHeight() const
 	return (int)(getHeight() * 1.25);
 }
 
-GlyphData *TrueTypeRasterizer::getGlyphData(uint32 glyph) const
+int TrueTypeRasterizer::getGlyphSpacing(uint32 glyph) const
+{
+	FT_Glyph ftglyph;
+	FT_Error err = FT_Err_Ok;
+	FT_UInt loadoption = hintingToLoadOption(hinting);
+
+	// Initialize
+	err = FT_Load_Glyph(face, FT_Get_Char_Index(face, glyph), FT_LOAD_DEFAULT | loadoption);
+	if (err != FT_Err_Ok)
+		return 0;
+
+	err = FT_Get_Glyph(face->glyph, &ftglyph);
+	if (err != FT_Err_Ok)
+		return 0;
+
+	return (int)(ftglyph->advance.x >> 16);
+}
+
+int TrueTypeRasterizer::getGlyphIndex(uint32 glyph) const
+{
+	return FT_Get_Char_Index(face, glyph);
+}
+
+GlyphData *TrueTypeRasterizer::getGlyphDataForIndex(int index) const
 {
 	love::font::GlyphMetrics glyphMetrics = {};
 	FT_Glyph ftglyph;
@@ -84,7 +108,7 @@ GlyphData *TrueTypeRasterizer::getGlyphData(uint32 glyph) const
 	FT_UInt loadoption = hintingToLoadOption(hinting);
 
 	// Initialize
-	err = FT_Load_Glyph(face, FT_Get_Char_Index(face, glyph), FT_LOAD_DEFAULT | loadoption);
+	err = FT_Load_Glyph(face, index, FT_LOAD_DEFAULT | loadoption);
 
 	if (err != FT_Err_Ok)
 		throw love::Exception("TrueType Font glyph error: FT_Load_Glyph failed (0x%x)", err);
@@ -115,7 +139,8 @@ GlyphData *TrueTypeRasterizer::getGlyphData(uint32 glyph) const
 		}
 	}
 	FT_BitmapGlyph bitmap_glyph = (FT_BitmapGlyph) ftglyph;
-	FT_Bitmap &bitmap = bitmap_glyph->bitmap;//just to make things easier
+	const FT_Bitmap &bitmap = bitmap_glyph->bitmap; //just to make things easier
+
 	// Get metrics
 	glyphMetrics.bearingX = bitmap_glyph->left;
 	glyphMetrics.bearingY = bitmap_glyph->top;
@@ -123,7 +148,8 @@ GlyphData *TrueTypeRasterizer::getGlyphData(uint32 glyph) const
 	glyphMetrics.width = bitmap.width;
 	glyphMetrics.advance = (int) (ftglyph->advance.x >> 16);
 
-	GlyphData *glyphData = new GlyphData(glyph, glyphMetrics, PIXELFORMAT_LA8);
+	// TODO: https://stackoverflow.com/questions/60526004/how-to-get-glyph-unicode-using-freetype/69730502#69730502
+	GlyphData *glyphData = new GlyphData(0, glyphMetrics, PIXELFORMAT_LA8_UNORM);
 
 	const uint8 *pixels = bitmap.buffer;
 	uint8 *dest = (uint8 *) glyphData->getData();
@@ -196,6 +222,11 @@ Rasterizer::DataType TrueTypeRasterizer::getDataType() const
 	return DATA_TRUETYPE;
 }
 
+TextShaper *TrueTypeRasterizer::newTextShaper()
+{
+	return new HarfbuzzShaper(this);
+}
+
 bool TrueTypeRasterizer::accepts(FT_Library library, love::Data *data)
 {
 	const FT_Byte *fbase = (const FT_Byte *) data->getData();

src/modules/font/freetype/TrueTypeRasterizer.h

@@ -49,11 +49,16 @@ public:
 
 	// Implement Rasterizer
 	int getLineHeight() const override;
-	GlyphData *getGlyphData(uint32 glyph) const override;
+	int getGlyphSpacing(uint32 glyph) const override;
+	int getGlyphIndex(uint32 glyph) const override;
+	GlyphData *getGlyphDataForIndex(int index) const override;
 	int getGlyphCount() const override;
 	bool hasGlyph(uint32 glyph) const override;
 	float getKerning(uint32 leftglyph, uint32 rightglyph) const override;
 	DataType getDataType() const override;
+	TextShaper *newTextShaper() override;
+
+	ptrdiff_t getHandle() const override { return (ptrdiff_t) face; }
 
 	static bool accepts(FT_Library library, love::Data *data);
 

src/modules/font/wrap_Font.cpp

@@ -72,7 +72,7 @@ int w_newTrueTypeRasterizer(lua_State *L)
 	if (lua_type(L, 1) == LUA_TNUMBER || lua_isnone(L, 1))
 	{
 		// First argument is a number: use the default TrueType font.
-		int size = (int) luaL_optinteger(L, 1, 12);
+		int size = (int) luaL_optinteger(L, 1, 13);
 
 		const char *hintstr = lua_isnoneornil(L, 2) ? nullptr : luaL_checkstring(L, 2);
 		if (hintstr && !TrueTypeRasterizer::getConstant(hintstr, hinting))