Merge pull request #8847 from unknownbrackets/ui-textwrap

Allow text wrapping in UI TextViews

CMakeLists.txt

@@ -1042,6 +1042,8 @@ add_library(native STATIC
 	ext/native/util/text/utf8.cpp
 	ext/native/util/text/parsers.h
 	ext/native/util/text/parsers.cpp
+	ext/native/util/text/wrap_text.h
+	ext/native/util/text/wrap_text.cpp
 	ext/native/util/const_map.h
 	ext/native/ext/jpge/jpgd.cpp
 	ext/native/ext/jpge/jpgd.h

Qt/Native.pro

@@ -101,6 +101,7 @@ SOURCES += \
 	$$P/ext/native/thread/*.cpp \
 	$$P/ext/native/ui/*.cpp \
 	$$P/ext/native/util/hash/hash.cpp \
+	$$P/ext/native/util/text/wrap_text.cpp \
 	$$P/ext/native/util/text/utf8.cpp \
 	$$P/ext/native/util/text/parsers.cpp
 
@@ -134,5 +135,6 @@ HEADERS += \
 	$$P/ext/native/ui/*.h \
 	$$P/ext/native/util/hash/hash.h \
 	$$P/ext/native/util/random/*.h \
+	$$P/ext/native/util/text/wrap_text.h \
 	$$P/ext/native/util/text/utf8.h \
 	$$P/ext/native/util/text/parsers.h

UI/MiscScreens.cpp

@@ -19,6 +19,7 @@
 
 #include "base/functional.h"
 #include "base/colorutil.h"
+#include "base/display.h"
 #include "base/timeutil.h"
 #include "gfx_es2/draw_buffer.h"
 #include "math/curves.h"
@@ -231,7 +232,8 @@ void PromptScreen::CreateViews() {
 	ViewGroup *leftColumn = new AnchorLayout(new LinearLayoutParams(1.0f));
 	root_->Add(leftColumn);
 
-	leftColumn->Add(new TextView(message_, ALIGN_LEFT, false, new AnchorLayoutParams(10, 10, NONE, NONE)))->SetClip(false);
+	float leftColumnWidth = dp_xres - actionMenuMargins.left - actionMenuMargins.right - 300.0f;
+	leftColumn->Add(new TextView(message_, ALIGN_LEFT | FLAG_WRAP_TEXT, false, new AnchorLayoutParams(leftColumnWidth, WRAP_CONTENT, 10, 10, NONE, NONE)))->SetClip(false);
 
 	ViewGroup *rightColumnItems = new LinearLayout(ORIENT_VERTICAL, new LinearLayoutParams(300, FILL_PARENT, actionMenuMargins));
 	root_->Add(rightColumnItems);

ext/native/Android.mk

@@ -92,6 +92,7 @@ LOCAL_SRC_FILES :=\
     ui/virtual_input.cpp \
     util/text/utf8.cpp \
     util/text/parsers.cpp \
+    util/text/wrap_text.cpp \
     util/hash/hash.cpp
 
 LOCAL_CFLAGS := -O3 -DUSING_GLES2 -fsigned-char -fno-strict-aliasing -Wall -Wno-multichar -D__STDC_CONSTANT_MACROS

ext/native/gfx_es2/draw_buffer.cpp

@@ -13,6 +13,7 @@
 #include "gfx_es2/draw_text.h"
 #include "gfx_es2/glsl_program.h"
 #include "util/text/utf8.h"
+#include "util/text/wrap_text.h"
 
 enum {
 	// Enough?
@@ -331,6 +332,31 @@ void DrawBuffer::DrawImage2GridH(ImageID atlas_image, float x1, float y1, float
 	DrawTexRect(xb, y1, x2, y2, um, v1, u2, v2, color);
 }
 
+class AtlasWordWrapper : public WordWrapper {
+public:
+	// Note: maxW may be height if rotated.
+	AtlasWordWrapper(const AtlasFont &atlasfont, float scale, const char *str, float maxW) : WordWrapper(str, maxW), atlasfont_(atlasfont), scale_(scale) {
+	}
+
+protected:
+	float MeasureWidth(const char *str, size_t bytes) override;
+
+	const AtlasFont &atlasfont_;
+	const float scale_;
+};
+
+float AtlasWordWrapper::MeasureWidth(const char *str, size_t bytes) {
+	float w = 0.0f;
+	for (UTF8 utf(str); utf.byteIndex() < bytes; ) {
+		const AtlasChar *ch = atlasfont_.getChar(utf.next());
+		if (!ch)
+			ch = atlasfont_.getChar('?');
+
+		w += ch->wx * scale_;
+	}
+	return w;
+}
+
 void DrawBuffer::MeasureTextCount(int font, const char *text, int count, float *w, float *h) {
 	const AtlasFont &atlasfont = *atlas->fonts[font];
 
@@ -367,6 +393,16 @@ void DrawBuffer::MeasureTextCount(int font, const char *text, int count, float *
 	if (h) *h = atlasfont.height * fontscaley * lines;
 }
 
+void DrawBuffer::MeasureTextRect(int font, const char *text, int count, const Bounds &bounds, float *w, float *h, int align) {
+	std::string toMeasure = std::string(text, count);
+	if (align & FLAG_WRAP_TEXT) {
+		AtlasWordWrapper wrapper(*atlas->fonts[font], fontscalex, toMeasure.c_str(), bounds.w);
+		toMeasure = wrapper.Wrapped();
+	}
+
+	MeasureTextCount(font, toMeasure.c_str(), (int)toMeasure.length(), w, h);
+}
+
 void DrawBuffer::MeasureText(int font, const char *text, float *w, float *h) {
 	return MeasureTextCount(font, text, (int)strlen(text), w, h);
 }
@@ -402,7 +438,12 @@ void DrawBuffer::DrawTextRect(int font, const char *text, float x, float y, floa
 		y += h;
 	}
 
-	DrawText(font, text, x, y, color, align);
+	std::string toDraw = text;
+	if (align & FLAG_WRAP_TEXT) {
+		AtlasWordWrapper wrapper(*atlas->fonts[font], fontscalex, toDraw.c_str(), w);
+		toDraw = wrapper.Wrapped();
+	}
+	DrawText(font, toDraw.c_str(), x, y, color, align);
 }
 
 // ROTATE_* doesn't yet work right.

ext/native/gfx_es2/draw_buffer.h

@@ -38,7 +38,8 @@ enum {
 	// Avoids using system font drawing as it's too slow.
 	// Not actually used here but is reserved for whatever system wraps DrawBuffer.
 	FLAG_DYNAMIC_ASCII = 2048,
-	FLAG_NO_PREFIX = 4096  // means to not process ampersands
+	FLAG_NO_PREFIX = 4096,  // means to not process ampersands
+	FLAG_WRAP_TEXT = 8192,
 };
 
 class Thin3DShaderSet;
@@ -126,6 +127,7 @@ public:
 
 	// NOTE: Count is in plain chars not utf-8 chars!
 	void MeasureTextCount(int font, const char *text, int count, float *w, float *h);
+	void MeasureTextRect(int font, const char *text, int count, const Bounds &bounds, float *w, float *h, int align = 0);
 
 	void DrawTextRect(int font, const char *text, float x, float y, float w, float h, Color color = 0xFFFFFFFF, int align = 0);
 	void DrawText(int font, const char *text, float x, float y, Color color = 0xFFFFFFFF, int align = 0);

ext/native/gfx_es2/draw_text.cpp

@@ -2,6 +2,7 @@
 #include "base/stringutil.h"
 #include "thin3d/thin3d.h"
 #include "util/hash/hash.h"
+#include "util/text/wrap_text.h"
 #include "util/text/utf8.h"
 #include "gfx_es2/draw_text.h"
 
@@ -12,6 +13,23 @@
 #include <QtOpenGL/QGLWidget>
 #endif
 
+class TextDrawerWordWrapper : public WordWrapper {
+public:
+	TextDrawerWordWrapper(TextDrawer *drawer, const char *str, float maxW) : WordWrapper(str, maxW), drawer_(drawer) {
+	}
+
+protected:
+	float MeasureWidth(const char *str, size_t bytes) override;
+
+	TextDrawer *drawer_;
+};
+
+float TextDrawerWordWrapper::MeasureWidth(const char *str, size_t bytes) {
+	float w, h;
+	drawer_->MeasureString(str, bytes, &w, &h);
+	return w;
+}
+
 #if defined(_WIN32) && !defined(USING_QT_UI)
 
 #define WIN32_LEAN_AND_MEAN
@@ -114,18 +132,51 @@ void TextDrawer::SetFont(uint32_t fontHandle) {
 }
 
 void TextDrawer::MeasureString(const char *str, float *w, float *h) {
+	MeasureString(str, strlen(str), w, h);
+}
+
+void TextDrawer::MeasureString(const char *str, size_t len, float *w, float *h) {
 	auto iter = fontMap_.find(fontHash_);
 	if (iter != fontMap_.end()) {
 		SelectObject(ctx_->hDC, iter->second->hFont);
 	}
 
 	SIZE size;
-	std::wstring wstr = ConvertUTF8ToWString(ReplaceAll(str, "\n", "\r\n"));
+	std::wstring wstr = ConvertUTF8ToWString(ReplaceAll(std::string(str, len), "\n", "\r\n"));
 	GetTextExtentPoint32(ctx_->hDC, wstr.c_str(), (int)wstr.size(), &size);
 	*w = size.cx * fontScaleX_;
 	*h = size.cy * fontScaleY_;
 }
 
+void TextDrawer::MeasureStringRect(const char *str, size_t len, const Bounds &bounds, float *w, float *h, int align) {
+	auto iter = fontMap_.find(fontHash_);
+	if (iter != fontMap_.end()) {
+		SelectObject(ctx_->hDC, iter->second->hFont);
+	}
+
+	std::string toMeasure = std::string(str, len);
+	if (align & FLAG_WRAP_TEXT) {
+		bool rotated = (align & (ROTATE_90DEG_LEFT | ROTATE_90DEG_RIGHT)) != 0;
+		WrapString(toMeasure, toMeasure.c_str(), rotated ? bounds.h : bounds.w);
+	}
+
+	std::vector<std::string> lines;
+	SplitString(toMeasure, '\n', lines);
+	float total_w = 0.0f;
+	float total_h = 0.0f;
+	for (size_t i = 0; i < lines.size(); i++) {
+		SIZE size;
+		std::wstring wstr = ConvertUTF8ToWString(lines[i].length() == 0 ? " " : lines[i]);
+		GetTextExtentPoint32(ctx_->hDC, wstr.c_str(), (int)wstr.size(), &size);
+		if (total_w < size.cx * fontScaleX_) {
+			total_w = size.cx * fontScaleX_;
+		}
+		total_h += size.cy * fontScaleY_;
+	}
+	*w = total_w;
+	*h = total_h;
+}
+
 void TextDrawer::DrawString(DrawBuffer &target, const char *str, float x, float y, uint32_t color, int align) {
 	if (!strlen(str))
 		return;
@@ -250,10 +301,33 @@ void TextDrawer::SetFont(uint32_t fontHandle) {
 }
 
 void TextDrawer::MeasureString(const char *str, float *w, float *h) {
+	MeasureString(str, strlen(str), w, h);
+}
+
+void TextDrawer::MeasureString(const char *str, size_t len, float *w, float *h) {
 #ifdef USING_QT_UI
 	QFont* font = fontMap_.find(fontHash_)->second;
 	QFontMetrics fm(*font);
-	QSize size = fm.size(0, QString::fromUtf8(str));
+	QSize size = fm.size(0, QString::fromUtf8(str, (int)len));
+	*w = (float)size.width() * fontScaleX_;
+	*h = (float)size.height() * fontScaleY_;
+#else
+	*w = 0;
+	*h = 0;
+#endif
+}
+
+void TextDrawer::MeasureStringRect(const char *str, size_t len, const Bounds &bounds, float *w, float *h, int align) {
+	std::string toMeasure = std::string(str, len);
+	if (align & FLAG_WRAP_TEXT) {
+		bool rotated = (align & (ROTATE_90DEG_LEFT | ROTATE_90DEG_RIGHT)) != 0;
+		WrapString(toMeasure, toMeasure.c_str(), rotated ? bounds.h : bounds.w);
+	}
+
+#ifdef USING_QT_UI
+	QFont* font = fontMap_.find(fontHash_)->second;
+	QFontMetrics fm(*font);
+	QSize size = fm.size(0, QString::fromUtf8(toMeasure.c_str(), (int)toMeasure.size()));
 	*w = (float)size.width() * fontScaleX_;
 	*h = (float)size.height() * fontScaleY_;
 #else
@@ -325,6 +399,11 @@ void TextDrawer::DrawString(DrawBuffer &target, const char *str, float x, float
 
 #endif
 
+void TextDrawer::WrapString(std::string &out, const char *str, float maxW) {
+	TextDrawerWordWrapper wrapper(this, str, maxW);
+	out = wrapper.Wrapped();
+}
+
 void TextDrawer::SetFontScale(float xscale, float yscale) {
 	fontScaleX_ = xscale;
 	fontScaleY_ = xscale;
@@ -344,7 +423,13 @@ void TextDrawer::DrawStringRect(DrawBuffer &target, const char *str, const Bound
 		y = bounds.y2();
 	}
 
-	DrawString(target, str, x, y, color, align);
+	std::string toDraw = str;
+	if (align & FLAG_WRAP_TEXT) {
+		bool rotated = (align & (ROTATE_90DEG_LEFT | ROTATE_90DEG_RIGHT)) != 0;
+		WrapString(toDraw, str, rotated ? bounds.h : bounds.w);
+	}
+
+	DrawString(target, toDraw.c_str(), x, y, color, align);
 }
 
 void TextDrawer::OncePerFrame() {

ext/native/gfx_es2/draw_text.h

@@ -49,6 +49,8 @@ public:
 
 	void SetFontScale(float xscale, float yscale);
 	void MeasureString(const char *str, float *w, float *h);
+	void MeasureString(const char *str, size_t len, float *w, float *h);
+	void MeasureStringRect(const char *str, size_t len, const Bounds &bounds, float *w, float *h, int align = ALIGN_TOPLEFT);
 	void DrawString(DrawBuffer &target, const char *str, float x, float y, uint32_t color, int align = ALIGN_TOPLEFT);
 	void DrawStringRect(DrawBuffer &target, const char *str, const Bounds &bounds, uint32_t color, int align);
 	// Use for housekeeping like throwing out old strings.
@@ -57,6 +59,8 @@ public:
 private:
 	Thin3DContext *thin3d_;
 
+	void WrapString(std::string &out, const char *str, float maxWidth);
+
 	int frameCount_;
 	float fontScaleX_;
 	float fontScaleY_;

ext/native/native.vcxproj

@@ -234,6 +234,7 @@
     <ClInclude Include="gfx\gl_debug_log.h" />
     <ClInclude Include="gfx\gl_lost_manager.h" />
     <ClInclude Include="gfx\texture_atlas.h" />
+    <ClInclude Include="util\text\wrap_text.h" />
     <ClInclude Include="gfx_es2\draw_buffer.h" />
     <ClInclude Include="gfx_es2\draw_text.h" />
     <ClInclude Include="gfx_es2\gl3stub.h" />
@@ -689,6 +690,7 @@
     <ClCompile Include="gfx\gl_debug_log.cpp" />
     <ClCompile Include="gfx\gl_lost_manager.cpp" />
     <ClCompile Include="gfx\texture_atlas.cpp" />
+    <ClCompile Include="util\text\wrap_text.cpp" />
     <ClCompile Include="gfx_es2\draw_buffer.cpp" />
     <ClCompile Include="gfx_es2\draw_text.cpp" />
     <ClCompile Include="gfx_es2\gl3stub.c">

ext/native/native.vcxproj.filters

@@ -311,6 +311,9 @@
     <ClInclude Include="net\sinks.h">
       <Filter>net</Filter>
     </ClInclude>
+    <ClInclude Include="util\text\wrap_text.h">
+      <Filter>util</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="gfx\gl_debug_log.cpp">
@@ -751,6 +754,9 @@
     <ClCompile Include="net\sinks.cpp">
       <Filter>net</Filter>
     </ClCompile>
+    <ClCompile Include="util\text\wrap_text.cpp">
+      <Filter>util</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <Filter Include="gfx">

ext/native/ui/ui_context.cpp

@@ -138,8 +138,23 @@ void UIContext::MeasureTextCount(const UI::FontStyle &style, const char *str, in
 		Draw()->MeasureTextCount(style.atlasFont, str, count, x, y);
 	} else {
 		textDrawer_->SetFontScale(fontScaleX_, fontScaleY_);
-		std::string subset(str, count);
-		textDrawer_->MeasureString(subset.c_str(), x, y);
+		textDrawer_->MeasureString(str, count, x, y);
+	}
+}
+
+void UIContext::MeasureTextRect(const UI::FontStyle &style, const char *str, int count, const Bounds &bounds, float *x, float *y, int align) const {
+	if ((align & FLAG_WRAP_TEXT) == 0) {
+		MeasureTextCount(style, str, count, x, y, align);
+		return;
+	}
+
+	if (!textDrawer_ || (align & FLAG_DYNAMIC_ASCII)) {
+		float sizeFactor = (float)style.sizePts / 24.0f;
+		Draw()->SetFontScale(fontScaleX_ * sizeFactor, fontScaleY_ * sizeFactor);
+		Draw()->MeasureTextRect(style.atlasFont, str, count, bounds, x, y, align);
+	} else {
+		textDrawer_->SetFontScale(fontScaleX_, fontScaleY_);
+		textDrawer_->MeasureStringRect(str, count, bounds, x, y, align);
 	}
 }
 

ext/native/ui/ui_context.h

@@ -61,6 +61,7 @@ public:
 	void SetFontScale(float scaleX, float scaleY);
 	void MeasureTextCount(const UI::FontStyle &style, const char *str, int count, float *x, float *y, int align = 0) const;
 	void MeasureText(const UI::FontStyle &style, const char *str, float *x, float *y, int align = 0) const;
+	void MeasureTextRect(const UI::FontStyle &style, const char *str, int count, const Bounds &bounds, float *x, float *y, int align = 0) const;
 	void DrawText(const char *str, float x, float y, uint32_t color, int align = 0);
 	void DrawTextShadow(const char *str, float x, float y, uint32_t color, int align = 0);
 	void DrawTextRect(const char *str, const Bounds &bounds, uint32_t color, int align = 0);

ext/native/ui/view.cpp

@@ -630,20 +630,9 @@ void Thin3DTextureView::Draw(UIContext &dc) {
 }
 
 void TextView::GetContentDimensions(const UIContext &dc, float &w, float &h) const {
-	// MeasureText doesn't seem to work with line breaks, so do something more sophisticated.
-	std::vector<std::string> lines;
-	SplitString(text_, '\n', lines);
-	float total_w = 0.f;
-	float total_h = 0.f;
-	for (size_t i = 0; i < lines.size(); i++) {
-		float temp_w, temp_h;
-		dc.MeasureText(small_ ? dc.theme->uiFontSmall : dc.theme->uiFont, lines[i].c_str(), &temp_w, &temp_h);
-		if (temp_w > total_w)
-			total_w = temp_w;
-		total_h += temp_h;
-	}
-	w = total_w;
-	h = total_h;
+	// We don't have the bounding w/h yet, so stick with hardset layout params.
+	Bounds bounds(0, 0, layoutParams_->width, layoutParams_->height);
+	dc.MeasureTextRect(small_ ? dc.theme->uiFontSmall : dc.theme->uiFont, text_.c_str(), (int)text_.length(), bounds, &w, &h, textAlign_);
 }
 
 void TextView::Draw(UIContext &dc) {

ext/native/util/CMakeLists.txt

@@ -1,6 +1,7 @@
 set(SRCS
   hash/hash.cpp
   text/utf8.cpp
+  text/wrap_text.cpp
 )
 
 set(SRCS ${SRCS})

ext/native/util/text/wrap_text.cpp

@@ -0,0 +1,183 @@
+#include <cstring>
+#include "util/text/utf8.h"
+#include "util/text/wrap_text.h"
+
+bool WordWrapper::IsCJK(uint32_t c) {
+	if (c < 0x1000) {
+		return false;
+	}
+
+	// CJK characters can be wrapped more freely.
+	bool result = (c >= 0x1100 && c <= 0x11FF); // Hangul Jamo.
+	result = result || (c >= 0x2E80 && c <= 0x2FFF); // Kangxi Radicals etc.
+#if 0
+	result = result || (c >= 0x3040 && c <= 0x31FF); // Hiragana, Katakana, Hangul Compatibility Jamo etc.
+	result = result || (c >= 0x3200 && c <= 0x32FF); // CJK Enclosed
+	result = result || (c >= 0x3300 && c <= 0x33FF); // CJK Compatibility
+	result = result || (c >= 0x3400 && c <= 0x4DB5); // CJK Unified Ideographs Extension A
+#else
+	result = result || (c >= 0x3040 && c <= 0x4DB5); // Above collapsed
+#endif
+	result = result || (c >= 0x4E00 && c <= 0x9FBB); // CJK Unified Ideographs
+	result = result || (c >= 0xAC00 && c <= 0xD7AF); // Hangul Syllables
+	result = result || (c >= 0xF900 && c <= 0xFAD9); // CJK Compatibility Ideographs
+	result = result || (c >= 0x20000 && c <= 0x2A6D6); // CJK Unified Ideographs Extension B
+	result = result || (c >= 0x2F800 && c <= 0x2FA1D); // CJK Compatibility Supplement
+	return result;
+}
+
+bool WordWrapper::IsPunctuation(uint32_t c) {
+	switch (c) {
+	// TODO: This list of punctuation is very incomplete.
+	case ',':
+	case '.':
+	case ':':
+	case '!':
+	case ')':
+	case '?':
+	case 0x00AD: // SOFT HYPHEN
+	case 0x3001: // IDEOGRAPHIC COMMA
+	case 0x3002: // IDEOGRAPHIC FULL STOP
+	case 0x06D4: // ARABIC FULL STOP
+	case 0xFF01: // FULLWIDTH EXCLAMATION MARK
+	case 0xFF09: // FULLWIDTH RIGHT PARENTHESIS
+	case 0xFF1F: // FULLWIDTH QUESTION MARK
+		return true;
+
+	default:
+		return false;
+	}
+}
+
+bool WordWrapper::IsSpace(uint32_t c) {
+	switch (c) {
+	case '\t':
+	case ' ':
+	case 0x2002: // EN SPACE
+	case 0x2003: // EM SPACE
+	case 0x3000: // IDEOGRAPHIC SPACE
+		return true;
+
+	default:
+		return false;
+	}
+}
+
+bool WordWrapper::IsShy(uint32_t c) {
+	return c == 0x00AD; // SOFT HYPHEN
+}
+
+std::string WordWrapper::Wrapped() {
+	if (out_.empty()) {
+		Wrap();
+	}
+	return out_;
+}
+
+void WordWrapper::WrapBeforeWord() {
+	if (x_ + wordWidth_ > maxW_) {
+		if (IsShy(out_[out_.size() - 1])) {
+			// Soft hyphen, replace it with a real hyphen since we wrapped at it.
+			// TODO: There's an edge case here where the hyphen might not fit.
+			out_[out_.size() - 1] = '-';
+		}
+		out_ += "\n";
+		x_ = 0.0f;
+		forceEarlyWrap_ = false;
+	}
+}
+
+void WordWrapper::AppendWord(int endIndex, bool addNewline) {
+	WrapBeforeWord();
+	// This will include the newline.
+	out_ += std::string(str_ + lastIndex_, endIndex - lastIndex_);
+	if (addNewline) {
+		out_ += "\n";
+	}
+	lastIndex_ = endIndex;
+}
+
+void WordWrapper::Wrap() {
+	out_.clear();
+
+	// First, let's check if it fits as-is.
+	size_t len = strlen(str_);
+	if (MeasureWidth(str_, len) <= maxW_) {
+		// If it fits, we don't need to go through each character.
+		out_ = str_;
+		return;
+	}
+
+	for (UTF8 utf(str_); !utf.end(); ) {
+		int beforeIndex = utf.byteIndex();
+		uint32_t c = utf.next();
+		int afterIndex = utf.byteIndex();
+
+		// Is this a newline character, hard wrapping?
+		if (c == '\n') {
+			// This will include the newline character.
+			AppendWord(afterIndex, false);
+			x_ = 0.0f;
+			wordWidth_ = 0.0f;
+			// We wrapped once, so stop forcing.
+			forceEarlyWrap_ = false;
+			continue;
+		}
+
+		float newWordWidth = 0.0f;
+		if (c == '\n') {
+			newWordWidth = wordWidth_;
+		} else {
+			// Measure the entire word for kerning purposes.  May not be 100% perfect.
+			newWordWidth = MeasureWidth(str_ + lastIndex_, afterIndex - lastIndex_);
+		}
+
+		// Is this the end of a word (space)?
+		if (wordWidth_ > 0.0f && IsSpace(c)) {
+			AppendWord(afterIndex, false);
+			// We include the space in the x increase.
+			// If the space takes it over, we'll wrap on the next word.
+			x_ += newWordWidth;
+			wordWidth_ = 0.0f;
+			continue;
+		}
+
+		// Can the word fit on a line even all by itself so far?
+		if (wordWidth_ > 0.0f && newWordWidth > maxW_) {
+			// Nope.  Let's drop what's there so far onto its own line.
+			if (x_ > 0.0f && x_ + wordWidth_ > maxW_ && beforeIndex > lastIndex_) {
+				// Let's put as many characters as will fit on the previous line.
+				// This word can't fit on one line even, so it's going to be cut into pieces anyway.
+				// Better to avoid huge gaps, in that case.
+				forceEarlyWrap_ = true;
+
+				// Now rewind back to where the word started so we can wrap at the opportune moment.
+				wordWidth_ = 0.0f;
+				while (utf.byteIndex() > lastIndex_) {
+					utf.bwd();
+				}
+				continue;
+			}
+			// Now, add the word so far (without this latest character) and break.
+			AppendWord(beforeIndex, true);
+			x_ = 0.0f;
+			wordWidth_ = 0.0f;
+			forceEarlyWrap_ = false;
+			// The current character will be handled as part of the next word.
+			continue;
+		}
+
+		wordWidth_ = newWordWidth;
+
+		// Is this the end of a word via punctuation / CJK?
+		if (wordWidth_ > 0.0f && (IsCJK(c) || IsPunctuation(c) || forceEarlyWrap_)) {
+			// CJK doesn't require spaces, so we treat each letter as its own word.
+			AppendWord(afterIndex, false);
+			x_ += wordWidth_;
+			wordWidth_ = 0.0f;
+		}
+	}
+
+	// Now insert the rest of the string - the last word.
+	AppendWord((int)len, false);
+}

ext/native/util/text/wrap_text.h

@@ -0,0 +1,35 @@
+#pragma once
+
+#include <string>
+
+class WordWrapper {
+public:
+	WordWrapper(const char *str, float maxW)
+		: str_(str), maxW_(maxW), lastIndex_(0), x_(0.0f), forceEarlyWrap_(false) {
+	}
+
+	std::string Wrapped();
+
+protected:
+	virtual float MeasureWidth(const char *str, size_t bytes) = 0;
+	void Wrap();
+	void WrapBeforeWord();
+	void AppendWord(int endIndex, bool addNewline);
+
+	static bool IsCJK(uint32_t c);
+	static bool IsPunctuation(uint32_t c);
+	static bool IsSpace(uint32_t c);
+	static bool IsShy(uint32_t c);
+
+	const char *const str_;
+	const float maxW_;
+	std::string out_;
+	// Index of last output / start of current word.
+	int lastIndex_;
+	// Position the current word starts at.
+	float x_;
+	// Most recent width of word since last index.
+	float wordWidth_;
+	// Force the next word to cut partially and wrap.
+	bool forceEarlyWrap_;
+};