New text width ops

src/PowderToy.cpp

@@ -101,16 +101,14 @@ void BlueScreen(String detailMessage)
 	String errorTitle = "ERROR";
 	String errorDetails = "Details: " + detailMessage;
 	String errorHelp = String("An unrecoverable fault has occurred, please report the error by visiting the website below\n") + SCHEME + SERVER;
-	int currentY = 0, width, height;
+
-	int errorWidth = 0;
+	// We use the width of errorHelp to center, but heights of the individual texts for vertical spacing
-	Graphics::textsize(errorTitle, errorWidth, height);
+	auto pos = engine.g->Size() / 2 - Vec2(Graphics::TextSize(errorHelp).X / 2, 100);
-	engine.g->BlendText(engine.g->Size() / 2 - Vec2(errorWidth / 2, 100 - currentY), errorTitle, 0xFFFFFF_rgb .WithAlpha(0xFF));
+	engine.g->BlendText(pos, errorTitle, 0xFFFFFF_rgb .WithAlpha(0xFF));
-	currentY += height + 4;
+	pos.Y += 4 + Graphics::TextSize(errorTitle).Y;
-	Graphics::textsize(errorDetails, width, height);
+	engine.g->BlendText(pos, errorDetails, 0xFFFFFF_rgb .WithAlpha(0xFF));
-	engine.g->BlendText(engine.g->Size() / 2 - Vec2(errorWidth / 2, 100 - currentY), errorDetails, 0xFFFFFF_rgb .WithAlpha(0xFF));
+	pos.Y += 4 + Graphics::TextSize(errorDetails).Y;
-	currentY += height + 4;
+	engine.g->BlendText(pos, errorHelp, 0xFFFFFF_rgb .WithAlpha(0xFF));
-	Graphics::textsize(errorHelp, width, height);
-	engine.g->BlendText(engine.g->Size() / 2 - Vec2(errorWidth / 2, 100 - currentY), errorHelp, 0xFFFFFF_rgb .WithAlpha(0xFF));
 
 	//Death loop
 	SDL_Event event;

src/graphics/Graphics.cpp

@@ -169,97 +169,19 @@ Graphics::Graphics()
 
 int Graphics::textwidth(const String &str)
 {
-	int x = 0;
+	return TextSize(str).X;
-	for (size_t i = 0; i < str.length(); i++)
-	{
-		if (str[i] == '\b')
-		{
-			if (str.length() <= i+1)
-				break;
-			i++;
-			continue;
-		}
-		else if (str[i] == '\x0F')
-		{
-			if (str.length() <= i+3)
-				break;
-			i += 3;
-			continue;
-		}
-		x += FontReader(str[i]).GetWidth();
-	}
-	return x-1;
-}
-
-int Graphics::CharWidth(String::value_type c)
-{
-	return FontReader(c).GetWidth();
 }
 
 int Graphics::textwidthx(const String &str, int w)
 {
-	int x = 0,n = 0,cw = 0;
+	return TextFit(str, w) - str.begin();
-	for (size_t i = 0; i < str.length(); i++)
-	{
-		if (str[i] == '\b')
-		{
-			if (str.length() <= i+1)
-				break;
-			i++;
-			continue;
-		} else if (str[i] == '\x0F') {
-			if (str.length() <= i+3)
-				break;
-			i += 3;
-			continue;
-		}
-		cw = FontReader(str[i]).GetWidth();
-		if (x+(cw/2) >= w)
-			break;
-		x += cw;
-		n++;
-	}
-	return n;
 }
 
 void Graphics::textsize(const String &str, int & width, int & height)
 {
-	if(!str.size())
+	auto size = TextSize(str);
-	{
+	width = size.X;
-		width = 0;
+	height = size.Y;
-		height = FONT_H-2;
-		return;
-	}
-
-	int cHeight = FONT_H-2, cWidth = 0, lWidth = 0;
-	for (size_t i = 0; i < str.length(); i++)
-	{
-		if (str[i] == '\n')
-		{
-			cWidth = 0;
-			cHeight += FONT_H;
-		}
-		else if (str[i] == '\x0F')
-		{
-			if (str.length() <= i+3)
-				break;
-			i += 3;
-		}
-		else if (str[i] == '\b')
-		{
-			if (str.length() <= i+1)
-				break;
-			i++;
-		}
-		else
-		{
-			cWidth += FontReader(str[i]).GetWidth();
-			if(cWidth>lWidth)
-				lWidth = cWidth;
-		}
-	}
-	width = lWidth;
-	height = cHeight;
 }
 
 void Graphics::draw_icon(int x, int y, Icon icon, unsigned char alpha, bool invert)

src/graphics/Graphics.h

@@ -95,9 +95,11 @@ public:
 	static std::vector<pixel> Gradient(std::vector<GradientStop> stops, int resolution);
 
 	//Font/text metrics
-	static int CharWidth(String::value_type c);
+	[[deprecated("Use TextFit()")]]
 	static int textwidthx(const String &s, int w);
+	[[deprecated("Use TextSize().X")]]
 	static int textwidth(const String &s);
+	[[deprecated("Use TextSize()")]]
 	static void textsize(const String &s, int & width, int & height);
 
 	VideoBuffer DumpFrame();

src/graphics/RasterDrawMethods.h

@@ -50,6 +50,14 @@ struct RasterDrawMethods
 
 	Vec2<int> BlendTextOutline(Vec2<int>, String const &, RGBA<uint8_t>);
 
+	static int CharWidth(String::value_type);
+	// Considers the first line to be FONT_H-2 tall with successive lines adding
+	// FONT_H each
+	static Vec2<int> TextSize(String const &);
+	// Return iterator to the end of an initial portion of text that fits in
+	// the given width
+	static String::const_iterator TextFit(String const &, int width);
+
 	void Clear();
 
 	[[deprecated("Use BlendTextOutline")]]

src/graphics/RasterDrawMethodsImpl.h

@@ -324,6 +324,83 @@ void RasterDrawMethods<Derived>::Clear()
 	std::fill_n(video.data(), video.Size().X * video.Size().Y, 0x000000_rgb .Pack());
 }
 
+template<typename Derived>
+int RasterDrawMethods<Derived>::CharWidth(String::value_type ch)
+{
+	return FontReader(ch).GetWidth();
+}
+
+template<typename Derived>
+Vec2<int> RasterDrawMethods<Derived>::TextSize(String const &str)
+{
+	Vec2<int> size = Vec2(0, FONT_H - 2);
+	int curX = -1; // characters have 1px of spacing between them
+	for (size_t i = 0; i < str.length(); i++)
+	{
+		if (str[i] == '\n')
+		{
+			size.X = std::max(curX, size.X);
+			size.Y += FONT_H;
+			curX = 0;
+		}
+		else if (str[i] == '\x0F')
+		{
+			if (str.length() <= i + 3)
+				break;
+			i += 3;
+		}
+		else if (str[i] == '\x0E')
+			continue;
+		else if (str[i] == '\x01')
+			continue;
+		else if (str[i] == '\b')
+		{
+			if (str.length() <= i + 1)
+				break;
+			i++;
+		}
+		else
+			curX += CharWidth(str[i]);
+	}
+	size.X = std::max(curX, size.X);
+	return size;
+}
+
+template<typename Derived>
+String::const_iterator RasterDrawMethods<Derived>::TextFit(String const &str, int width)
+{
+	int curX = 0;
+	for (size_t i = 0; i < str.length(); i++)
+	{
+		if (str[i] == '\n')
+			curX = 0;
+		else if (str[i] == '\x0F')
+		{
+			if (str.length() <= i + 3)
+				break;
+			i += 3;
+		}
+		else if (str[i] == '\x0E')
+			continue;
+		else if (str[i] == '\x01')
+			continue;
+		else if (str[i] == '\b')
+		{
+			if (str.length() <= i + 1)
+				break;
+			i++;
+		}
+		else
+		{
+			int dx = CharWidth(str[i]);
+			if (curX + dx / 2 >= width)
+				return str.begin() + i;
+			curX += dx;
+		}
+	}
+	return str.end();
+}
+
 template<typename Derived>
 int RasterDrawMethods<Derived>::drawtext_outline(int x, int y, const String &s, int r, int g, int b, int a)
 {