Fix DPI Scaling Issues

.gitignore

@@ -1 +1,3 @@
-/build/
+/build/
+/build-SimpleGraphic
+/.idea

engine/render.h

@@ -102,6 +102,8 @@ class r_IRenderer {
 	virtual int		VirtualScreenWidth() = 0;
 	virtual int		VirtualScreenHeight() = 0;
 	virtual float	VirtualScreenScaleFactor() = 0;
+	virtual void	SetDpiScaleOverridePercent(int percent) = 0;
+	virtual int		DpiScaleOverridePercent() const = 0;
 	virtual int		VirtualMap(int properValue) = 0;
 	virtual int		VirtualUnmap(int mappedValue) = 0;
 

engine/render/r_font.cpp

@@ -10,6 +10,7 @@
 #include <iostream>
 #include <fstream>
 #include <string>
+#include <cmath>
 
 // =======
 // Classes
@@ -144,12 +145,12 @@ int r_font_c::StringWidthInternal(f_fontHeight_s* fh, std::u32string_view str, i
 	int heightIdx = (int)(std::find(fontHeights, fontHeights + numFontHeight, fh) - fontHeights);
 	auto tofuFont = FindSmallerFontHeight(height, heightIdx, tofuSizeReduction);
 
-	auto measureCodepoint = [](f_fontHeight_s* fh, char32_t cp) {
-		auto& glyph = fh->Glyph((char)(unsigned char)cp);
+	auto measureCodepoint = [](f_fontHeight_s* glyphFh, char32_t cp) {
+		auto& glyph = glyphFh->Glyph((char)(unsigned char)cp);
 		return glyph.width + glyph.spLeft + glyph.spRight;
 	};
 
-	int width = 0;
+	float width = 0.0f;
 	for (size_t idx = 0; idx < str.size();) {
 		auto ch = str[idx];
 		int escLen = IsColorEscape(str.substr(idx));
@@ -158,23 +159,26 @@ int r_font_c::StringWidthInternal(f_fontHeight_s* fh, std::u32string_view str, i
 		}
 		else if (ch >= (unsigned)fh->numGlyph) {
 			auto tofu = BuildTofuString(ch);
-			for (auto ch : tofu) {
-				width += measureCodepoint(tofuFont.fh, ch);
+			for (auto cp : tofu) {
+				width += measureCodepoint(tofuFont.fh, cp);
+				width = std::ceil(width);
 			}
 			++idx;
 		}
 		else if (ch == U'\t') {
 			auto& glyph = fh->Glyph(' ');
 			int spWidth = glyph.width + glyph.spLeft + glyph.spRight;
-			width += (int)(spWidth * 4 * scale);
+			width += spWidth * 4 * scale;
+			width = std::ceil(width);
 			++idx;
 		}
 		else {
-			width += (int)(measureCodepoint(fh, ch) * scale);
+			width += measureCodepoint(fh, ch) * scale;
+			width = std::ceil(width);
 			++idx;
 		}
 	}
-	return width;
+	return static_cast<int>(width);
 }
 
 int r_font_c::StringWidth(int height, std::u32string_view str)
@@ -187,7 +191,7 @@ int r_font_c::StringWidth(int height, std::u32string_view str)
 		auto lineEnd = std::find(I, str.end(), U'\n');
 		if (I != lineEnd) {
 			std::u32string_view line(&*I, std::distance(I, lineEnd));
-			int lw = (int)StringWidthInternal(fh, line, height, scale);
+			int lw = StringWidthInternal(fh, line, height, scale);
 			max = (std::max)(max, lw);
 		}
 		if (lineEnd == str.end()) {
@@ -203,12 +207,12 @@ size_t r_font_c::StringCursorInternal(f_fontHeight_s* fh, std::u32string_view st
 	int heightIdx = (int)(std::find(fontHeights, fontHeights + numFontHeight, fh) - fontHeights);
 	auto tofuFont = FindSmallerFontHeight(height, heightIdx, tofuSizeReduction);
 
-	auto measureCodepoint = [](f_fontHeight_s* fh, char32_t cp) {
-		auto& glyph = fh->Glyph((char)(unsigned char)cp);
+	auto measureCodepoint = [](f_fontHeight_s* glyphFh, char32_t cp) {
+		auto& glyph = glyphFh->Glyph((char)(unsigned char)cp);
 		return glyph.width + glyph.spLeft + glyph.spRight;
 	};
 
-	int x = 0;
+	float x = 0.0f;
 	auto I = str.begin();
 	auto lineEnd = std::find(I, str.end(), U'\n');
 	while (I != lineEnd) {
@@ -219,32 +223,34 @@ size_t r_font_c::StringCursorInternal(f_fontHeight_s* fh, std::u32string_view st
 		}
 		else if (*I >= (unsigned)fh->numGlyph) {
 			auto tofu = BuildTofuString(*I);
-			int tofuWidth = 0;
-			for (auto ch : tofu) {
-				tofuWidth += measureCodepoint(tofuFont.fh, ch);
+			for (auto cp : tofu) {
+				x += measureCodepoint(tofuFont.fh, cp);
+				x = std::ceil(x);
+				if (curX <= x) {
+					return std::distance(str.begin(), I);
+				}
 			}
-			int halfWidth = (int)(tofuWidth / 2.0f);
-			x += halfWidth;
-			if (curX <= x) {
-				break;
-			}
-			x += tofuWidth - halfWidth;
 			++I;
 		}
 		else if (*I == U'\t') {
 			auto& glyph = fh->Glyph(' ');
-			int spWidth = glyph.width + glyph.spLeft + glyph.spRight;
-			int fullWidth = (int)(spWidth * 4 * scale);
-			int halfWidth = (int)(fullWidth / 2.0f);
+			float fullWidth = (glyph.width + glyph.spLeft + glyph.spRight) * 4.0f * scale;
+			float halfWidth = std::ceil(fullWidth / 2.0f);
 			x += halfWidth;
+			x = std::ceil(x);
 			if (curX <= x) {
 				break;
 			}
 			x += fullWidth - halfWidth;
+			x = std::ceil(x);
+			if (curX <= x) {
+				break;
+			}
 			++I;
 		}
 		else {
-			x += (int)(measureCodepoint(fh, *I) * scale);
+			x += measureCodepoint(fh, *I) * scale;
+			x = std::ceil(x);
 			if (curX <= x) {
 				break;
 			}
@@ -339,10 +345,10 @@ void r_font_c::DrawTextLine(scp_t pos, int align, int height, col4_t col, std::u
 
 	// Calculate the string position
 	float x = pos[X];
-	float y = pos[Y];
+	float y = std::floor(pos[Y]);
 	if (align != F_LEFT) {
 		// Calculate the real width of the string
-		float width = (float)StringWidthInternal(fh, str, height, scale);
+		float width = StringWidthInternal(fh, str, height, scale);
 		switch (align) {
 		case F_CENTRE:
 			x = floor((renderer->VirtualScreenWidth() - width) / 2.0f + pos[X]);
@@ -359,6 +365,9 @@ void r_font_c::DrawTextLine(scp_t pos, int align, int height, col4_t col, std::u
 		}
 	}
 
+	// Snap the starting x position to the pixel grid so the leading glyph isn't blurred.
+	x = std::round(x);
+
 	r_tex_c* curTex{};
 
 	auto drawCodepoint = [this, &curTex, &x, y](f_fontHeight_s* fh, int height, float scale, int yShift, char32_t cp) {

engine/render/r_main.cpp

@@ -1852,32 +1852,45 @@ int r_renderer_c::DrawStringCursorIndex(int height, int font, const char* str, i
 // ==============
 
 int r_renderer_c::VirtualScreenWidth() {
-	return VirtualMap(sys->video->vid.size[0]);
+	int const properWidth = apiDpiAware ? sys->video->vid.fbSize[0] : sys->video->vid.size[0];
+	return VirtualMap(properWidth);
 }
 
 int r_renderer_c::VirtualScreenHeight() {
-	return VirtualMap(sys->video->vid.size[1]);
+	int const properHeight = apiDpiAware ? sys->video->vid.fbSize[1] : sys->video->vid.size[1];
+	return VirtualMap(properHeight);
 }
 
 float r_renderer_c::VirtualScreenScaleFactor() {
 	if (apiDpiAware) {
+		if (dpiScaleOverridePercent > 0) {
+			return dpiScaleOverridePercent / 100.0f;
+		}
 		return sys->video->vid.dpiScale;
 	}
 	return 1.0f;
 }
 
+void r_renderer_c::SetDpiScaleOverridePercent(int percent) {
+	dpiScaleOverridePercent = percent;
+}
+
+int r_renderer_c::DpiScaleOverridePercent() const {
+	return dpiScaleOverridePercent;
+}
+
 int r_renderer_c::VirtualMap(int properValue) {
 	if (apiDpiAware) {
 		return properValue;
 	}
-	return (int)(properValue / sys->video->vid.dpiScale);
+	return static_cast<int>(properValue / sys->video->vid.dpiScale);
 }
 
 int r_renderer_c::VirtualUnmap(int mappedValue) {
 	if (apiDpiAware) {
 		return mappedValue;
 	}
-	return (int)(mappedValue * sys->video->vid.dpiScale);
+	return static_cast<int>(mappedValue * sys->video->vid.dpiScale);
 }
 
 // =====

engine/render/r_main.h

@@ -99,6 +99,8 @@ class r_renderer_c: public r_IRenderer, public conCmdHandler_c {
 	int		VirtualScreenWidth();
 	int		VirtualScreenHeight();
 	float	VirtualScreenScaleFactor();
+	void	SetDpiScaleOverridePercent(int percent);
+	int		DpiScaleOverridePercent() const;
 	int		VirtualMap(int properValue);
 	int		VirtualUnmap(int mappedValue);
 
@@ -126,7 +128,7 @@ class r_renderer_c: public r_IRenderer, public conCmdHandler_c {
 	PFNGLINSERTEVENTMARKEREXTPROC	glInsertEventMarkerEXT = nullptr;
 	PFNGLPUSHGROUPMARKEREXTPROC		glPushGroupMarkerEXT = nullptr;
 	PFNGLPOPGROUPMARKEREXTPROC		glPopGroupMarkerEXT = nullptr;
-	
+
 	conVar_c*	r_compress = nullptr;
 	conVar_c*	r_screenshotFormat = nullptr;
 	conVar_c*	r_layerDebug = nullptr;
@@ -173,6 +175,7 @@ class r_renderer_c: public r_IRenderer, public conCmdHandler_c {
 	};
 
 	bool apiDpiAware{};
+	int dpiScaleOverridePercent = 0;
 	RenderTarget rttMain[2];
 	int	presentRtt = 0;