X-Git-Url: https://git.lyx.org/gitweb/?a=blobdiff_plain;f=src%2Flyxlength.C;h=2e16c84ed3ea28f122cd381397dfbcd31f59d159;hb=5091380d6bad1686800e384ed1bbb03836a15aab;hp=b9586b1c3bb5ef88d4ff211ae8d5bef251eb9a55;hpb=cf216cd7fc8ec452e3147171ab6a107c88906b06;p=lyx.git

diff --git a/src/lyxlength.C b/src/lyxlength.C
index b9586b1c3b..2e16c84ed3 100644
--- a/src/lyxlength.C
+++ b/src/lyxlength.C
@@ -53,7 +53,7 @@ string const LyXLength::asString() const
 {
 	ostringstream buffer;
 	buffer << val_ << unit_name[unit_]; // setw?
-	return buffer.str().c_str();
+	return STRCONV(buffer.str());
 }
 
 
@@ -89,7 +89,7 @@ string const LyXLength::asLatexString() const
 	    buffer << val_ << unit_name[unit_]; // setw?
 	    break;
 	}
-	return buffer.str().c_str();
+	return STRCONV(buffer.str());
 }
 
 
@@ -123,7 +123,7 @@ bool LyXLength::zero() const
 }
 
 
-int LyXLength::inPixels(int default_width, int default_height) const
+int LyXLength::inPixels(int text_width, int em_width_base) const
 {
 	// Zoom factor specified by user in percent
 	double const zoom = lyxrc.zoom / 100.0; // [percent]
@@ -131,18 +131,23 @@ int LyXLength::inPixels(int default_width, int default_height) const
 	// DPI setting for monitor: pixels/inch
 	double const dpi = lyxrc.dpi; // screen resolution [pixels/inch]
 
+	double const em_width = (em_width_base > 0)
+		? em_width_base
+		: 10*(dpi/72.27)*zoom;
+	// A different estimate for em_width is
+	// font_metrics::width('M', LyXFont(LyXFont::ALL_SANE))
+	// but this estimate might not be more accurate as the screen font
+	// is different then the latex font.
+
 	// Pixel values are scaled so that the ratio
 	// between lengths and font sizes on the screen
 	// is the same as on paper.
 
-	// we don't care about sign of value, we
-	// display negative space with text too
 #ifdef WITH_WARNINGS
 #warning if you don't care than either call this function differently or let it return negative values and call abs() explicitly when needed (Andre')
 #endif
 
 	double result = 0.0;
-	int val_sign = val_ < 0.0 ? -1 : 1;
 
 	switch (unit_) {
 	case LyXLength::SP:
@@ -191,31 +196,37 @@ int LyXLength::inPixels(int default_width, int default_height) const
 		break;
 	case LyXLength::EX:
 		// Ex: The height of an "x"
-		result = zoom * val_ * default_height / 2; // what to / width?
+		// 0.4305 is the ration between 1ex and 1em in cmr10
+		result = val_ * em_width * 0.4305;
 		break;
-	case LyXLength::EM: // what to / width?
+	case LyXLength::EM:
 		// Em: The width of an "m"
-		result = zoom * val_ * default_height / 2; // Why 2?
+		result = val_ * em_width;
 		break;
-	case LyXLength::MU: // This is probably only allowed in
-		// math mode
-		result = zoom * val_ * default_height;
+	case LyXLength::MU:
+		// math unit = 1/18em
+		result = val_ * em_width / 18;
 		break;
 	case LyXLength::PCW: // Always % of workarea
 	case LyXLength::PTW:
-	case LyXLength::PPW:
 	case LyXLength::PLW:
-		result = val_ * default_width / 100;
+		result = val_ * text_width / 100;
+		break;
+	case LyXLength::PPW:
+		// paperwidth/textwidth is 1.7 for A4 paper with default margins
+		result = val_ * text_width * 1.7 / 100;
 		break;
 	case LyXLength::PTH:
+		result = val_ * text_width * 1.787 / 100;
+		break;
 	case LyXLength::PPH:
-		result = val_ * default_height / 100;
+		result = val_ * text_width * 2.2 / 100;
 		break;
 	case LyXLength::UNIT_NONE:
 		result = 0;  // this cannot happen
 		break;
 	}
-	return static_cast<int>(result * val_sign + 0.5);
+	return static_cast<int>(result + ((result >= 0) ? 0.5 : -0.5));
 }