(Herbert): add a new method, inBP, to LyXLength.

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@3974 a592a061-630c-0410-9148-cb99ea01b6c8

src/ChangeLog

@@ -1,3 +1,8 @@
+2002-03-28  Herbert Voss  <voss@lyx.org>
+
+	* lyxlength.[Ch]: add inBP() to get the right PS-point
+	units (BigPoint). With inPixels we have rounding errors
+
 2002-04-11  Juergen Vigna  <jug@sad.it>
 
 	* text2.C (setCursorFromCoordinates): set iy to the right value.

src/lyxlength.C

@@ -238,6 +238,34 @@ int LyXLength::inPixels(int default_width, int default_height) const
 }
 
 
+int LyXLength::inBP() const
+{
+	// return any LyXLength value as a one with
+	// the PostScript point, called bp (big points)
+	double result = 0.0;
+	int val_sign = val_ < 0.0 ? -1 : 1;
+	switch (unit_) {
+	case LyXLength::CM:
+		// 1bp = 0.2835cm
+		result = val_ * 28.346;
+		break;
+	case LyXLength::MM:
+		// 1bp = 0.02835mm
+		result = val_ * 2.8346;
+		break;
+	case LyXLength::IN:
+		// 1pt = 1/72in
+		result = val_ * 72.0;
+		break;
+	default:
+		// no other than bp possible
+		result = val_;
+		break;
+	}
+	return static_cast<int>(result * val_sign + 0.5);
+}
+
+
 bool operator==(LyXLength const & l1, LyXLength const & l2)
 {
 	return l1.value() == l2.value() && l1.unit() == l2.unit();

src/lyxlength.h

@@ -67,6 +67,8 @@ public:
 	string const asLatexString() const;
 	/// return the on-screen size of this length
 	int inPixels(int default_width, int default_height) const;
+	/// return the on-screen size of this length of an image
+	int inBP() const;
 
 	/** If "data" is valid, the length represented by it is
 	  stored into "result", if that is not 0. */