tdf#127316 ooxml/ww8export: DFLT_ESC_*_AUTO - use better formulas

See tdf#99602 and tdf#120412 for many fixes related to escapement.
The poor formulas for AUTO style came to light in 6.3.0.1
with 6.4 commit 32262b0a537207832d7d126d8427d8949b9e821d

Looking at sw/source/core/txtnode/swfont.cxx, we can see in
CalcEsc() that for superscript the DFLT_ESC_SUPER_AUTO
is calculated as the difference between the two ascents.
Because the superscript is smaller, it has a smaller ascent,
so to reach the same ascent line as the original, we can
raise its baseline by fontAscent(fA) - superscriptAscent(ssA).
Since the ascent is approximately 80% of the total fontheight(fH),
we can calculate the Esc number (percentage * 100) as:
EscHeight = fA - ssA  (formula in CalcEsc)
ssA = nProp/100 * fA  (superscript ascent/height reduced by nProp)
.8 = fA/fHeight       (improvement would be to query font.GetAscent)
Esc% = EscHeight / fHeight

Esc% = (fA - nProp/100*fA) / fHeight
Esc% = (1 - nProp/100)*fA/fHeight
Esc = (100 - nProp) * 0.8

DFLT_ESC_SUB_AUTO subscript is similar with the descent(fD)
being the remainding 20% of the fontHeight.
EscHeight = fD - ssD (formula in CalcEsc)
ssD = nProp/100 * fD (by definition of the function of nProp)
.2 = fD/fHeight      (an approximation - each font will be different)

Esc% = (fD - nProp/100*fD) / fHeight
Esc% = (1 - nProp/100)*fD/fHeight
Esc = (100 - nProp) * 0.2 (in the negative direction)

For RTF, I can see no reason for the ++nProp except
to try and avoid nProp == 0. It is only .01% after all...

Change-Id: Ia7b9f8784572193dd05cb80afa56c90540c3e676
Reviewed-on: https://gerrit.libreoffice.org/80306
Tested-by: Jenkins
Reviewed-by: Justin Luth <justin_luth@sil.org>
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>
(cherry picked from commit d6e2d624a124454fa4ac80cb30a924571a609101)
Reviewed-on: https://gerrit.libreoffice.org/83665

1 files changed, 13 insertions, 17 deletions

diff --git a/sw/source/filter/ww8/rtfattributeoutput.cxx b/sw/source/filter/ww8/rtfattributeoutput.cxx
index 6a04e707a706..a16424b01e2e 100644
--- a/sw/source/filter/ww8/rtfattributeoutput.cxx
+++ b/sw/source/filter/ww8/rtfattributeoutput.cxx
@@ -2324,8 +2324,8 @@ void RtfAttributeOutput::CharCrossedOut(const SvxCrossedOutItem& rCrossedOut)
 
 void RtfAttributeOutput::CharEscapement(const SvxEscapementItem& rEscapement)
 {
-    short nEsc = rEscapement.GetEsc();
-    if (rEscapement.GetProportionalHeight() == DFLT_ESC_PROP)
+    short nEsc = rEscapement.GetEsc(), nProp = rEscapement.GetProportionalHeight();
+    if (DFLT_ESC_PROP == nProp || nProp < 1 || nProp > 100)
     {
         if (DFLT_ESC_SUB == nEsc || DFLT_ESC_AUTO_SUB == nEsc)
             m_aStyles.append(OOO_STRING_SVTOOLS_RTF_SUB);
@@ -2333,14 +2333,22 @@ void RtfAttributeOutput::CharEscapement(const SvxEscapementItem& rEscapement)
             m_aStyles.append(OOO_STRING_SVTOOLS_RTF_SUPER);
         return;
     }
+    else if (DFLT_ESC_AUTO_SUPER == nEsc)
+    {
+        nEsc = .8 * (100 - nProp);
+    }
+    else if (DFLT_ESC_AUTO_SUB == nEsc)
+    {
+        nEsc = .2 * -(100 - nProp);
+    }
 
     const char* pUpDn;
 
     double fHeight = m_rExport.GetItem(RES_CHRATR_FONTSIZE).GetHeight();
 
-    if (0 < rEscapement.GetEsc())
+    if (0 < nEsc)
         pUpDn = OOO_STRING_SVTOOLS_RTF_UP;
-    else if (0 > rEscapement.GetEsc())
+    else if (0 > nEsc)
     {
         pUpDn = OOO_STRING_SVTOOLS_RTF_DN;
         fHeight = -fHeight;
@@ -2348,22 +2356,10 @@ void RtfAttributeOutput::CharEscapement(const SvxEscapementItem& rEscapement)
     else
         return;
 
-    short nProp = rEscapement.GetProportionalHeight() * 100;
-    if (DFLT_ESC_AUTO_SUPER == nEsc)
-    {
-        nEsc = 100 - rEscapement.GetProportionalHeight();
-        ++nProp;
-    }
-    else if (DFLT_ESC_AUTO_SUB == nEsc)
-    {
-        nEsc = -100 + rEscapement.GetProportionalHeight();
-        ++nProp;
-    }
-
     m_aStyles.append('{');
     m_aStyles.append(OOO_STRING_SVTOOLS_RTF_IGNORE);
     m_aStyles.append(OOO_STRING_SVTOOLS_RTF_UPDNPROP);
-    m_aStyles.append(static_cast<sal_Int32>(nProp));
+    m_aStyles.append(static_cast<sal_Int32>(nProp * 100));
     m_aStyles.append('}');
     m_aStyles.append(pUpDn);