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[Plplot-cvs] SF.net SVN: plplot:[11783] trunk
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From: <ai...@us...> - 2011-07-03 17:06:24
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Revision: 11783
http://plplot.svn.sourceforge.net/plplot/?rev=11783&view=rev
Author: airwin
Date: 2011-07-03 17:06:18 +0000 (Sun, 03 Jul 2011)
Log Message:
-----------
Implement a private plP_script_scale function that calculates scale
values for font size and magnitude of the vertical offset associated
with superscripts/subscripts. Currently, the font scale and offset
calculations associated with superscripts and subscripts are done in
an idiosyncratic (and often incorrect) way in various locations within
the core code and drivers. plP_script_scale is designed to
consolidate those bits of logic in one place where the calculation is
done correctly.
As a first use of this new logic, use plP_script_scale for the Hershey
font superscripts/subscripts. plP_script_scale produces completely
symmetrical vertical offsets between superscripts and subscripts.
Therefore, this change corrects a very long-standing error (since
before 1993) in the vertical offset of the Hershey subscripts which
previously were not consistent with the magnitude of the vertical
offsets of the superscripts.
Modified Paths:
--------------
trunk/include/plplotP.h
trunk/src/plsym.c
Modified: trunk/include/plplotP.h
===================================================================
--- trunk/include/plplotP.h 2011-07-01 06:27:21 UTC (rev 11782)
+++ trunk/include/plplotP.h 2011-07-03 17:06:18 UTC (rev 11783)
@@ -620,6 +620,14 @@
PLDLLIMPEXP void
difilt_clip( PLINT *, PLINT * );
+// Calculate scale of font size and scale of magnitude of vertical
+// offset associated with superscripts and subscripts.
+
+PLDLLIMPEXP void
+plP_script_scale( PLBOOL ifupper, PLINT *level,
+ PLFLT *old_scale, PLFLT *scale,
+ PLFLT *old_offset, PLFLT *offset);
+
// Driver draws text
void
Modified: trunk/src/plsym.c
===================================================================
--- trunk/src/plsym.c 2011-07-01 06:27:21 UTC (rev 11782)
+++ trunk/src/plsym.c 2011-07-03 17:06:18 UTC (rev 11783)
@@ -787,6 +787,7 @@
PLINT ch, i, length, level = 0, style, oline = 0, uline = 0;
PLFLT width = 0., xorg = 0., yorg = 0., def, ht, dscale, scale;
+ PLFLT old_sscale, sscale, old_soffset, soffset;
plgchr( &def, &ht );
dscale = 0.05 * ht;
@@ -802,17 +803,19 @@
for ( i = 0; i < length; i++ )
{
ch = symbol[i];
- if ( ch == -1 ) // super-script
+ if ( ch == -1 ) // superscript
{
- level++;
- yorg += 16.0 * scale;
- scale = dscale * pow( 0.75, (double) ABS( level ) );
+ plP_script_scale( TRUE, &level,
+ &old_sscale, &sscale, &old_soffset, &soffset);
+ yorg = 16.0*dscale*soffset;
+ scale = dscale * sscale;
}
- else if ( ch == -2 ) // sub-script
+ else if ( ch == -2 ) // subscript
{
- level--;
- scale = dscale * pow( 0.75, (double) ABS( level ) );
- yorg -= 16.0 * scale;
+ plP_script_scale( FALSE, &level,
+ &old_sscale, &sscale, &old_soffset, &soffset);
+ yorg = -16.0*dscale*soffset;
+ scale = dscale * sscale;
}
else if ( ch == -3 ) // back-char
xorg -= width * scale;
@@ -1229,6 +1232,74 @@
}
//--------------------------------------------------------------------------
+//! Calculate scale of font size and scale of magnitude of vertical
+//! offset associated with superscripts and subscripts.
+//! Notes on arguments: ifupper must be either TRUE or FALSE on every
+//! call to plP_script_scale. The contents of the location pointed to
+//! by the level pointer must be zero on the first call to
+//! plP_script_scale, but not modified externally from then on. The
+//! contents of the locations pointed to by all other pointer
+//! arguments are initialized internally, and should not be modified
+//! externally.
+//!
+//! @param ifupper Value which is TRUE if superscripting, i.e., if
+//! incrementing the previous level, and FALSE if subscripting, i.e.,
+//! decrementing the previous level.
+//! @param level Pointer to a location which contains the value of the
+//! superscript/subscript level. That value is 0, +-1, +-2, etc., for
+//! no superscript/subscript, the first level of
+//! superscript/subscript, the second level of superscript/subscript,
+//! etc. Before the call the value is the old level, and after the
+//! call the value will be incremented (ifupper TRUE) or decremented
+//! (ifupper FALSE) from the previous value.
+//! @param old_scale A pointer to a location that contains after the
+//! call the old font size scale value.
+//! @param scale A pointer to a location that contains after the call
+//! the font size scale value. This value is 0.75^{|level|} where
+//! |level| is the magnitude of the value of the superscript/subscript
+//! level after the call.
+//! @param old_offset A pointer to a location that contains after the
+//! call the old value of the magnitude of the superscript/subscript
+//! offset.
+//! @param offset A pointer to a location that contains after the call
+//! the value of the magnitude of the superscript/subscript offset
+//! which is zero for |level|=0 and sum_{i=1}^{i=|level|} 0.75^{i-1},
+//! otherwise.
+
+void
+plP_script_scale( PLBOOL ifupper, PLINT *level,
+ PLFLT *old_scale, PLFLT *scale,
+ PLFLT *old_offset, PLFLT *offset)
+{
+ if (*level == 0)
+ {
+ *old_scale = 1.;
+ *old_offset = 0.;
+ }
+ else
+ {
+ *old_scale = *scale;
+ *old_offset = *offset;
+ }
+ if((*level >=0 && ifupper) || (*level <=0 && !ifupper))
+ {
+ // If superscript of subscript moves further away from centerline....
+ *scale = 0.75 * *old_scale;
+ *offset = *old_offset + *old_scale;
+ }
+ else
+ {
+ // If superscript of subscript moves closer to centerline....
+ *scale = *old_scale/0.75;
+ *offset = *old_offset - *scale;
+ }
+ if(ifupper)
+ (*level)++;
+ else
+ (*level)--;
+}
+
+//--------------------------------------------------------------------------
// void c_plfont(ifont)
//
// Sets the global font flag to 'ifont'.
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