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authordkf <donal.k.fellows@manchester.ac.uk>2010-01-05 08:49:47 (GMT)
committerdkf <donal.k.fellows@manchester.ac.uk>2010-01-05 08:49:47 (GMT)
commitaacf8d739e27f7131d0a7322da993ba8158df5e6 (patch)
treeb53ca9c943b91ed43676acd0f73612577ebae655 /unix/tkUnixRFont.c
parenta580567464cda1d5a6116339acc707e451e7854e (diff)
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Corrected rounding of coordinates when working with fonts. [Bug 2824916]
Diffstat (limited to 'unix/tkUnixRFont.c')
-rw-r--r--unix/tkUnixRFont.c31
1 files changed, 24 insertions, 7 deletions
diff --git a/unix/tkUnixRFont.c b/unix/tkUnixRFont.c
index eef42d5..34f504e 100644
--- a/unix/tkUnixRFont.c
+++ b/unix/tkUnixRFont.c
@@ -8,7 +8,7 @@
* See the file "license.terms" for information on usage and redistribution of
* this file, and for a DISCLAIMER OF ALL WARRANTIES.
*
- * RCS: @(#) $Id: tkUnixRFont.c,v 1.32 2010/01/02 18:40:35 dkf Exp $
+ * RCS: @(#) $Id: tkUnixRFont.c,v 1.33 2010/01/05 08:49:50 dkf Exp $
*/
#include "tkUnixInt.h"
@@ -16,8 +16,6 @@
#include <X11/Xft/Xft.h>
#include <ctype.h>
-#define ROUND16(x) ((short)((x) + 0.5))
-
typedef struct {
XftFont *ftFont;
XftFont *ft0Font;
@@ -827,6 +825,25 @@ Tk_DrawChars(
}
}
+/*
+ *---------------------------------------------------------------------------
+ *
+ * TkpDrawAngledChars --
+ *
+ * Draw some characters at an angle. This would be simple code, except
+ * Xft has bugs with cumulative errors in character positioning which are
+ * caused by trying to perform all calculations internally with integers.
+ * So we have to do the work ourselves with floating-point math.
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * Target drawable is updated.
+ *
+ *---------------------------------------------------------------------------
+ */
+
void
TkpDrawAngledChars(
Display *display, /* Display on which to draw. */
@@ -923,8 +940,8 @@ TkpDrawAngledChars(
XftDrawGlyphs(fontPtr->ftDraw, &fontPtr->color, currentFtFont,
originX, originY, glyphs, nglyph);
}
- originX = (int) floor(x + 0.5);
- originY = (int) floor(y + 0.5);
+ originX = ROUND16(x);
+ originY = ROUND16(y);
if (nglyph) {
XftGlyphExtents(fontPtr->display, currentFtFont, glyphs,
nglyph, &metrics);
@@ -993,8 +1010,8 @@ TkpDrawAngledChars(
if (ftFont && ft0Font) {
specs[nspec].font = ftFont;
specs[nspec].glyph = XftCharIndex(fontPtr->display, ftFont, c);
- specs[nspec].x = (int) floor(x + 0.5);
- specs[nspec].y = (int) floor(y + 0.5);
+ specs[nspec].x = ROUND16(x);
+ specs[nspec].y = ROUND16(y);
XftGlyphExtents(fontPtr->display, ft0Font, &specs[nspec].glyph, 1,
&metrics);
x += metrics.xOff*cosA + metrics.yOff*sinA;