Fix text clipping when working with the Xft-based renderer.

1 files changed, 28 insertions, 0 deletions

diff --git a/unix/tkUnixRFont.c b/unix/tkUnixRFont.c
index 134bb45..deecceb 100644
--- a/unix/tkUnixRFont.c
+++ b/unix/tkUnixRFont.c
@@ -33,6 +33,16 @@ typedef struct {
     XftDraw *ftDraw;
     XftColor color;
 } UnixFtFont;
+
+/*
+ * Used to describe the current clipping box. Can't be passed normally because
+ * the information isn't retrievable from the GC.
+ */
+
+typedef struct ThreadSpecificData {
+    Region clipRegion;		/* The clipping region, or None. */
+} ThreadSpecificData;
+static Tcl_ThreadDataKey dataKey;
 
 /*
  * Package initialization:
@@ -712,6 +722,8 @@ Tk_DrawChars(
     int clen, nspec, xStart = x;
     XftGlyphFontSpec specs[NUM_SPEC];
     XGlyphInfo metrics;
+    ThreadSpecificData *tsdPtr = (ThreadSpecificData *)
+            Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));
 
     if (fontPtr->ftDraw == 0) {
 #if DEBUG_FONTSEL
@@ -738,6 +750,9 @@ Tk_DrawChars(
 	fontPtr->color.color.alpha = 0xffff;
 	fontPtr->color.pixel = values.foreground;
     }
+    if (tsdPtr->clipRegion != None) {
+	XftDrawSetClip(fontPtr->ftDraw, tsdPtr->clipRegion);
+    }
     nspec = 0;
     while (numBytes > 0 && x <= maxCoord && y <= maxCoord) {
 	XftFont *ftFont;
@@ -775,6 +790,9 @@ Tk_DrawChars(
     if (nspec) {
 	XftDrawGlyphFontSpec(fontPtr->ftDraw, &fontPtr->color, specs, nspec);
     }
+    if (tsdPtr->clipRegion != None) {
+	XftDrawSetClip(fontPtr->ftDraw, None);
+    }
 
   doUnderlineStrikeout:
     if (fontPtr->font.fa.underline != 0) {
@@ -789,3 +807,13 @@ Tk_DrawChars(
 		(unsigned) fontPtr->font.underlineHeight);
     }
 }
+
+void
+TkUnixSetXftClipRegion(
+    Region clipRegion)		/* The clipping region to install. */
+{
+    ThreadSpecificData *tsdPtr = (ThreadSpecificData *)
+            Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));
+
+    tsdPtr->clipRegion = clipRegion;
+}