From fd1696d18e8fac4dfec6da537af79cb2d5a4c1a1 Mon Sep 17 00:00:00 2001
From: Manolo Gouy <Manolo>
Date: Sat, 10 Mar 2018 06:46:13 +0000
Subject: Fl_Xlib_Graphics_Driver::scale_clip: restrict the computed X11 region
 to the 16-bit coordinate space.

This member function transforms the current clip region from FLTK units to pixel units
multiplying FLTK units by the current value of the scale factor to get pixel units.
The current clip region has been, by construction, restricted to the 16-bit coordinate space.
But these data can evade this space after multiplication by the scale factor.
Thus, it's necessary to enforce the 16-bit space here which is done with Fl_Xlib_Graphics_Driver::XRectangleRegion.

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.4@12727 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
---
 src/drivers/Xlib/Fl_Xlib_Graphics_Driver.cxx | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

(limited to 'src/drivers/Xlib/Fl_Xlib_Graphics_Driver.cxx')

diff --git a/src/drivers/Xlib/Fl_Xlib_Graphics_Driver.cxx b/src/drivers/Xlib/Fl_Xlib_Graphics_Driver.cxx
index dfae0c006..568143811 100644
--- a/src/drivers/Xlib/Fl_Xlib_Graphics_Driver.cxx
+++ b/src/drivers/Xlib/Fl_Xlib_Graphics_Driver.cxx
@@ -249,15 +249,16 @@ Region Fl_Xlib_Graphics_Driver::scale_clip(float f) {
   if (r == 0 || (f == 1 && offset_x_ == 0 && offset_y_ == 0) ) return 0;
   int deltaf = f/2;
   Region r2 = XCreateRegion();
-  XRectangle R;
   for (int i = 0; i < r->numRects; i++) {
     int x = (r->rects[i].x1 + offset_x_)*f;
     int y = (r->rects[i].y1 + offset_y_)*f;
-    R.x = x - deltaf + line_delta_;
-    R.y = y - deltaf + line_delta_;
-    R.width = int((r->rects[i].x2 + offset_x_) * f) - x;
-    R.height = int((r->rects[i].y2 + offset_y_) * f) - y;
-    XUnionRectWithRegion(&R, r2, r2);
+    int w = int((r->rects[i].x2 + offset_x_) * f) - x;
+    int h = int((r->rects[i].y2 + offset_y_) * f) - y;
+    x += line_delta_ - deltaf;
+    y += line_delta_ - deltaf;
+    Region R = XRectangleRegion(x, y, w, h);
+    XUnionRegion(R, r2, r2);
+    ::XDestroyRegion(R);
   }
   rstack[rstackptr] = r2;
   return r;
-- 
cgit v1.2.3