From 1562396ec09cc747c21118efbfe0bd4e866a0e13 Mon Sep 17 00:00:00 2001
From: ManoloFLTK <41016272+ManoloFLTK@users.noreply.github.com>
Date: Tue, 9 Aug 2022 16:05:53 +0200
Subject: Fix Fl_Xlib_Graphics_Driver for RGB image drawing under XQuartz.

---
 src/drivers/Xlib/Fl_Xlib_Graphics_Driver_image.cxx | 8 ++++++++
 1 file changed, 8 insertions(+)

(limited to 'src/drivers/Xlib')

diff --git a/src/drivers/Xlib/Fl_Xlib_Graphics_Driver_image.cxx b/src/drivers/Xlib/Fl_Xlib_Graphics_Driver_image.cxx
index 0ea0b0529..dd9b7135e 100644
--- a/src/drivers/Xlib/Fl_Xlib_Graphics_Driver_image.cxx
+++ b/src/drivers/Xlib/Fl_Xlib_Graphics_Driver_image.cxx
@@ -799,6 +799,14 @@ void Fl_Xlib_Graphics_Driver::draw_rgb(Fl_RGB_Image *rgb, int XP, int YP, int WP
  */
 int Fl_Xlib_Graphics_Driver::scale_and_render_pixmap(Fl_Offscreen pixmap, int depth, double scale_x, double scale_y, int XP, int YP, int WP, int HP) {
   bool has_alpha = (depth == 2 || depth == 4);
+  if (!has_alpha && scale_x == 1 && scale_y == 1) {
+    // Fix for a problem visible under XQuartz with test/device and Fl_Image_Surface:
+    // the drawn image is fully black. The problem does not occur under linux.
+    // Why the problem occurs under XQuartz remains unknown.
+    // The fix is to use XCopyArea() when adequate, rather than using Xrender.
+    XCopyArea(fl_display, pixmap, fl_window, gc_, 0, 0, WP, HP, XP, YP);
+    return 1;
+  }
   XRenderPictureAttributes srcattr;
   memset(&srcattr, 0, sizeof(XRenderPictureAttributes));
   static XRenderPictFormat *fmt24 = XRenderFindStandardFormat(fl_display, PictStandardRGB24);
-- 
cgit v1.2.3