Cirrus: Fixed lags caused by incorrect redraw value for backward BitBlt.

bochs-emu · Oct 29, 2024 · 2ddb701 · 2ddb701
1 parent 42e7c31
commit 2ddb701
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Showing 2 changed files with 5 additions and 2 deletions.
diff --git a/bochs/CHANGES b/bochs/CHANGES
@@ -57,6 +57,7 @@ Detailed change log :
     - Fixed Cirrus PCI issues found with Windows 3.11 driver (missing / unreadable text in 8 bpp and 16 bpp modes)
     - Added support for graphics controller mode extensions in VGA mode
       Now the GD5446 PCI driver and the GD5430 ISA driver work correctly
+    - Fixed lags caused by incorrect redraw value for backward BitBlt
   - Voodoo / Banshee
     - Banshee: Fixes for address wrap handling during display update
       Original Banshee / Voodoo3 VGABIOS reporting wrong number of image pages in

diff --git a/bochs/iodev/display/svga_cirrus.cc b/bochs/iodev/display/svga_cirrus.cc
@@ -3182,8 +3182,10 @@ void bx_svga_cirrus_c::svga_bitblt()
         BX_CIRRUS_THIS redraw.x -= BX_CIRRUS_THIS redraw.w;
       }
       if (BX_CIRRUS_THIS redraw.h > BX_CIRRUS_THIS redraw.y) {
-        BX_CIRRUS_THIS redraw.h = BX_CIRRUS_THIS redraw.y;
-        BX_CIRRUS_THIS redraw.y = 0;
+        if (BX_CIRRUS_THIS redraw.y > 0) {
+          BX_CIRRUS_THIS redraw.h = BX_CIRRUS_THIS redraw.y;
+          BX_CIRRUS_THIS redraw.y = 0;
+        }
       } else {
         BX_CIRRUS_THIS redraw.y -= BX_CIRRUS_THIS redraw.h;
       }