Florian Will : win32u: Only retrieve the dc size if needed.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 6dfad4c2fb238620296942ec57171136f8db4ff7
URL:    https://source.winehq.org/git/wine.git/?a=commit;h=6dfad4c2fb238620296942ec5...

Author: Florian Will 
Date:   Fri Nov 26 09:20:26 2021 +0000

win32u: Only retrieve the dc size if needed.

SetMapMode(.., MM_TEXT) is called a lot in common gdiplus use cases via
gdi_transform_acquire(). Querying the size and resolution can be
expensive, so skip it when its not needed.

When running the "ZusiDisplay" ET423 diagnostic display, which uses
gdiplus heavily, this change increases the "indicator blinking speed"
from 0.6 per second to 1 per second and probably hits the FPS limit now.
Also, CPU usage of the ZusiDisplay.exe process goes down from ~75% to
~42% of one core according to "top", and wineserver CPU usage goes down
from ~48% to ~3%.

Signed-off-by: Florian Will 
Signed-off-by: Huw Davies 
Signed-off-by: Alexandre Julliard

---

dlls/win32u/mapping.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/dlls/win32u/mapping.c b/dlls/win32u/mapping.c
index 6c20f50a302..6e7c42fe7cc 100644
--- a/dlls/win32u/mapping.c
+++ b/dlls/win32u/mapping.c
@@ -117,8 +117,6 @@ BOOL set_map_mode( DC *dc, int mode )
     if (mode == dc->attr->map_mode && (mode == MM_ISOTROPIC || mode == MM_ANISOTROPIC))
         return TRUE;

-    virtual_size = get_dc_virtual_size( dc );
-    virtual_res = get_dc_virtual_res( dc );
     switch (mode)
     {
     case MM_TEXT:
@@ -129,30 +127,40 @@ BOOL set_map_mode( DC *dc, int mode )
         break;
     case MM_LOMETRIC:
     case MM_ISOTROPIC:
+        virtual_size           = get_dc_virtual_size( dc );
+        virtual_res            = get_dc_virtual_res( dc );
         dc->attr->wnd_ext.cx   = virtual_size.cx * 10;
         dc->attr->wnd_ext.cy   = virtual_size.cy * 10;
         dc->attr->vport_ext.cx = virtual_res.cx;
         dc->attr->vport_ext.cy = -virtual_res.cy;
         break;
     case MM_HIMETRIC:
+        virtual_size           = get_dc_virtual_size( dc );
+        virtual_res            = get_dc_virtual_res( dc );
         dc->attr->wnd_ext.cx   = virtual_size.cx * 100;
         dc->attr->wnd_ext.cy   = virtual_size.cy * 100;
         dc->attr->vport_ext.cx = virtual_res.cx;
         dc->attr->vport_ext.cy = -virtual_res.cy;
         break;
     case MM_LOENGLISH:
+        virtual_size           = get_dc_virtual_size( dc );
+        virtual_res            = get_dc_virtual_res( dc );
         dc->attr->wnd_ext.cx   = muldiv(1000, virtual_size.cx, 254);
         dc->attr->wnd_ext.cy   = muldiv(1000, virtual_size.cy, 254);
         dc->attr->vport_ext.cx = virtual_res.cx;
         dc->attr->vport_ext.cy = -virtual_res.cy;
         break;
     case MM_HIENGLISH:
+        virtual_size           = get_dc_virtual_size( dc );
+        virtual_res            = get_dc_virtual_res( dc );
         dc->attr->wnd_ext.cx   = muldiv(10000, virtual_size.cx, 254);
         dc->attr->wnd_ext.cy   = muldiv(10000, virtual_size.cy, 254);
         dc->attr->vport_ext.cx = virtual_res.cx;
         dc->attr->vport_ext.cy = -virtual_res.cy;
         break;
     case MM_TWIPS:
+        virtual_size           = get_dc_virtual_size( dc );
+        virtual_res            = get_dc_virtual_res( dc );
         dc->attr->wnd_ext.cx   = muldiv(14400, virtual_size.cx, 254);
         dc->attr->wnd_ext.cy   = muldiv(14400, virtual_size.cy, 254);
         dc->attr->vport_ext.cx = virtual_res.cx;