Maintain static screen DPI on resize

Trying to dynamically track the DPI did not really work as we'd
start accumulating errors and eventually the DPI would start to
drift. Instead maintain a fixed, sensible DPI at all times.

diff --git a/unix/x0vncserver/RandrGlue.c b/unix/x0vncserver/RandrGlue.c
index ff12902fdd8ee7373c16558c4ce53ca976dbd12b..c26ac6adf5c7d51cb7f47b93c90cc0d2b45003f1 100644 (file)
--- a/unix/x0vncserver/RandrGlue.c
+++ b/unix/x0vncserver/RandrGlue.c
@@ -117,15 +117,15 @@ int vncRandRResizeScreen(int width, int height)
 {
   vncGlueContext *ctx = &randrGlueContext;
 
-  int xwidth = DisplayWidth(ctx->dpy, DefaultScreen(ctx->dpy));
-  int xheight = DisplayHeight(ctx->dpy, DefaultScreen(ctx->dpy));
-  int xwidthmm = DisplayWidthMM(ctx->dpy, DefaultScreen(ctx->dpy));
-  int xheightmm = DisplayHeightMM(ctx->dpy, DefaultScreen(ctx->dpy));
-
-  /* Try to retain DPI when we resize */
-  XRRSetScreenSize(ctx->dpy, DefaultRootWindow(ctx->dpy), width, height,
-                   xwidthmm * width / xwidth,
-                   xheightmm * height / xheight);
+  int mwidth, mheight;
+
+  // Always calculate a DPI of 96.
+  // It's what mutter does, so good enough for us.
+  mwidth = width * 254 / 96 / 10;
+  mheight = height * 254 / 96 / 10;
+
+  XRRSetScreenSize(ctx->dpy, DefaultRootWindow(ctx->dpy),
+                   width, height, mwidth, mheight);
 
   return 1;
 }

diff --git a/unix/xserver/hw/vnc/RandrGlue.c b/unix/xserver/hw/vnc/RandrGlue.c
index 82e85524faf951529aae83b282685a5ea44340d6..a291688828ee391435275eb638c4737c3a1f7c27 100644 (file)
--- a/unix/xserver/hw/vnc/RandrGlue.c
+++ b/unix/xserver/hw/vnc/RandrGlue.c
@@ -64,11 +64,14 @@ int vncRandRIsValidScreenSize(int width, int height)
 int vncRandRResizeScreen(int width, int height)
 {
   ScreenPtr pScreen = screenInfo.screens[scrIdx];
+  int dpi, mwidth, mheight;
 
-  /* Try to retain DPI when we resize */
-  return RRScreenSizeSet(pScreen, width, height,
-                         pScreen->mmWidth * width / pScreen->width,
-                         pScreen->mmHeight * height / pScreen->height);
+  /* Keep the DPI specified at start */
+  dpi = monitorResolution ? monitorResolution : 96;
+  mwidth = width * 254 / dpi / 10;
+  mheight = height * 254 / dpi / 10;
+
+  return RRScreenSizeSet(pScreen, width, height, mwidth, mheight);
 }
 
 void vncRandRUpdateSetTime(void)