linux_window_manager: query default refresh rate via xrandr, rather than assuming 60 (oops!)

.github/workflows/builds.yml

@@ -40,7 +40,7 @@ jobs:
         shell: bash
         run: |
           sudo apt-get update
-          sudo apt-get install --no-install-recommends -y pkg-config libfreetype6-dev libx11-dev libxext-dev libxfixes-dev libgl1-mesa-dev libegl1-mesa-dev
+          sudo apt-get install --no-install-recommends -y pkg-config libfreetype6-dev libx11-dev libxext-dev libxfixes-dev libxrandr-dev libgl1-mesa-dev libegl1-mesa-dev
 
       - name: Install clang-17 Dependencies
         if: ${{ matrix.compiler == 'clang-17' }}
@@ -162,7 +162,7 @@ jobs:
           wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
           sudo apt-add-repository -y "deb http://apt.llvm.org/noble/ llvm-toolchain-noble-22 main"
           sudo apt-get update
-          sudo apt-get install -y clang-22 lld-22 llvm-22 gcc-14 pkg-config libfreetype6-dev libx11-dev libxext-dev libxfixes-dev libgl1-mesa-dev libegl1-mesa-dev
+          sudo apt-get install -y clang-22 lld-22 llvm-22 gcc-14 pkg-config libfreetype6-dev libx11-dev libxext-dev libxfixes-dev libxrandr-dev libgl1-mesa-dev libegl1-mesa-dev
           # crash callstack symbolizer depends on LLVM
           sudo ln -s /usr/bin/llvm-symbolizer-22 /usr/bin/llvm-symbolizer
       - name: Run

README.md

@@ -247,6 +247,7 @@ on the system:
 - `libx11`
 - `libxext`
 - `libxfixes`
+- `libxrandr`
 - `libgl`
 - `libegl`
 
@@ -256,13 +257,13 @@ installed using one of the following commands, depending on your distribution:
 #### Ubuntu / Debian / Mint 
 
 ```
-sudo apt install -y libfreetype6-dev libx11-dev libxext-dev libxfixes-dev libgl-dev libegl-dev
+sudo apt install -y libfreetype6-dev libx11-dev libxext-dev libxfixes-dev libxrandr-dev libgl-dev libegl-dev
 ```
 
 #### Arch / Manjaro
 
 ```
-sudo pacman -S --needed freetype2 libx11 libxext libxfixes libglvnd
+sudo pacman -S --needed freetype2 libx11 libxext libxfixes libxrandr libglvnd
 ```
 
 ### 3. Building

build.sh

@@ -29,14 +29,14 @@ cc_link="-lpthread -lm -lrt -ldl"
 cc_link_dll="-fPIC"
 
 # --- External Libraries ------------------------------------------------------
-# sudo apt install -y pkg-config libfreetype6-dev libx11-dev libxext-dev libxfixes-dev libgl-dev libegl-dev
+# sudo apt install -y pkg-config libfreetype6-dev libx11-dev libxext-dev libxfixes-dev libxrandr-dev libgl-dev libegl-dev
 if [[ -x "$(command -v pkg-config)" ]]; then
   cc_font_provider="$(pkg-config --cflags --libs freetype2)"  
-  cc_os_gfx="$(pkg-config --cflags --libs x11 xext xfixes)"
+  cc_os_gfx="$(pkg-config --cflags --libs x11 xext xfixes xrandr)"
   cc_render="$(pkg-config --cflags --libs gl egl)"
 else
   cc_font_provider="-I/usr/include/freetype2 -lfreetype"
-  cc_os_gfx="-lX11 -lXext -lXfixes"
+  cc_os_gfx="-lX11 -lXext -lXfixes -lXrandr"
   cc_render="-lGL -lEGL"
 fi
 

src/linux/window_manager/linux_window_manager.c

@@ -374,11 +374,41 @@ wm_init(void)
   //- rjf: open im
   lnx_wm_state->xim = XOpenIM(lnx_wm_state->display, 0, 0, 0);
   
-  //- rjf: fill out gfx info
+  //- rjf: fill out default gfx info
   lnx_wm_state->gfx_info.double_click_time = 0.5f;
   lnx_wm_state->gfx_info.caret_blink_time = 0.5f;
   lnx_wm_state->gfx_info.default_refresh_rate = 60.f;
   
+  //- rjf: determine default refresh rate
+  {
+    XRRScreenResources *res = XRRGetScreenResourcesCurrent(lnx_wm_state->display, DefaultRootWindow(lnx_wm_state->display));
+    for EachIndex(idx, res->noutput)
+    {
+      XRROutputInfo *out_info = XRRGetOutputInfo(lnx_wm_state->display, res, res->outputs[idx]);
+      if(out_info && out_info->connection == RR_Connected && out_info->crtc != None)
+      {
+        XRRCrtcInfo *crtc_info = XRRGetCrtcInfo(lnx_wm_state->display, res, out_info->crtc);
+        if(crtc_info)
+        {
+          for EachIndex(mode_idx, res->nmode)
+          {
+            if(res->modes[mode_idx].id == crtc_info->mode)
+            {
+              XRRModeInfo *mode_info = &res->modes[mode_idx];
+              if(mode_info->vTotal != 0 && mode_info->hTotal != 0)
+              {
+                lnx_wm_state->gfx_info.default_refresh_rate = (F32)mode_info->dotClock / ((F32)mode_info->hTotal * (F32)mode_info->vTotal);
+              }
+            }
+          }
+          XRRFreeCrtcInfo(crtc_info);
+        }
+        XRRFreeOutputInfo(out_info);
+      }
+    }
+    XRRFreeScreenResources(res);
+  }
+  
   //- rjf: fill out cursors
   {
     struct

src/linux/window_manager/linux_window_manager.h

@@ -12,6 +12,7 @@
 #include <X11/cursorfont.h>
 #include <X11/extensions/sync.h>
 #include <X11/extensions/Xfixes.h>
+#include <X11/extensions/Xrandr.h>
 #include <X11/keysym.h>
 #include <X11/keysymdef.h>
 #include <poll.h>