allow onscreen cpu rendering (#30510)

* spinner POC cpu

* should be single threaded

* how tf did that get added

* allow non offscreen

---------

Co-authored-by: Comma Device <device@comma.ai>

selfdrive/navd/main.cc

@@ -11,7 +11,7 @@
 #include "system/hardware/hw.h"
 
 int main(int argc, char *argv[]) {
-  Hardware::config_cpu_rendering();
+  Hardware::config_cpu_rendering(true);
 
   qInstallMessageHandler(swagLogMessageHandler);
   setpriority(PRIO_PROCESS, 0, -20);

system/hardware/base.h

@@ -34,7 +34,7 @@ public:
   static bool get_ssh_enabled() { return false; }
   static void set_ssh_enabled(bool enabled) {}
 
-  static void config_cpu_rendering();
+  static void config_cpu_rendering(bool offscreen);
 
   static bool PC() { return false; }
   static bool TICI() { return false; }

system/hardware/pc/hardware.h

@@ -21,8 +21,10 @@ public:
     std::system(("pactl set-sink-volume @DEFAULT_SINK@ " + std::string(volume_str)).c_str());
   }
 
-  static void config_cpu_rendering() {
-    setenv("QT_QPA_PLATFORM", "offscreen", 1);
+  static void config_cpu_rendering(bool offscreen) {
+    if (offscreen) {
+      setenv("QT_QPA_PLATFORM", "offscreen", 1);
+    }
     setenv("__GLX_VENDOR_LIBRARY_NAME", "mesa", 1);
     setenv("LP_NUM_THREADS", "0", 1); // disable threading so we stay on our assigned CPU
   }

system/hardware/tici/hardware.h

@@ -104,8 +104,10 @@ public:
   static bool get_ssh_enabled() { return Params().getBool("SshEnabled"); }
   static void set_ssh_enabled(bool enabled) { Params().putBool("SshEnabled", enabled); }
 
-  static void config_cpu_rendering() {
-    setenv("QT_QPA_PLATFORM", "eglfs", 1); // offscreen doesn't work with EGL/GLES
+  static void config_cpu_rendering(bool offscreen) {
+    if (offscreen) {
+      setenv("QT_QPA_PLATFORM", "eglfs", 1); // offscreen doesn't work with EGL/GLES
+    }
     setenv("LP_NUM_THREADS", "0", 1); // disable threading so we stay on our assigned CPU
   }
 };