Turn off reflection and shadow in simulate when a GPU is not present.

Note that The GLFW adapter currently assumes that a GPU is always present, so this new code path is never reached at the moment.

PiperOrigin-RevId: 504617048
Change-Id: I04a323c33d9cff73686d39e4a6676ca6a4484c98

simulate/glfw_adapter.cc

@@ -129,6 +129,10 @@ std::pair<int, int> GlfwAdapter::GetWindowSize() const {
   return {width, height};
 }
 
+bool GlfwAdapter::IsGPUAccelerated() const {
+  return true;
+}
+
 void GlfwAdapter::PollEvents() {
   Glfw().glfwPollEvents();
 }

simulate/glfw_adapter.h

@@ -31,6 +31,7 @@ class GlfwAdapter : public PlatformUIAdapter {
   double GetDisplayPixelsPerInch() const override;
   std::pair<int, int> GetFramebufferSize() const override;
   std::pair<int, int> GetWindowSize() const override;
+  bool IsGPUAccelerated() const override;
   void PollEvents() override;
   void SetClipboardString(const char* text) override;
   void SetVSync(bool enabled) override;

simulate/platform_ui_adapter.h

@@ -46,6 +46,7 @@ class PlatformUIAdapter {
   virtual double GetDisplayPixelsPerInch() const = 0;
   virtual std::pair<int, int> GetFramebufferSize() const = 0;
   virtual std::pair<int, int> GetWindowSize() const = 0;
+  virtual bool IsGPUAccelerated() const = 0;
   virtual void PollEvents() = 0;
   virtual void SetClipboardString(const char* text) = 0;
   virtual void SetVSync(bool enabled) = 0;

simulate/simulate.cc

@@ -26,6 +26,7 @@
 #include <utility>
 
 #include "lodepng.h"
+#include <mujoco/mjvisualize.h>
 #include <mujoco/mjxmacro.h>
 #include <mujoco/mujoco.h>
 #include "platform_ui_adapter.h"
@@ -1606,6 +1607,11 @@ void Simulate::loadmodel() {
   mjv_makeScene(this->m, &this->scn, maxgeom);
   this->platform_ui->RefreshMjrContext(this->m, 50*(this->font+1));
 
+  if (!this->platform_ui->IsGPUAccelerated()) {
+    this->scn.flags[mjRND_SHADOW] = 0;
+    this->scn.flags[mjRND_REFLECTION] = 0;
+  }
+
   // clear perturbation state
   this->pert.active = 0;
   this->pert.select = 0;
@@ -1896,6 +1902,10 @@ void Simulate::renderloop() {
   // make empty scene
   mjv_defaultScene(&this->scn);
   mjv_makeScene(nullptr, &this->scn, maxgeom);
+  if (!this->platform_ui->IsGPUAccelerated()) {
+    this->scn.flags[mjRND_SHADOW] = 0;
+    this->scn.flags[mjRND_REFLECTION] = 0;
+  }
 
   // select default font
   int fontscale = ComputeFontScale(*this->platform_ui);