improve messages

include/polyscope/messages.h

@@ -9,7 +9,8 @@ namespace polyscope {
 // == Register various kinds of messages
 
 // General details, things you would print to stdout. For now, that's exactly what it does
-void info(std::string message);
+void info(std::string message); // default verbosityLevel = 0
+void info(int verbosityLevel, std::string message); // only printed if verbosity > vebosityLevel
 
 // Non-fatal warnings. Warnings with the same base message are batched together, so the UI doesn't get completely
 // overwhelmed if you call this in a dense loop.

src/messages.cpp

@@ -203,8 +203,9 @@ void buildWarningUI(std::string warningBaseString, std::string warningDetailStri
 } // namespace
 
 
-void info(std::string message) {
-  if (options::verbosity > 0) {
+void info(std::string message) { info(0, message); }
+void info(int verbosityLevel, std::string message) {
+  if (options::verbosity > verbosityLevel) {
     std::cout << options::printPrefix << message << std::endl;
   }
 }

src/polyscope.cpp

@@ -143,6 +143,8 @@ void init(std::string backend) {
     return;
   }
 
+  info(5, "Initializing Polyscope");
+
   state::backend = backend;
 
   if (options::usePrefsFile) {

src/render/opengl/gl_engine_egl.cpp

@@ -285,28 +285,21 @@ void GLEngineEGL::resolveEGL() {
   // We are furthermore loading `libEGL.so` dynamically in the middle of runtime, rather than at load time as via ldd
   // etc. At the end of this function we also load EGL extensions in the usual way.
 
-
-  if (options::verbosity > 5) {
-    std::cout << polyscope::options::printPrefix << "Attempting to dlopen libEGL.so" << std::endl;
-  }
+  info(5, "Attempting to dlopen libEGL.so");
   void* handle = dlopen("libEGL.so", RTLD_LAZY);
-  if (handle && options::verbosity > 5) {
-    std::cout << polyscope::options::printPrefix << "  ...loaded libEGL.so" << std::endl;
-  }
+  if (handle) info(5, "  ...loaded libEGL.so");
   if (!handle) {
     handle = dlopen("libEGL.so.1", RTLD_LAZY); // try it while we're at it, happens on OSMesa without dev headers
   }
-  if (handle && options::verbosity > 5) {
-    std::cout << polyscope::options::printPrefix << "  ...loaded libEGL.so.1" << std::endl;
-  }
+  if (handle) info(5, "  ...loaded libEGL.so.1");
   if (!handle) {
-    error("EGL: Could not open libEGL.so");
+    error(
+        "EGL: Could not open libEGL.so. Ensure graphics drivers are installed, or fall back on (much slower!) software "
+        "rendering by installing OSMesa from your package manager.");
   }
 
   // Get EGL functions
-  if (options::verbosity > 5) {
-    std::cout << polyscope::options::printPrefix << "Attempting to dlsym resolve EGL functions" << std::endl;
-  }
+  info(5, "Attempting to dlsym resolve EGL functions");
 
   eglGetError = (eglGetErrorT)dlsym(handle, "eglGetError");
   eglGetPlatformDisplay = (eglGetPlatformDisplayT)dlsym(handle, "eglGetPlatformDisplay");
@@ -383,10 +376,7 @@ void GLEngineEGL::sortAvailableDevicesByPreference(
     // NOTE: on many machines (cloud VMs?) the query string above is nullptr, and this whole function does nothing
     // useful
     if (vendorStrRaw == nullptr) {
-      if (polyscope::options::verbosity > 5) {
-        std::cout << polyscope::options::printPrefix << "  EGLDevice " << iDevice << " -- vendor: " << "NULL"
-                  << "  priority score: " << score << std::endl;
-      }
+      info(5, "EGLDevice " + std::to_string(iDevice) + " -- vendor: NULL  priority score: " std::to_string(score);
       scoreDevices.emplace_back(score, iDevice);
       continue;
     }
@@ -415,8 +405,7 @@ void GLEngineEGL::sortAvailableDevicesByPreference(
 
     // at high verbosity levels, log the priority
     if (polyscope::options::verbosity > 5) {
-      std::cout << polyscope::options::printPrefix << "  EGLDevice " << iDevice << " -- vendor: " << vendorStr
-                << "  priority score: " << score << std::endl;
+      info(5, "EGLDevice " + std::to_string(iDevice) + " -- vendor: " + vendorStr + "  priority score: " std::to_string(score);
     }
 
     scoreDevices.emplace_back(score, iDevice);