Add UI scaling command line parameter

src/main.cpp

@@ -106,6 +106,7 @@ int main(int argc, char* argv[])
 {
 	int driver_id = -1;
 	int device_id = -1;
+	float ui_scale = 1.0f;
 	int carg = 1;
 	while(carg < argc)
 	{
@@ -117,6 +118,10 @@ int main(int argc, char* argv[])
 		{
 			device_id = strtol(argv[++carg], NULL, 0);
 		}
+		if(!std::strcmp(argv[carg], "--ui-scale") && (argc > carg))
+		{
+			ui_scale = strtof(argv[++carg], NULL);
+		}
 		carg++;
 	}
 
@@ -199,7 +204,7 @@ int main(int argc, char* argv[])
 	// Setup scaling
 	float scale;
 	glfwGetWindowContentScale(window, &scale, NULL);
-	restyle_with_scale(scale);
+	restyle_with_scale(scale * ui_scale);
 
 	glfwSetWindowContentScaleCallback(window, [](GLFWwindow* window, float xscale, float yscale) {
 		restyle_with_scale(xscale);

src/main_window.cpp

@@ -37,6 +37,7 @@ static bool debug_imgui_metrics = false;
 #endif
 static bool debug_state_window = false;
 static bool debug_audio_window = false;
+static bool debug_ui_window = false;
 
 static void debug_menu()
 {
@@ -48,6 +49,7 @@ static void debug_menu()
 #endif
 	ImGui::MenuItem("Select audio device", NULL, &debug_audio_window);
 	ImGui::MenuItem("Display dump state", NULL, &debug_state_window);
+	ImGui::MenuItem("UI settings", NULL, &debug_ui_window);
 	if (ImGui::MenuItem("Quit"))
 	{
 		// if ctrl+shift was held, stimulate a segfault
@@ -128,6 +130,14 @@ static void debug_window()
 		}
 		ImGui::End();
 	}
+	if(debug_ui_window)
+	{
+		ImGui::Begin("UI settings", &debug_ui_window, ImGuiWindowFlags_NoResize | ImGuiWindowFlags_AlwaysAutoResize);
+
+		ImGui::DragFloat("UI scaling", &ImGui::GetIO().FontGlobalScale, 0.005f, 0.3f, 2.0f, "%.2f");
+
+		ImGui::End();
+	}
 }
 
 //=====================================================================