deal with broken shaders

src/game/rendering/Rendering.cpp

@@ -6,6 +6,9 @@
 #include "bx/timer.h"
 #include <bx/file.h>
 #include <bgfx/bgfx.h>
+#include <thread>
+
+using namespace std::chrono_literals;
 
 namespace Game
 {
@@ -88,17 +91,30 @@ namespace Game
 
 			Log("Loading shader at %s", buffer);
 
-			FILE* file = fopen(buffer, "rb");
-			fseek(file, 0, SEEK_END);
-			long fileSize = ftell(file);
-			fseek(file, 0, SEEK_SET);
+			FILE* file;
+			for (int32_t i = 0; i < 3; ++i)
+			{
+				file = fopen(buffer, "rb");
+				if (file == nullptr)
+				{
+					std::this_thread::sleep_for(100ms);
+					break;
+				}
+				
+				fseek(file, 0, SEEK_END);
+				long fileSize = ftell(file);
+				fseek(file, 0, SEEK_SET);
 
-			const bgfx::Memory* mem = bgfx::alloc(fileSize + 1);
-			fread(mem->data, 1, fileSize, file);
-			mem->data[mem->size - 1] = '\0';
-			fclose(file);
+				const bgfx::Memory* mem = bgfx::alloc(fileSize + 1);
+				fread(mem->data, 1, fileSize, file);
+				mem->data[mem->size - 1] = '\0';
+				fclose(file);
 
-			return bgfx::createShader(mem);
+				return bgfx::createShader(mem);
+			}
+			
+			Log("Failed to load shader %s", FILENAME);
+			return {};
 		}
 	}
 
@@ -158,10 +174,22 @@ namespace Game
 		{
 			shared.Dev.ChangedShaderCount = 0;
 			
-			bgfx::destroy(Shader);			
+			// TODO: when to destroy shader?
+			// bgfx::destroy(Shader);
 			bgfx::ShaderHandle vertexShader = loadShader("vert");
 			bgfx::ShaderHandle fragmentShader = loadShader("frag");
-			Shader = bgfx::createProgram(vertexShader, fragmentShader, true);
+			if (isValid(vertexShader) && isValid(fragmentShader))
+			{
+				bgfx::ProgramHandle newProgram = bgfx::createProgram(vertexShader, fragmentShader, true);
+				if (isValid(newProgram))
+				{
+					Shader = newProgram;
+	            }
+	            else
+	            {
+	            	Log("Failed to load shader!");
+	            }
+			}
 		}
 		
 		int64_t tickDelta = bx::getHPCounter() - GetInstance().StartTime;