Implementing Custom SDL Error Logging

Implementing a custom error logging system for SDL errors can greatly improve your ability to debug issues, especially in deployed applications. Here's how you can create a system that logs SDL errors to a file:

First, let's create a simple Logger class that can write messages to a file:

1#include <SDL.h>
2#include <chrono>
3#include <fstream>
4#include <iomanip>
5#include <string>
6
7class Logger {
8public:
9  Logger(const std::string& filename)
10    : logFile{filename} {}
11
12  void Log(const std::string& message) {
13    using namespace std::chrono;
14    auto now = system_clock::now();
15    auto time = system_clock::to_time_t(now);
16
17    logFile << std::put_time(
18            std::localtime(&time),
19            "%Y-%m-%d %H:%M:%S")
20        << " - " << message << "\n";
21    logFile.flush();
22  }
23
24private:
25  std::ofstream logFile;
26};

This Logger class opens a file when constructed and provides a Log() method to write timestamped messages to the file.

Next, let's create a custom error checking function that uses our Logger:

1Logger errorLogger{"sdl_errors.log"};
2
3void CheckSDLError(
4  const std::string& operation
5) {
6  const char* error = SDL_GetError();
7  if (*error != '\0') {
8    std::string errorMessage =
9        operation + " Error: " + error;
10    errorLogger.Log(errorMessage);
11    SDL_ClearError();
12  }
13}

This function checks for SDL errors and logs them to our file if any are found.

Now we can use our custom error logging system in our SDL application:

1#include <SDL.h>
2#include <iostream>
3
4int main(int argc, char* argv[]) {
5  if (SDL_Init(SDL_INIT_VIDEO) < 0) {
6    CheckSDLError("SDL Initialization");
7    return 1;
8  }
9
10  SDL_Window* window{SDL_CreateWindow(
11    "SDL2 Window",
12    SDL_WINDOWPOS_CENTERED,
13    SDL_WINDOWPOS_CENTERED,
14    640, 480,
15    SDL_WINDOW_SHOWN
16  )};
17
18  if (!window) {
19    CheckSDLError("Window Creation");
20    SDL_Quit();
21    return 1;
22  }
23
24  // Intentionally cause an error for
25  // demonstration
26  SDL_Surface* surface{
27    SDL_GetWindowSurface(nullptr)}; 
28  CheckSDLError("Get Window Surface");
29
30  SDL_DestroyWindow(window);
31  SDL_Quit();
32
33  return 0;
34}

In this example, we're using our CheckSDLError() function after each SDL operation that could potentially fail. If an error occurs, it will be logged to our file instead of being printed to the console.

This approach allows you to maintain a record of errors that occur during your application's execution, which can be invaluable for debugging issues that may not be immediately apparent or that occur on users' systems.

Remember to include proper error handling and cleanup in your actual applications, and consider adding more detailed information to your log messages as needed for your specific use case.