add error handling

code broken in fullscreen due to double(or more) buffering

main.cpp

@@ -3,16 +3,44 @@
 #include <SDL2/SDL.h>
 
 #include <chrono>
+#include <format>
 #include <memory>
 #include <print>
 #include <random>
+#include <source_location>
+#include <stdexcept>
 
 namespace {
 
+auto sdl_throw_current_error(const std::source_location location) {
+	throw std::runtime_error{std::format(
+		"error at {}:{}:{} {}", location.file_name(), location.line(),
+		location.column(), SDL_GetError()
+	)};
+}
+
+auto sdl_check(
+	int errc,
+	const std::source_location location = std::source_location::current()
+) {
+	if (errc != 0) { sdl_throw_current_error(location); }
+}
+
+// make sure someone already owns passed sdl_obj, or memory will be leaked
+auto sdl_check(
+	auto* sdl_obj,
+	const std::source_location location = std::source_location::current()
+) {
+	if (sdl_obj == nullptr) { sdl_throw_current_error(location); }
+	return sdl_obj;
+}
+
 template <typename SDLT, auto deletef>
 struct sdl_wrapper_t : std::unique_ptr<SDLT, decltype(deletef)> {
 	explicit sdl_wrapper_t(SDLT* p)
-		: std::unique_ptr<SDLT, decltype(deletef)>{p, deletef} {}
+		: std::unique_ptr<SDLT, decltype(deletef)>{p, deletef} {
+		sdl_check(p);
+	}
 
 	operator SDLT*() { return std::unique_ptr<SDLT, decltype(deletef)>::get(); }
 };
@@ -38,7 +66,7 @@ auto operator==(const SDL_Point& a, const SDL_Point& b) {
 // constexpr int width = 1000;
 // constexpr int height = 1000;
 constexpr int width = 3440;
-constexpr int height = 1300;
+constexpr int height = 1440;
 
 template <auto EF>
 struct [[nodiscard("give this a name so SDL_Quit is called at the end"
@@ -61,7 +89,7 @@ auto poll_events(bool& continu) {
 }
 } // namespace
 
-int main() {
+int main() try {
 	if (SDL_Init(SDL_INIT_VIDEO) < 0) {
 		std::println("fuck");
 		return EXIT_FAILURE;
@@ -70,7 +98,7 @@ int main() {
 
 	window_t window{SDL_CreateWindow(
 		"random walk", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, width,
-		height, 0
+		height, SDL_WINDOW_FULLSCREEN
 	)};
 	if (!window) {
 		std::println(
@@ -80,19 +108,22 @@ int main() {
 	}
 
 	// owned by window
-	auto* window_surface = SDL_GetWindowSurface(window);
-	if (!window_surface) { return EXIT_FAILURE; }
-	if (window_surface->format->palette) { return EXIT_FAILURE; }
+	auto* window_surface = sdl_check(SDL_GetWindowSurface(window));
+	if (window_surface->format->palette) {
+		std::println("unsupported window format, palette");
+		return EXIT_FAILURE;
+	}
 	std::println(
 		"got surface with {} bits per pixel",
 		window_surface->format->BitsPerPixel
 	);
 	if (!(window_surface->format->format & SDL_PIXELFORMAT_RGBA32)) {
+		std::println("unsupported window format, rgb");
 		return EXIT_FAILURE;
 	}
 
 	SDL_Point pos{.x = width / 2, .y = height / 2};
-	const SDL_Point directions[] = {
+	constexpr SDL_Point directions[] = {
 		{.x = -1, .y = 0}, {.x = 1, .y = 0}, {.x = 0, .y = -1}, {.x = 0, .y = 1}
 	};
 
@@ -103,7 +134,7 @@ int main() {
 	constexpr Uint32 walk_color = 0xff0d0f14;
 	constexpr auto batchsize = 1000;
 
-	SDL_LockSurface(window_surface);
+	sdl_check(SDL_LockSurface(window_surface));
 	for (int i = 0; i < window_surface->w * window_surface->h; ++i) {
 		static_cast<Uint32*>(window_surface->pixels)[i] = bg_color;
 	}
@@ -127,7 +158,7 @@ int main() {
 			);
 		}
 
-		SDL_LockSurface(window_surface);
+		sdl_check(SDL_LockSurface(window_surface));
 		for (auto step = 0z; step < batchsize; ++step) {
 			SDL_Point newpoint;
 			do {
@@ -139,8 +170,11 @@ int main() {
 			)[pos.x + pos.y * window_surface->w] = walk_color;
 		}
 		SDL_UnlockSurface(window_surface);
-		SDL_UpdateWindowSurface(window);
+		sdl_check(SDL_UpdateWindowSurface(window));
 	}
 
 	// leaking memory, nothing I can do
+} catch (const std::exception& e) {
+	std::puts(e.what());
+	return EXIT_FAILURE;
 }