From 39feecded0d281b66580e462a7a026f04db627ee Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jakob=20H=C3=B6rdt?=
 <6329417-neop_@users.noreply.gitlab.com>
Date: Sat, 3 Aug 2024 23:06:35 +0200
Subject: [PATCH] remove rendering, we need software rendering

---
 main.cpp | 77 +++++++++-----------------------------------------------
 1 file changed, 12 insertions(+), 65 deletions(-)

diff --git a/main.cpp b/main.cpp
index 5ca6824..6804914 100644
--- a/main.cpp
+++ b/main.cpp
@@ -36,8 +36,8 @@ auto operator==(const SDL_Point& a, const SDL_Point& b) {
 	return a.x == b.x && a.y == b.y;
 }
 
-constexpr int width = 3440;
-constexpr int height = 1440;
+constexpr int width = 1000;
+constexpr int height = 1000;
 
 template <auto EF>
 struct [[nodiscard("give this a name so SDL_Quit is called at the end"
@@ -60,7 +60,7 @@ int main() {
 
 	window_t window{SDL_CreateWindow(
 		"random walk", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, width,
-		height, SDL_WINDOW_FULLSCREEN
+		height, 0
 	)};
 	if (!window) {
 		std::println(
@@ -70,20 +70,11 @@ int main() {
 	}
 
 	// owned by window
-	// auto* window_surface = SDL_GetWindowSurface(window);
+	auto* window_surface = SDL_GetWindowSurface(window);
+	if (!window_surface) { return EXIT_FAILURE; }
+	if (window_surface->format->palette) { return EXIT_FAILURE; }
 
-	renderer_t renderer{SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED)
-	};
-	SDL_SetRenderDrawColor(renderer, 0, 0, 0, 0);
-	SDL_RenderClear(renderer);
-	SDL_SetRenderDrawColor(renderer, 255, 0, 0, 255);
-
-
-	auto surface = surface_t{SDL_GetWindowSurface(window)};
-
-	std::vector<SDL_Point> points;
 	SDL_Point pos{.x = width / 2, .y = height / 2};
-	points.push_back(pos);
 	const SDL_Point directions[] = {
 		{.x = -1, .y = 0}, {.x = 1, .y = 0}, {.x = 0, .y = -1}, {.x = 0, .y = 1}
 	};
@@ -91,11 +82,8 @@ int main() {
 	std::mt19937_64 rne(std::random_device{}());
 	std::uniform_int_distribution dist(0, 3);
 
-	bool continu = true;
-	const auto start = std::chrono::steady_clock::now();
-	auto next_frame = start;
-	long total_points = 0;
-	while (continu) {
+	for (bool continu = true; continu;) {
+
 		{
 			SDL_Point newpoint;
 			do {
@@ -103,54 +91,13 @@ int main() {
 			} while (newpoint.x < 0 or newpoint.x >= width or newpoint.y < 0 or
 			         newpoint.y >= height);
 			pos = newpoint;
-			points.push_back(newpoint);
-			++total_points;
-		}
-		const auto goal = 200'000'000;
-		if (total_points >= goal) {
-			continu = false;
-			std::println(
-				"took {} to get to {} random steps",
-				std::chrono::duration_cast<std::chrono::duration<double>>(
-					std::chrono::steady_clock::now() - start
-				),
-				goal
-			);
 		}
 
-		// render present; poll events
-		auto render_start = std::chrono::steady_clock::now();
-		if (render_start > next_frame) {
-			next_frame += std::chrono::milliseconds{200};
-
-			{
-				std::ranges::sort(points, std::less<>{});
-				auto [first, last] = std::ranges::unique(points);
-				points.resize(std::ranges::distance(points.begin(), first));
-			}
-			SDL_SetRenderDrawColor(renderer, 255, 0, 0, 255);
-			SDL_RenderDrawPoints(renderer, points.data(), std::ssize(points));
-			SDL_RenderPresent(renderer);
-			SDL_SetRenderDrawColor(renderer, 0, 0, 0, 0);
-			SDL_RenderClear(renderer);
-
-			SDL_Event e;
-			while (SDL_PollEvent(&e)) {
-				if (e.type == SDL_QUIT) { continu = false; }
-			}
-
-			auto render_end = std::chrono::steady_clock::now();
-
-			std::println(
-				"drawn {} points in {}", std::ssize(points),
-				std::chrono::duration_cast<std::chrono::milliseconds>(
-					render_end - render_start
-				)
-			);
-			if (render_end > next_frame) {
-				next_frame = render_end + std::chrono::milliseconds{100};
-			}
+		for (SDL_Event e; SDL_PollEvent(&e);) {
+			if (e.type == SDL_QUIT) { continu = false; }
 		}
+
+		SDL_UpdateWindowSurface(window);
 	}
 
 	// leaking memory, nothing I can do