From 767607ede15a87cfbbc5ccf3f332adb76c733b2a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jakob=20H=C3=B6rdt?=
 <6329417-neop_@users.noreply.gitlab.com>
Date: Sun, 4 Aug 2024 19:40:28 +0200
Subject: [PATCH] batch draw points and color

---
 main.cpp | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/main.cpp b/main.cpp
index 2a37db2..f22a551 100644
--- a/main.cpp
+++ b/main.cpp
@@ -95,14 +95,11 @@ int main() try {
 
 	window_t window{SDL_CreateWindow(
 		"random walk", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, width,
-		height, 0 // SDL_WINDOW_FULLSCREEN
+		height, SDL_WINDOW_FULLSCREEN
 	)};
 	renderer_t renderer{SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED)
 	};
 	SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "1");
-	sdl_check(SDL_SetRenderDrawColor(renderer, 0, 0, 0, SDL_ALPHA_OPAQUE));
-	sdl_check(SDL_RenderClear(renderer));
-	sdl_check(SDL_SetRenderDrawColor(renderer, 0, 0, 255, SDL_ALPHA_OPAQUE));
 	{
 		// dump renderer info
 		SDL_RendererInfo renderer_info;
@@ -119,6 +116,10 @@ int main() try {
 		renderer, SDL_PIXELFORMAT_ARGB8888, SDL_TEXTUREACCESS_TARGET, width,
 		height
 	);
+	sdl_check(SDL_SetRenderTarget(renderer, texture));
+	sdl_check(SDL_SetRenderDrawColor(renderer, 0xdb, 0xd7, 0xc0, SDL_ALPHA_OPAQUE));
+	sdl_check(SDL_RenderClear(renderer));
+	sdl_check(SDL_SetRenderDrawColor(renderer, 0x0d, 0x0f, 0x14, SDL_ALPHA_OPAQUE));
 
 		SDL_Point pos{.x = width / 2, .y = height / 2};
 	constexpr SDL_Point directions[] = {
@@ -130,7 +131,7 @@ int main() try {
 	//                              aarrggbb??
 	constexpr Uint32 bg_color = 0xffdbd7c0;
 	constexpr Uint32 walk_color = 0xff0d0f14;
-	constexpr auto batchsize = 1;
+	constexpr auto batchsize = 100;
 
 	const auto start_time = clock::now();
 	auto next_poll_events_time = start_time;
@@ -151,6 +152,7 @@ int main() try {
 		}
 
 		sdl_check(SDL_SetRenderTarget(renderer, texture));
+		std::array<SDL_Point, batchsize> point_batch;
 		for (auto step = 0z; step < batchsize; ++step) {
 			SDL_Point newpoint;
 			do {
@@ -158,8 +160,9 @@ int main() try {
 			} while (newpoint.x < 0 or newpoint.x >= width or newpoint.y < 0 or
 			         newpoint.y >= height);
 			pos = newpoint;
-			sdl_check(SDL_RenderDrawPoint(renderer, pos.x, pos.y));
+			point_batch[step] = newpoint;
 		}
+		sdl_check(SDL_RenderDrawPoints(renderer, point_batch.data(), point_batch.size()));
 
 		sdl_check(SDL_SetRenderTarget(renderer, nullptr));
 		sdl_check(SDL_RenderCopy(renderer, texture, nullptr, nullptr));