From b13d7aaf6ddf63ce9b7179219542af885740d304 Mon Sep 17 00:00:00 2001
From: CrispyPin <crispin@tasa.se>
Date: Mon, 7 Oct 2024 00:01:02 +0200
Subject: [PATCH] culled board rendering, much better performance with enormous
 boards

---
 src/marble_engine/board.rs | 41 ++++++++++++++++++++++++--------------
 1 file changed, 26 insertions(+), 15 deletions(-)

diff --git a/src/marble_engine/board.rs b/src/marble_engine/board.rs
index 90c0518..f764751 100644
--- a/src/marble_engine/board.rs
+++ b/src/marble_engine/board.rs
@@ -214,21 +214,32 @@ impl Board {
 
 	pub fn draw(&self, d: &mut RaylibDrawHandle, textures: &Textures, offset: Vector2, zoom: i32) {
 		let tile_size = 16 << zoom;
-		for x in 0..self.width {
-			for y in 0..self.height {
-				let tile = self.rows[y][x];
-				let px =
-					(x as i32 - self.offset_x as i32) * tile_size + offset.x as i32 + tile_size / 2;
-				let py =
-					(y as i32 - self.offset_y as i32) * tile_size + offset.y as i32 + tile_size / 2;
-				let texture = textures.get(&tile.texture());
-				d.draw_texture_ex(
-					texture,
-					Vector2::new((px - tile_size / 2) as f32, (py - tile_size / 2) as f32),
-					0.0,
-					(1 << zoom) as f32,
-					Color::WHITE,
-				);
+
+		let start_x = (-offset.x as i32) / tile_size + self.offset_x as i32 - 1;
+		let tile_width = d.get_screen_width() / tile_size + 2;
+		let start_y = (-offset.y as i32) / tile_size + self.offset_y as i32 - 1;
+		let tile_height = d.get_screen_height() / tile_size + 2;
+
+		for x in start_x..(start_x + tile_width) {
+			for y in start_y..(start_y + tile_height) {
+				if self.in_bounds(Pos {
+					x: x as isize,
+					y: y as isize,
+				}) {
+					let tx = x as usize;
+					let ty = y as usize;
+					let tile = self.rows[ty][tx];
+					let px = (x - self.offset_x as i32) * tile_size + offset.x as i32;
+					let py = (y - self.offset_y as i32) * tile_size + offset.y as i32;
+					let texture = textures.get(&tile.texture());
+					d.draw_texture_ex(
+						texture,
+						Vector2::new(px as f32, py as f32),
+						0.0,
+						(1 << zoom) as f32,
+						Color::WHITE,
+					);
+				}
 			}
 		}
 	}