From: Lukas Krickl <lukas@krickl.dev>
Date: Sat, 7 Mar 2026 12:02:53 +0000 (+0100)
Subject: rendering: fixed view culling
X-Git-Url: https://git.krickl.dev/?a=commitdiff_plain;h=7e47c7d67634194fc99271b47eb77ef3cd2f56f8;p=lrts%2F.git

rendering: fixed view culling

Previously it would incorectly render way too many tiles.
---

diff --git a/src/lrts.c b/src/lrts.c
index 25f2050..8f34d7c 100644
--- a/src/lrts.c
+++ b/src/lrts.c
@@ -89,6 +89,7 @@ void lrts_init(void) {
 
 	t_main_camera = t_camera_init(res.x, res.y);
 	t_map = t_map_init();
+	r_render_update_visible_tiles();
 
 	state->frame_count = 0;
 	state->tick_count = 0;
diff --git a/src/r_render.c b/src/r_render.c
index bbf5e87..b493929 100644
--- a/src/r_render.c
+++ b/src/r_render.c
@@ -56,27 +56,29 @@ void r_render_frame(void) {
 
 void r_render_update_visible_tiles(void) {
 	i32 x, y;
-	struct u_vec2 t, tt, tl, tb;
+	struct u_vec2 t0, t1, t2, t3;
 	struct t_camera *c = &t_main_camera;
 
 	r_render_state.start_tile.x = t_map.width;
 	r_render_state.start_tile.y = t_map.height;
+	r_render_state.end_tile.x = 0;
+	r_render_state.end_tile.y = 0;
 
 	for (x = 0; x < t_map.width; x++) {
 		for (y = 0; y < t_map.height; y++) {
-			t = t_camera_zoom_vec2(c, u_tile_to_screen(x, y));
-			tt = t_camera_zoom_vec2(c, u_tile_to_screen(x+1, y+1));
-			tl = t_camera_zoom_vec2(c, u_tile_to_screen(x+2, y));
-			tb = t_camera_zoom_vec2(c, u_tile_to_screen(x+2, y-2));
+			t0 = t_camera_zoom_vec2(c, u_tile_to_screen(x, y));
+			t1 = t_camera_zoom_vec2(c, u_tile_to_screen(x+1, y+1));
+			t2 = t_camera_zoom_vec2(c, u_tile_to_screen(x+2, y));
+			t3 = t_camera_zoom_vec2(c, u_tile_to_screen(x+2, y-2));
 
 			/* do not draw if tile is not visible at all
 			 * also include a few points outside the camera to avoid tiles
 			 * popping in
 			 */
-			if (t_camera_is_visible_screen(&t_main_camera, t.x, t.y)
-					|| t_camera_is_visible_screen(&t_main_camera, tt.x, tt.y)
-					|| t_camera_is_visible_screen(&t_main_camera, tb.x, tb.y)
-					|| t_camera_is_visible_screen(&t_main_camera, tl.x, tl.y)) {
+			if (t_camera_is_visible_screen(&t_main_camera, t0.x, t0.y)
+					|| t_camera_is_visible_screen(&t_main_camera, t1.x, t1.y)
+					|| t_camera_is_visible_screen(&t_main_camera, t2.x, t2.y)
+					|| t_camera_is_visible_screen(&t_main_camera, t3.x, t3.y)) {
 					
 					if (r_render_state.end_tile.x < x) {
 						r_render_state.end_tile.x = x;
@@ -95,4 +97,7 @@ void r_render_update_visible_tiles(void) {
 			}
 		}
 	}
+
+	r_render_state.end_tile.x += 1;
+	U_CLAMP(r_render_state.end_tile.x, 0, t_map.width);
 }
diff --git a/src/t_map.c b/src/t_map.c
index 018ac29..f1f796a 100644
--- a/src/t_map.c
+++ b/src/t_map.c
@@ -17,7 +17,6 @@ struct t_map t_map_init(void) {
 			m.tiles[j * m.width + i].type = T_TILE_TYPE_GRASS;
 		}
 	}
-	r_render_update_visible_tiles();
 	return m;
 }
 
@@ -25,10 +24,12 @@ void t_map_draw(struct t_map *m) {
 	i32 i, j;
 	struct u_vec2 start = r_render_state.start_tile;
 	struct u_vec2 end = r_render_state.end_tile;
+	u32 drawn_tiles = 0;
 
 	for (i = start.x; i < end.x; i++) {
 		for (j = start.y; j < end.y; j++) {
 			r_draw_tile(&m->tiles[j * m->width + i], i, j);
+			drawn_tiles++;
 		}
 	}
 }