Add light propagation on block change

source/block/block_bed.c

@@ -96,6 +96,7 @@ struct block block_bed = {
 	.luminance = 0,
 	.double_sided = false,
 	.can_see_through = true,
+	.opacity = 1,
 	.ignore_lighting = false,
 	.flammable = false,
 	.block_item = {

source/block/block_brown_mushroom.c

@@ -60,6 +60,7 @@ struct block block_brown_mushroom = {
 	.luminance = 1,
 	.double_sided = true,
 	.can_see_through = true,
+	.opacity = 0,
 	.render_block_data.cross_random_displacement = false,
 	.ignore_lighting = false,
 	.flammable = false,

source/block/block_cactus.c

@@ -73,6 +73,7 @@ struct block block_cactus = {
 	.luminance = 0,
 	.double_sided = false,
 	.can_see_through = true,
+	.opacity = 0,
 	.ignore_lighting = false,
 	.flammable = false,
 	.block_item = {

source/block/block_cake.c

@@ -77,6 +77,7 @@ struct block block_cake = {
 	.luminance = 0,
 	.double_sided = false,
 	.can_see_through = true,
+	.opacity = 0,
 	.ignore_lighting = false,
 	.flammable = false,
 	.block_item = {

source/block/block_cobweb.c

@@ -60,6 +60,7 @@ struct block block_cobweb = {
 	.luminance = 0,
 	.double_sided = true,
 	.can_see_through = true,
+	.opacity = 1,
 	.render_block_data.cross_random_displacement = false,
 	.ignore_lighting = false,
 	.flammable = false,

source/block/block_crops.c

@@ -60,6 +60,7 @@ struct block block_crops = {
 	.luminance = 0,
 	.double_sided = true,
 	.can_see_through = true,
+	.opacity = 0,
 	.ignore_lighting = false,
 	.flammable = false,
 	.block_item = {

source/block/block_farmland.c

@@ -69,6 +69,7 @@ struct block block_farmland = {
 	.luminance = 0,
 	.double_sided = false,
 	.can_see_through = true,
+	.opacity = 15,
 	.ignore_lighting = true,
 	.flammable = false,
 	.block_item = {

source/block/block_fence.c

@@ -69,6 +69,7 @@ struct block block_fence = {
 	.luminance = 0,
 	.double_sided = false,
 	.can_see_through = true,
+	.opacity = 0,
 	.ignore_lighting = false,
 	.flammable = true,
 	.block_item = {

source/block/block_fire.c

@@ -59,6 +59,7 @@ struct block block_fire = {
 	.luminance = 15,
 	.double_sided = false,
 	.can_see_through = true,
+	.opacity = 0,
 	.ignore_lighting = false,
 	.flammable = false,
 	.block_item = {

source/block/block_flower.c

@@ -60,6 +60,7 @@ struct block block_flower = {
 	.luminance = 0,
 	.double_sided = true,
 	.can_see_through = true,
+	.opacity = 0,
 	.render_block_data.cross_random_displacement = false,
 	.ignore_lighting = false,
 	.flammable = false,

source/block/block_glass.c

@@ -61,6 +61,7 @@ struct block block_glass = {
 	.luminance = 0,
 	.double_sided = false,
 	.can_see_through = true,
+	.opacity = 0,
 	.ignore_lighting = false,
 	.flammable = false,
 	.block_item = {

source/block/block_ice.c

@@ -61,6 +61,7 @@ struct block block_ice = {
 	.luminance = 0,
 	.double_sided = false,
 	.can_see_through = true,
+	.opacity = 1,
 	.ignore_lighting = false,
 	.flammable = false,
 	.block_item = {

source/block/block_ladder.c

@@ -77,6 +77,7 @@ struct block block_ladder = {
 	.luminance = 0,
 	.double_sided = false,
 	.can_see_through = true,
+	.opacity = 0,
 	.ignore_lighting = false,
 	.flammable = false,
 	.block_item = {

source/block/block_lava.c

@@ -73,6 +73,7 @@ struct block block_lava = {
 	.luminance = 15,
 	.double_sided = false,
 	.can_see_through = true,
+	.opacity = 15,
 	.ignore_lighting = false,
 	.flammable = false,
 	.block_item = {

source/block/block_leaves.c

@@ -78,6 +78,7 @@ struct block block_leaves = {
 	.luminance = 0,
 	.double_sided = true,
 	.can_see_through = true,
+	.opacity = 1,
 	.ignore_lighting = false,
 	.flammable = true,
 	.block_item = {

source/block/block_portal.c

@@ -59,6 +59,7 @@ struct block block_portal = {
 	.luminance = 11,
 	.double_sided = false,
 	.can_see_through = true,
+	.opacity = 1,
 	.ignore_lighting = false,
 	.flammable = false,
 	.block_item = {

source/block/block_pressure_plate.c

@@ -73,6 +73,7 @@ struct block block_stone_pressure_plate = {
 	.luminance = 0,
 	.double_sided = false,
 	.can_see_through = true,
+	.opacity = 0,
 	.ignore_lighting = false,
 	.flammable = false,
 	.block_item = {
@@ -97,6 +98,7 @@ struct block block_wooden_pressure_plate = {
 	.luminance = 0,
 	.double_sided = false,
 	.can_see_through = true,
+	.opacity = 0,
 	.ignore_lighting = false,
 	.flammable = false,
 	.block_item = {

source/block/block_rail.c

@@ -75,6 +75,7 @@ struct block block_rail = {
 	.luminance = 0,
 	.double_sided = true,
 	.can_see_through = true,
+	.opacity = 0,
 	.render_block_data.rail_curved_possible = true,
 	.ignore_lighting = false,
 	.flammable = false,
@@ -99,6 +100,7 @@ struct block block_powered_rail = {
 	.luminance = 0,
 	.double_sided = true,
 	.can_see_through = true,
+	.opacity = 0,
 	.render_block_data.rail_curved_possible = false,
 	.ignore_lighting = false,
 	.flammable = false,
@@ -123,6 +125,7 @@ struct block block_detector_rail = {
 	.luminance = 0,
 	.double_sided = true,
 	.can_see_through = true,
+	.opacity = 0,
 	.render_block_data.rail_curved_possible = false,
 	.ignore_lighting = false,
 	.flammable = false,

source/block/block_red_mushroom.c

@@ -60,6 +60,7 @@ struct block block_red_mushroom = {
 	.luminance = 0,
 	.double_sided = true,
 	.can_see_through = true,
+	.opacity = 0,
 	.render_block_data.cross_random_displacement = false,
 	.ignore_lighting = false,
 	.flammable = false,

source/block/block_reed.c

@@ -60,6 +60,7 @@ struct block block_reed = {
 	.luminance = 0,
 	.double_sided = true,
 	.can_see_through = true,
+	.opacity = 0,
 	.render_block_data.cross_random_displacement = false,
 	.ignore_lighting = false,
 	.flammable = false,

source/block/block_rose.c

@@ -60,6 +60,7 @@ struct block block_rose = {
 	.luminance = 0,
 	.double_sided = true,
 	.can_see_through = true,
+	.opacity = 0,
 	.render_block_data.cross_random_displacement = false,
 	.ignore_lighting = false,
 	.flammable = false,

source/block/block_sapling.c

@@ -64,6 +64,7 @@ struct block block_sapling = {
 	.luminance = 0,
 	.double_sided = true,
 	.can_see_through = true,
+	.opacity = 0,
 	.render_block_data.cross_random_displacement = false,
 	.ignore_lighting = false,
 	.flammable = false,

source/block/block_slab.c

@@ -77,6 +77,7 @@ struct block block_slab = {
 	.luminance = 0,
 	.double_sided = false,
 	.can_see_through = true,
+	.opacity = 15,
 	.ignore_lighting = true,
 	.flammable = false,
 	.block_item = {

source/block/block_snow.c

@@ -75,6 +75,7 @@ struct block block_snow = {
 	.luminance = 0,
 	.double_sided = false,
 	.can_see_through = true,
+	.opacity = 0,
 	.ignore_lighting = false,
 	.flammable = false,
 	.block_item = {

source/block/block_spawner.c

@@ -60,6 +60,7 @@ struct block block_spawner = {
 	.luminance = 0,
 	.double_sided = false,
 	.can_see_through = true,
+	.opacity = 1,
 	.ignore_lighting = false,
 	.flammable = false,
 	.block_item = {

source/block/block_stairs.c

@@ -127,6 +127,7 @@ struct block block_wooden_stairs = {
 	.luminance = 0,
 	.double_sided = false,
 	.can_see_through = true,
+	.opacity = 15,
 	.ignore_lighting = true,
 	.flammable = true,
 	.block_item = {
@@ -153,6 +154,7 @@ struct block block_stone_stairs = {
 	.luminance = 0,
 	.double_sided = false,
 	.can_see_through = true,
+	.opacity = 15,
 	.ignore_lighting = true,
 	.flammable = false,
 	.block_item = {

source/block/block_tallgrass.c

@@ -68,6 +68,7 @@ struct block block_tallgrass = {
 	.luminance = 0,
 	.double_sided = true,
 	.can_see_through = true,
+	.opacity = 0,
 	.render_block_data.cross_random_displacement = true,
 	.ignore_lighting = false,
 	.flammable = true,
@@ -92,6 +93,7 @@ struct block block_deadbush = {
 	.luminance = 0,
 	.double_sided = true,
 	.can_see_through = true,
+	.opacity = 0,
 	.render_block_data.cross_random_displacement = false,
 	.ignore_lighting = false,
 	.flammable = true,

source/block/block_torch.c

@@ -77,6 +77,7 @@ struct block block_torch = {
 	.luminance = 14,
 	.double_sided = false,
 	.can_see_through = true,
+	.opacity = 0,
 	.ignore_lighting = false,
 	.flammable = false,
 	.block_item = {
@@ -100,6 +101,7 @@ struct block block_redstone_torch = {
 	.luminance = 0,
 	.double_sided = false,
 	.can_see_through = true,
+	.opacity = 0,
 	.ignore_lighting = false,
 	.flammable = false,
 	.block_item = {
@@ -123,6 +125,7 @@ struct block block_redstone_torch_lit = {
 	.luminance = 7,
 	.double_sided = false,
 	.can_see_through = true,
+	.opacity = 0,
 	.ignore_lighting = false,
 	.flammable = false,
 	.block_item = {

source/block/block_water.c

@@ -77,6 +77,7 @@ struct block block_water_still = {
 	.luminance = 0,
 	.double_sided = false,
 	.can_see_through = true,
+	.opacity = 3,
 	.ignore_lighting = false,
 	.flammable = false,
 	.block_item = {
@@ -100,6 +101,7 @@ struct block block_water_flowing = {
 	.luminance = 0,
 	.double_sided = false,
 	.can_see_through = true,
+	.opacity = 3,
 	.ignore_lighting = false,
 	.flammable = false,
 	.block_item = {

source/block/blocks.h

@@ -104,7 +104,8 @@ struct block {
 	size_t (*renderBlockAlways)(struct displaylist*, struct block_info*,
 								enum side, struct block_info*, uint8_t*, bool);
 	bool transparent;
-	int luminance;
+	uint8_t luminance : 4;
+	uint8_t opacity : 4;
 	bool double_sided;
 	bool can_see_through;
 	bool ignore_lighting;

source/chunk.c

@@ -126,20 +126,8 @@ struct block_data chunk_lookup_block(struct chunk* c, w_coord_t x, w_coord_t y,
 		};
 }
 
-void chunk_set_block(struct chunk* c, c_coord_t x, c_coord_t y, c_coord_t z,
-					 struct block_data blk) {
-	assert(c && x < CHUNK_SIZE && y < CHUNK_SIZE && z < CHUNK_SIZE);
-
-	size_t idx = CHUNK_INDEX(x, y, z) / 2 * 5;
-	size_t off = CHUNK_INDEX(x, y, z) % 2;
-
-	c->blocks[idx + off + 0] = blk.type;
-	c->blocks[idx + off + 2] = (blk.torch_light << 4) | blk.sky_light;
-	c->blocks[idx + 4] = (c->blocks[idx + 4] & ~(0x0F << (off * 4)))
-		| (blk.metadata << (off * 4));
-	c->rebuild_displist = true;
-
-	// trigger neighbour chunk updates
+static void chunk_trigger_neighbour_update(struct chunk* c, c_coord_t x,
+										   c_coord_t y, c_coord_t z) {
 	// TODO: diagonal chunks, just sharing edge or single point
 
 	bool cond[6] = {
@@ -163,6 +151,35 @@ void chunk_set_block(struct chunk* c, c_coord_t x, c_coord_t y, c_coord_t z,
 	}
 }
 
+void chunk_set_light(struct chunk* c, c_coord_t x, c_coord_t y, c_coord_t z,
+					 uint8_t light) {
+	assert(c && x < CHUNK_SIZE && y < CHUNK_SIZE && z < CHUNK_SIZE);
+
+	size_t idx = CHUNK_INDEX(x, y, z) / 2 * 5;
+	size_t off = CHUNK_INDEX(x, y, z) % 2;
+
+	c->blocks[idx + off + 2] = light;
+	c->rebuild_displist = true;
+
+	chunk_trigger_neighbour_update(c, x, y, z);
+}
+
+void chunk_set_block(struct chunk* c, c_coord_t x, c_coord_t y, c_coord_t z,
+					 struct block_data blk) {
+	assert(c && x < CHUNK_SIZE && y < CHUNK_SIZE && z < CHUNK_SIZE);
+
+	size_t idx = CHUNK_INDEX(x, y, z) / 2 * 5;
+	size_t off = CHUNK_INDEX(x, y, z) % 2;
+
+	c->blocks[idx + off + 0] = blk.type;
+	c->blocks[idx + off + 2] = (blk.torch_light << 4) | blk.sky_light;
+	c->blocks[idx + 4] = (c->blocks[idx + 4] & ~(0x0F << (off * 4)))
+		| (blk.metadata << (off * 4));
+	c->rebuild_displist = true;
+
+	chunk_trigger_neighbour_update(c, x, y, z);
+}
+
 bool chunk_check_built(struct chunk* c) {
 	assert(c);
 

source/chunk.h

@@ -79,6 +79,8 @@ struct block_data chunk_lookup_block(struct chunk* c, w_coord_t x, w_coord_t y,
 void chunk_set_block(struct chunk* c, c_coord_t x, c_coord_t y, c_coord_t z,
 					 struct block_data blk);
 bool chunk_check_built(struct chunk* c);
+void chunk_set_light(struct chunk* c, c_coord_t x, c_coord_t y, c_coord_t z,
+					 uint8_t light);
 void chunk_render(struct chunk* c, bool pass, float x, float y, float z);
 void chunk_pre_render(struct chunk* c, mat4 view, bool has_fog);
 

source/game/gui/screen_ingame.c

@@ -94,9 +94,10 @@ static void screen_ingame_update(struct screen* s, float dt) {
 							(struct block_data) {
 								.type = BLOCK_AIR,
 								.metadata = 0,
-								.sky_light = 15,
+								.sky_light = 0,
 								.torch_light = 0,
-							});
+							},
+							true);
 			gstate.held_item_animation = (struct held_anim) {
 				.start = time_get(),
 				.type = false,
@@ -110,15 +111,16 @@ static void screen_ingame_update(struct screen* s, float dt) {
 			   && item_is_block(&item)) {
 				int x, y, z;
 				blocks_side_offset(gstate.camera_hit.side, &x, &y, &z);
-				world_set_block(
-					&gstate.world, gstate.camera_hit.x + x,
-					gstate.camera_hit.y + y, gstate.camera_hit.z + z,
-					(struct block_data) {
-						.type = item.id,
-						.metadata = 0,
-						.sky_light = blocks[item.id]->can_see_through ? 15 : 0,
-						.torch_light = blocks[item.id]->luminance,
-					});
+				world_set_block(&gstate.world, gstate.camera_hit.x + x,
+								gstate.camera_hit.y + y,
+								gstate.camera_hit.z + z,
+								(struct block_data) {
+									.type = item.id,
+									.metadata = 0,
+									.sky_light = 0,
+									.torch_light = 0,
+								},
+								true);
 			}
 			gstate.held_item_animation = (struct held_anim) {
 				.start = time_get(),

source/main.c

@@ -143,6 +143,8 @@ int main(void) {
 			gstate.current_screen->update(gstate.current_screen,
 										  gstate.stats.dt);
 
+		world_update_lighting(&gstate.world);
+
 		gfx_flip_buffers(&gstate.stats.dt_gpu, &gstate.stats.dt_vsync);
 
 		// must not modify displaylists while still rendering!

source/network/client_interface.c

@@ -47,7 +47,8 @@ void clin_chunk(w_coord_t x, w_coord_t y, w_coord_t z, w_coord_t sx,
 									.metadata = md,
 									.sky_light = (*lighting_t) & 0xF,
 									.torch_light = (*lighting_t) >> 4,
-								});
+								},
+								false);
 				ids_t++;
 				lighting_t++;
 

source/world.c

@@ -131,6 +131,8 @@ void world_create(struct world* w) {
 	dict_wsection_init(w->sections);
 	ilist_chunks_init(w->render);
 	ilist_chunks2_init(w->gpu_busy_chunks);
+	stack_create(&w->lighting_updates, 16,
+				 sizeof(struct world_modification_entry));
 	w->world_chunk_cache = NULL;
 	w->anim_timer = time_get();
 }
@@ -138,6 +140,20 @@ void world_create(struct world* w) {
 void world_destroy(struct world* w) {
 	assert(w);
 
+	stack_destroy(&w->lighting_updates);
+
+	dict_wsection_it_t it;
+	dict_wsection_it(it, w->sections);
+
+	while(!dict_wsection_end_p(it)) {
+		struct world_section* s = &dict_wsection_ref(it)->value;
+		for(size_t k = 0; k < COLUMN_HEIGHT; k++) {
+			if(s->column[k])
+				chunk_unref(s->column[k]);
+		}
+		dict_wsection_next(it);
+	}
+
 	dict_wsection_clear(w->sections);
 }
 
@@ -181,7 +197,8 @@ static void wsection_heightmap_update(struct world_section* s, c_coord_t x,
 
 	int8_t* height = s->heightmap + x + z * CHUNK_SIZE;
 
-	if(blocks[type]) {
+	if(blocks[type]
+	   && (!blocks[type]->can_see_through || blocks[type]->opacity > 0)) {
 		if(y > *height)
 			*height = y;
 	} else if(y == *height) {
@@ -189,7 +206,9 @@ static void wsection_heightmap_update(struct world_section* s, c_coord_t x,
 			struct chunk* c = s->column[y / CHUNK_SIZE];
 			struct block_data blk = chunk_get_block(c, x, W2C_COORD(y), z);
 			if(c) {
-				if(blocks[blk.type])
+				if(blocks[blk.type]
+				   && (!blocks[blk.type]->can_see_through
+					   || blocks[blk.type]->opacity > 0))
 					break;
 				y--;
 			} else {
@@ -202,42 +221,158 @@ static void wsection_heightmap_update(struct world_section* s, c_coord_t x,
 }
 
 void world_set_block(struct world* w, w_coord_t x, w_coord_t y, w_coord_t z,
-					 struct block_data blk) {
+					 struct block_data blk, bool light_update) {
 	assert(w);
 
 	if(y < 0 || y >= WORLD_HEIGHT)
 		return;
 
-	w_coord_t cx = WCOORD_CHUNK_OFFSET(x);
-	w_coord_t cz = WCOORD_CHUNK_OFFSET(z);
-	struct world_section* s
-		= dict_wsection_get(w->sections, SECTION_TO_ID(cx, cz));
+	if(light_update) {
+		stack_push(&w->lighting_updates,
+				   &(struct world_modification_entry) {
+					   .x = x,
+					   .y = y,
+					   .z = z,
+					   .blk = blk,
+				   });
+	} else {
+		w_coord_t cx = WCOORD_CHUNK_OFFSET(x);
+		w_coord_t cz = WCOORD_CHUNK_OFFSET(z);
+		struct world_section* s
+			= dict_wsection_get(w->sections, SECTION_TO_ID(cx, cz));
 
-	struct chunk* c = world_find_chunk(w, x, y, z);
+		struct chunk* c = world_find_chunk(w, x, y, z);
 
-	if(!c) {
-		c = malloc(sizeof(struct chunk));
-		assert(c);
+		if(!c) {
+			c = malloc(sizeof(struct chunk));
+			assert(c);
 
-		w_coord_t cy = y / CHUNK_SIZE;
-		chunk_init(c, w, cx * CHUNK_SIZE, cy * CHUNK_SIZE, cz * CHUNK_SIZE);
-		chunk_ref(c);
+			w_coord_t cy = y / CHUNK_SIZE;
+			chunk_init(c, w, cx * CHUNK_SIZE, cy * CHUNK_SIZE, cz * CHUNK_SIZE);
+			chunk_ref(c);
 
-		w->world_chunk_cache = c;
+			w->world_chunk_cache = c;
 
-		if(!s) {
-			s = dict_wsection_safe_get(w->sections, SECTION_TO_ID(cx, cz));
-			assert(s);
-			memset(s->heightmap, -1, sizeof(s->heightmap));
-			memset(s->column, 0, sizeof(s->column));
+			if(!s) {
+				s = dict_wsection_safe_get(w->sections, SECTION_TO_ID(cx, cz));
+				assert(s);
+				memset(s->heightmap, -1, sizeof(s->heightmap));
+				memset(s->column, 0, sizeof(s->column));
+			}
+
+			assert(s->column[cy] == NULL);
+			s->column[cy] = c;
 		}
 
-		assert(s->column[cy] == NULL);
-		s->column[cy] = c;
+		chunk_set_block(c, W2C_COORD(x), W2C_COORD(y), W2C_COORD(z), blk);
+		wsection_heightmap_update(s, W2C_COORD(x), y, W2C_COORD(z), blk.type);
+	}
+}
+
+static inline int8_t MAX_I8(int8_t a, int8_t b) {
+	return a > b ? a : b;
+}
+
+struct lighting_update_entry {
+	w_coord_t x, y, z;
+};
+
+void world_update_lighting(struct world* w) {
+	assert(w);
+
+	if(stack_empty(&w->lighting_updates))
+		return;
+
+	struct world_modification_entry source;
+	stack_pop(&w->lighting_updates, &source);
+
+	struct stack queue;
+	stack_create(&queue, 128, sizeof(struct lighting_update_entry));
+	stack_push(&queue,
+			   &(struct lighting_update_entry) {
+				   .x = source.x,
+				   .y = source.y,
+				   .z = source.z,
+			   });
+
+	world_set_block(w, source.x, source.y, source.z, source.blk, false);
+
+	while(!stack_empty(&queue)) {
+		struct lighting_update_entry current;
+		stack_pop(&queue, &current);
+
+		struct world_section* s
+			= dict_wsection_get(w->sections,
+								SECTION_TO_ID(WCOORD_CHUNK_OFFSET(current.x),
+											  WCOORD_CHUNK_OFFSET(current.z)));
+		struct chunk* c = world_chunk_from_section(w, s, current.y);
+		struct block_data old
+			= chunk_get_block(c, W2C_COORD(current.x), W2C_COORD(current.y),
+							  W2C_COORD(current.z));
+
+		uint8_t old_light = (old.torch_light << 4) | old.sky_light;
+		uint8_t new_light_sky = 0, new_light_torch = 0;
+
+		if(current.y > s->heightmap[W2C_COORD(current.x)
+									+ W2C_COORD(current.z) * CHUNK_SIZE])
+			new_light_sky = 0xF;
+
+		if(blocks[old.type])
+			new_light_torch = blocks[old.type]->luminance;
+
+		if(!blocks[old.type] || blocks[old.type]->can_see_through) {
+			for(enum side s = 0; s < SIDE_MAX; s++) {
+				int x, y, z;
+				blocks_side_offset(s, &x, &y, &z);
+
+				struct chunk* c_other = world_find_chunk(
+					w, current.x + x, current.y + y, current.z + z);
+
+				if(c_other) {
+					struct block_data other = chunk_get_block(
+						c_other, W2C_COORD(current.x + x),
+						W2C_COORD(current.y + y), W2C_COORD(current.z + z));
+					int8_t opacity = blocks[old.type] ?
+						MAX_I8(blocks[old.type]->opacity, 1) :
+						1;
+
+					new_light_sky
+						= MAX_I8(MAX_I8((int8_t)other.sky_light - opacity, 0),
+								 new_light_sky);
+					new_light_torch
+						= MAX_I8(MAX_I8((int8_t)other.torch_light - opacity, 0),
+								 new_light_torch);
+				}
+			}
+		}
+
+		uint8_t new_light = (new_light_torch << 4) | new_light_sky;
+
+		if(old_light != new_light
+		   || (source.x == current.x && source.y == current.y
+			   && source.z == current.z)) {
+			chunk_set_light(c, W2C_COORD(current.x), W2C_COORD(current.y),
+							W2C_COORD(current.z), new_light);
+
+			for(enum side s = 0; s < SIDE_MAX; s++) {
+				int x, y, z;
+				blocks_side_offset(s, &x, &y, &z);
+
+				struct chunk* c_other = world_find_chunk(
+					w, current.x + x, current.y + y, current.z + z);
+
+				if(c_other)
+					stack_push(&queue,
+							   &(struct lighting_update_entry) {
+								   .x = current.x + x,
+								   .y = current.y + y,
+								   .z = current.z + z,
+							   });
+			}
+		}
 	}
 
-	chunk_set_block(c, W2C_COORD(x), W2C_COORD(y), W2C_COORD(z), blk);
-	wsection_heightmap_update(s, W2C_COORD(x), y, W2C_COORD(z), blk.type);
+	stack_destroy(&queue);
 }
 
 struct chunk* world_find_chunk_neighbour(struct world* w, struct chunk* c,
@@ -258,6 +393,12 @@ struct chunk* world_find_chunk_neighbour(struct world* w, struct chunk* c,
 	return res ? res->column[y + c->y / CHUNK_SIZE] : NULL;
 }
 
+struct chunk* world_chunk_from_section(struct world* w, struct world_section* s,
+									   w_coord_t y) {
+	assert(w);
+	return (y >= 0 && y < WORLD_HEIGHT && s) ? s->column[y / CHUNK_SIZE] : NULL;
+}
+
 struct chunk* world_find_chunk(struct world* w, w_coord_t x, w_coord_t y,
 							   w_coord_t z) {
 	assert(w);

source/world.h

@@ -26,6 +26,8 @@
 
 #include "cglm/cglm.h"
 
+#include "stack.h"
+
 #define WORLD_HEIGHT 128
 
 typedef int32_t w_coord_t;
@@ -55,6 +57,11 @@ struct world_section {
 	struct chunk* column[COLUMN_HEIGHT];
 };
 
+struct world_modification_entry {
+	w_coord_t x, y, z;
+	struct block_data blk;
+};
+
 #define SECTION_TO_ID(x, z) (((int64_t)(z) << 32) | (((int64_t)(x)&0xFFFFFFFF)))
 
 DICT_DEF2(dict_wsection, int64_t, M_BASIC_OPLIST, struct world_section,
@@ -66,6 +73,7 @@ struct world {
 	ilist_chunks_t render;
 	ilist_chunks2_t gpu_busy_chunks;
 	ptime_t anim_timer;
+	struct stack lighting_updates;
 };
 
 void world_create(struct world* w);
@@ -77,12 +85,15 @@ size_t world_build_chunks(struct world* w, size_t tokens);
 void world_render_completed(struct world* w, bool new_render);
 struct chunk* world_find_chunk_neighbour(struct world* w, struct chunk* c,
 										 enum side s);
+struct chunk* world_chunk_from_section(struct world* w, struct world_section* s,
+									   w_coord_t y);
 struct chunk* world_find_chunk(struct world* w, w_coord_t x, w_coord_t y,
 							   w_coord_t z);
 struct block_data world_get_block(struct world* w, w_coord_t x, w_coord_t y,
 								  w_coord_t z);
 void world_set_block(struct world* w, w_coord_t x, w_coord_t y, w_coord_t z,
-					 struct block_data blk);
+					 struct block_data blk, bool light_update);
+void world_update_lighting(struct world* w);
 void world_preload(struct world* w,
 				   void (*progress)(struct world* w, float percent));
 bool world_block_intersection(struct world* w, struct ray* r, w_coord_t x,