chunk.c

/*
	Copyright (c) 2017-2020 ByteBit

	This file is part of BetterSpades.

	BetterSpades is free software: you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	BetterSpades is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with BetterSpades.  If not, see <http://www.gnu.org/licenses/>.
*/

#include <pthread.h>
#include <signal.h>
#include <math.h>
#include <stdlib.h>
#include <float.h>
#include <string.h>

#include "common.h"
#include "window.h"
#include "config.h"
#include "texture.h"
#include "log.h"
#include "matrix.h"
#include "map.h"
#include "camera.h"
#include "tesselator.h"
#include "chunk.h"
#include "channel.h"
#include "utils.h"

struct chunk chunks[CHUNKS_PER_DIM * CHUNKS_PER_DIM];

HashTable chunk_block_queue;
struct channel chunk_work_queue;
struct channel chunk_result_queue;

struct chunk_work_packet {
	size_t chunk_x;
	size_t chunk_y;
	struct chunk* chunk;
};

struct chunk_result_packet {
	struct chunk* chunk;
	int max_height;
	struct tesselator tesselator;
	uint32_t* minimap_data;
};

struct chunk_render_call {
	struct chunk* chunk;
	int mirror_x;
	int mirror_y;
};

void chunk_init() {
	for(size_t x = 0; x < CHUNKS_PER_DIM; x++) {
		for(size_t y = 0; y < CHUNKS_PER_DIM; y++) {
			struct chunk* c = chunks + x + y * CHUNKS_PER_DIM;
			c->created = false;
			c->max_height = 1;
			c->x = x;
			c->y = y;
		}
	}

	channel_create(&chunk_work_queue, sizeof(struct chunk_work_packet), CHUNKS_PER_DIM * CHUNKS_PER_DIM);
	channel_create(&chunk_result_queue, sizeof(struct chunk_result_packet), CHUNKS_PER_DIM * CHUNKS_PER_DIM);
	ht_setup(&chunk_block_queue, sizeof(struct chunk*), sizeof(struct chunk_result_packet), 64);

	int chunk_enabled_cores = min(max(window_cpucores() / 2, 1), CHUNK_WORKERS_MAX);
	log_info("%i cores enabled for chunk generation", chunk_enabled_cores);

	pthread_t threads[chunk_enabled_cores];

	for(size_t k = 0; k < chunk_enabled_cores; k++)
		pthread_create(threads + k, NULL, chunk_generate, NULL);
}

static int chunk_sort(const void* a, const void* b) {
	struct chunk_render_call* aa = (struct chunk_render_call*)a;
	struct chunk_render_call* bb = (struct chunk_render_call*)b;
	return distance2D(aa->chunk->x * CHUNK_SIZE + CHUNK_SIZE / 2, aa->chunk->y * CHUNK_SIZE + CHUNK_SIZE / 2, camera_x,
					  camera_z)
		- distance2D(bb->chunk->x * CHUNK_SIZE + CHUNK_SIZE / 2, bb->chunk->y * CHUNK_SIZE + CHUNK_SIZE / 2, camera_x,
					 camera_z);
}

void chunk_render(struct chunk_render_call* c) {
	if(c->chunk->created) {
		matrix_push();
		matrix_translate(c->mirror_x * map_size_x, 0.0F, c->mirror_y * map_size_z);
		matrix_upload();

		// glPolygonMode(GL_FRONT, GL_LINE);

		glx_displaylist_draw(&c->chunk->display_list, GLX_DISPLAYLIST_NORMAL);

		// glPolygonMode(GL_FRONT, GL_FILL);

		matrix_pop();
	}
}

void chunk_draw_visible() {
	struct chunk_render_call chunks_draw[CHUNKS_PER_DIM * CHUNKS_PER_DIM * 2];
	int index = 0;

	int overshoot = (settings.render_distance + CHUNK_SIZE - 1) / CHUNK_SIZE + 1;

	// go through all possible chunks and store all in range and view
	for(int y = -overshoot; y < CHUNKS_PER_DIM + overshoot; y++) {
		for(int x = -overshoot; x < CHUNKS_PER_DIM + overshoot; x++) {
			if(distance2D((x + 0.5F) * CHUNK_SIZE, (y + 0.5F) * CHUNK_SIZE, camera_x, camera_z)
			   <= pow(settings.render_distance + 1.414F * CHUNK_SIZE, 2)) {
				uint32_t tmp_x = ((uint32_t)x) % CHUNKS_PER_DIM;
				uint32_t tmp_y = ((uint32_t)y) % CHUNKS_PER_DIM;

				struct chunk* c = chunks + tmp_x + tmp_y * CHUNKS_PER_DIM;

				if(camera_CubeInFrustum((x + 0.5F) * CHUNK_SIZE, 0.0F, (y + 0.5F) * CHUNK_SIZE, CHUNK_SIZE / 2,
										c->max_height))
					chunks_draw[index++] = (struct chunk_render_call) {
						.chunk = c,
						.mirror_x = (x < 0) ? -1 : ((x >= CHUNKS_PER_DIM) ? 1 : 0),
						.mirror_y = (y < 0) ? -1 : ((y >= CHUNKS_PER_DIM) ? 1 : 0),
					};
			}
		}
	}

	// sort all chunks to draw those in front first
	qsort(chunks_draw, index, sizeof(struct chunk_render_call), chunk_sort);

	for(int k = 0; k < index; k++)
		chunk_render(chunks_draw + k);
}

static __attribute__((always_inline)) inline uint32_t solid_array_isair(uint32_t* array, uint32_t x, uint32_t y,
																		uint32_t z) {
	if(y < 0)
		return 0;
	if(y >= map_size_y)
		return 1;

	size_t offset = (map_size_y - 1 - y) + ((x % map_size_x) + (z % map_size_z) * map_size_x) * map_size_y;

	return !(array[offset / (sizeof(uint32_t) * 8)] & (1 << (offset % (sizeof(uint32_t) * 8))));
}

static __attribute__((always_inline)) inline float solid_sunblock(uint32_t* array, uint32_t x, uint32_t y, uint32_t z) {
	int dec = 18;
	int i = 127;

	while(dec && y < map_size_y) {
		if(!solid_array_isair(array, x, ++y, --z))
			i -= dec;
		dec -= 2;
	}
	return (float)i / 127.0F;
}

void* chunk_generate(void* data) {
	pthread_detach(pthread_self());

	while(1) {
		struct chunk_work_packet work;
		channel_await(&chunk_work_queue, &work);

		if(!work.chunk)
			break;

		struct chunk_result_packet result;
		result.chunk = work.chunk;
		result.minimap_data = malloc(CHUNK_SIZE * CHUNK_SIZE * sizeof(uint32_t));
		tesselator_create(&result.tesselator, VERTEX_INT, 0);

		uint32_t blocks_count;
		struct libvxl_block* blocks = map_copy_blocks(work.chunk_x, work.chunk_y, &blocks_count);
		uint32_t* blocks_solid = map_copy_solids();

		/*if(settings.greedy_meshing)
			chunk_generate_greedy(worker->chunk_x, worker->chunk_y, &worker->tesselator, &worker->max_height);
		else*/
		chunk_generate_naive(blocks, blocks_count, blocks_solid, &result.tesselator, &result.max_height,
							 settings.ambient_occlusion);

		// use the fact that libvxl orders libvxl_blocks by top-down coordinate first in its data structure
		size_t chunk_x = work.chunk_x * CHUNK_SIZE;
		size_t chunk_y = work.chunk_y * CHUNK_SIZE;
		uint32_t last_position = 0;
		for(int k = blocks_count - 1; k >= 0; k--) {
			struct libvxl_block* blk = blocks + k;

			if(blk->position != last_position || k == blocks_count - 1) {
				last_position = blk->position;

				int x = key_getx(blk->position);
				int z = key_gety(blk->position);

				uint32_t* out = result.minimap_data + (x - chunk_x + (z - chunk_y) * CHUNK_SIZE);

				if((x % 64) > 0 && (z % 64) > 0) {
					*out = rgb2bgr(blk->color) | 0xFF000000;
				} else {
					*out = rgba(255, 255, 255, 255);
				}
			}
		}

		free(blocks);
		free(blocks_solid);

		channel_put(&chunk_result_queue, &result);
	}

	return NULL;
}

void chunk_generate_greedy(int start_x, int start_z, struct tesselator* tess, int* max_height) {
	*max_height = 0;

	int checked_voxels[2][CHUNK_SIZE * CHUNK_SIZE];
	int checked_voxels2[2][CHUNK_SIZE * map_size_y];

	for(int z = start_z; z < start_z + CHUNK_SIZE; z++) {
		memset(checked_voxels2[0], 0, sizeof(int) * CHUNK_SIZE * map_size_y);
		memset(checked_voxels2[1], 0, sizeof(int) * CHUNK_SIZE * map_size_y);

		for(int x = start_x; x < start_x + CHUNK_SIZE; x++) {
			for(int y = 0; y < map_size_y; y++) {
				if(!map_isair(x, y, z)) {
					if(*max_height < y) {
						*max_height = y;
					}

					unsigned int col = map_get(x, y, z);
					int r = red(col);
					int g = green(col);
					int b = blue(col);

					if((z == 0 && map_isair(x, y, map_size_z - 1)) || (z > 0 && map_isair(x, y, z - 1))) {
						if(checked_voxels2[0][y + (x - start_x) * map_size_y] == 0) {
							int len_y = 0;
							int len_x = 1;

							for(int a = 0; a < map_size_y - y; a++) {
								if(map_get(x, y + a, z) == col
								   && checked_voxels2[0][y + a + (x - start_x) * map_size_y] == 0
								   && ((z == 0 && map_isair(x, y + a, map_size_z - 1))
									   || (z > 0 && map_isair(x, y + a, z - 1))))
									len_y++;
								else
									break;
							}

							for(int b = 1; b < (start_x + CHUNK_SIZE - x); b++) {
								int a;
								for(a = 0; a < len_y; a++) {
									if(map_get(x + b, y + a, z) != col
									   || checked_voxels2[0][y + a + (x + b - start_x) * map_size_y] != 0
									   || !((z == 0 && map_isair(x + b, y + a, map_size_z - 1))
											|| (z > 0 && map_isair(x + b, y + a, z - 1))))
										break;
								}
								if(a == len_y)
									len_x++;
								else
									break;
							}

							for(int b = 0; b < len_x; b++)
								for(int a = 0; a < len_y; a++)
									checked_voxels2[0][y + a + (x + b - start_x) * map_size_y] = 1;

							tesselator_set_color(tess, rgba(r * 0.875F, g * 0.875F, b * 0.875F, 255));
							tesselator_addi_simple(
								tess, (int16_t[]) {x, y, z, x, y + len_y, z, x + len_x, y + len_y, z, x + len_x, y, z});
						}
					}

					if((z == map_size_z - 1 && map_isair(x, y, 0)) || (z < map_size_z - 1 && map_isair(x, y, z + 1))) {
						if(checked_voxels2[1][y + (x - start_x) * map_size_y] == 0) {
							int len_y = 0;
							int len_x = 1;

							for(int a = 0; a < map_size_y - y; a++) {
								if(map_get(x, y + a, z) == col
								   && checked_voxels2[1][y + a + (x - start_x) * map_size_y] == 0
								   && ((z == map_size_z - 1 && map_isair(x, y + a, 0))
									   || (z < map_size_z - 1 && map_isair(x, y + a, z + 1))))
									len_y++;
								else
									break;
							}

							for(int b = 1; b < (start_x + CHUNK_SIZE - x); b++) {
								int a;
								for(a = 0; a < len_y; a++) {
									if(map_get(x + b, a + a, z) != col
									   || checked_voxels2[1][y + a + (x + b - start_x) * map_size_y] != 0
									   || !((z == map_size_z - 1 && map_isair(x + b, y + a, 0))
											|| (z < map_size_z - 1 && map_isair(x + b, y + a, z + 1))))
										break;
								}
								if(a == len_y)
									len_x++;
								else
									break;
							}

							for(int b = 0; b < len_x; b++)
								for(int a = 0; a < len_y; a++)
									checked_voxels2[1][y + a + (x + b - start_x) * map_size_y] = 1;

							tesselator_set_color(tess, rgba(r * 0.625F, g * 0.625F, b * 0.625F, 255));
							tesselator_addi_simple(tess,
												   (int16_t[]) {x, y, z + 1, x + len_x, y, z + 1, x + len_x, y + len_y,
																z + 1, x, y + len_y, z + 1});
						}
					}
				}
			}
		}
	}

	for(int x = start_x; x < start_x + CHUNK_SIZE; x++) {
		memset(checked_voxels2[0], 0, sizeof(int) * CHUNK_SIZE * map_size_y);
		memset(checked_voxels2[1], 0, sizeof(int) * CHUNK_SIZE * map_size_y);

		for(int z = start_z; z < start_z + CHUNK_SIZE; z++) {
			for(int y = 0; y < map_size_y; y++) {
				if(!map_isair(x, y, z)) {
					if(*max_height < y) {
						*max_height = y;
					}

					unsigned int col = map_get(x, y, z);
					int r = red(col);
					int g = green(col);
					int b = blue(col);

					if((x == 0 && map_isair(map_size_x - 1, y, z)) || (x > 0 && map_isair(x - 1, y, z))) {
						if(checked_voxels2[0][y + (z - start_z) * map_size_y] == 0) {
							int len_y = 0;
							int len_z = 1;

							for(int a = 0; a < map_size_y - y; a++) {
								if(map_get(x, y + a, z) == col
								   && checked_voxels2[0][y + a + (z - start_z) * map_size_y] == 0
								   && ((x == 0 && map_isair(map_size_x - 1, y + a, z))
									   || (x > 0 && map_isair(x - 1, y + a, z))))
									len_y++;
								else
									break;
							}

							for(int b = 1; b < (start_z + CHUNK_SIZE - z); b++) {
								int a;
								for(a = 0; a < len_y; a++) {
									if(map_get(x, y + a, z + b) != col
									   || checked_voxels2[0][y + a + (z + b - start_z) * map_size_y] != 0
									   || !((x == 0 && map_isair(map_size_x - 1, y + a, z + b))
											|| (x > 0 && map_isair(x - 1, y + a, z + b))))
										break;
								}
								if(a == len_y)
									len_z++;
								else
									break;
							}

							for(int b = 0; b < len_z; b++)
								for(int a = 0; a < len_y; a++)
									checked_voxels2[0][y + a + (z + b - start_z) * map_size_y] = 1;

							tesselator_set_color(tess, rgba(r * 0.75F, g * 0.75F, b * 0.75F, 255));
							tesselator_addi_simple(
								tess, (int16_t[]) {x, y, z, x, y, z + len_z, x, y + len_y, z + len_z, x, y + len_y, z});
						}
					}

					if((x == map_size_x - 1 && map_isair(0, y, z)) || (x < map_size_x - 1 && map_isair(x + 1, y, z))) {
						if(checked_voxels2[1][y + (z - start_z) * map_size_y] == 0) {
							int len_y = 0;
							int len_z = 1;

							for(int a = 0; a < map_size_y - y; a++) {
								if(map_get(x, y + a, z) == col
								   && checked_voxels2[1][y + a + (z - start_z) * map_size_y] == 0
								   && ((x == map_size_x - 1 && map_isair(0, y + a, z))
									   || (x < map_size_x - 1 && map_isair(x + 1, y + a, z))))
									len_y++;
								else
									break;
							}

							for(int b = 1; b < (start_z + CHUNK_SIZE - z); b++) {
								int a;
								for(a = 0; a < len_y; a++) {
									if(map_get(x, y + a, z + b) != col
									   || checked_voxels2[1][y + a + (z + b - start_z) * map_size_y] != 0
									   || !((x == map_size_x - 1 && map_isair(0, y + a, z + b))
											|| (x < map_size_x - 1 && map_isair(x + 1, y + a, z + b))))
										break;
								}
								if(a == len_y)
									len_z++;
								else
									break;
							}

							for(unsigned char b = 0; b < len_z; b++)
								for(unsigned char a = 0; a < len_y; a++)
									checked_voxels2[1][y + a + (z + b - start_z) * map_size_y] = 1;

							tesselator_set_color(tess, rgba(r * 0.75F, g * 0.75F, b * 0.75F, 255));
							tesselator_addi_simple(tess,
												   (int16_t[]) {x + 1, y, z, x + 1, y + len_y, z, x + 1, y + len_y,
																z + len_z, x + 1, y, z + len_z});
						}
					}
				}
			}
		}
	}

	for(int y = 0; y < map_size_y; y++) {
		memset(checked_voxels[0], 0, sizeof(int) * CHUNK_SIZE * CHUNK_SIZE);
		memset(checked_voxels[1], 0, sizeof(int) * CHUNK_SIZE * CHUNK_SIZE);

		for(int x = start_x; x < start_x + CHUNK_SIZE; x++) {
			for(int z = start_z; z < start_z + CHUNK_SIZE; z++) {
				if(!map_isair(x, y, z)) {
					if(*max_height < y) {
						*max_height = y;
					}

					unsigned int col = map_get(x, y, z);
					int r = red(col);
					int g = green(col);
					int b = blue(col);

					if(y == map_size_y - 1 || map_isair(x, y + 1, z)) {
						if(checked_voxels[0][(x - start_x) + (z - start_z) * CHUNK_SIZE] == 0) {
							int len_x = 0;
							int len_z = 1;

							for(int a = 0; a < (start_x + CHUNK_SIZE - x); a++) {
								if(map_get(x + a, y, z) == col
								   && checked_voxels[0][(x + a - start_x) + (z - start_z) * CHUNK_SIZE] == 0
								   && (y == map_size_y - 1 || map_isair(x + a, y + 1, z)))
									len_x++;
								else
									break;
							}

							for(int b = 1; b < (start_z + CHUNK_SIZE - z); b++) {
								int a;
								for(a = 0; a < len_x; a++) {
									if(map_get(x + a, y, z + b) != col
									   || checked_voxels[0][(x + a - start_x) + (z + b - start_z) * CHUNK_SIZE] != 0
									   || !(y == map_size_y - 1 || map_isair(x + a, y + 1, z + b)))
										break;
								}
								if(a == len_x)
									len_z++;
								else
									break;
							}

							for(int b = 0; b < len_z; b++)
								for(int a = 0; a < len_x; a++)
									checked_voxels[0][(x + a - start_x) + (z + b - start_z) * CHUNK_SIZE] = 1;

							tesselator_set_color(tess, rgba(r, g, b, 255));
							tesselator_addi_simple(tess,
												   (int16_t[]) {x, y + 1, z, x, y + 1, z + len_z, x + len_x, y + 1,
																z + len_z, x + len_x, y + 1, z});
						}
					}

					if(y > 0 && map_isair(x, y - 1, z)) {
						if(checked_voxels[1][(x - start_x) + (z - start_z) * CHUNK_SIZE] == 0) {
							int len_x = 0;
							int len_z = 1;

							for(int a = 0; a < (start_x + CHUNK_SIZE - x); a++) {
								if(map_get(x + a, y, z) == col
								   && checked_voxels[1][(x + a - start_x) + (z - start_z) * CHUNK_SIZE] == 0
								   && (y > 0 && map_isair(x + a, y - 1, z)))
									len_x++;
								else
									break;
							}

							for(int b = 1; b < (start_z + CHUNK_SIZE - z); b++) {
								int a;
								for(a = 0; a < len_x; a++) {
									if(map_get(x + a, y, z + b) != col
									   || checked_voxels[1][(x + a - start_x) + (z + b - start_z) * CHUNK_SIZE] != 0
									   || !(y > 0 && map_isair(x + a, y - 1, z + b)))
										break;
								}
								if(a == len_x)
									len_z++;
								else
									break;
							}

							for(int b = 0; b < len_z; b++)
								for(int a = 0; a < len_x; a++)
									checked_voxels[1][(x + a - start_x) + (z + b - start_z) * CHUNK_SIZE] = 1;

							tesselator_set_color(tess, rgba(r * 0.5F, g * 0.5F, b * 0.5F, 255));
							tesselator_addi_simple(
								tess, (int16_t[]) {x, y, z, x + len_x, y, z, x + len_x, y, z + len_z, x, y, z + len_z});
						}
					}
				}
			}
		}
	}

	(*max_height)++;
}

//+X = 0.75
//-X = 0.75
//+Y = 1.0
//-Y = 0.5
//+Z = 0.625
//-Z = 0.875

// credit: https://0fps.net/2013/07/03/ambient-occlusion-for-minecraft-like-worlds/
static float vertexAO(int side1, int side2, int corner) {
	if(!side1 && !side2) {
		return 0.25F;
	}

	return 0.75F - (!side1 + !side2 + !corner) * 0.25F + 0.25F;
}

void chunk_generate_naive(struct libvxl_block* blocks, int count, uint32_t* solid, struct tesselator* tess,
						  int* max_height, int ao) {
	*max_height = 0;

	for(int k = 0; k < count; k++) {
		struct libvxl_block* blk = blocks + k;

		int x = key_getx(blk->position);
		int y = map_size_y - 1 - key_getz(blk->position);
		int z = key_gety(blk->position);

		*max_height = max(*max_height, y);

		uint32_t col = blk->color;
		int r = blue(col);
		int g = green(col);
		int b = red(col);

		float shade = solid_sunblock(solid, x, y, z);
		r *= shade;
		g *= shade;
		b *= shade;

		if(solid_array_isair(solid, x, y, z - 1)) {
			if(ao) {
				float A = vertexAO(solid_array_isair(solid, x - 1, y, z - 1), solid_array_isair(solid, x, y - 1, z - 1),
								   solid_array_isair(solid, x - 1, y - 1, z - 1));
				float B = vertexAO(solid_array_isair(solid, x - 1, y, z - 1), solid_array_isair(solid, x, y + 1, z - 1),
								   solid_array_isair(solid, x - 1, y + 1, z - 1));
				float C = vertexAO(solid_array_isair(solid, x + 1, y, z - 1), solid_array_isair(solid, x, y + 1, z - 1),
								   solid_array_isair(solid, x + 1, y + 1, z - 1));
				float D = vertexAO(solid_array_isair(solid, x + 1, y, z - 1), solid_array_isair(solid, x, y - 1, z - 1),
								   solid_array_isair(solid, x + 1, y - 1, z - 1));

				tesselator_addi(tess, (int16_t[]) {x, y, z, x, y + 1, z, x + 1, y + 1, z, x + 1, y, z},
								(uint32_t[]) {
									rgba(r * 0.875F * A, g * 0.875F * A, b * 0.875F * A, 255),
									rgba(r * 0.875F * B, g * 0.875F * B, b * 0.875F * B, 255),
									rgba(r * 0.875F * C, g * 0.875F * C, b * 0.875F * C, 255),
									rgba(r * 0.875F * D, g * 0.875F * D, b * 0.875F * D, 255),
								},
								NULL);
			} else {
				tesselator_set_color(tess, rgba(r * 0.875F, g * 0.875F, b * 0.875F, 255));
				tesselator_addi_cube_face(tess, CUBE_FACE_Z_N, x, y, z);
			}
		}

		if(solid_array_isair(solid, x, y, z + 1)) {
			if(ao) {
				float A = vertexAO(solid_array_isair(solid, x - 1, y, z + 1), solid_array_isair(solid, x, y - 1, z + 1),
								   solid_array_isair(solid, x - 1, y - 1, z + 1));
				float B = vertexAO(solid_array_isair(solid, x + 1, y, z + 1), solid_array_isair(solid, x, y - 1, z + 1),
								   solid_array_isair(solid, x + 1, y - 1, z + 1));
				float C = vertexAO(solid_array_isair(solid, x + 1, y, z + 1), solid_array_isair(solid, x, y + 1, z + 1),
								   solid_array_isair(solid, x + 1, y + 1, z + 1));
				float D = vertexAO(solid_array_isair(solid, x - 1, y, z + 1), solid_array_isair(solid, x, y + 1, z + 1),
								   solid_array_isair(solid, x - 1, y + 1, z + 1));
				tesselator_addi(tess, (int16_t[]) {x, y, z + 1, x + 1, y, z + 1, x + 1, y + 1, z + 1, x, y + 1, z + 1},
								(uint32_t[]) {
									rgba(r * 0.625F * A, g * 0.625F * A, b * 0.625F * A, 255),
									rgba(r * 0.625F * B, g * 0.625F * B, b * 0.625F * B, 255),
									rgba(r * 0.625F * C, g * 0.625F * C, b * 0.625F * C, 255),
									rgba(r * 0.625F * D, g * 0.625F * D, b * 0.625F * D, 255),
								},
								NULL);
			} else {
				tesselator_set_color(tess, rgba(r * 0.625F, g * 0.625F, b * 0.625F, 255));
				tesselator_addi_cube_face(tess, CUBE_FACE_Z_P, x, y, z);
			}
		}

		if(solid_array_isair(solid, x - 1, y, z)) {
			if(ao) {
				float A = vertexAO(solid_array_isair(solid, x - 1, y - 1, z), solid_array_isair(solid, x - 1, y, z - 1),
								   solid_array_isair(solid, x - 1, y - 1, z - 1));
				float B = vertexAO(solid_array_isair(solid, x - 1, y - 1, z), solid_array_isair(solid, x - 1, y, z + 1),
								   solid_array_isair(solid, x - 1, y - 1, z + 1));
				float C = vertexAO(solid_array_isair(solid, x - 1, y + 1, z), solid_array_isair(solid, x - 1, y, z + 1),
								   solid_array_isair(solid, x - 1, y + 1, z + 1));
				float D = vertexAO(solid_array_isair(solid, x - 1, y + 1, z), solid_array_isair(solid, x - 1, y, z - 1),
								   solid_array_isair(solid, x - 1, y + 1, z - 1));

				tesselator_addi(tess, (int16_t[]) {x, y, z, x, y, z + 1, x, y + 1, z + 1, x, y + 1, z},
								(uint32_t[]) {
									rgba(r * 0.75F * A, g * 0.75F * A, b * 0.75F * A, 255),
									rgba(r * 0.75F * B, g * 0.75F * B, b * 0.75F * B, 255),
									rgba(r * 0.75F * C, g * 0.75F * C, b * 0.75F * C, 255),
									rgba(r * 0.75F * D, g * 0.75F * D, b * 0.75F * D, 255),
								},
								NULL);
			} else {
				tesselator_set_color(tess, rgba(r * 0.75F, g * 0.75F, b * 0.75F, 255));
				tesselator_addi_cube_face(tess, CUBE_FACE_X_N, x, y, z);
			}
		}

		if(solid_array_isair(solid, x + 1, y, z)) {
			if(ao) {
				float A = vertexAO(solid_array_isair(solid, x + 1, y - 1, z), solid_array_isair(solid, x + 1, y, z - 1),
								   solid_array_isair(solid, x + 1, y - 1, z - 1));
				float B = vertexAO(solid_array_isair(solid, x + 1, y + 1, z), solid_array_isair(solid, x + 1, y, z - 1),
								   solid_array_isair(solid, x + 1, y + 1, z - 1));
				float C = vertexAO(solid_array_isair(solid, x + 1, y + 1, z), solid_array_isair(solid, x + 1, y, z + 1),
								   solid_array_isair(solid, x + 1, y + 1, z + 1));
				float D = vertexAO(solid_array_isair(solid, x + 1, y - 1, z), solid_array_isair(solid, x + 1, y, z + 1),
								   solid_array_isair(solid, x + 1, y - 1, z + 1));

				tesselator_addi(tess, (int16_t[]) {x + 1, y, z, x + 1, y + 1, z, x + 1, y + 1, z + 1, x + 1, y, z + 1},
								(uint32_t[]) {
									rgba(r * 0.75F * A, g * 0.75F * A, b * 0.75F * A, 255),
									rgba(r * 0.75F * B, g * 0.75F * B, b * 0.75F * B, 255),
									rgba(r * 0.75F * C, g * 0.75F * C, b * 0.75F * C, 255),
									rgba(r * 0.75F * D, g * 0.75F * D, b * 0.75F * D, 255),
								},
								NULL);
			} else {
				tesselator_set_color(tess, rgba(r * 0.75F, g * 0.75F, b * 0.75F, 255));
				tesselator_addi_cube_face(tess, CUBE_FACE_X_P, x, y, z);
			}
		}

		if(y == map_size_y - 1 || solid_array_isair(solid, x, y + 1, z)) {
			if(ao) {
				float A = vertexAO(solid_array_isair(solid, x - 1, y + 1, z), solid_array_isair(solid, x, y + 1, z - 1),
								   solid_array_isair(solid, x - 1, y + 1, z - 1));
				float B = vertexAO(solid_array_isair(solid, x - 1, y + 1, z), solid_array_isair(solid, x, y + 1, z + 1),
								   solid_array_isair(solid, x - 1, y + 1, z + 1));
				float C = vertexAO(solid_array_isair(solid, x + 1, y + 1, z), solid_array_isair(solid, x, y + 1, z + 1),
								   solid_array_isair(solid, x + 1, y + 1, z + 1));
				float D = vertexAO(solid_array_isair(solid, x + 1, y + 1, z), solid_array_isair(solid, x, y + 1, z - 1),
								   solid_array_isair(solid, x + 1, y + 1, z - 1));

				tesselator_addi(tess, (int16_t[]) {x, y + 1, z, x, y + 1, z + 1, x + 1, y + 1, z + 1, x + 1, y + 1, z},
								(uint32_t[]) {
									rgba(r * A, g * A, b * A, 255),
									rgba(r * B, g * B, b * B, 255),
									rgba(r * C, g * C, b * C, 255),
									rgba(r * D, g * D, b * D, 255),
								},
								NULL);
			} else {
				tesselator_set_color(tess, rgba(r, g, b, 255));
				tesselator_addi_cube_face(tess, CUBE_FACE_Y_P, x, y, z);
			}
		}

		if(y > 0 && solid_array_isair(solid, x, y - 1, z)) {
			if(ao) {
				float A = vertexAO(solid_array_isair(solid, x - 1, y - 1, z), solid_array_isair(solid, x, y - 1, z - 1),
								   solid_array_isair(solid, x - 1, y - 1, z - 1));
				float B = vertexAO(solid_array_isair(solid, x + 1, y - 1, z), solid_array_isair(solid, x, y - 1, z - 1),
								   solid_array_isair(solid, x + 1, y - 1, z - 1));
				float C = vertexAO(solid_array_isair(solid, x + 1, y - 1, z), solid_array_isair(solid, x, y - 1, z + 1),
								   solid_array_isair(solid, x + 1, y - 1, z + 1));
				float D = vertexAO(solid_array_isair(solid, x - 1, y - 1, z), solid_array_isair(solid, x, y - 1, z + 1),
								   solid_array_isair(solid, x - 1, y - 1, z + 1));

				tesselator_addi(tess, (int16_t[]) {x, y, z, x + 1, y, z, x + 1, y, z + 1, x, y, z + 1},
								(uint32_t[]) {
									rgba(r * 0.5F * A, g * 0.5F * A, b * 0.5F * A, 255),
									rgba(r * 0.5F * B, g * 0.5F * B, b * 0.5F * B, 255),
									rgba(r * 0.5F * C, g * 0.5F * C, b * 0.5F * C, 255),
									rgba(r * 0.5F * D, g * 0.5F * D, b * 0.5F * D, 255),
								},
								NULL);
			} else {
				tesselator_set_color(tess, rgba(r * 0.5F, g * 0.5F, b * 0.5F, 255));
				tesselator_addi_cube_face(tess, CUBE_FACE_Y_N, x, y, z);
			}
		}
	}

	(*max_height)++;
}

void chunk_update_all() {
	size_t drain = channel_size(&chunk_result_queue);

	if(drain > 0) {
		struct chunk_result_packet results[drain];

		for(size_t k = 0; k < drain; k++) {
			channel_await(&chunk_result_queue, results + k);
			results[k].chunk->updated = false;
		}

		struct chunk_result_packet* result = results + drain - 1;

		for(size_t k = 0; k < drain; k++, result--) {
			if(!result->chunk->updated) {
				result->chunk->updated = true;

				if(!result->chunk->created) {
					glx_displaylist_create(&result->chunk->display_list, true, false);
					result->chunk->created = true;
				}

				result->chunk->max_height = result->max_height;

				tesselator_glx(&result->tesselator, &result->chunk->display_list);

				glBindTexture(GL_TEXTURE_2D, texture_minimap.texture_id);
				glTexSubImage2D(GL_TEXTURE_2D, 0, result->chunk->x * CHUNK_SIZE, result->chunk->y * CHUNK_SIZE,
								CHUNK_SIZE, CHUNK_SIZE, GL_RGBA, GL_UNSIGNED_BYTE, result->minimap_data);
				glBindTexture(GL_TEXTURE_2D, 0);
			}

			tesselator_free(&result->tesselator);
			free(result->minimap_data);
		}
	}
}

void chunk_rebuild_all() {
	channel_clear(&chunk_work_queue);

	for(size_t k = 0; k < CHUNKS_PER_DIM * CHUNKS_PER_DIM; k++) {
		channel_put(&chunk_work_queue,
					&(struct chunk_work_packet) {
						.chunk = chunks + k,
						.chunk_x = (chunks + k)->x,
						.chunk_y = (chunks + k)->y,
					});
	}
}

void chunk_block_update(int x, int y, int z) {
	struct chunk* c = chunks + (x / CHUNK_SIZE) + (z / CHUNK_SIZE) * CHUNKS_PER_DIM;

	ht_insert(&chunk_block_queue, &c,
			  &(struct chunk_work_packet) {
				  .chunk = c,
				  .chunk_x = c->x,
				  .chunk_y = c->y,
			  });
}

static bool iterate_chunk_updates(void* key, void* value, void* user) {
	channel_put(&chunk_work_queue, value);

	return true;
}

void chunk_queue_blocks() {
	ht_iterate(&chunk_block_queue, NULL, iterate_chunk_updates);
	ht_clear(&chunk_block_queue);
}