skcblitz/world.h

uint map_f_chunkhash(void *ptr) {
	ulong hash = (ulong)ptr;
	hash = (hash & 0x3f) | (((hash >> 21) & 0x0f) << 12) | (((hash >> 42) & 0x3f) << 6);
	return (uint)hash;
}

void world_init(window_t *win, double x, double y, double z, float yaw, float pitch) {
	world_t *world = win->world = mem_zeros(sizeof(world_t), MEM_WORLD);
	tbl_init(&world->global_geom, 4, 32, sizeof(geometry_t*), MEM_OBJECT);
	world->obj_id = 0ULL;
	// world->size_x = x;
	// world->size_y = y;
	// world->size_z = z;
	// world->clamp_xz = (clamp & WORLD_CLAMP_XZ) ? 1 : 0;
	// world->clamp_y = (clamp & WORLD_CLAMP_Y) ? 1 : 0;
	world->n_chunks = world->n_objects = world->n_lights = world->s_lights = 0;
	map_init(&world->chunk_map, map_f_chunkhash, map_f_inteq, 32, MEM_WORLD);
	// world->chunks = mem_alloc(sizeof(chunk_t*) * x * y * z, MEM_WORLD);
	// memset(world->chunks, 0, sizeof(chunk_t*) * x * y * z);
	tbl_init(&world->chunk_table, 16384, 32, sizeof(chunk_t), MEM_CHUNK);
	map_init(&world->obj_map, map_f_inthash, map_f_inteq, 32, MEM_OBJMAP);
	world->light_dirty = world->chunks_dirty = 0;
	world->dirty_first = world->dirty_queue = NULL;
	
	world->gravity = 0.8;
	world->friction = 0.8;
	
	world->entity = &world->entity_base;
	ent_init(world->entity, world, x, y, z, yaw, pitch);
	cam_init(&world->camera, x, y + world->entity->eye, z, yaw, pitch);
	
	sys_assert(world->post_buf = fb_init(&world->fb_post, &world->fbtex_post, &world->rbo_post, win, 0));
	glCreateBuffers(1, &world->light_buf);
	glNamedBufferData(world->light_buf, LIGHT_SSIZE * gdr.light_max, NULL, GL_DYNAMIC_DRAW);
}

void world_unload(world_t *world);

void world_delete(window_t *win) {
	world_t *world = win->world;
	// logd("t", "%d", world->obj_map.stored);
	world_unload(world);
	// chunk_delete(&world->global, 0);
	// mem_free(world->chunks);
	// tbl_clear(&world->chunk_table);
	// map_clear(&world->obj_map);
	
	glDeleteBuffers(1, &world->light_buf);
	fb_remove(world->post_buf);
	
	mem_free(world);
}

void chunk_dirty(chunk_t *chunk) {
	if(!(chunk->dirty)) {
		if(chunk->world->dirty_first)
			chunk->world->dirty_queue->next_dirty = chunk;
		else
			chunk->world->dirty_first = chunk;
		chunk->world->dirty_queue = chunk;
		chunk->next_dirty = NULL;
		chunk->world->chunks_dirty = 1;
		chunk->dirty = 1;
	}
}

chunk_t *chunk_get(world_t *world, int x, int y, int z, byte load) {
	ulong id = CHUNK_ID(x, y, z);
	// if(CHUNK_OUT(world, x, y, z))
		// return &world->global;
	// int offset = CHUNK_STRIDE(world, x, y, z);
	chunk_t *chunk = map_get(&world->chunk_map, (void*)id);
	if(chunk)
		return chunk;
	else if(!load)
		return NULL;
	sys_assert(chunk = (chunk_t*)tbl_push(&world->chunk_table));
	chunk->x = x;
	chunk->y = y;
	chunk->z = z;
	chunk->drawlist = NULL;
	chunk->dirty = 0;
	chunk->size = 1;
	chunk->world = world;
	tbl_init(&chunk->obj_table, 4, 32, sizeof(geometry_t), MEM_OBJECT);
	tbl_init(&chunk->light_table, 2, 32, sizeof(light_t), MEM_LIGHTS);
	lst_init(&chunk->poly_list, CHUNK_POLY_GROW, MEM_POLY);
	chunk->poly_pool = mem_alloc(CHUNK_POLY_GROW * sizeof(polygon_t), MEM_POLY);
	AABB_SET(chunk->box, (double)(int)(x * CHUNK_SIZE), (double)(int)(y * CHUNK_SIZE), (double)(int)(z * CHUNK_SIZE), 
		(double)(int)((x + 1) * CHUNK_SIZE), (double)(int)((y + 1) * CHUNK_SIZE), (double)(int)((z + 1) * CHUNK_SIZE))
	map_put(&world->chunk_map, (void*)id, chunk);
	world->n_chunks += 1;
	return chunk;
}

void chunk_resize(chunk_t *chunk, int size) {
	// table_t obj_table;
	list_t poly_list;
	polygon_t *poly_pool;
	ulong pos = 0;
	uint id;
	geometry_t *geom;
	// geometry_t *ngeom;
	polygon_t *poly;
	polygon_t *npoly;
	// tbl_init(&obj_table, size * wld.chunk_cap / 32, 32, sizeof(geometry_t), MEM_OBJECT);
	lst_init(&poly_list, size * CHUNK_POLY_GROW, MEM_POLY);
	poly_pool = mem_alloc(size * CHUNK_POLY_GROW * sizeof(polygon_t), MEM_POLY);
	// logd("TST", "chunk @ %d %d %d -> %d %d ---> %d %d", chunk->x, chunk->y, chunk->z, chunk->obj_table.size, chunk->poly_list.size, obj_table.size, poly_list.size);
	while(geom = tbl_iter(&chunk->obj_table, &pos)) {
		// ngeom = (geometry_t*)tbl_push(&obj_table);
		// memcpy(ngeom, geom, sizeof(geometry_t));
		// sys_assert(!map_put(&chunk->world->obj_map, (void*)geom->id, ngeom))
		poly = &chunk->poly_pool[geom->polys];
		geom->polys = 0xffffffff;
		while(poly) {
			id = lst_push(&poly_list);
			if(geom->polys != 0xffffffff) {
				npoly->next = id;
			}
			else {
				geom->polys = id;
			}
			npoly = &poly_pool[id];
			memcpy(npoly, poly, sizeof(polygon_t));
			// npoly->id = id;
			poly = (poly->next == 0xffffffff) ? NULL : &chunk->poly_pool[poly->next];
		}
		npoly->next = 0xffffffff;
	}
	// tbl_clear(&chunk->obj_table);
	lst_free(&chunk->poly_list);
	mem_free(chunk->poly_pool);
	// memcpy(&chunk->obj_table, &obj_table, sizeof(table_t));
	memcpy(&chunk->poly_list, &poly_list, sizeof(list_t));
	chunk->poly_pool = poly_pool;
	chunk->size = size;
}

// void chunk_resize_light(chunk_t *chunk, int size) {
	// table_t light_table;
	// ulong pos = 0;
	// light_t *light;
	// light_t *nlight;
	// tbl_init(&light_table, size * wld.chunk_light / 32, 32, sizeof(light_t), MEM_LIGHTS);
	// logd("TST", "chunk @ %d %d %d -> %d ---> %d", chunk->x, chunk->y, chunk->z, chunk->light_table.size, light_table.size);
	// while(light = tbl_iter(&chunk->light_table, &pos)) {
		// nlight = (light_t*)tbl_push(&light_table);
		// memcpy(nlight, light, sizeof(light_t));
		// sys_assert(!map_put(&chunk->world->obj_map, (void*)light->id, nlight))
	// }
	// tbl_clear(&chunk->light_table);
	// memcpy(&chunk->light_table, &light_table, sizeof(table_t));
	// chunk->light_size = size;
// }

void vec_tri_normal(vertex_t *result, vertex_b *vertices) {
	vec3 u, v;
	glm_vec3_sub(vertices[1].pos, vertices[0].pos, u);
	glm_vec3_sub(vertices[2].pos, vertices[0].pos, v);
	glm_vec3_crossn(u, v, v);
	for(int n = 0; n < 3; n++) {
		glm_vec3_copy(v, result[n].normal);
	}
}

geometry_t *chunk_add(chunk_t *chunk, polygon_b *polys, int n_polys, float x, float y, float z) {
	geometry_t *obj;
	if(chunk->poly_list.stored + n_polys > chunk->poly_list.size)
		chunk_resize(chunk, chunk->size + (((chunk->poly_list.stored + n_polys) - chunk->poly_list.size) + (CHUNK_POLY_GROW - 1)) / CHUNK_POLY_GROW);
	sys_assert(obj = (geometry_t*)tbl_push(&chunk->obj_table));
	// if(!obj) {
		// chunk_resize(chunk, chunk->size + 1);
		// obj = (geometry_t*)tbl_push(&chunk->obj_table);
	// }
	// logd("TST", "chunk @ %d %d %d -> %d %d", chunk->x, chunk->y, chunk->z, chunk->obj_table.stored, chunk->poly_list.stored);
	vertex_b *bvertex;
	vertex_t *nvertex;
	uint id;
	polygon_t *poly;
	AABB_SET(obj->collision, x + polys[0].vertices[0].pos[0], y + polys[0].vertices[0].pos[1], z + polys[0].vertices[0].pos[2], x + polys[0].vertices[0].pos[0], y + polys[0].vertices[0].pos[1], z + polys[0].vertices[0].pos[2])
	obj->polys = id = lst_push(&chunk->poly_list);
	poly = &chunk->poly_pool[id];
	for(int c = 0; c < n_polys; c++) {
		if(c) {
			id = lst_push(&chunk->poly_list);
			poly->next = id;
			poly = &chunk->poly_pool[id];
		}
		// poly->id = id;
		poly->material = polys[c].material;
		vec_tri_normal(poly->vertices, polys[c].vertices);
		for(int v = 0; v < 3; v++) {
			bvertex = &polys[c].vertices[v];
			nvertex = &poly->vertices[v];
			box_union(NULL, &obj->collision, x + bvertex->pos[0], y + bvertex->pos[1], z + bvertex->pos[2]);
			nvertex->pos[0] = x + bvertex->pos[0] - chunk->box.x1;
			nvertex->pos[1] = y + bvertex->pos[1] - chunk->box.y1;
			nvertex->pos[2] = z + bvertex->pos[2] - chunk->box.z1;
			// norm(nvertex->pos, nvertex->normal);
			// VEC3_SET(nvertex->normal, 0.0f, 1.0f, 0.0f);
			nvertex->coord[0] = bvertex->coord[0];
			nvertex->coord[1] = bvertex->coord[1];
		}
	}
	poly->next = 0xffffffff;
	// obj->n_polys = n_polys;
	// chunk->dirty = 1;
	if(obj->collision.x2 - obj->collision.x1 >= (float)CHUNK_SIZE || obj->collision.y2 - obj->collision.y1 >= (float)CHUNK_SIZE || 
			obj->collision.z2 - obj->collision.z1 >= (float)CHUNK_SIZE) {
		obj->global = tbl_push(&chunk->world->global_geom);
		*(obj->global) = obj;
	}
	else {
		obj->global = NULL;
	}
	return obj;
}

ulong world_add(world_t *world, polygon_b *polys, int n_polys, float x, float y, float z) {
	chunk_t *chunk;
	geometry_t *obj;
	ulong id;
	chunk = chunk_get(world, NEG_OFFSET(x, CHUNK_SIZE), NEG_OFFSET(y, CHUNK_SIZE), NEG_OFFSET(z, CHUNK_SIZE), 1);
	// if(!chunk)
	// 	return 0;
	obj = chunk_add(chunk, polys, n_polys, x, y, z);
	// if(!obj)
	// 	return 0;
	id = world->obj_id += 1ULL;
	map_put(&world->obj_map, (void*)id, obj);
	obj->id = id;
	obj->chunk_x = chunk->x;
	obj->chunk_y = chunk->y;
	obj->chunk_z = chunk->z;
	world->n_objects += 1;
	chunk_dirty(chunk);
	return id;
}

void chunk_remove(chunk_t *chunk, geometry_t *geom) {
	uint poly = geom->polys;
	while(poly != 0xffffffff) {
		lst_pop(&chunk->poly_list, poly);
		poly = (&chunk->poly_pool[poly])->next;
	}
	if(geom->global)
		tbl_pop(&chunk->world->global_geom, geom->global);
	tbl_pop(&chunk->obj_table, geom);
	if((chunk->size > 1) && (chunk->poly_list.stored <= (CHUNK_POLY_GROW * (chunk->size - 1))))
		// && (chunk->obj_table.stored <= (((wld.chunk_cap / 32) * (chunk->size - 1)) * (32 * (chunk->size - 1)))))
		chunk_resize(chunk, chunk->size - 1);
	// chunk->dirty = 1;
}

void world_remove(world_t *world, ulong id) {
	chunk_t *chunk;
	geometry_t *obj;
	obj = map_get(&world->obj_map, (void*)id);
	if(!obj)
		return;
	chunk = chunk_get(world, obj->chunk_x, obj->chunk_y, obj->chunk_z, 0);
	if(!chunk)
		return;
	chunk_remove(chunk, obj);
	map_remove(&world->obj_map, (void*)id);
	world->n_objects -= 1;
	chunk_dirty(chunk);
}

// void chunk_remove_light(chunk_t *chunk, light_t *light) {
	// tbl_pop(&chunk->light_table, light);
// }

ulong world_add_light(world_t *world, light_b *lamp, float x, float y, float z) {
	chunk_t *chunk;
	light_t *light;
	ulong id;
	chunk = chunk_get(world, NEG_OFFSET(x, CHUNK_SIZE), NEG_OFFSET(y, CHUNK_SIZE), NEG_OFFSET(z, CHUNK_SIZE), 1);
	// if(!chunk)
	// 	return 0;
	sys_assert(light = (light_t*)tbl_push(&chunk->light_table));
	// if(!light) {
		// chunk_resize_light(chunk, chunk->light_size + 1);
		// light = (light_t*)tbl_push(&chunk->light_table);
	// }
	id = world->obj_id += 1ULL;
	map_put(&world->obj_map, (void*)id, light);
	light_init_base(light, lamp);
	light->id = id;
	VEC3_SET(light->pos, x, y, z);
	world->n_lights += 1;
	world->light_dirty = 1;
	return id;
}

void world_set_light(world_t *world, ulong id, light_b *lamp) {
	light_t *light = map_get(&world->obj_map, (void*)id);
	if(!light)
		return;
	light_init_base(light, lamp);
	world->light_dirty = 1;
}

void world_remove_light(world_t *world, ulong id) {
	chunk_t *chunk;
	light_t *light;
	light = map_get(&world->obj_map, (void*)id);
	if(!light)
		return;
	chunk = chunk_get(world, NEG_OFFSET(light->pos[0], CHUNK_SIZE), NEG_OFFSET(light->pos[1], CHUNK_SIZE), NEG_OFFSET(light->pos[2], CHUNK_SIZE), 0);
	if(!chunk)
		return;
	tbl_pop(&chunk->light_table, light);
	map_remove(&world->obj_map, (void*)id);
	world->n_lights -= 1;
	// if((chunk->light_size > 1) && (chunk->light_table.stored <= (((wld.chunk_light / 32) * (chunk->light_size - 1)) * (32 * (chunk->light_size - 1)))))
		// chunk_resize_light(chunk, chunk->light_size - 1);
	world->light_dirty = 1;
}

void chunk_clear(chunk_t *chunk, byte unmap) {
	ulong pos = 0;
	geometry_t *geom;
	uint poly;
	while(geom = tbl_iter(&chunk->obj_table, &pos)) {
		if(unmap)
			map_remove(&chunk->world->obj_map, (void*)geom->id);
		poly = geom->polys;
		while(poly != 0xffffffff) {
			lst_pop(&chunk->poly_list, poly);
			poly = (&chunk->poly_pool[poly])->next;
		}
		if(geom->global)
			tbl_pop(&chunk->world->global_geom, geom->global);
	}
	chunk->world->n_objects -= chunk->obj_table.stored;
	chunk->world->n_lights -= chunk->light_table.stored;
	if(chunk->light_table.stored)
		chunk->world->light_dirty = 1;
	tbl_clear(&chunk->obj_table);
	tbl_clear(&chunk->light_table);
	if(chunk->size > 1)
		chunk_resize(chunk, 1);
	// if(chunk->light_size > 1)
		// chunk_resize_light(chunk, 1);
	// chunk->dirty = 1;
	chunk_dirty(chunk);
}

void chunk_update(chunk_t *chunk) {
	if(chunk->dirty) {
		drawlist_t *list = chunk->drawlist;
		if(list) {
			draw_destroy(list);
		}
		else if(chunk->obj_table.stored) {
			chunk->drawlist = list = tbl_push(&gdr.drawlists);
		}
		if(chunk->obj_table.stored && list) {
			draw_build(chunk, list);
		}
		else if(list) {
			tbl_pop(&gdr.drawlists, list);
			chunk->drawlist = NULL;
		}
		chunk->dirty = 0;
	}
}

void chunk_delete(chunk_t *chunk, byte unmap) {
	chunk_clear(chunk, unmap);
	chunk_update(chunk);
	tbl_clear(&chunk->obj_table);
	tbl_clear(&chunk->light_table);
	lst_free(&chunk->poly_list);
	mem_free(chunk->poly_pool);
}

void chunk_unload(world_t *world, int x, int y, int z) {
	// if(CHUNK_OUT(world, x, y, z))
		// return;
	ulong id = CHUNK_ID(x, y, z);
	chunk_t *chunk = map_remove(&world->chunk_map, (void*)id);
	if(chunk) {
		chunk_delete(chunk, 1);
		// world->chunks[offset] = NULL;
		tbl_pop(&world->chunk_table, chunk);
		world->n_chunks -= 1;
	}
}

void world_update(world_t *world) {
	if(world->chunks_dirty) {
		int pos = 0;
		chunk_t *chunk = world->dirty_first;
		chunk_t *nchunk;
		while(chunk) {
			chunk_update(chunk);
			if(chunk->obj_table.stored == 0 && chunk->light_table.stored == 0) {
				nchunk = chunk->next_dirty;
				chunk_unload(world, chunk->x, chunk->y, chunk->z);
				chunk = nchunk;
			}
			else {
				chunk = chunk->next_dirty;
			}
		}
		world->dirty_first = world->dirty_queue = NULL;
		world->chunks_dirty = 0;
	}
	if(world->light_dirty) {
		light_calc(world);
		world->light_dirty = 0;
	}
}

void world_unload(world_t *world) {
	ulong pos = 0;
	chunk_t *chunk;
	while(chunk = tbl_iter(&world->chunk_table, &pos)) {
		chunk_delete(chunk, 0);
	}
	map_clear(&world->chunk_map);
	tbl_clear(&world->global_geom);
	tbl_clear(&world->chunk_table);
	map_clear(&world->obj_map);
	world->n_chunks = world->n_objects = world->n_lights = 0;
}

void vec_make_quad(polygon_b *polys, float u, float v, float w, float p, float q, int m, int n, int o) {
	byte uflip = m < 0;
	byte vflip = n < 0;
	m = (m < 0) ? (-1 - m) : (m - 1);
	n = (n < 0) ? (-1 - n) : (n - 1);
	o -= 1;
	
	for(int c = 0; c < 3; c++) {
		polys[0].vertices[c].pos[o] = w;
		polys[1].vertices[c].pos[o] = w;
	}
	
	polys[0].vertices[0].pos[m] = polys[1].vertices[2].pos[m] = u;
	polys[0].vertices[0].pos[n] = polys[1].vertices[2].pos[n] = v;
	polys[0].vertices[0].coord[0] = polys[1].vertices[2].coord[0] = uflip ? p : 0.0f;
	polys[0].vertices[0].coord[1] = polys[1].vertices[2].coord[1] = vflip ? q : 0.0f;
	
	polys[0].vertices[1].pos[m] = u + p;
	polys[0].vertices[1].pos[n] = v;
	polys[0].vertices[1].coord[0] = uflip ? 0.0f : p;
	polys[0].vertices[1].coord[1] = vflip ? q : 0.0f;
	
	polys[0].vertices[2].pos[m] = polys[1].vertices[0].pos[m] = u + p;
	polys[0].vertices[2].pos[n] = polys[1].vertices[0].pos[n] = v + q;
	polys[0].vertices[2].coord[0] = polys[1].vertices[0].coord[0] = uflip ? 0.0f : p;
	polys[0].vertices[2].coord[1] = polys[1].vertices[0].coord[1] = vflip ? 0.0f : q;
	
	polys[1].vertices[1].pos[m] = u;
	polys[1].vertices[1].pos[n] = v + q;
	polys[1].vertices[1].coord[0] = uflip ? p : 0.0f;
	polys[1].vertices[1].coord[1] = vflip ? 0.0f : q;
}

void vec_make_dquad(polygon_b *polys, float x, float y, float z, float xsize, float ysize, float zsize, material_t *material, byte dir, byte shift) {
	float offset = shift ? 1.0f : 0.0f;
	switch(dir) {
		case FACE_WEST:
			vec_make_quad(polys, z, y, x, zsize, ysize, 3, 2, 1);
			break;
		case FACE_EAST:
			vec_make_quad(polys, z, y, x + offset * xsize, zsize, ysize, -3, 2, 1);
			break;
		case FACE_DOWN:
			vec_make_quad(polys, x, z, y, xsize, zsize, 1, 3, 2);
			break;
		case FACE_UP:
			vec_make_quad(polys, x, z, y + offset * ysize, xsize, zsize, 1, 3, 2);
			break;
		case FACE_NORTH:
			vec_make_quad(polys, x, y, z, xsize, ysize, 1, 2, 3);
			break;
		case FACE_SOUTH:
			vec_make_quad(polys, x, y, z + offset * zsize, xsize, ysize, -1, 2, 3);
			break;
	}
	polys[0].material = polys[1].material = material;
}

ulong world_add_floor(world_t *world, float x, float y, float z, float xsize, float zsize, material_t *material) {
	polygon_b polys[2];
	vec_make_dquad(polys, 0.0f, 0.0f, 0.0f, xsize, 0.0f, zsize, material, FACE_UP, 0);
	return world_add(world, polys, 2, x, y, z);
}

ulong world_add_box(world_t *world, float x, float y, float z, float xsize, float ysize, float zsize, material_t *material) {
	polygon_b polys[12];
	for(int n = 0; n < 6; n++) {
		vec_make_dquad(&polys[n << 1], 0.0f, 0.0f, 0.0f, xsize, ysize, zsize, material, n, 1);
	}
	return world_add(world, polys, 12, x, y, z);
}

void vec_make_gquad(polygon_b *polys, float x, float z, float p, float q, float y00, float y10, float y01, float y11) {
	polys[0].vertices[0].pos X = polys[1].vertices[2].pos X = x;
	polys[0].vertices[0].pos Y = polys[1].vertices[2].pos Y = y00;
	polys[0].vertices[0].pos Z = polys[1].vertices[2].pos Z = z;
	polys[0].vertices[0].coord[0] = polys[1].vertices[2].coord[0] = 0.0f;
	polys[0].vertices[0].coord[1] = polys[1].vertices[2].coord[1] = 0.0f;
	
	polys[0].vertices[1].pos X = x + p;
	polys[0].vertices[1].pos Y = y10;
	polys[0].vertices[1].pos Z = z;
	polys[0].vertices[1].coord[0] = p;
	polys[0].vertices[1].coord[1] = 0.0f;
	
	polys[0].vertices[2].pos X = polys[1].vertices[0].pos X = x + p;
	polys[0].vertices[2].pos Y = polys[1].vertices[0].pos Y = y11;
	polys[0].vertices[2].pos Z = polys[1].vertices[0].pos Z = z + q;
	polys[0].vertices[2].coord[0] = polys[1].vertices[0].coord[0] = p;
	polys[0].vertices[2].coord[1] = polys[1].vertices[0].coord[1] = q;
	
	polys[1].vertices[1].pos X = x;
	polys[1].vertices[1].pos Y = y01;
	polys[1].vertices[1].pos Z = z + q;
	polys[1].vertices[1].coord[0] = 0.0f;
	polys[1].vertices[1].coord[1] = q;
}

void world_add_graph(world_t *world, graph2_func *func, void *p, float x, float y, float z, float xsize, float ysize, float zsize, 
		material_t *material, uint xvals, uint zvals, float xoffset, float zoffset, float xrange, float zrange, uint frag) {
	uint xfrags = (xvals + frag - 1) / frag;
	uint zfrags = (zvals + frag - 1) / frag;
	uint fdx = frag;
	uint fdz = frag;
	uint sx, sz, fx, fz, gx, gz;
	polygon_b *polys = mem_alloc(sizeof(polygon_b) * 2 * frag * frag, MEM_POLY);
	polygon_b *poly;
	for(sx = 0; sx < xfrags; sx++) {
		if(sx == xfrags - 1)
			fdx = xvals - ((xfrags - 1) * frag);
		for(sz = 0; sz < zfrags; sz++) {
			if(sz == zfrags - 1)
				fdz = zvals - ((zfrags - 1) * frag);
			for(fx = 0; fx < fdx; fx++) {
				gx = sx * frag + fx;
				for(fz = 0; fz < fdz; fz++) {
					gz = sz * frag + fz;
					poly = &polys[(fx + fz * fdx) * 2];
					poly[0].material = poly[1].material = material;
					vec_make_gquad(poly, xsize * (float)fx / (float)xvals, zsize * (float)fz / (float)zvals, xsize / (float)xvals, zsize / (float)zvals,
						func(p, xoffset + (float)gx / (float)xvals * xrange, zoffset + (float)gz / (float)zvals * zrange) * ysize, 
						func(p, xoffset + (float)(gx + 1) / (float)xvals * xrange, zoffset + (float)gz / (float)zvals * zrange) * ysize,
						func(p, xoffset + (float)gx / (float)xvals * xrange, zoffset + (float)(gz + 1) / (float)zvals * zrange) * ysize, 
						func(p, xoffset + (float)(gx + 1) / (float)xvals * xrange, zoffset + (float)(gz + 1) / (float)zvals * zrange) * ysize);
					// logi("t", "%d %d; %d %d; %d %d; %.1f %.1f -> %.1f", sx, sz, fx, fz, gx, gz, 
					// 	xoffset + (float)gx / (float)xvals * xrange, zoffset + (float)gz / (float)zvals * zrange, poly[0].vertices[0].pos Y);
				}
			}
			world_add(world, polys, fdx * fdz * 2, x + (xsize * (float)(sx * frag) / (float)xvals), y, z + (zsize * (float)(sz * frag) / (float)zvals));
		}
	}
	mem_free(polys);
}