const Game = @This();
const std = @import("std");

const glfw = @import("zglfw");
const math = @import("math.zig");
const shaders = @import("shaders.zig");
const vk = @import("vulkan");
const worldgen = @import("worldgen.zig");

const Blocks = @import("assets/Blocks.zig");
const Chunk = @import("assets/Chunk.zig");
const CommandBuffer = @import("engine/CommandBuffer.zig");
const Engine = @import("engine/Engine.zig");
const Iterator2 = math.Iterator2;
const Materials = @import("assets/Materials.zig");
const Matrix4x4 = math.Matrix4x4;
const Player = @import("Player.zig");
const Quaternion = math.Quaternion;
const Skybox = @import("engine/Skybox.zig");
const StagingBuffer = @import("engine/StagingBuffer.zig");
const Swapchain = @import("engine/Swapchain.zig");
const Textures = @import("assets/Textures.zig");
const Vector2 = math.Vector2;
const Vector2x8 = math.Vector2x8;
const Vector3 = math.Vector3;

allocator: std.mem.Allocator,
engine: *Engine,
swapchain: *Swapchain,
global_descriptor_set_layout: vk.DescriptorSetLayout,
per_batch_descriptor_set_layout: vk.DescriptorSetLayout,
descriptor_pool: vk.DescriptorPool,
global_descriptor_set: vk.DescriptorSet,
pipeline_layout: vk.PipelineLayout,
pipeline: vk.Pipeline,

vertex_buffer: shaders.VertexBuffer,
index_buffer: shaders.IndexBuffer,

global_uniforms: shaders.GlobalUniformsBuffer,
global_uniforms_staging_buffer: StagingBuffer,
global_uniforms_transfer_command_buffer: CommandBuffer,
global_uniforms_transfer_semaphores: []vk.Semaphore,
point_lights: shaders.PointLightBuffer,
directional_lights: shaders.DirectionalLightBuffer,
sampler: vk.Sampler,

blocks: Blocks,
materials: Materials,
textures: Textures,
chunks: std.AutoHashMapUnmanaged([3]i16, Chunk),
skybox: Skybox,

player: Player,

const max_textures = 1024;
const max_point_lights = 1024;
const max_directional_lights = 4;
const chunk_descriptor_pool = 512;

const camera_near_plane = 0.1;

pub fn init(allocator: std.mem.Allocator, engine: *Engine, swapchain: *Swapchain) !Game {
    var materials = try Materials.init(engine, allocator);
    errdefer materials.deinit(engine, allocator);

    var textures = try Textures.init(engine, allocator);
    errdefer textures.deinit(engine, allocator);

    var blocks = try Blocks.init(allocator);
    errdefer blocks.deinit(allocator);

    // JANK HACK When this line is removed, capturing a frame with RenderDoc
    // will crash the game with segfault reading address 0x140 (presumably
    // within librenderdoc.so).

    blocks.loadAll(engine, &materials, &textures, allocator);

    const sampler = try engine.createSampler(.{
        .mag_filter = .linear,
        .min_filter = .linear,
        .mipmap_mode = .linear,
        .address_mode_u = .repeat,
        .address_mode_v = .repeat,
        .address_mode_w = .repeat,
        .mip_lod_bias = 0,
        .anisotropy_enable = .false,
        .max_anisotropy = 0,
        .compare_enable = .false,
        .compare_op = .always,
        .min_lod = 0,
        .max_lod = vk.LOD_CLAMP_NONE,
        .border_color = .float_transparent_black,
        .unnormalized_coordinates = .false,
    });
    errdefer engine.destroySampler(sampler);

    const global_descriptor_set_layout = try engine.createDescriptorSetLayout(.{
        .bindings = &.{
            .{
                .binding = 0,
                .descriptor_type = .uniform_buffer,
                .descriptor_count = 1,
                .stage_flags = .{ .vertex_bit = true, .fragment_bit = true },
            },
            .{
                .binding = 1,
                .descriptor_type = .storage_buffer,
                .descriptor_count = 1,
                .stage_flags = .{ .vertex_bit = true, .fragment_bit = true },
            },
            .{
                .binding = 2,
                .descriptor_type = .storage_buffer,
                .descriptor_count = 1,
                .stage_flags = .{ .vertex_bit = true, .fragment_bit = true },
            },
            .{
                .binding = 3,
                .descriptor_type = .storage_buffer,
                .descriptor_count = 1,
                .stage_flags = .{ .vertex_bit = true, .fragment_bit = true },
            },
            .{
                .binding = 4,
                .descriptor_type = .sampler,
                .descriptor_count = 1,
                .stage_flags = .{ .vertex_bit = true, .fragment_bit = true },
                .immutable_samplers = &.{sampler},
            },
            .{
                .binding = 5,
                .descriptor_type = .sampled_image,
                .descriptor_count = max_textures,
                .stage_flags = .{ .vertex_bit = true, .fragment_bit = true },
                .flags = .{ .variable_descriptor_count_bit = true },
            },
        },
    });
    errdefer engine.destroyDescriptorSetLayout(global_descriptor_set_layout);
    engine.setObjectName(global_descriptor_set_layout, "DSL Global", .{});

    const per_batch_descriptor_set_layout = try engine.createDescriptorSetLayout(.{
        .bindings = &.{
            .{
                .binding = 0,
                .descriptor_type = .storage_buffer,
                .descriptor_count = 1,
                .stage_flags = .{ .vertex_bit = true, .fragment_bit = true },
            },
        },
    });
    errdefer engine.destroyDescriptorSetLayout(per_batch_descriptor_set_layout);
    engine.setObjectName(per_batch_descriptor_set_layout, "DSL PerBatch", .{});

    const pipeline_layout = try engine.createPipelineLayout(.{
        .set_layouts = &.{
            global_descriptor_set_layout,
            per_batch_descriptor_set_layout,
        },
    });
    errdefer engine.destroyPipelineLayout(pipeline_layout);
    engine.setObjectName(pipeline_layout, "PL", .{});

    const vertex_shader = try engine.createShaderModule(.{ .code = &shaders.main_vert_spv });
    defer engine.destroyShaderModule(vertex_shader);
    engine.setObjectName(vertex_shader, "SM main_vert", .{});

    const fragment_shader = try engine.createShaderModule(.{ .code = &shaders.main_frag_spv });
    defer engine.destroyShaderModule(fragment_shader);
    engine.setObjectName(fragment_shader, "SM main_frag", .{});

    var vertex_buffer = try shaders.VertexBuffer.init(engine, .{
        .usage = .vertex,
        .target_queue = .graphics,
        .array_capacity = 4,
        .name = "QuadVB",
    });
    errdefer vertex_buffer.deinit(engine);
    try vertex_buffer.write(engine, .{
        .elements = &.{
            .init(
                .init(-0.5, -0.5, 0),
                .init(0, 1),
                .init(0, 0, 1),
                .init(1, 0, 0, -1),
            ),
            .init(
                .init(0.5, -0.5, 0),
                .init(1, 1),
                .init(0, 0, 1),
                .init(1, 0, 0, -1),
            ),
            .init(
                .init(-0.5, 0.5, 0),
                .init(0, 0),
                .init(0, 0, 1),
                .init(1, 0, 0, -1),
            ),
            .init(
                .init(0.5, 0.5, 0),
                .init(1, 0),
                .init(0, 0, 1),
                .init(1, 0, 0, -1),
            ),
        },
    });

    var index_buffer = try shaders.IndexBuffer.init(engine, .{
        .usage = .index,
        .target_queue = .graphics,
        .array_capacity = 6,
        .name = "QuadIB",
    });
    errdefer index_buffer.deinit(engine);
    try index_buffer.write(engine, .{
        .elements = &.{ 0, 1, 2, 2, 1, 3 },
    });

    var global_uniforms = try shaders.GlobalUniformsBuffer.init(engine, .{
        .usage = .uniform,
        .target_queue = .graphics,
        .name = "GlobalUniforms",
    });
    errdefer global_uniforms.deinit(engine);

    var global_uniforms_staging_buffer = try StagingBuffer.init(engine, .{
        .capacity = @sizeOf(shaders.GlobalUniforms),
        .target_queue = .graphics,
    });
    errdefer global_uniforms_staging_buffer.deinit(engine);

    var global_uniforms_transfer_command_buffer: CommandBuffer = try .init(engine, .transfer, .persistent);
    errdefer global_uniforms_transfer_command_buffer.deinit(engine);

    try global_uniforms_transfer_command_buffer.beginCommandBuffer();
    global_uniforms_transfer_command_buffer.copyBuffer(
        global_uniforms_staging_buffer.buffer,
        global_uniforms.buffer,
        &.{
            .{
                .src_offset = 0,
                .dst_offset = 0,
                .size = @sizeOf(shaders.GlobalUniforms),
            },
        },
    );
    try global_uniforms_transfer_command_buffer.endCommandBuffer();

    const global_uniforms_transfer_semaphores = blk: {
        var semaphores: std.ArrayList(vk.Semaphore) = try .initCapacity(allocator, swapchain.swapchain_images.len);
        errdefer semaphores.deinit(allocator);

        errdefer for (semaphores.items) |x| engine.destroySemaphore(x);

        for (0..swapchain.swapchain_images.len) |i| {
            const semaphore = try engine.createSemaphore();
            engine.setObjectName(semaphore, "S Transfer[{d}]", .{i});
            semaphores.appendAssumeCapacity(semaphore);
        }

        break :blk try semaphores.toOwnedSlice(allocator);
    };
    errdefer {
        for (global_uniforms_transfer_semaphores) |semaphore| {
            engine.destroySemaphore(semaphore);
        }
        allocator.free(global_uniforms_transfer_semaphores);
    }

    var point_lights = try shaders.PointLightBuffer.init(engine, .{
        .usage = .storage,
        .target_queue = .graphics,
        .array_capacity = max_point_lights,
        .name = "PointLights",
    });
    errdefer point_lights.deinit(engine);

    var directional_lights = try shaders.DirectionalLightBuffer.init(engine, .{
        .usage = .storage,
        .target_queue = .graphics,
        .array_capacity = max_directional_lights,
        .name = "DirectionalLights",
    });
    errdefer directional_lights.deinit(engine);

    const pipeline = try engine.createGraphicsPipeline(.{
        .stages = &.{
            .{
                .stage = .{ .vertex_bit = true },
                .module = vertex_shader,
                .name = "main",
            },
            .{
                .stage = .{ .fragment_bit = true },
                .module = fragment_shader,
                .name = "main",
            },
        },
        .vertex_input_state = .{
            .vertex_binding_descriptions = &.{
                .{
                    .binding = 0,
                    .stride = @sizeOf(shaders.Vertex),
                    .input_rate = .vertex,
                },
            },
            .vertex_attribute_descriptions = &.{
                .{
                    .location = 0,
                    .binding = 0,
                    .format = .r32g32b32_sfloat,
                    .offset = @offsetOf(shaders.Vertex, "positionOS"),
                },
                .{
                    .location = 1,
                    .binding = 0,
                    .format = .r16g16_unorm,
                    .offset = @offsetOf(shaders.Vertex, "texCoord"),
                },
                .{
                    .location = 2,
                    .binding = 0,
                    .format = .r8g8b8_snorm,
                    .offset = @offsetOf(shaders.Vertex, "normalOS"),
                },
                .{
                    .location = 3,
                    .binding = 0,
                    .format = .r8g8b8a8_snorm,
                    .offset = @offsetOf(shaders.Vertex, "tangentOS"),
                },
            },
        },
        .input_assembly_state = .{
            .topology = .triangle_list,
            .primitive_restart_enable = .false,
        },
        .viewport_state = .{
            .viewports = &.{undefined}, // dynamic
            .scissors = &.{undefined}, // dynamic
        },
        .rasterization_state = .{
            .depth_clamp_enable = .false,
            .rasterizer_discard_enable = .false,
            .polygon_mode = .fill,
            .cull_mode = .{ .back_bit = true },
            .front_face = .counter_clockwise,
            .depth_bias_enable = .false,
            .depth_bias_constant_factor = 0,
            .depth_bias_clamp = 0,
            .depth_bias_slope_factor = 0,
            .line_width = 1,
        },
        .multisample_state = .{
            .rasterization_samples = .{ .@"1_bit" = true },
            .sample_shading_enable = .false,
            .min_sample_shading = 1,
            .alpha_to_coverage_enable = .false,
            .alpha_to_one_enable = .false,
        },
        .depth_stencil_state = .{
            .depth_test_enable = .true,
            .depth_write_enable = .true,
            .depth_compare_op = .greater,
            .depth_bounds_test_enable = .false,
            .stencil_test_enable = .false,
            .front = undefined,
            .back = undefined,
            .min_depth_bounds = 0,
            .max_depth_bounds = 1,
        },
        .color_blend_state = .{
            .logic_op_enable = .false,
            .logic_op = .copy,
            .attachments = &.{
                .{
                    .blend_enable = .false,
                    .src_color_blend_factor = .one,
                    .dst_color_blend_factor = .zero,
                    .color_blend_op = .add,
                    .src_alpha_blend_factor = .one,
                    .dst_alpha_blend_factor = .zero,
                    .alpha_blend_op = .add,
                    .color_write_mask = .{
                        .r_bit = true,
                        .g_bit = true,
                        .b_bit = true,
                        .a_bit = true,
                    },
                },
            },
            .blend_constants = .{ 0, 0, 0, 0 },
        },
        .dynamic_state = .{
            .dynamic_states = &.{ .viewport, .scissor },
        },
        .layout = pipeline_layout,
        .render_pass = swapchain.render_pass,
        .subpass = 0,
    });
    errdefer engine.destroyPipeline(pipeline);
    engine.setObjectName(pipeline, "P", .{});

    const descriptor_pool = try engine.createDescriptorPool(.{
        .max_sets = 1 + chunk_descriptor_pool,
        .pool_sizes = &.{
            .{
                .type = .sampler,
                .descriptor_count = 1,
            },
            .{
                .type = .sampled_image,
                .descriptor_count = max_textures,
            },
            .{
                .type = .uniform_buffer,
                .descriptor_count = 1,
            },
            .{
                .type = .storage_buffer,
                .descriptor_count = 3 + chunk_descriptor_pool,
            },
        },
    });
    errdefer engine.destroyDescriptorPool(descriptor_pool);
    engine.setObjectName(descriptor_pool, "DP", .{});

    const global_descriptor_set = try engine.allocateDescriptorSet(.{
        .descriptor_pool = descriptor_pool,
        .set_layout = global_descriptor_set_layout,
        .variable_descriptor_count = @intCast(textures.array.items.len),
    });
    engine.setObjectName(global_descriptor_set, "DS Global", .{});

    const block_grass = try blocks.getOrLoad(engine, &materials, &textures, "Grass.json", allocator);
    const block_dirt = try blocks.getOrLoad(engine, &materials, &textures, "Dirt.json", allocator);
    const block_stone = try blocks.getOrLoad(engine, &materials, &textures, "Stone.json", allocator);
    const block_bedrock = try blocks.getOrLoad(engine, &materials, &textures, "Bedrock.json", allocator);

    // VOLATILE Load all assets before this point

    const descriptor_images = try allocator.alloc(vk.DescriptorImageInfo, textures.array.items.len);
    for (textures.array.items, descriptor_images) |texture, *info| {
        info.* = .{
            .sampler = .null_handle,
            .image_view = texture.image_view,
            .image_layout = .shader_read_only_optimal,
        };
    }
    defer allocator.free(descriptor_images);

    try engine.updateDescriptorSets(.{
        .writes = &.{
            .{
                .dst_set = global_descriptor_set,
                .dst_binding = 0,
                .dst_array_element = 0,
                .descriptor_type = .uniform_buffer,
                .descriptor_infos = .{
                    .buffer = &.{
                        .{
                            .buffer = global_uniforms.buffer,
                            .offset = 0,
                            .range = vk.WHOLE_SIZE,
                        },
                    },
                },
            },
            .{
                .dst_set = global_descriptor_set,
                .dst_binding = 1,
                .dst_array_element = 0,
                .descriptor_type = .storage_buffer,
                .descriptor_infos = .{
                    .buffer = &.{
                        .{
                            .buffer = point_lights.buffer,
                            .offset = 0,
                            .range = vk.WHOLE_SIZE,
                        },
                    },
                },
            },
            .{
                .dst_set = global_descriptor_set,
                .dst_binding = 2,
                .dst_array_element = 0,
                .descriptor_type = .storage_buffer,
                .descriptor_infos = .{
                    .buffer = &.{
                        .{
                            .buffer = directional_lights.buffer,
                            .offset = 0,
                            .range = vk.WHOLE_SIZE,
                        },
                    },
                },
            },
            .{
                .dst_set = global_descriptor_set,
                .dst_binding = 3,
                .dst_array_element = 0,
                .descriptor_type = .storage_buffer,
                .descriptor_infos = .{
                    .buffer = &.{
                        .{
                            .buffer = materials.material_buffer.buffer,
                            .offset = 0,
                            .range = vk.WHOLE_SIZE,
                        },
                    },
                },
            },
            .{
                .dst_set = global_descriptor_set,
                .dst_binding = 5,
                .dst_array_element = 0,
                .descriptor_type = .sampled_image,
                .descriptor_infos = .{ .image = descriptor_images },
            },
        },
    });

    var chunks: std.AutoHashMapUnmanaged([3]i16, Chunk) = .empty;
    errdefer {
        var it = chunks.valueIterator();
        while (it.next()) |chunk| {
            chunk.deinit(engine, descriptor_pool);
        }
        chunks.deinit(allocator);
    }

    const world_seed = engine.random.int(u64);
    std.log.info("Using world seed 0x{x:0<16}", .{world_seed});
    var it = Iterator2(i16).init(.{
        .min = .{ -8, -8 },
        .max = .{ 7, 7 },
    });
    while (it.next()) |chunk_coords2| {
        const chunk_coords3 = chunk_coords2 ++ [_]i16{0};

        const origin = Vector3.init(
            @floatFromInt(chunk_coords3[0]),
            @floatFromInt(chunk_coords3[1]),
            @floatFromInt(chunk_coords3[2]),
        ).mulScalar(16);

        try chunks.ensureUnusedCapacity(allocator, 1);
        chunks.putAssumeCapacityNoClobber(
            chunk_coords3,
            try Chunk.init(engine, .{
                .origin = origin,
                .descriptor_pool = descriptor_pool,
                .per_batch_descriptor_set_layout = per_batch_descriptor_set_layout,
            }),
        );
        const chunk = chunks.getPtr(chunk_coords3).?;

        var y: usize = 0;
        while (y < 16) : (y += 1) {
            const fpos0 = Vector2x8.initScalars(
                .{ 0, 1, 2, 3, 4, 5, 6, 7 },
                @splat(@floatFromInt(y)),
            ).add(.initVector(origin.asVector2()));
            const fpos1 = Vector2x8.initScalars(
                .{ 8, 9, 10, 11, 12, 13, 14, 15 },
                @splat(@floatFromInt(y)),
            ).add(.initVector(origin.asVector2()));

            const iheight0 = worldgen.heightIv(world_seed, fpos0);
            const iheight1 = worldgen.heightIv(world_seed, fpos1);

            const iheightv: [16]i32 = @as([8]i32, iheight0) ++ @as([8]i32, iheight1);
            var x: usize = 0;
            while (x < 16) : (x += 1) {
                chunk.blocks[0][y][x] = block_bedrock;
                const iheight = iheightv[x];
                var i: i32 = 0;
                while (i < iheight) : (i += 1) {
                    const iz = i + 1;
                    const block = if (i + 1 == iheight)
                        block_grass
                    else if (i + 4 >= iheight)
                        block_dirt
                    else
                        block_stone;
                    chunk.blocks[@intCast(iz)][y][x] = block;
                }
            }
        }
    }

    const player_position = Vector3.init(0, 0, worldgen.heightF(world_seed, .zero) + 0.5);

    var chunk_it = chunks.iterator();
    while (chunk_it.next()) |entry| {
        const x, const y, const z = entry.key_ptr.*;
        const chunk = entry.value_ptr;
        try chunk.refresh(engine, &blocks, .{
            .positive_x = chunks.getPtr(.{ x + 1, y, z }),
            .negative_x = chunks.getPtr(.{ x - 1, y, z }),
            .positive_y = chunks.getPtr(.{ x, y + 1, z }),
            .negative_y = chunks.getPtr(.{ x, y - 1, z }),
            .positive_z = chunks.getPtr(.{ x, y, z + 1 }),
            .negative_z = chunks.getPtr(.{ x, y, z - 1 }),
        }, allocator);
    }

    const point_lights_data: []const shaders.PointLight = &.{};
    try point_lights.write(engine, .{
        .header = @intCast(point_lights_data.len),
        .elements = point_lights_data,
    });

    const directional_lights_data: []const shaders.DirectionalLight = &.{
        .{
            .directionWS = .{ 0, 0, -1 },
            .color = .{ 0.3, 0.3, 0.3 },
        },
    };
    try directional_lights.write(engine, .{
        .header = @intCast(directional_lights_data.len),
        .elements = directional_lights_data,
    });

    var skybox = try Skybox.load("skybox.hdr", engine, 512, global_uniforms.buffer, swapchain.render_pass, allocator);
    errdefer skybox.deinit(engine);

    return .{
        .allocator = allocator,
        .engine = engine,
        .swapchain = swapchain,
        .global_descriptor_set_layout = global_descriptor_set_layout,
        .per_batch_descriptor_set_layout = per_batch_descriptor_set_layout,
        .descriptor_pool = descriptor_pool,
        .global_descriptor_set = global_descriptor_set,
        .pipeline_layout = pipeline_layout,
        .pipeline = pipeline,

        .vertex_buffer = vertex_buffer,
        .index_buffer = index_buffer,

        .global_uniforms = global_uniforms,
        .global_uniforms_staging_buffer = global_uniforms_staging_buffer,
        .global_uniforms_transfer_command_buffer = global_uniforms_transfer_command_buffer,
        .global_uniforms_transfer_semaphores = global_uniforms_transfer_semaphores,
        .point_lights = point_lights,
        .directional_lights = directional_lights,
        .sampler = sampler,

        .blocks = blocks,
        .materials = materials,
        .textures = textures,
        .chunks = chunks,
        .skybox = skybox,

        .player = .init(player_position, 0, 0),
    };
}

pub fn deinit(self: *Game) void {
    std.log.scoped(.deinit).debug("Deinitializing {*}", .{self});

    self.vertex_buffer.deinit(self.engine);
    self.index_buffer.deinit(self.engine);

    var it = self.chunks.valueIterator();
    while (it.next()) |chunk| {
        chunk.deinit(self.engine, self.descriptor_pool);
    }
    self.chunks.deinit(self.allocator);
    self.skybox.deinit(self.engine);

    self.global_uniforms.deinit(self.engine);
    self.global_uniforms_staging_buffer.deinit(self.engine);
    self.global_uniforms_transfer_command_buffer.deinit(self.engine);
    self.point_lights.deinit(self.engine);
    self.directional_lights.deinit(self.engine);

    for (self.global_uniforms_transfer_semaphores) |semaphore| {
        self.engine.destroySemaphore(semaphore);
    }
    self.allocator.free(self.global_uniforms_transfer_semaphores);

    self.engine.destroyDescriptorPool(self.descriptor_pool);
    self.engine.destroySampler(self.sampler);
    self.engine.destroyPipeline(self.pipeline);
    self.engine.destroyPipelineLayout(self.pipeline_layout);
    self.engine.destroyDescriptorSetLayout(self.per_batch_descriptor_set_layout);
    self.engine.destroyDescriptorSetLayout(self.global_descriptor_set_layout);

    self.textures.deinit(self.engine, self.allocator);
    self.materials.deinit(self.engine, self.allocator);
    self.blocks.deinit(self.allocator);
    self.* = undefined;
}

pub fn update(self: *Game, dt: f32) void {
    self.player.update(dt);

    self.render() catch |err| {
        std.log.err("Failed to render: {s}", .{@errorName(err)});
        @panic("Frame update failed");
    };
}

pub fn onKeyDown(self: *Game, key: glfw.Key) void {
    self.player.onKeyDown(key);
}

pub fn onKeyUp(self: *Game, key: glfw.Key) void {
    self.player.onKeyUp(key);
}

pub fn onMouseMove(self: *Game, dx: f32, dy: f32) void {
    self.player.onMouseMove(dx, dy);
}

pub fn onMouseDown(self: *Game, button: glfw.MouseButton) void {
    _ = self;
    _ = button;
}

pub fn onMouseUp(self: *Game, button: glfw.MouseButton) void {
    _ = self;
    _ = button;
}

fn render(self: *Game) !void {
    const framebuffer_width, const framebuffer_height = blk: {
        const w, const h = self.engine.mode.surface.window.getFramebufferSize();
        break :blk [_]u32{ @intCast(w), @intCast(h) };
    };

    if (framebuffer_width == 0 or framebuffer_height == 0) {
        return;
    }

    if (framebuffer_width != self.swapchain.extent.width or framebuffer_height != self.swapchain.extent.height) {
        try self.recreateSwapchain();
    }

    if (self.swapchain.swapchain == .null_handle) {
        return;
    }

    self.swapchain.acquire(self.engine) catch |err| switch (err) {
        error.OutOfDateKHR => return self.recreateSwapchain(),
        else => return err,
    };

    const extent = self.swapchain.extent;

    const framebuffer_size = Vector2.init(
        @floatFromInt(extent.width),
        @floatFromInt(extent.height),
    );

    const camera_position = self.player.position.add(.init(0, 0, Player.camera_height));
    const camera_rotation = Quaternion.mulQuaternion(
        .initRotationXY(self.player.yaw_rad),
        .initRotationYZ(self.player.pitch_rad),
    );
    const camera_aspect_ratio = framebuffer_size.getX() / framebuffer_size.getY();
    const camera_yscale = 1.0 / @tan(0.5 * self.player.vertical_fov_deg * std.math.rad_per_deg);
    const camera_xscale = camera_yscale / camera_aspect_ratio;

    const matrix_ws_to_vs = Matrix4x4.mulMatrix(
        Matrix4x4.initRotation(camera_rotation.conjugate()),
        Matrix4x4.initTranslation(camera_position.negate()),
    );

    // zig fmt: off
    const matrix_vs_to_cs = Matrix4x4.init(
        camera_xscale,  0,             0,                 0,
        0,              0,             0,                 1,
        0,             -camera_yscale, 0,                 0,
        0,              0,             camera_near_plane, 0,
    );
    // zig fmt: on

    const ambient_light = Vector3.init(0.01, 0.01, 0.01);

    const global_uniforms_data: shaders.GlobalUniforms = .{
        .matrixWStoVS = matrix_ws_to_vs.asArray(),
        .matrixVStoCS = matrix_vs_to_cs.asArray(),
        .ambientLight = ambient_light.asArray(),
    };

    const staging_memory = try self.global_uniforms_staging_buffer.map(self.engine);
    @memcpy(staging_memory, std.mem.asBytes(&global_uniforms_data));
    self.global_uniforms_staging_buffer.unmap(self.engine);

    try self.global_uniforms_transfer_command_buffer.submit(self.engine, .{
        .signal_semaphores = &.{self.global_uniforms_transfer_semaphores[self.swapchain.image_index.?]},
    });

    var command_buffer: CommandBuffer = try .init(self.engine, .graphics, .transient);
    defer command_buffer.deinit(self.engine);

    try command_buffer.beginCommandBuffer();
    {
        command_buffer.beginRenderPass(.{
            .render_pass = self.swapchain.render_pass,
            .framebuffer = self.swapchain.swapchain_images[self.swapchain.image_index.?].framebuffer,
            .render_area = .{
                .offset = .{ .x = 0, .y = 0 },
                .extent = extent,
            },
            .clear_values = &.{
                .{
                    .color = .{
                        .float_32 = .{ 0, 0, 0, 0 },
                    },
                },
                .{
                    .depth_stencil = .{
                        .depth = 0,
                        .stencil = 0,
                    },
                },
            },
        }, .@"inline");
        defer command_buffer.endRenderPass();

        command_buffer.setViewport(0, &.{
            .{
                .x = 0,
                .y = 0,
                .width = @floatFromInt(extent.width),
                .height = @floatFromInt(extent.height),
                .min_depth = 0,
                .max_depth = 1,
            },
        });
        command_buffer.setScissor(0, &.{
            .{
                .offset = .{ .x = 0, .y = 0 },
                .extent = extent,
            },
        });

        command_buffer.bindPipeline(.graphics, self.pipeline);
        try command_buffer.bindVertexBuffers(0, &.{
            .{
                .buffer = self.vertex_buffer.buffer,
                .offset = 0,
            },
        });
        command_buffer.bindIndexBuffer(self.index_buffer.buffer, 0, .uint16);
        command_buffer.bindDescriptorSet(.graphics, self.pipeline_layout, 0, self.global_descriptor_set, null);

        var it = self.chunks.valueIterator();
        while (it.next()) |chunk| {
            chunk.draw(self.pipeline_layout, command_buffer);
        }

        try self.skybox.bind(command_buffer, extent);
        self.skybox.draw(command_buffer);
    }
    try command_buffer.endCommandBuffer();

    self.swapchain.present(self.engine, .{
        .command_buffer = command_buffer,
        .wait_semaphores = &.{
            .{
                .semaphore = self.global_uniforms_transfer_semaphores[self.swapchain.image_index.?],
                .stage_flags = .{ .vertex_shader_bit = true },
            },
        },
    }) catch |err| switch (err) {
        error.OutOfDateKHR => return self.recreateSwapchain(),
        else => return err,
    };
}

fn recreateSwapchain(self: *Game) !void {
    try self.swapchain.recreate(self.engine);
    for (self.global_uniforms_transfer_semaphores, 0..) |*semaphore, i| {
        self.engine.destroySemaphore(semaphore.*);
        semaphore.* = try self.engine.createSemaphore();
        self.engine.setObjectName(semaphore.*, "S Transfer[{d}]", .{i});
    }
}