No more staging buffer; generic buffer doubles as staging

src/Chunk.zig

@@ -1,6 +1,7 @@
 const Chunk = @This();
 const std = @import("std");
 
+const c = @import("const.zig");
 const ctx = @import("AppContext.zig");
 const math = @import("math.zig");
 const shaders = @import("shaders.zig");
@@ -15,9 +16,7 @@ const Game = @import("Game.zig");
 const GenericBuffer = @import("engine/GenericBuffer.zig").GenericBuffer;
 const Materials = @import("engine/Materials.zig");
 
-const ObjectUniformsBuffer = GenericBuffer(void, shaders.ObjectUniforms);
-
-pub const chunk_size = 16;
+const chunk_size = c.vx_per_ck;
 
 const initial_capacity = 256;
 var next_chunk_id: std.atomic.Value(u64) = .init(0);
@@ -27,7 +26,7 @@ var next_chunk_id: std.atomic.Value(u64) = .init(0);
 blocks: [chunk_size][chunk_size][chunk_size]Blocks.Id,
 origin: vm.Vector3,
 descriptor_set: vk.DescriptorSet,
-object_buffer: ObjectUniformsBuffer,
+object_buffer: shaders.ObjectUniformsBuffer,
 object_count: u32,
 
 /// For debug purposes, a unique "name" per chunk instance.
@@ -50,10 +49,10 @@ pub fn init(init_info: InitInfo) !Chunk {
     });
     errdefer engine.freeDescriptorSet(init_info.descriptor_pool, descriptor_set);
 
-    var object_buffer: ObjectUniformsBuffer = try .init(.{
+    var object_buffer: shaders.ObjectUniformsBuffer = try .init(.{
         .usage = .storage,
         .target_queue = .graphics,
-        .array_capacity = initial_capacity,
+        .capacity = initial_capacity,
     });
     errdefer object_buffer.deinit();
 
@@ -135,12 +134,12 @@ pub fn refresh(self: *Chunk, blocks: *const Blocks, neighbors: Neighbors) !void
     }
 
     const object_count: u32 = @intCast(uniforms.items.len);
-    if (self.object_buffer.array_capacity < object_count) {
+    if (self.object_buffer.capacity < object_count) {
         const desired_capacity = std.math.ceilPowerOfTwoAssert(u32, object_count);
-        const new_object_buffer: ObjectUniformsBuffer = try .init(.{
+        const new_object_buffer: shaders.ObjectUniformsBuffer = try .init(.{
             .usage = .storage,
             .target_queue = .graphics,
-            .array_capacity = desired_capacity,
+            .capacity = desired_capacity,
         });
 
         try engine.updateDescriptorSets(.{
@@ -169,7 +168,7 @@ pub fn refresh(self: *Chunk, blocks: *const Blocks, neighbors: Neighbors) !void
         engine.setObjectName(new_object_buffer.device_memory, "DM Chunk[{d}]", .{self.chunk_id});
     }
 
-    try self.object_buffer.write(.{ .elements = uniforms.items });
+    try self.object_buffer.writeSlice(uniforms.items);
     self.object_count = object_count;
 }
 

src/Game.zig

@@ -21,7 +21,6 @@ const Iterator2 = math.Iterator2;
 const Materials = @import("engine/Materials.zig");
 const Player = @import("Player.zig");
 const Skybox = @import("engine/Skybox.zig");
-const StagingBuffer = @import("engine/StagingBuffer.zig");
 const Swapchain = @import("engine/Swapchain.zig");
 const Texture = @import("engine/Texture.zig");
 const Textures = @import("engine/Textures.zig");
@@ -37,7 +36,8 @@ vertex_buffer: shaders.VertexBuffer,
 index_buffer: shaders.IndexBuffer,
 
 global_uniforms: shaders.GlobalUniformsBuffer,
-global_uniforms_staging_buffer: StagingBuffer,
+global_uniforms_staging_buffer: shaders.GlobalUniformsBuffer,
+global_uniforms_staging_ptr: *shaders.GlobalUniforms,
 global_uniforms_transfer_semaphores: []vk.Semaphore,
 point_lights: shaders.PointLightBuffer,
 directional_lights: shaders.DirectionalLightBuffer,
@@ -174,49 +174,45 @@ pub fn init() !Game {
     var vertex_buffer = try shaders.VertexBuffer.init(.{
         .usage = .vertex,
         .target_queue = .graphics,
-        .array_capacity = 4,
+        .capacity = 4,
         .name = "QuadVB",
     });
     errdefer vertex_buffer.deinit();
-    try vertex_buffer.write(.{
-        .elements = &.{
-            .init(
-                .init(0, 0, 0),
-                .init(0, 1),
-                .init(0, 0, 1),
-                .init(1, 0, 0, -1),
-            ),
-            .init(
-                .init(1, 0, 0),
-                .init(1, 1),
-                .init(0, 0, 1),
-                .init(1, 0, 0, -1),
-            ),
-            .init(
-                .init(0, 1, 0),
-                .init(0, 0),
-                .init(0, 0, 1),
-                .init(1, 0, 0, -1),
-            ),
-            .init(
-                .init(1, 1, 0),
-                .init(1, 0),
-                .init(0, 0, 1),
-                .init(1, 0, 0, -1),
-            ),
-        },
+    try vertex_buffer.writeSlice(&.{
+        .init(
+            .init(0, 0, 0),
+            .init(0, 1),
+            .init(0, 0, 1),
+            .init(1, 0, 0, -1),
+        ),
+        .init(
+            .init(1, 0, 0),
+            .init(1, 1),
+            .init(0, 0, 1),
+            .init(1, 0, 0, -1),
+        ),
+        .init(
+            .init(0, 1, 0),
+            .init(0, 0),
+            .init(0, 0, 1),
+            .init(1, 0, 0, -1),
+        ),
+        .init(
+            .init(1, 1, 0),
+            .init(1, 0),
+            .init(0, 0, 1),
+            .init(1, 0, 0, -1),
+        ),
     });
 
     var index_buffer = try shaders.IndexBuffer.init(.{
         .usage = .index,
         .target_queue = .graphics,
-        .array_capacity = 6,
+        .capacity = 6,
         .name = "QuadIB",
     });
     errdefer index_buffer.deinit();
-    try index_buffer.write(.{
-        .elements = &.{ 0, 1, 2, 2, 1, 3 },
-    });
+    try index_buffer.writeSlice(&.{ 0, 1, 2, 2, 1, 3 });
 
     var global_uniforms = try shaders.GlobalUniformsBuffer.init(.{
         .usage = .uniform,
@@ -225,12 +221,17 @@ pub fn init() !Game {
     });
     errdefer global_uniforms.deinit();
 
-    var global_uniforms_staging_buffer = try StagingBuffer.init(.{
-        .capacity = @sizeOf(shaders.GlobalUniforms),
+    var global_uniforms_staging_buffer = try shaders.GlobalUniformsBuffer.init(.{
+        .usage = .staging,
         .target_queue = .graphics,
+        .mappable = true,
+        .name = "GlobalUniforms Staging",
     });
     errdefer global_uniforms_staging_buffer.deinit();
 
+    const global_uniforms_staging_ptr = try global_uniforms_staging_buffer.map();
+    errdefer global_uniforms_staging_buffer.unmap();
+
     const global_uniforms_transfer_semaphores = blk: {
         var semaphores: std.ArrayList(vk.Semaphore) = try .initCapacity(allocator_general, swapchain.swapchain_images.len);
         errdefer semaphores.deinit(allocator_general);
@@ -255,7 +256,7 @@ pub fn init() !Game {
     var point_lights = try shaders.PointLightBuffer.init(.{
         .usage = .storage,
         .target_queue = .graphics,
-        .array_capacity = max_point_lights,
+        .capacity = max_point_lights,
         .name = "PointLights",
     });
     errdefer point_lights.deinit();
@@ -263,7 +264,7 @@ pub fn init() !Game {
     var directional_lights = try shaders.DirectionalLightBuffer.init(.{
         .usage = .storage,
         .target_queue = .graphics,
-        .array_capacity = max_directional_lights,
+        .capacity = max_directional_lights,
         .name = "DirectionalLights",
     });
     errdefer directional_lights.deinit();
@@ -620,8 +621,8 @@ pub fn init() !Game {
         });
     }
 
-    try point_lights.write(.{ .elements = &point_lights_data });
-    try directional_lights.write(.{ .elements = &directional_lights_data });
+    try point_lights.writeSlice(&point_lights_data);
+    try directional_lights.writeSlice(&directional_lights_data);
 
     var skybox = try Skybox.load("skybox.hdr", 512, global_uniforms.buffer);
     errdefer skybox.deinit();
@@ -748,6 +749,7 @@ pub fn init() !Game {
 
         .global_uniforms = global_uniforms,
         .global_uniforms_staging_buffer = global_uniforms_staging_buffer,
+        .global_uniforms_staging_ptr = global_uniforms_staging_ptr,
         .global_uniforms_transfer_semaphores = global_uniforms_transfer_semaphores,
         .point_lights = point_lights,
         .directional_lights = directional_lights,
@@ -780,6 +782,7 @@ pub fn deinit(self: *Game) void {
     self.skybox.deinit();
 
     self.global_uniforms.deinit();
+    self.global_uniforms_staging_buffer.unmap();
     self.global_uniforms_staging_buffer.deinit();
     self.point_lights.deinit();
     self.directional_lights.deinit();
@@ -905,7 +908,7 @@ fn render(self: *Game) !void {
 
     const ambient_light = vm.Vector3.init(0.01, 0.01, 0.01);
 
-    const global_uniforms_data: shaders.GlobalUniforms = .{
+    self.global_uniforms_staging_ptr.* = .{
         .matrixWStoVS = matrix_ws_to_vs,
         .matrixVStoCS = matrix_vs_to_cs,
         .matrixSSPXtoCS = matrix_sspx_to_cs,
@@ -914,10 +917,7 @@ fn render(self: *Game) !void {
         .directionalLightCount = directional_lights_data.len,
         .ambientLight = ambient_light,
     };
-
-    const staging_memory = try self.global_uniforms_staging_buffer.map();
-    @memcpy(staging_memory, std.mem.asBytes(&global_uniforms_data));
-    self.global_uniforms_staging_buffer.unmap();
+    try self.global_uniforms_staging_buffer.flush(0, 1);
 
     try self.deferred_command_buffers.ensureUnusedCapacity(allocator_general, 1);
     const global_uniforms_transfer_command_buffer = try CommandBuffer.init(.transfer);

src/engine/Font.zig

@@ -39,9 +39,9 @@ codepoint_glyph_id: std.hash_map.AutoHashMapUnmanaged(u21, u16),
 kerning_em: std.hash_map.AutoHashMapUnmanaged([2]u16, f32),
 cap_height_em: f32,
 
-glyph_data: GenericBuffer(void, shaders.GlyphData),
-control_points: GenericBuffer(void, [2]f16),
-band_data: GenericBuffer(void, u32),
+glyph_data: GenericBuffer(shaders.GlyphData),
+control_points: GenericBuffer([2]f16),
+band_data: GenericBuffer(u32),
 
 const BandHelper = struct {
     allocator: std.mem.Allocator,
@@ -394,39 +394,39 @@ pub fn init(ttf_buffer: []const u8, init_info: InitInfo) !Font {
 
     // std.debug.print("Kerning table size: {d}\n", .{kerning_em.size});
 
-    var glyph_data: GenericBuffer(void, shaders.GlyphData) = try .init(.{
+    var glyph_data: GenericBuffer(shaders.GlyphData) = try .init(.{
         .usage = .storage,
         .target_queue = .graphics,
-        .array_capacity = @intCast(gpu_glyph_data.items.len),
+        .capacity = @intCast(gpu_glyph_data.items.len),
         .name = "Glyph data",
     });
     errdefer glyph_data.deinit();
 
     // std.debug.print("Glyph data size: {d} [B]\n", .{gpu_glyph_data.items.len * @sizeOf(shaders.GlyphData)});
 
-    var control_points: GenericBuffer(void, [2]f16) = try .init(.{
+    var control_points: GenericBuffer([2]f16) = try .init(.{
         .usage = .storage,
         .target_queue = .graphics,
-        .array_capacity = @intCast(control_points_array.items.len),
+        .capacity = @intCast(control_points_array.items.len),
         .name = "Control points",
     });
     errdefer control_points.deinit();
 
     // std.debug.print("Control points size: {d} [B]\n", .{control_points_array.items.len * @sizeOf([2]f16)});
 
-    var band_data: GenericBuffer(void, u32) = try .init(.{
+    var band_data: GenericBuffer(u32) = try .init(.{
         .usage = .storage,
         .target_queue = .graphics,
-        .array_capacity = @intCast(band_data_array.items.len),
+        .capacity = @intCast(band_data_array.items.len),
         .name = "Band data",
     });
     errdefer band_data.deinit();
 
     // std.debug.print("Band data size: {d} [B]\n", .{band_data_array.items.len * @sizeOf(u32)});
 
-    try glyph_data.write(.{ .elements = gpu_glyph_data.items });
-    try control_points.write(.{ .elements = control_points_array.items });
-    try band_data.write(.{ .elements = band_data_array.items });
+    try glyph_data.writeSlice(gpu_glyph_data.items);
+    try control_points.writeSlice(control_points_array.items);
+    try band_data.writeSlice(band_data_array.items);
 
     return .{
         .cpu_glyph_data = cpu_glyph_data.toOwnedSliceAssert(),

src/engine/GenericBuffer.zig

@@ -5,7 +5,6 @@ const vk = @import("vulkan");
 
 const CommandBuffer = @import("CommandBuffer.zig");
 const Engine = @import("Engine.zig");
-const StagingBuffer = @import("StagingBuffer.zig");
 const TargetQueue = @import("TargetQueue.zig").TargetQueue;
 
 pub const Usage = enum {
@@ -14,6 +13,7 @@ pub const Usage = enum {
     index,
     vertex,
     indirect,
+    staging,
 
     pub fn asBufferUsageFlags(self: Usage) vk.BufferUsageFlags {
         return switch (self) {
@@ -22,6 +22,7 @@ pub const Usage = enum {
             .index => .{ .transfer_dst_bit = true, .index_buffer_bit = true },
             .vertex => .{ .transfer_dst_bit = true, .vertex_buffer_bit = true },
             .indirect => .{ .transfer_dst_bit = true, .indirect_buffer_bit = true },
+            .staging => .{ .transfer_src_bit = true },
         };
     }
 };
@@ -29,34 +30,27 @@ pub const Usage = enum {
 pub const InitInfo = struct {
     usage: Usage,
     target_queue: TargetQueue,
-    array_capacity: u32 = 0,
+    mappable: bool = false,
+    capacity: u32 = 1,
     name: ?[]const u8 = null,
 };
 
-pub fn GenericBuffer(comptime Header: type, comptime Element: type) type {
+pub fn GenericBuffer(comptime T: type) type {
     return struct {
         const Self = @This();
 
         buffer: vk.Buffer,
         device_memory: vk.DeviceMemory,
+        mappable: bool,
         target_queue: TargetQueue,
-        array_capacity: u32,
+        capacity: u32,
 
-        const header_size: u32 = @sizeOf(Header);
-        const element_size: u32 = @sizeOf(Element);
-        const array_offset: u32 = std.mem.alignForward(usize, header_size, @alignOf(Element));
-
-        pub const WriteInfo = struct {
-            header: ?Header = null,
-            element_offset: u32 = 0,
-            elements: []const Element = &.{},
-        };
+        const element_size: u32 = @sizeOf(T);
 
         pub fn init(init_info: InitInfo) !Self {
             const engine = ctx.engine;
 
-            const array_size = try std.math.mul(u32, init_info.array_capacity, element_size);
-            const size = try std.math.add(u32, array_offset, array_size);
+            const size = try std.math.mul(u32, init_info.capacity, element_size);
 
             const target_queue_family = switch (init_info.target_queue) {
                 .graphics => engine.graphics_queue.allocation.family,
@@ -71,14 +65,17 @@ pub fn GenericBuffer(comptime Header: type, comptime Element: type) type {
             });
             errdefer engine.destroyBuffer(buffer);
             if (init_info.name) |name| {
-                engine.setObjectName(buffer, "B {s} [{s}, {s}]", .{ name, @typeName(Header), @typeName(Element) });
+                engine.setObjectName(buffer, "B {s} [{s}]", .{ name, @typeName(T) });
             }
 
             const memory_requirements = engine.getBufferMemoryRequirements(buffer);
-            const device_memory = try engine.allocate(memory_requirements, .{ .device_local_bit = true });
+            const device_memory = try engine.allocate(memory_requirements, .{
+                .device_local_bit = !init_info.mappable,
+                .host_visible_bit = init_info.mappable,
+            });
             errdefer engine.freeMemory(device_memory);
             if (init_info.name) |name| {
-                engine.setObjectName(device_memory, "DM {s} [{s}, {s}]", .{ name, @typeName(Header), @typeName(Element) });
+                engine.setObjectName(device_memory, "DM {s} [{s}]", .{ name, @typeName(T) });
             }
 
             try engine.bindBufferMemory(buffer, device_memory, 0);
@@ -86,8 +83,9 @@ pub fn GenericBuffer(comptime Header: type, comptime Element: type) type {
             return .{
                 .buffer = buffer,
                 .device_memory = device_memory,
+                .mappable = init_info.mappable,
                 .target_queue = init_info.target_queue,
-                .array_capacity = init_info.array_capacity,
+                .capacity = init_info.capacity,
             };
         }
 
@@ -102,120 +100,130 @@ pub fn GenericBuffer(comptime Header: type, comptime Element: type) type {
             self.* = undefined;
         }
 
-        pub fn write(self: Self, write_info: WriteInfo) !void {
-            const engine = ctx.engine;
-
-            const element_count = std.math.cast(u32, write_info.elements.len) orelse return error.Overflow;
-            std.debug.assert(write_info.element_offset + element_count <= self.array_capacity);
-
-            const header_write_size: u32 = if (write_info.header != null) header_size else 0;
-            const array_write_size = element_count * element_size;
-            const array_write_offset: u32 = if (header_write_size > 0) array_offset else 0;
-            const write_size = array_write_offset + array_write_size;
-
-            if (write_size == 0) {
-                return;
-            }
-
-            var regions_buffer: [2]vk.BufferCopy = undefined;
-            var regions: std.ArrayList(vk.BufferCopy) = .initBuffer(&regions_buffer);
-
-            // One continuous write
-            if (header_write_size > 0 and array_write_size > 0 and write_info.element_offset == 0) {
-                regions.appendAssumeCapacity(.{
-                    .src_offset = 0,
-                    .dst_offset = 0,
-                    .size = write_size,
-                });
-            }
-            // Separate writes for header and array (if they exist)
-            else {
-                if (header_write_size > 0) {
-                    regions.appendAssumeCapacity(.{
-                        .src_offset = 0,
-                        .dst_offset = 0,
-                        .size = header_write_size,
-                    });
-                }
-                if (array_write_size > 0) {
-                    regions.appendAssumeCapacity(.{
-                        .src_offset = array_write_offset,
-                        .dst_offset = array_offset + write_info.element_offset * element_size,
-                        .size = array_write_size,
-                    });
-                }
-
-                std.debug.assert(regions.items.len > 0);
-            }
-
-            var staging_buffer: StagingBuffer = try .init(.{
-                .target_queue = self.target_queue,
-                .capacity = write_size,
-            });
-            defer staging_buffer.deinit();
-
-            const staging_memory = try staging_buffer.map();
-            if (write_info.header) |header| {
-                @memcpy(staging_memory[0..header_size], std.mem.asBytes(&header));
-            }
-            @memcpy(staging_memory[array_write_offset..write_size], std.mem.sliceAsBytes(write_info.elements));
-            staging_buffer.unmap();
-
-            var command_buffer: CommandBuffer = try .init(.transfer);
-            defer command_buffer.deinit();
-
-            try command_buffer.beginCommandBuffer();
-            command_buffer.copyBuffer(staging_buffer.buffer, self.buffer, regions.items);
-            try command_buffer.endCommandBuffer();
-
-            const fence = try engine.createFence(.{});
-            defer engine.destroyFence(fence);
-
-            try command_buffer.submit(.{ .fence = fence });
-            try engine.waitForFence(fence);
+        pub fn write(self: Self, value: T) !void {
+            return self.writeSliceAt(0, &.{value});
         }
 
-        pub fn writeRaw(self: Self, data_offset: u32, data: []const u8) !void {
+        pub fn writeAt(self: Self, index: u32, value: T) !void {
+            return self.writeSliceAt(index, &.{value});
+        }
+
+        pub fn writeSlice(self: Self, values: []const T) !void {
+            return self.writeSliceAt(0, values);
+        }
+
+        pub fn writeSliceAt(self: Self, first_index: u32, values: []const T) !void {
             const engine = ctx.engine;
 
-            const array_size = self.array_capacity * element_size;
-            const size = array_offset + array_size;
+            const element_count = std.math.cast(u32, values.len) orelse return error.Overflow;
+            std.debug.assert(first_index + element_count <= self.capacity);
 
-            const data_size = std.math.cast(u32, data.len) orelse return error.Overflow;
-            std.debug.assert(data_offset + data_size <= size);
+            const write_size = element_count * element_size;
+            if (element_count == 0) return;
 
-            var staging_buffer = try StagingBuffer.init(engine, .{
-                .target_queue = self.target_queue,
-                .capacity = data_size,
-            });
-            defer staging_buffer.deinit(engine);
+            if (self.mappable) {
+                const slice = try self.mapSliceAt(first_index, element_count);
+                defer self.unmap();
 
-            const staging_memory = try staging_buffer.map(engine);
-            @memcpy(staging_memory, data);
-            staging_buffer.unmap(engine);
+                @memcpy(slice, values);
+                try self.flush(first_index, element_count);
+            } else {
+                var staging_buffer: GenericBuffer(T) = try .init(.{
+                    .usage = .staging,
+                    .target_queue = self.target_queue,
+                    .mappable = true,
+                    .capacity = element_count,
+                });
+                defer staging_buffer.deinit();
 
-            var command_buffer = try CommandBuffer.init(engine, .transfer);
-            defer command_buffer.deinit(engine);
+                {
+                    const staging_slice = try staging_buffer.mapSlice();
+                    defer staging_buffer.unmap();
 
-            try command_buffer.beginCommandBuffer(.{});
-            command_buffer.copyBuffer(
-                staging_buffer.buffer,
-                self.buffer,
-                &.{
+                    @memcpy(staging_slice, values);
+                    try staging_buffer.flush(0, element_count);
+                }
+
+                var command_buffer: CommandBuffer = try .init(.transfer);
+                defer command_buffer.deinit();
+
+                try command_buffer.beginCommandBuffer();
+                const regions = [_]vk.BufferCopy{
                     .{
                         .src_offset = 0,
-                        .dst_offset = data_offset,
-                        .size = data_size,
+                        .dst_offset = first_index * element_size,
+                        .size = write_size,
                     },
+                };
+                command_buffer.copyBuffer(staging_buffer.buffer, self.buffer, &regions);
+                try command_buffer.endCommandBuffer();
+
+                const fence = try engine.createFence(.{});
+                defer engine.destroyFence(fence);
+
+                try command_buffer.submit(.{ .fence = fence });
+                try engine.waitForFence(fence);
+            }
+        }
+
+        pub fn map(self: Self) !*T {
+            std.debug.assert(self.mappable);
+
+            const slice = try self.mapSliceAt(0, 1);
+            return &slice[0];
+        }
+
+        pub fn mapAt(self: Self, index: u32) !*T {
+            std.debug.assert(self.mappable);
+
+            const slice = try self.mapSliceAt(index, 1);
+            return &slice[0];
+        }
+
+        pub fn mapSlice(self: Self) ![]T {
+            std.debug.assert(self.mappable);
+
+            return self.mapSliceAt(0, self.capacity);
+        }
+
+        pub fn mapSliceAt(self: Self, first_index: u32, count: u32) ![]T {
+            const engine = ctx.engine;
+
+            std.debug.assert(self.mappable);
+            std.debug.assert(first_index + count <= self.capacity);
+
+            const byte_offset = @as(u64, first_index) * @as(u64, element_size);
+            const byte_length = @as(u64, count) * @as(u64, element_size);
+
+            const mapped_memory = try engine.mapMemory(self.device_memory, byte_offset, byte_length, .{});
+            const slice = @as([*]T, @ptrCast(@alignCast(mapped_memory.ptr)))[0..count];
+
+            return slice;
+        }
+
+        pub fn flush(self: Self, first_index: u32, count: u32) !void {
+            const engine = ctx.engine;
+
+            std.debug.assert(self.mappable);
+            std.debug.assert(first_index + count <= self.capacity);
+
+            const byte_offset = @as(u64, first_index) * @as(u64, element_size);
+            const byte_length = @as(u64, count) * @as(u64, element_size);
+
+            try engine.device.flushMappedMemoryRanges(&.{
+                .{
+                    .memory = self.device_memory,
+                    .offset = byte_offset,
+                    .size = byte_length,
                 },
-            );
-            try command_buffer.endCommandBuffer();
+            });
+        }
 
-            const fence = try engine.createFence(.{});
-            defer engine.destroyFence(fence);
+        pub fn unmap(self: Self) void {
+            const engine = ctx.engine;
 
-            try command_buffer.submit(engine, .{ .fence = fence });
-            try engine.waitForFence(fence);
+            std.debug.assert(self.mappable);
+            engine.unmapMemory(self.device_memory);
         }
     };
 }

src/engine/Gui.zig

@@ -48,9 +48,9 @@ pub const Batch = struct {
     instance_count: u32,
 };
 
-box_gpu_buffer: GenericBuffer(void, Draw.Box),
-text_gpu_buffer: GenericBuffer(void, Draw.Text),
-image_gpu_buffer: GenericBuffer(void, Draw.Image),
+box_gpu_buffer: GenericBuffer(Draw.Box),
+text_gpu_buffer: GenericBuffer(Draw.Text),
+image_gpu_buffer: GenericBuffer(Draw.Image),
 
 box_cpu_buffer: std.ArrayList(Draw.Box),
 text_cpu_buffer: std.ArrayList(Draw.Text),
@@ -91,26 +91,26 @@ pub fn init() !*Gui {
 
     const gui = try allocator_persistent.create(Gui);
 
-    var box_gpu_buffer: GenericBuffer(void, Draw.Box) = try .init(.{
+    var box_gpu_buffer: GenericBuffer(Draw.Box) = try .init(.{
         .usage = .storage,
         .target_queue = .graphics,
-        .array_capacity = max_box_draws,
+        .capacity = max_box_draws,
         .name = "GUI box draws",
     });
     errdefer box_gpu_buffer.deinit();
 
-    var text_gpu_buffer: GenericBuffer(void, Draw.Text) = try .init(.{
+    var text_gpu_buffer: GenericBuffer(Draw.Text) = try .init(.{
         .usage = .storage,
         .target_queue = .graphics,
-        .array_capacity = max_text_draws,
+        .capacity = max_text_draws,
         .name = "GUI text draws",
     });
     errdefer text_gpu_buffer.deinit();
 
-    var image_gpu_buffer: GenericBuffer(void, Draw.Image) = try .init(.{
+    var image_gpu_buffer: GenericBuffer(Draw.Image) = try .init(.{
         .usage = .storage,
         .target_queue = .graphics,
-        .array_capacity = max_image_draws,
+        .capacity = max_image_draws,
         .name = "GUI image draws",
     });
     errdefer image_gpu_buffer.deinit();
@@ -123,13 +123,11 @@ pub fn init() !*Gui {
     var index_buffer = try shaders.IndexBuffer.init(.{
         .usage = .index,
         .target_queue = .graphics,
-        .array_capacity = 6,
+        .capacity = 6,
         .name = "QuadIB",
     });
     errdefer index_buffer.deinit();
-    try index_buffer.write(.{
-        .elements = &.{ 0, 1, 2, 2, 1, 3 },
-    });
+    try index_buffer.writeSlice(&.{ 0, 1, 2, 2, 1, 3 });
 
     const sampler = try engine.createSampler(.{
         .mag_filter = .linear,
@@ -842,9 +840,9 @@ fn extendOrAddBatch(self: *Gui, draw_type: std.meta.DeclEnum(Draw), instance: u3
 pub fn draw(self: *const Gui, command_buffer: CommandBuffer) !void {
     command_buffer.bindIndexBuffer(self.index_buffer.buffer, 0, .uint16);
 
-    try self.box_gpu_buffer.write(.{ .elements = self.box_cpu_buffer.items });
-    try self.text_gpu_buffer.write(.{ .elements = self.text_cpu_buffer.items });
-    try self.image_gpu_buffer.write(.{ .elements = self.image_cpu_buffer.items });
+    try self.box_gpu_buffer.writeSlice(self.box_cpu_buffer.items);
+    try self.text_gpu_buffer.writeSlice(self.text_cpu_buffer.items);
+    try self.image_gpu_buffer.writeSlice(self.image_cpu_buffer.items);
 
     for (self.batches.items) |batch| {
         switch (batch.draw_type) {

src/engine/Materials.zig

@@ -90,7 +90,7 @@ pub fn init() !*Materials {
     materials.material_buffer = try .init(.{
         .usage = .storage,
         .target_queue = .graphics,
-        .array_capacity = max_materials,
+        .capacity = max_materials,
         .name = "Materials",
     });
     errdefer materials.material_buffer.deinit();
@@ -114,11 +114,7 @@ pub fn init() !*Materials {
     };
 
     materials.array.appendSliceAssumeCapacity(&material_data);
-
-    try materials.material_buffer.write(.{
-        .element_offset = Id.empty.toInt(),
-        .elements = &material_data,
-    });
+    try materials.material_buffer.writeSlice(&material_data);
 
     std.debug.assert(materials.array.items.len == @typeInfo(Id).@"enum".fields.len);
     return materials;
@@ -314,26 +310,20 @@ fn loadMaterial(self: *Materials, filename: []const u8, index: u32) !shaders.Mat
         .allocate = .alloc_if_needed,
     });
 
-    const material_data = [_]shaders.Material{
-        .{
-            .base_color = .initArray(material_json.baseColor),
-            .emissive = .initArray(material_json.emissive),
-            .ior = material_json.ior,
-            .metallic = material_json.metallic,
-            .normal_scale = material_json.normalScale,
-            .occlusion_texture_strength = material_json.occlusionTextureStrength,
-            .roughness = material_json.roughness,
-            .base_color_texture = try textures.getOrLoad(material_json.baseColorTexture, .base_color),
-            .emissive_texture = try textures.getOrLoad(material_json.emissiveTexture, .emissive),
-            .normal_texture = try textures.getOrLoad(material_json.normalTexture, .normal),
-            .occlusion_roughness_metallic_texture = try textures.getOrLoad(material_json.occlusionRoughnessMetallicTexture, .occlusion_roughness_metallic),
-        },
+    const material_data: shaders.Material = .{
+        .base_color = .initArray(material_json.baseColor),
+        .emissive = .initArray(material_json.emissive),
+        .ior = material_json.ior,
+        .metallic = material_json.metallic,
+        .normal_scale = material_json.normalScale,
+        .occlusion_texture_strength = material_json.occlusionTextureStrength,
+        .roughness = material_json.roughness,
+        .base_color_texture = try textures.getOrLoad(material_json.baseColorTexture, .base_color),
+        .emissive_texture = try textures.getOrLoad(material_json.emissiveTexture, .emissive),
+        .normal_texture = try textures.getOrLoad(material_json.normalTexture, .normal),
+        .occlusion_roughness_metallic_texture = try textures.getOrLoad(material_json.occlusionRoughnessMetallicTexture, .occlusion_roughness_metallic),
     };
 
-    try self.material_buffer.write(.{
-        .element_offset = index,
-        .elements = &material_data,
-    });
-
-    return material_data[0];
+    try self.material_buffer.writeAt(index, material_data);
+    return material_data;
 }

src/engine/Skybox.zig

@@ -10,7 +10,6 @@ const vm = @import("vecmath");
 const CommandBuffer = @import("CommandBuffer.zig");
 const Engine = @import("Engine.zig");
 const GenericBuffer = @import("GenericBuffer.zig").GenericBuffer;
-const StagingBuffer = @import("StagingBuffer.zig");
 const Swapchain = @import("Swapchain.zig");
 const Texture = @import("Texture.zig");
 
@@ -18,7 +17,7 @@ image: vk.Image,
 image_view: vk.ImageView,
 device_memory: vk.DeviceMemory,
 
-vertex_buffer: GenericBuffer(void, vm.Vector3),
+vertex_buffer: GenericBuffer(vm.Vector3),
 index_buffer: shaders.IndexBuffer,
 sampler: vk.Sampler,
 
@@ -69,15 +68,21 @@ pub fn load(
 
     // --- LOAD IMAGE INTO STAGING BUFFER --------------------------------------
 
-    var staging_buffer = try StagingBuffer.init(.{
-        .capacity = @intCast(img.width * img.height * @sizeOf(vm.ColorHdr)),
+    var staging_buffer = try GenericBuffer(vm.ColorHdr).init(.{
+        .usage = .staging,
         .target_queue = .compute,
+        .mappable = true,
+        .capacity = img.width * img.height,
     });
     defer staging_buffer.deinit();
 
-    const staging_memory = try staging_buffer.map();
-    @memcpy(staging_memory, @as([*]const u8, @ptrCast(img.data)));
-    staging_buffer.unmap();
+    {
+        const staging_memory = try staging_buffer.mapSlice();
+        defer staging_buffer.unmap();
+
+        @memcpy(staging_memory, img.data);
+        try staging_buffer.flush(0, img.width * img.height);
+    }
 
     // --- CREATE EQUIRECTANGULAR IMAGE ----------------------------------------
 
@@ -495,10 +500,10 @@ pub fn load(
 
     // --- SKYBOX PIPELINE -----------------------------------------------------
 
-    var vertex_buffer = try GenericBuffer(void, vm.Vector3).init(.{
+    var vertex_buffer = try GenericBuffer(vm.Vector3).init(.{
         .usage = .vertex,
         .target_queue = .graphics,
-        .array_capacity = 8,
+        .capacity = 8,
     });
     errdefer vertex_buffer.deinit();
 
@@ -510,47 +515,43 @@ pub fn load(
     // ┃╱   ┃╱    │╱
     // 0━━━━1     O────X
 
-    try vertex_buffer.write(.{
-        .elements = &.{
-            .init(-1, -1, -1),
-            .init(1, -1, -1),
-            .init(-1, 1, -1),
-            .init(1, 1, -1),
-            .init(-1, -1, 1),
-            .init(1, -1, 1),
-            .init(-1, 1, 1),
-            .init(1, 1, 1),
-        },
+    try vertex_buffer.writeSlice(&.{
+        .init(-1, -1, -1),
+        .init(1, -1, -1),
+        .init(-1, 1, -1),
+        .init(1, 1, -1),
+        .init(-1, -1, 1),
+        .init(1, -1, 1),
+        .init(-1, 1, 1),
+        .init(1, 1, 1),
     });
 
-    var index_buffer = try GenericBuffer(void, u16).init(.{
+    var index_buffer: shaders.IndexBuffer = try .init(.{
         .usage = .index,
         .target_queue = .graphics,
-        .array_capacity = 36,
+        .capacity = 36,
     });
     errdefer index_buffer.deinit();
 
-    try index_buffer.write(.{
-        .elements = &.{
-            // Positive X
-            3, 1, 7,
-            7, 1, 5,
-            // Negative X
-            0, 2, 4,
-            4, 2, 6,
-            // Positive Y
-            2, 3, 6,
-            6, 3, 7,
-            // Negative Y
-            1, 0, 5,
-            5, 0, 4,
-            // Positive Z
-            6, 7, 4,
-            4, 7, 5,
-            // Negative Z
-            0, 1, 2,
-            2, 1, 3,
-        },
+    try index_buffer.writeSlice(&.{
+        // Positive X
+        3, 1, 7,
+        7, 1, 5,
+        // Negative X
+        0, 2, 4,
+        4, 2, 6,
+        // Positive Y
+        2, 3, 6,
+        6, 3, 7,
+        // Negative Y
+        1, 0, 5,
+        5, 0, 4,
+        // Positive Z
+        6, 7, 4,
+        4, 7, 5,
+        // Negative Z
+        0, 1, 2,
+        2, 1, 3,
     });
 
     const descriptor_set_layout = try engine.createDescriptorSetLayout(.{

src/engine/StagingBuffer.zig

@@ -1,83 +0,0 @@
-const StagingBuffer = @This();
-const std = @import("std");
-
-const ctx = @import("../AppContext.zig");
-const vk = @import("vulkan");
-
-const Engine = @import("Engine.zig");
-const TargetQueue = @import("TargetQueue.zig").TargetQueue;
-
-buffer: vk.Buffer,
-device_memory: vk.DeviceMemory,
-capacity: u32,
-
-pub const InitInfo = struct {
-    target_queue: TargetQueue,
-    capacity: u32,
-};
-
-pub fn init(init_info: InitInfo) !StagingBuffer {
-    const engine = ctx.engine;
-
-    const target_queue_family = switch (init_info.target_queue) {
-        .graphics => engine.graphics_queue.allocation.family,
-        .compute => engine.compute_queue.allocation.family,
-    };
-    const transfer_queue_family = engine.transfer_queue.allocation.family;
-
-    const buffer = try engine.createBuffer(.{
-        .size = init_info.capacity,
-        .usage = .{
-            .transfer_src_bit = true,
-        },
-        .queue_family_indices = &.{ target_queue_family, transfer_queue_family },
-    });
-    errdefer engine.destroyBuffer(buffer);
-
-    const memory_requirements = engine.getBufferMemoryRequirements(buffer);
-    const device_memory = try engine.allocate(
-        memory_requirements,
-        .{
-            .host_visible_bit = true,
-            .host_coherent_bit = true,
-        },
-    );
-    errdefer engine.freeMemory(device_memory);
-
-    try engine.bindBufferMemory(buffer, device_memory, 0);
-
-    return .{
-        .buffer = buffer,
-        .device_memory = device_memory,
-        .capacity = init_info.capacity,
-    };
-}
-
-pub fn deinit(self: *StagingBuffer) void {
-    const engine = ctx.engine;
-
-    std.log.scoped(.deinit).debug("Deinitializing {*}", .{self});
-
-    engine.freeMemory(self.device_memory);
-    engine.destroyBuffer(self.buffer);
-
-    self.* = undefined;
-}
-
-pub fn map(self: StagingBuffer) ![]u8 {
-    const mapped_memory = try self.mapPartial(0, self.capacity);
-    return mapped_memory;
-}
-
-pub fn mapPartial(self: StagingBuffer, offset: u32, len: u32) ![]u8 {
-    const engine = ctx.engine;
-
-    const mapped_memory = try engine.mapMemory(self.device_memory, offset, len, .{});
-    return mapped_memory;
-}
-
-pub fn unmap(self: StagingBuffer) void {
-    const engine = ctx.engine;
-
-    engine.unmapMemory(self.device_memory);
-}

src/engine/Texture.zig

@@ -7,7 +7,7 @@ const vk = @import("vulkan");
 const CommandBuffer = @import("CommandBuffer.zig");
 const DeviceAllocation = @import("DeviceAllocation.zig");
 const Engine = @import("Engine.zig");
-const StagingBuffer = @import("StagingBuffer.zig");
+const GenericBuffer = @import("GenericBuffer.zig").GenericBuffer;
 const TargetQueue = @import("TargetQueue.zig").TargetQueue;
 
 pub const Usage = enum {
@@ -207,15 +207,21 @@ pub fn writeRaw(self: Texture, data: []const u8) !void {
     std.debug.assert(data.len == byte_length);
     std.debug.assert(self.usage != .depth);
 
-    var staging_buffer = try StagingBuffer.init(.{
-        .capacity = @intCast(byte_length),
+    var staging_buffer = try GenericBuffer(u8).init(.{
+        .usage = .staging,
         .target_queue = self.target_queue,
+        .mappable = true,
+        .capacity = @intCast(byte_length),
     });
     defer staging_buffer.deinit();
 
-    const staging_memory = try staging_buffer.map();
-    @memcpy(staging_memory, data);
-    staging_buffer.unmap();
+    {
+        const staging_memory = try staging_buffer.mapSlice();
+        defer staging_buffer.unmap();
+
+        @memcpy(staging_memory, data);
+        try staging_buffer.flush(0, byte_length);
+    }
 
     // --- TRANSITION TO TRANSFER_DST_OPTIMAL AND COPY -----------------
 

src/shaders.zig

@@ -5,13 +5,13 @@ const Materials = @import("engine/Materials.zig");
 const GenericBuffer = @import("engine/GenericBuffer.zig").GenericBuffer;
 const Textures = @import("engine/Textures.zig");
 
-pub const VertexBuffer = GenericBuffer(void, Vertex);
-pub const IndexBuffer = GenericBuffer(void, Index);
-pub const GlobalUniformsBuffer = GenericBuffer(GlobalUniforms, void);
-pub const PointLightBuffer = GenericBuffer(void, PointLight);
-pub const DirectionalLightBuffer = GenericBuffer(void, DirectionalLight);
-pub const MaterialBuffer = GenericBuffer(void, Material);
-pub const ObjectUniformsBuffer = GenericBuffer(void, ObjectUniforms);
+pub const VertexBuffer = GenericBuffer(Vertex);
+pub const IndexBuffer = GenericBuffer(Index);
+pub const GlobalUniformsBuffer = GenericBuffer(GlobalUniforms);
+pub const PointLightBuffer = GenericBuffer(PointLight);
+pub const DirectionalLightBuffer = GenericBuffer(DirectionalLight);
+pub const MaterialBuffer = GenericBuffer(Material);
+pub const ObjectUniformsBuffer = GenericBuffer(ObjectUniforms);
 
 pub const Vertex = extern struct {
     positionOS: vm.Vector3,