path: root/src/scene.zig

const std = @import("std");
const mem = std.mem;
const Allocator = mem.Allocator;
const dg = @import("diligent");
const glm = @import("glm");
const graphics = @import("graphics.zig");
usingnamespace @import("xrvk.zig");
const math = @import("math.zig");

const geometry_source =
    \\layout(triangles, invocations = 2) in;
    \\layout(max_vertices = 3, triangle_strip) out;
    \\
    \\struct ViewUBO {
    \\    mat4 projection;
    \\    mat4 modelview;
    \\};
    \\
    \\layout(binding = 0) uniform Views {
    \\    ViewUBO views[2];
    \\};
    \\
    \\layout(location = 0) in vec3 in_WorldPos[3];
    \\layout(location = 1) in vec3 in_Normal[3];
    \\layout(location = 2) in vec2 in_UV0[3];
    \\layout(location = 3) in vec2 in_UV1[3];
    \\layout(location = 0) out vec3 out_WorldPos;
    \\layout(location = 1) out vec3 out_Normal;
    \\layout(location = 2) out vec2 out_UV0;
    \\layout(location = 3) out vec2 out_UV1;
    \\
    \\void main() {
    \\    for (int i = 0; i < 3; i++) {
    \\        vec4 worldPos = views[gl_InvocationID].modelview * gl_in[i].gl_Position;
    \\        gl_Position = views[gl_InvocationID].projection * worldPos;
    \\        gl_ViewportIndex = int(gl_InvocationID);
    \\        out_WorldPos = in_WorldPos[i];
    \\        out_Normal = in_Normal[i];
    \\        out_UV0 = in_UV0[i];
    \\        out_UV1 = in_UV1[i];
    \\        EmitVertex();
    \\    }
    \\    EndPrimitive();
    \\}
;

const CameraAttribs = packed struct {
    position: glm.Vec4 = glm.Vec4.zeroes(), // camera world position
    viewport_size: glm.Vec4, // (width, height, 1/width, 1/height)
    viewport_origin: glm.Vec2 = glm.Vec2.zeroes(), // (min_x, min_y)
    z_near: f32 = 1,
    z_far: f32 = 1000,

    view: glm.Mat4 = glm.Mat4.IDENTITY,
    proj: glm.Mat4 = glm.Mat4.IDENTITY,
    viewproj: glm.Mat4 = glm.Mat4.IDENTITY,
    view_inv: glm.Mat4 = glm.Mat4.IDENTITY,
    proj_inv: glm.Mat4 = glm.Mat4.IDENTITY,
    viewproj_inv: glm.Mat4 = glm.Mat4.IDENTITY,

    extra_data: [5 * 4]f32 = undefined,

    pub fn init(vp: dg.Viewport, view: glm.Mat4, proj: glm.Mat4) CameraAttribs {
        var viewproj = view.mul(proj);

        return .{
            .viewport_size = glm.Vec4.init([_]f32{ vp.Width, vp.Height, 1 / vp.Width, 1 / vp.Height }),

            .view = view,
            .proj = proj,
            .viewproj = viewproj,
            .view_inv = view.invert() orelse unreachable,
            .proj_inv = proj.invert() orelse unreachable,
            .viewproj_inv = viewproj.invert() orelse unreachable,
        };
    }

    pub fn initFake(vp: dg.Viewport, position: glm.Vec4) CameraAttribs {
        return .{
            .position = position,
            .viewport_size = glm.Vec4.init([_]f32{ vp.Width, vp.Height, 1 / vp.Width, 1 / vp.Height }),
        };
    }
};

const CascadeAttribs = packed struct {
    light_space_scale: glm.Vec4,
    light_space_scaled_bias: glm.Vec4,
    start_end_z: glm.Vec4,
    margin_proj_space: glm.Vec4,
};

const ShadowMapAttribs = packed struct {
    world_to_light: glm.Mat4 = glm.Mat4.IDENTITY, // transform from view space to light projection space

    cascades: [8]CascadeAttribs = undefined,
    world_to_shadow_map_uv_depth: [8]glm.Mat4 = undefined,
    cascade_cam_space_zend: [8]f32 = [_]f32{0} ** 8,

    shadow_map_dim: glm.Vec4 = undefined, // width, height, 1/width, 1/height

    num_cascades_i: i32 = 0,
    num_cascades_f: f32 = 0,

    visualize_cascades: u32 = 0,
    visualize_shadowing: u32 = 0,

    receiver_plane_depth_bias_clamp: f32 = 10,
    fixed_depth_bias: f32 = 1e-5,
    cascade_transition_region: f32 = 0.1,
    max_anisotropy: i32 = 4,

    vsm_bias: f32 = 1e-4,
    vsm_light_bleeding_reduction: f32 = 0,
    evsm_positive_exponent: f32 = 40,
    evsm_negative_exponent: f32 = 5,

    is_32bit_evsm: u32 = 1,
    fixed_filter_size: i32 = 3,
    filter_world_size: f32 = 0,
    dummy: f32 = 0,
};

const LightAttribs = packed struct {
    direction: glm.Vec4 = glm.Vec4.init([_]f32{ 0, -1, 0, 0 }),
    ambient_light: glm.Vec4 = glm.Vec4.init([_]f32{ 0, 0, 0, 0 }),
    intensity: glm.Vec4 = glm.Vec4.init([_]f32{ 1, 1, 1, 1 }),

    shadow_attribs: ShadowMapAttribs = .{},
};

const defaultSampler = dg.SamplerDesc{
    ._DeviceObjectAttribs = .{ .Name = "Default Sampler" },
    .MinFilter = dg.FILTER_TYPE_LINEAR,
    .MagFilter = dg.FILTER_TYPE_LINEAR,
    .MipFilter = dg.FILTER_TYPE_LINEAR,

    .AddressU = dg.TEXTURE_ADDRESS_WRAP,
    .AddressV = dg.TEXTURE_ADDRESS_WRAP,
    .AddressW = dg.TEXTURE_ADDRESS_WRAP,

    .MipLODBias = 0,
    .MaxAnisotropy = 0,

    .ComparisonFunc = dg.COMPARISON_FUNC_NEVER,
    .BorderColor = [_]f32{ 0, 0, 0, 0 },

    .MinLOD = 0,
    .MaxLOD = 3.402823466e+38,
};

pub const Model = struct {
    model: dg.IGLTFModel_Wrapper,
    bindings: dg.GLTF_ModelResourceBindings,
    params: dg.GLTF_RenderInfo,

    node_indices: std.ArrayList(u32),
    node_transforms: std.ArrayList(Transform),

    const DEFAULT_PARAMS = dg.GLTF_RenderInfo{
        .ModelTransform = @bitCast([16]f32, glm.Mat4.IDENTITY),
        .AlphaModes = dg.ALPHA_MODE_FLAG_ALL,
        .DebugView = 0,
        .OcclusionStrength = 1,
        .EmissionScale = 1,
        .IBLScale = 1,
        .AverageLogLum = 0.3,
        .MiddleGray = 0.18,
        .WhitePoint = 3,
    };

    pub const Transform = extern struct {
        position: glm.Vec3,
        scale: glm.Vec3,
        rotation: glm.Vec4,
        matrix: glm.Mat4,
    };

    pub fn initMemory(allocator: *Allocator, scene: *const Scene, data: []const u8) Model {
        const model = dg.Diligent_IGLTFModel_Create(
            @ptrCast(*dg.IRenderDevice, scene.dev.ptr),
            scene.ctx.ptr,
            &dg.IGLTFModelCreateInfo{
                .FileName = null,
                .Data = data.ptr,
                .DataSize = data.len,
                .FileType = ._BINARY,
                .pTextureCache = null,
                .pCacheInfo = null,
                .LoadAnimationAndSkin = true,
            },
        );

        return .{
            .model = dg.IGLTFModel_Wrapper.wrap(model),
            .bindings = scene.renderer.CreateResourceBindings(
                model,
                scene.camera_ubo.ptr,
                scene.light_ubo.ptr,
            ),
            .params = DEFAULT_PARAMS,

            .node_indices = std.ArrayList(u32).init(allocator),
            .node_transforms = std.ArrayList(Transform).init(allocator),
        };
    }

    pub fn initFile(allocator: *Allocator, scene: *const Scene, path: [:0]const u8) Model {
        const model = dg.Diligent_IGLTFModel_Create(
            @ptrCast(*dg.IRenderDevice, scene.dev.ptr),
            scene.ctx.ptr,
            &dg.IGLTFModelCreateInfo{
                .FileName = path.ptr,
                .Data = null,
                .DataSize = 0,
                .FileType = ._UNKNOWN,
                .pTextureCache = null,
                .pCacheInfo = null,
                .LoadAnimationAndSkin = true,
            },
        );

        return .{
            .model = dg.IGLTFModel_Wrapper.wrap(model),
            .bindings = scene.renderer.CreateResourceBindings(
                model,
                scene.camera_ubo.ptr,
                scene.light_ubo.ptr,
            ),
            .params = DEFAULT_PARAMS,

            .node_indices = std.ArrayList(u32).init(allocator),
            .node_transforms = std.ArrayList(Transform).init(allocator),
        };
    }

    pub fn deinit(self: *Model) void {
        self.bindings.Release();
        self.model.Release();
        self.node_transforms.deinit();
        self.node_indices.deinit();
    }

    pub fn setTransform(self: *Model, mat: glm.Mat4) void {
        self.params.ModelTransform = @bitCast([16]f32, mat);
    }

    pub fn draw(self: *Model, scene: *Scene) void {
        scene.renderer.Render(
            scene.ctx.ptr,
            self.model.ptr,
            &self.params,
            &self.bindings,
            null,
            scene.resource_binding.ptr,
        );
    }

    pub fn loadNodeTransform(self: *Model, name: [:0]const u8) !void {
        var index: u32 = undefined;
        if (self.model.GetNodeIndex(name.ptr, &index)) {
            try self.node_indices.append(index);
            const transform = try self.node_transforms.addOne();
            const ptr = @intToPtr(?*dg.GLTF_Transform, @ptrToInt(transform));
            self.model.GetNodeTransform(index, ptr);
        } else {
            return error.NodeNotFound;
        }
    }

    pub fn flushTransforms(self: *Model) void {
        for (self.node_indices.items) |index, i| {
            const ptr = @intToPtr(?*dg.GLTF_Transform, @ptrToInt(&self.node_transforms.items[i]));
            self.model.SetNodeTransform(index, ptr);
        }
        self.model.UpdateTransforms();
    }
};

pub const Scene = struct {
    viewports: []dg.Viewport,
    scissors: []dg.Rect,

    resource_binding: dg.IShaderResourceBinding_Wrapper,
    camera_ubo: dg.IBuffer_Wrapper,
    light_ubo: dg.IBuffer_Wrapper,
    views_ubo: dg.IBuffer_Wrapper,
    views: []ViewUBO,

    renderer: dg.IGLTF_PBR_Renderer_Wrapper,
    models: std.ArrayList(Model),
    envmap: ?*dg.ITextureView,

    ctx: dg.IDeviceContext_Wrapper,
    dev: dg.IRenderDeviceVk_Wrapper,
    swc: dg.ISwapChainVk_Wrapper,

    const ViewUBO = packed struct {
        projection: glm.Mat4,
        modelview: glm.Mat4,
    };

    pub fn init(gfx: *const graphics.Graphics) !Scene {
        const dev = gfx.dg_device;
        const swc = gfx.swapchain.dg_handle;

        var self: Scene = undefined;
        self.ctx = gfx.dg_ctx;
        self.dev = dev;
        self.swc = swc;

        self.viewports = try gfx.allocator.alloc(dg.Viewport, gfx.swapchain.image_rects.len);
        errdefer gfx.allocator.free(self.viewports);
        self.scissors = try gfx.allocator.alloc(dg.Rect, gfx.swapchain.image_rects.len);
        errdefer gfx.allocator.free(self.scissors);
        self.views = try gfx.allocator.alloc(ViewUBO, gfx.swapchain.image_rects.len);
        errdefer gfx.allocator.free(self.views);

        for (gfx.swapchain.image_rects) |rect, i| {
            self.viewports[i] = .{
                .TopLeftX = @intToFloat(f32, rect.offset.x),
                .TopLeftY = @intToFloat(f32, rect.offset.y),
                .Width = @intToFloat(f32, rect.extent.width),
                .Height = @intToFloat(f32, rect.extent.height),
                .MinDepth = 0,
                .MaxDepth = 1,
            };

            self.scissors[i] = .{
                .left = rect.offset.x,
                .right = rect.offset.x + rect.extent.width,
                .top = rect.offset.y,
                .bottom = rect.offset.y + rect.extent.height,
            };

            self.views[i] = .{
                .projection = glm.Mat4.IDENTITY,
                .modelview = glm.Mat4.IDENTITY,
            };
        }

        const geometry_shader = try self.createShader(
            "Geometry Shader",
            dg.SHADER_TYPE_GEOMETRY,
            dg.SHADER_SOURCE_LANGUAGE_GLSL,
            geometry_source,
        );

        // VR Geometry shader ting
        {
            self.views_ubo = try self.createBuffer(
                [2]ViewUBO,
                "View Uniform Buffer",
                null,
                dg.BIND_UNIFORM_BUFFER,
                dg.USAGE_DYNAMIC,
                dg.CPU_ACCESS_WRITE,
            );
            errdefer self.views_ubo.Release();

            var resource_signature: ?*dg.IPipelineResourceSignature = null;
            const ubo_resource = dg.PipelineResourceDesc{
                .Name = "Views",
                .ShaderStages = dg.SHADER_TYPE_GEOMETRY,
                .ArraySize = 1,
                .ResourceType = dg.SHADER_RESOURCE_TYPE_CONSTANT_BUFFER,
                .VarType = dg.SHADER_RESOURCE_VARIABLE_TYPE_STATIC,
                .Flags = 0,
            };
            self.dev.CreatePipelineResourceSignature(&dg.PipelineResourceSignatureDesc{
                ._DeviceObjectAttribs = .{ .Name = "Multiview Geometry Instancing Signature" },

                .Resources = &ubo_resource,
                .NumResources = 1,

                .ImmutableSamplers = null,
                .NumImmutableSamplers = 0,

                .BindingIndex = 1,
                .UseCombinedTextureSamplers = true,
                .CombinedSamplerSuffix = "_sampler",
                .SRBAllocationGranularity = 1,
            }, &resource_signature);
            const signature = dg.IPipelineResourceSignature_Wrapper.wrap(resource_signature);

            const shader_variable = signature.GetStaticVariableByName(dg.SHADER_TYPE_GEOMETRY, "Views");
            dg.IShaderResourceVariable_Wrapper.wrap(shader_variable).Set(@ptrCast(*dg.IDeviceObject, self.views_ubo.ptr));

            var resource_binding: ?*dg.IShaderResourceBinding = null;
            signature.CreateShaderResourceBinding(&resource_binding, true);
            self.resource_binding = dg.IShaderResourceBinding_Wrapper.wrap(resource_binding);
            errdefer self.resource_binding.Release();
        }

        // GLTF

        const renderer = dg.Diligent_IGLTF_PBR_Renderer_Create(
            @ptrCast(*dg.IRenderDevice, self.dev.ptr),
            self.ctx.ptr,
            &dg.GLTF_RendererCreateInfo{
                .RTVFmt = swc.GetDesc().*.ColorBufferFormat,
                .DSVFmt = swc.GetDesc().*.DepthBufferFormat,
                .FrontCCW = true,
                .AllowDebugView = false,
                .UseIBL = true,
                .UseAO = true,
                .UseEmissive = true,
                .UseImmutableSamplers = true,
                .UseTextureAtals = false,

                .ColorMapImmutableSampler = defaultSampler,
                .PhysDescMapImmutableSampler = defaultSampler,
                .NormalMapImmutableSampler = defaultSampler,
                .AOMapImmutableSampler = defaultSampler,
                .EmissiveMapImmutableSampler = defaultSampler,

                .MaxJointCount = 64,

                .pGS = geometry_shader,
            },
        );
        self.renderer = dg.IGLTF_PBR_Renderer_Wrapper.wrap(renderer);

        self.camera_ubo = try self.createBuffer(
            CameraAttribs,
            "Camera Uniform Buffer",
            null,
            dg.BIND_UNIFORM_BUFFER,
            dg.USAGE_DYNAMIC,
            dg.CPU_ACCESS_WRITE,
        );
        errdefer self.camera_ubo.Release();

        self.light_ubo = try self.createBuffer(
            LightAttribs,
            "Light Uniform Buffer",
            null,
            dg.BIND_UNIFORM_BUFFER,
            dg.USAGE_DYNAMIC,
            dg.CPU_ACCESS_WRITE,
        );
        errdefer self.camera_ubo.Release();

        const environment_map = try self.createTexture("Environment Map", "assets/papermill.ktx", dg.BIND_SHADER_RESOURCE, dg.USAGE_IMMUTABLE, 0);
        self.envmap = environment_map.GetDefaultView(dg.TEXTURE_VIEW_SHADER_RESOURCE);

        var barriers = [_]dg.StateTransitionDesc{
            .{
                .pResource = @ptrCast(*dg.IDeviceObject, self.camera_ubo.ptr),
                .FirstMipLevel = 0,
                .MipLevelsCount = dg.REMAINING_MIP_LEVELS,
                .FirstArraySlice = 0,
                .ArraySliceCount = dg.REMAINING_ARRAY_SLICES,
                .OldState = dg.RESOURCE_STATE_UNKNOWN,
                .NewState = dg.RESOURCE_STATE_CONSTANT_BUFFER,
                .TransitionType = dg.STATE_TRANSITION_TYPE_IMMEDIATE,
                .UpdateResourceState = true,
            },
            .{
                .pResource = @ptrCast(*dg.IDeviceObject, self.light_ubo.ptr),
                .FirstMipLevel = 0,
                .MipLevelsCount = dg.REMAINING_MIP_LEVELS,
                .FirstArraySlice = 0,
                .ArraySliceCount = dg.REMAINING_ARRAY_SLICES,
                .OldState = dg.RESOURCE_STATE_UNKNOWN,
                .NewState = dg.RESOURCE_STATE_CONSTANT_BUFFER,
                .TransitionType = dg.STATE_TRANSITION_TYPE_IMMEDIATE,
                .UpdateResourceState = true,
            },
            .{
                .pResource = @ptrCast(*dg.IDeviceObject, environment_map.ptr),
                .FirstMipLevel = 0,
                .MipLevelsCount = dg.REMAINING_MIP_LEVELS,
                .FirstArraySlice = 0,
                .ArraySliceCount = dg.REMAINING_ARRAY_SLICES,
                .OldState = dg.RESOURCE_STATE_UNKNOWN,
                .NewState = dg.RESOURCE_STATE_SHADER_RESOURCE,
                .TransitionType = dg.STATE_TRANSITION_TYPE_IMMEDIATE,
                .UpdateResourceState = true,
            },
        };
        self.ctx.TransitionResourceStates(barriers.len, &barriers);

        self.renderer.PrecomputeCubemaps(@ptrCast(*dg.IRenderDevice, self.dev.ptr), self.ctx.ptr, self.envmap);

        // model
        self.models = std.ArrayList(Model).init(gfx.allocator);

        return self;
    }

    pub fn deinit(self: *const Scene) void {
        self.views_ubo.Release();
        self.light_ubo.Release();
        self.camera_ubo.Release();

        for (self.models.items) |*model| {
            model.deinit();
        }
        self.models.deinit();
        self.renderer.Release();
        self.resource_binding.Release();

        self.gfx.allocator.free(self.viewports);
        self.gfx.allocator.free(self.scissors);
        self.gfx.allocator.free(self.views);
    }

    pub fn render(self: *Scene, views: []const xr.View) !void {
        // update uniform buffers
        for (self.views) |*view, i| {
            const fov = views[i].fov;
            const viewport = self.viewports[i];
            // const fovY = fov.angle_up - fov.angle_down;
            // const fovX = fov.angle_right - fov.angle_left;
            // const aspect = viewport.Width / viewport.Height;
            // view.projection = glm.perspective(fovX, aspect, 0.1, 100);
            view.projection = math.projection(fov, 0.1, 100);
            view.modelview = math.pose2matInverse(views[i].pose);
        }
        try self.updateBufferSlice(ViewUBO, self.views_ubo, self.views);

        try self.updateBuffer(
            CameraAttribs,
            self.camera_ubo,
            CameraAttribs.initFake(self.viewports[0], glm.Vec4.init([_]f32{
                views[0].pose.position.x,
                views[0].pose.position.y,
                views[0].pose.position.z,
                1,
            })),
        );
        try self.updateBuffer(LightAttribs, self.light_ubo, .{
            .direction = glm.Vec4.init([_]f32{ 1, 1, 1, 0 }),
            .intensity = glm.Vec4.init([_]f32{ 5, 3, 3, 3 }),
        });

        // setup and clear render targets
        var rtv = self.swc.GetCurrentBackBufferRTV();
        const dsv = self.swc.GetDepthBufferDSV();

        self.ctx.SetRenderTargets(1, &rtv, dsv, dg.RESOURCE_STATE_TRANSITION_MODE_TRANSITION);
        self.ctx.SetViewports(
            @intCast(u32, self.viewports.len),
            self.viewports.ptr,
            0,
            0,
        );
        self.ctx.SetScissorRects(
            @intCast(u32, self.scissors.len),
            self.scissors.ptr,
            0,
            0,
        );

        const clear_color = [_]f32{ 0.35, 0., 0.35, 1 };
        self.ctx.ClearRenderTarget(rtv, clear_color[0..], dg.RESOURCE_STATE_TRANSITION_MODE_TRANSITION);
        self.ctx.ClearDepthStencil(
            dsv,
            dg.CLEAR_DEPTH_FLAG,
            1,
            0,
            dg.RESOURCE_STATE_TRANSITION_MODE_TRANSITION,
        );

        // record renderpass
        self.renderer.Begin(self.ctx.ptr);
        for (self.models.items) |*model| {
            model.draw(self);
        }

        // self.renderer.Render(self.ctx.ptr, self.model.ptr, &self.render_params, &self.model_bindings, null, self.resource_binding.ptr);
    }

    fn createShader(
        self: *const Scene,
        name: [:0]const u8,
        shader_type: dg.SHADER_TYPE,
        language: dg.SHADER_SOURCE_LANGUAGE,
        source: [:0]const u8,
    ) !*dg.IShader {
        var shader: ?*dg.IShader = null;
        self.dev.CreateShader(&dg.ShaderCreateInfo{
            .Desc = .{
                ._DeviceObjectAttribs = .{ .Name = name },
                .ShaderType = shader_type,
            },

            .Source = source,
            .SourceLanguage = language,

            // default
            .FilePath = null,
            .pShaderSourceStreamFactory = null,
            .ppConversionStream = null,
            .ByteCode = null,
            .ByteCodeSize = 0,
            .EntryPoint = "main",
            .Macros = null,
            .UseCombinedTextureSamplers = false,
            .CombinedSamplerSuffix = "_sampler",
            .ShaderCompiler = dg.SHADER_COMPILER_DEFAULT,
            .CompileFlags = 0,
            .HLSLVersion = .{ .Major = 0, .Minor = 0 },
            .GLSLVersion = .{ .Major = 0, .Minor = 0 },
            .GLESSLVersion = .{ .Major = 0, .Minor = 0 },
            .ppCompilerOutput = null,
        }, &shader);

        return shader orelse error.ShaderCreationError;
    }

    fn createBuffer(
        self: *const Scene,
        comptime T: type,
        name: [:0]const u8,
        initial: ?*T,
        bind: dg.BIND_FLAGS,
        usage: dg.USAGE,
        cpu_access: dg.CPU_ACCESS_FLAGS,
    ) !dg.IBuffer_Wrapper {
        var buffer: ?*dg.IBuffer = null;
        var data_ptr: ?*const dg.BufferData = null;

        if (initial) |ptr| {
            const data = dg.BufferData{
                .pData = ptr,
                .DataSize = @sizeOf(T),
            };
            data_ptr = &data;
        }

        self.dev.CreateBuffer(&dg.BufferDesc{
            ._DeviceObjectAttribs = .{ .Name = name },
            .uiSizeInBytes = @sizeOf(T),
            .BindFlags = bind, // default: dg.BIND_NONE
            .Usage = usage, // default: dg.USAGE_DEFAULT
            .CPUAccessFlags = cpu_access, // default: dg.CPU_ACCESS_NONE
            .Mode = dg.BUFFER_MODE_UNDEFINED,
            .ElementByteStride = 0,
            .CommandQueueMask = 1,
        }, data_ptr, &buffer);

        return dg.IBuffer_Wrapper.wrap(buffer);
    }

    fn createTexture(
        self: *const Scene,
        name: [:0]const u8,
        path: [:0]const u8,
        bind: dg.BIND_FLAGS,
        usage: dg.USAGE,
        mip_levels: u32,
    ) !dg.ITexture_Wrapper {
        var texture: ?*dg.ITexture = null;

        dg.Diligent_CreateTextureFromFile(path, &dg.TextureLoadInfo{
            .Name = name,
            .Usage = usage, // default: dg.USAGE_DEFAULT
            .BindFlags = bind, // default: dg.BIND_NONE
            .IsSRGB = true,

            .CPUAccessFlags = dg.CPU_ACCESS_NONE,
            .MipLevels = mip_levels,
            .GenerateMips = mip_levels > 0,
            .Format = dg.TEX_FORMAT_UNKNOWN,
        }, @ptrCast(*dg.IRenderDevice, self.dev.ptr), &texture);

        return dg.ITexture_Wrapper.wrap(texture);
    }

    fn updateBuffer(
        self: *const Scene,
        comptime T: type,
        buffer: dg.IBuffer_Wrapper,
        value: T,
    ) !void {
        var data: ?*T = null;
        self.ctx.MapBuffer(buffer.ptr, dg.MAP_WRITE, dg.MAP_FLAG_DISCARD, @ptrCast([*c]?*c_void, &data));
        if (data) |ptr| {
            ptr.* = value;
            self.ctx.UnmapBuffer(buffer.ptr, dg.MAP_WRITE);
        } else {
            return error.MapFailed;
        }
    }

    fn updateBufferSlice(
        self: *const Scene,
        comptime T: type,
        buffer: dg.IBuffer_Wrapper,
        values: []const T,
    ) !void {
        var data: [*c]T = null;
        self.ctx.MapBuffer(buffer.ptr, dg.MAP_WRITE, dg.MAP_FLAG_DISCARD, @ptrCast([*c]?*c_void, &data));
        if (data) |ptr| {
            mem.copy(T, data[0..values.len], values);
            self.ctx.UnmapBuffer(buffer.ptr, dg.MAP_WRITE);
        } else {
            return error.MapFailed;
        }
    }
};