Add sampler support and refactor resource handling

Enhanced shader and resource systems with `Sampler` support, including updates to `ShaderPropertyType`, HLSL code, and resource management. Refactored `Result` structs for better type safety and added new enums for texture and comparison settings. Improved `MeshRenderPass` to dynamically load textures and samplers. Updated SDL compiler and token lexicon for `Sampler` handling. Embedded debug info in project files and streamlined resource state tracking.

Ghost.Graphics/RHI/Common.cs

@@ -10,14 +10,6 @@ using TerraFX.Interop.DirectX;
 
 namespace Ghost.Graphics.RHI;
 
-public interface IRHIObject
-{
-    string Name
-    {
-        get; set;
-    }
-}
-
 public readonly struct ShaderPassKey
 {
     public readonly ulong value;
@@ -603,6 +595,57 @@ public struct TextureDesc
     }
 }
 
+/// <summary>
+/// Describes the parameters used to configure a texture sampler for graphics rendering operations.
+/// </summary>
+public record struct SamplerDesc
+{
+    public TextureFilterMode FilterMode
+    {
+        get; set;
+    }
+
+    public TextureAddressMode AddressU
+    {
+        get; set;
+    }
+
+    public TextureAddressMode AddressV
+    {
+        get; set;
+    }
+
+    public TextureAddressMode AddressW
+    {
+        get; set;
+    }
+
+    public ComparisonFunction ComparisonFunc
+    {
+        get; set;
+    }
+
+    public float MipLODBias
+    {
+        get; set;
+    }
+
+    public uint MaxAnisotropy
+    {
+        get; set;
+    }
+
+    public float MinLOD
+    {
+        get; set;
+    }
+
+    public float MaxLOD
+    {
+        get; set;
+    }
+}
+
 /// <summary>
 /// Buffer description
 /// </summary>
@@ -865,3 +908,32 @@ public enum PrimitiveTopology
     Line,
     Triangle,
 }
+
+public enum TextureFilterMode
+{
+    Point,
+    Bilinear,
+    Trilinear,
+    Anisotropic
+}
+
+public enum TextureAddressMode
+{
+    Repeat,
+    Mirror,
+    Clamp,
+    Border,
+    MirrorOnce
+}
+
+public enum ComparisonFunction
+{
+    Never,
+    Less,
+    Equal,
+    LessEqual,
+    Greater,
+    NotEqual,
+    GreaterEqual,
+    Always
+}

Ghost.Graphics/RHI/ICommandBuffer.cs

@@ -91,6 +91,13 @@ public interface ICommandBuffer : IDisposable
     /// <param name="stateAfter">The desired state of the resource after the transition.</param>
     void ResourceBarrier(Handle<GPUResource> resource, ResourceState stateBefore, ResourceState stateAfter);
 
+    /// <summary>
+    /// Inserts a resource barrier for state transitions. The current state is tracked internally.
+    /// </summary>
+    /// <param name="resource">A handle to the GPU resource to transition.</param>
+    /// <param name="stateAfter">The desired state of the resource after the transition.</param>
+    void ResourceBarrier(Handle<GPUResource> resource, ResourceState stateAfter);
+
     /// <summary>
     /// Sets the pipeline state object
     /// </summary>

Ghost.Graphics/RHI/IResourceAllocator.cs

@@ -11,22 +11,29 @@ public interface IResourceAllocator : IDisposable
     /// Creates a texture resource
     /// </summary>
     /// <param name="desc">Texture description</param>
-    /// <returns>A new texture handle point to the resource</returns>
-    public Handle<Texture> CreateTexture(ref readonly TextureDesc desc, bool tempResource = false);
+    /// <returns>An <see cref="Handle{Texture}"/> point to the resource</returns>
+    Handle<Texture> CreateTexture(ref readonly TextureDesc desc, bool tempResource = false);
 
     /// <summary>
     /// Creates a render Target for off-screen rendering
     /// </summary>
     /// <param name="desc">Render Target description</param>
-    /// <returns>A new texture handle point to the resource</returns>
-    public Handle<Texture> CreateRenderTarget(ref readonly RenderTargetDesc desc, bool tempResource = false);
+    /// <returns>An <see cref="Handle{Texture}"/> point to the resource</returns>
+    Handle<Texture> CreateRenderTarget(ref readonly RenderTargetDesc desc, bool tempResource = false);
 
     /// <summary>
     /// Creates a buffer resource
     /// </summary>
     /// <param name="desc">Buffer description</param>
-    /// <returns>A new buffer handle point to the resource</returns>
-    public Handle<GraphicsBuffer> CreateBuffer(ref readonly BufferDesc desc, bool tempResource = false);
+    /// <returns>An <see cref="Handle{GraphicsBuffer}"/> point to the resource</returns>
+    Handle<GraphicsBuffer> CreateBuffer(ref readonly BufferDesc desc, bool tempResource = false);
+
+    /// <summary>
+    /// Creates a new sampler object using the specified sampler description.
+    /// </summary>
+    /// <param name="desc">A read-only reference to a <see cref="SamplerDesc"/> structure that defines the properties of the sampler to be created.</param>
+    /// <returns>An <see cref="Identifier{Sampler}"/> that uniquely identifies the created sampler object.</returns>
+    Identifier<Sampler> CreateSampler(ref readonly SamplerDesc desc);
 
     /// <summary>
     /// Creates a new mesh from the specified vertex and index data.
@@ -34,19 +41,19 @@ public interface IResourceAllocator : IDisposable
     /// <param name="vertices">A UnsafeList containing the vertices that define the geometry of the mesh. Must contain at least one vertex.</param>
     /// <param name="indices">A UnsafeList containing the indices that specify how vertices are connected to form primitives. Must contain at least one index.</param>
     /// <returns>An <see cref="Identifier{Mesh}"/> representing the newly created mesh.</returns>
-    public Handle<Mesh> CreateMesh(UnsafeList<Vertex> vertices, UnsafeList<uint> indices);
+    Handle<Mesh> CreateMesh(UnsafeList<Vertex> vertices, UnsafeList<uint> indices);
 
     /// <summary>
     /// Creates a new material instance using the specified shader.
     /// </summary>
     /// <param name="shader">The identifier of the shader to associate with the new material. Cannot be null.</param>
     /// <returns>An <see cref="Identifier{Material}"/> representing the newly created material.</returns>
-    public Handle<Material> CreateMaterial(Identifier<Shader> shader);
+    Handle<Material> CreateMaterial(Identifier<Shader> shader);
 
     /// <summary>
     /// Creates a new shader and returns its unique identifier.
     /// </summary>
     /// <returns>An <see cref="Identifier{Shader}"/> representing the newly created shader.</returns>
     /// <param name="descriptor">The viewGroup containing the shader's properties and passes.</param>
-    public Identifier<Shader> CreateGraphicsShader(ShaderDescriptor descriptor);
+    Identifier<Shader> CreateGraphicsShader(ShaderDescriptor descriptor);
 }

Ghost.Graphics/RHI/IResourceDatabase.cs

@@ -60,7 +60,7 @@ public interface IResourceDatabase : IDisposable
     /// </summary>
     /// <param name="handle">A handle to the GPU resource for which to obtain the bindless index. Must reference a valid, currently registered resource.</param>
     /// <returns>The bindless index corresponding to the specified GPU resource handle. -1 if the resource does not support bindless access or is not found.</returns>
-    int GetBindlessIndex(Handle<GPUResource> handle);
+    Result<uint, ResultStatus> GetBindlessIndex(Handle<GPUResource> handle);
 
     /// <summary>
     /// Retrieves the name of the GPU resource associated with the specified handle.
@@ -78,6 +78,23 @@ public interface IResourceDatabase : IDisposable
     /// <param name="handle">The handle of the resource to be removed.</param>
     void ReleaseResource(Handle<GPUResource> handle);
 
+    /// <summary>
+    /// Retrieves an existing sampler identifier that matches the specified description, or creates a new one if none
+    /// exists.
+    /// </summary>
+    /// <param name="desc">A read-only reference to a <see cref="SamplerDesc"/> structure that defines the properties of the sampler to retrieve or create.</param>
+    /// <param name="id">An integer identifier to associate with the sampler.</param>
+    /// <returns>An <see cref="Identifier{Sampler}"/> representing the sampler that matches the specified description.
+    ///     If a matching sampler does not exist, a new sampler is created and its identifier is returned.</returns>
+    Identifier<Sampler> CreateSampler(ref readonly SamplerDesc desc, int id);
+
+    /// <summary>
+    /// Determines whether a sampler with the specified identifier exists.
+    /// </summary>
+    /// <param name="id">The identifier of the sampler to check for existence.</param>
+    /// <returns>true if a sampler with the given identifier exists; otherwise, false.</returns>
+    bool TryGetSampler(ref readonly SamplerDesc desc, out Identifier<Sampler> id);
+
     /// <summary>
     /// Adds a mesh to the resource database and returns its handle.
     /// </summary>