1 files changed, 260 insertions, 0 deletions
diff --git a/src/Ryujinx.Graphics.Gpu/Image/SamplerDescriptor.cs b/src/Ryujinx.Graphics.Gpu/Image/SamplerDescriptor.cs
new file mode 100644
index 00000000..64a146fb
--- /dev/null
+++ b/src/Ryujinx.Graphics.Gpu/Image/SamplerDescriptor.cs
@@ -0,0 +1,260 @@
+using Ryujinx.Graphics.GAL;
+using System.Runtime.CompilerServices;
+using System.Runtime.Intrinsics;
+
+namespace Ryujinx.Graphics.Gpu.Image
+{
+    /// <summary>
+    /// Maxwell sampler descriptor structure.
+    /// This structure defines the sampler descriptor as it is packed on the GPU sampler pool region.
+    /// </summary>
+    struct SamplerDescriptor
+    {
+        private static readonly float[] _f5ToF32ConversionLut = new float[]
+        {
+            0.0f,
+            0.055555556f,
+            0.1f,
+            0.13636364f,
+            0.16666667f,
+            0.1923077f,
+            0.21428572f,
+            0.23333333f,
+            0.25f,
+            0.2777778f,
+            0.3f,
+            0.3181818f,
+            0.33333334f,
+            0.34615386f,
+            0.35714287f,
+            0.36666667f,
+            0.375f,
+            0.3888889f,
+            0.4f,
+            0.4090909f,
+            0.41666666f,
+            0.42307693f,
+            0.42857143f,
+            0.43333334f,
+            0.4375f,
+            0.44444445f,
+            0.45f,
+            0.45454547f,
+            0.45833334f,
+            0.46153846f,
+            0.4642857f,
+            0.46666667f
+        };
+
+        private static readonly float[] _maxAnisotropyLut = new float[]
+        {
+            1, 2, 4, 6, 8, 10, 12, 16
+        };
+
+        private const float Frac8ToF32 = 1.0f / 256.0f;
+
+#pragma warning disable CS0649
+        public uint Word0;
+        public uint Word1;
+        public uint Word2;
+        public uint Word3;
+        public float BorderColorR;
+        public float BorderColorG;
+        public float BorderColorB;
+        public float BorderColorA;
+#pragma warning restore CS0649
+
+        /// <summary>
+        /// Unpacks the texture wrap mode along the X axis.
+        /// </summary>
+        /// <returns>The texture wrap mode enum</returns>
+        public AddressMode UnpackAddressU()
+        {
+            return (AddressMode)(Word0 & 7);
+        }
+
+        // <summary>
+        /// Unpacks the texture wrap mode along the Y axis.
+        /// </summary>
+        /// <returns>The texture wrap mode enum</returns>
+        public AddressMode UnpackAddressV()
+        {
+            return (AddressMode)((Word0 >> 3) & 7);
+        }
+
+        // <summary>
+        /// Unpacks the texture wrap mode along the Z axis.
+        /// </summary>
+        /// <returns>The texture wrap mode enum</returns>
+        public AddressMode UnpackAddressP()
+        {
+            return (AddressMode)((Word0 >> 6) & 7);
+        }
+
+        /// <summary>
+        /// Unpacks the compare mode used for depth comparison on the shader, for
+        /// depth buffer texture.
+        /// This is only relevant for shaders with shadow samplers.
+        /// </summary>
+        /// <returns>The depth comparison mode enum</returns>
+        public CompareMode UnpackCompareMode()
+        {
+            return (CompareMode)((Word0 >> 9) & 1);
+        }
+
+        /// <summary>
+        /// Unpacks the compare operation used for depth comparison on the shader, for
+        /// depth buffer texture.
+        /// This is only relevant for shaders with shadow samplers.
+        /// </summary>
+        /// <returns>The depth comparison operation enum</returns>
+        public CompareOp UnpackCompareOp()
+        {
+            return (CompareOp)(((Word0 >> 10) & 7) + 1);
+        }
+
+        /// <summary>
+        /// Unpacks and converts the maximum anisotropy value used for texture anisotropic filtering.
+        /// </summary>
+        /// <returns>The maximum anisotropy</returns>
+        public float UnpackMaxAnisotropy()
+        {
+            return _maxAnisotropyLut[(Word0 >> 20) & 7];
+        }
+
+        /// <summary>
+        /// Unpacks the texture magnification filter.
+        /// This defines the filtering used when the texture covers an area on the screen
+        /// that is larger than the texture size.
+        /// </summary>
+        /// <returns>The magnification filter</returns>
+        public MagFilter UnpackMagFilter()
+        {
+            return (MagFilter)(Word1 & 3);
+        }
+
+        /// <summary>
+        /// Unpacks the texture minification filter.
+        /// This defines the filtering used when the texture covers an area on the screen
+        /// that is smaller than the texture size.
+        /// </summary>
+        /// <returns>The minification filter</returns>
+        public MinFilter UnpackMinFilter()
+        {
+            SamplerMinFilter minFilter = (SamplerMinFilter)((Word1 >> 4) & 3);
+            SamplerMipFilter mipFilter = (SamplerMipFilter)((Word1 >> 6) & 3);
+
+            return ConvertFilter(minFilter, mipFilter);
+        }
+
+        /// <summary>
+        /// Converts two minification and filter enum, to a single minification enum,
+        /// including mipmap filtering information, as expected from the host API.
+        /// </summary>
+        /// <param name="minFilter">The minification filter</param>
+        /// <param name="mipFilter">The mipmap level filter</param>
+        /// <returns>The combined, host API compatible filter enum</returns>
+        private static MinFilter ConvertFilter(SamplerMinFilter minFilter, SamplerMipFilter mipFilter)
+        {
+            switch (mipFilter)
+            {
+                case SamplerMipFilter.None:
+                    switch (minFilter)
+                    {
+                        case SamplerMinFilter.Nearest: return MinFilter.Nearest;
+                        case SamplerMinFilter.Linear:  return MinFilter.Linear;
+                    }
+                    break;
+
+                case SamplerMipFilter.Nearest:
+                    switch (minFilter)
+                    {
+                        case SamplerMinFilter.Nearest: return MinFilter.NearestMipmapNearest;
+                        case SamplerMinFilter.Linear:  return MinFilter.LinearMipmapNearest;
+                    }
+                    break;
+
+                case SamplerMipFilter.Linear:
+                    switch (minFilter)
+                    {
+                        case SamplerMinFilter.Nearest: return MinFilter.NearestMipmapLinear;
+                        case SamplerMinFilter.Linear:  return MinFilter.LinearMipmapLinear;
+                    }
+                    break;
+            }
+
+            return MinFilter.Nearest;
+        }
+
+        /// <summary>
+        /// Unpacks the seamless cubemap flag.
+        /// </summary>
+        /// <returns>The seamless cubemap flag</returns>
+        public bool UnpackSeamlessCubemap()
+        {
+            return (Word1 & (1 << 9)) != 0;
+        }
+
+        /// <summary>
+        /// Unpacks the reduction filter, used with texture minification linear filtering.
+        /// This describes how the final value will be computed from neighbouring pixels.
+        /// </summary>
+        /// <returns>The reduction filter</returns>
+        public ReductionFilter UnpackReductionFilter()
+        {
+            return (ReductionFilter)((Word1 >> 10) & 3);
+        }
+
+        /// <summary>
+        /// Unpacks the level-of-detail bias value.
+        /// This is a bias added to the level-of-detail value as computed by the GPU, used to select
+        /// which mipmap level to use from a given texture.
+        /// </summary>
+        /// <returns>The level-of-detail bias value</returns>
+        public float UnpackMipLodBias()
+        {
+            int fixedValue = (int)(Word1 >> 12) & 0x1fff;
+
+            fixedValue = (fixedValue << 19) >> 19;
+
+            return fixedValue * Frac8ToF32;
+        }
+
+        /// <summary>
+        /// Unpacks the level-of-detail snap value.
+        /// </summary>
+        /// <returns>The level-of-detail snap value</returns>
+        public float UnpackLodSnap()
+        {
+            return _f5ToF32ConversionLut[(Word1 >> 26) & 0x1f];
+        }
+
+        /// <summary>
+        /// Unpacks the minimum level-of-detail value.
+        /// </summary>
+        /// <returns>The minimum level-of-detail value</returns>
+        public float UnpackMinLod()
+        {
+            return (Word2 & 0xfff) * Frac8ToF32;
+        }
+
+        /// <summary>
+        /// Unpacks the maximum level-of-detail value.
+        /// </summary>
+        /// <returns>The maximum level-of-detail value</returns>
+        public float UnpackMaxLod()
+        {
+            return ((Word2 >> 12) & 0xfff) * Frac8ToF32;
+        }
+
+        /// <summary>
+        /// Check if two descriptors are equal.
+        /// </summary>
+        /// <param name="other">The descriptor to compare against</param>
+        /// <returns>True if they are equal, false otherwise</returns>
+        public bool Equals(ref SamplerDescriptor other)
+        {
+            return Unsafe.As<SamplerDescriptor, Vector256<byte>>(ref this).Equals(Unsafe.As<SamplerDescriptor, Vector256<byte>>(ref other));
+        }
+    }
+}