Texture/Vertex/Index data cache (#132)

* Initial implementation of the texture cache

* Cache vertex and index data aswell, some cleanup

* Improve handling of the cache by storing cached ranges on a list for each page

* Delete old data from the caches automatically, ensure that the cache is cleaned when the mapping/size changes, and some general cleanup

1 files changed, 73 insertions, 0 deletions

diff --git a/ChocolArm64/Memory/AMemoryWin32.cs b/ChocolArm64/Memory/AMemoryWin32.cs
new file mode 100644
index 00000000..d097dc87
--- /dev/null
+++ b/ChocolArm64/Memory/AMemoryWin32.cs
@@ -0,0 +1,73 @@
+using System;
+using System.Runtime.InteropServices;
+
+namespace ChocolArm64.Memory
+{
+    static class AMemoryWin32
+    {
+        private const int MEM_COMMIT      = 0x00001000;
+        private const int MEM_RESERVE     = 0x00002000;
+        private const int MEM_WRITE_WATCH = 0x00200000;
+
+        private const int PAGE_READWRITE = 0x04;
+
+        private const int MEM_RELEASE = 0x8000;
+
+        private const int WRITE_WATCH_FLAG_RESET = 1;
+
+        [DllImport("kernel32.dll")]
+        private static extern IntPtr VirtualAlloc(IntPtr lpAddress, IntPtr dwSize, int flAllocationType, int flProtect);
+
+        [DllImport("kernel32.dll")]
+        private static extern bool VirtualFree(IntPtr lpAddress, IntPtr dwSize, int dwFreeType);
+
+        [DllImport("kernel32.dll")]
+        private unsafe static extern int GetWriteWatch(
+            int      dwFlags,
+            IntPtr   lpBaseAddress,
+            IntPtr   dwRegionSize,
+            IntPtr[] lpAddresses,
+            long*    lpdwCount,
+            long*    lpdwGranularity);
+
+        public static IntPtr Allocate(IntPtr Size)
+        {
+            const int Flags = MEM_COMMIT | MEM_RESERVE | MEM_WRITE_WATCH;
+
+            IntPtr Address = VirtualAlloc(IntPtr.Zero, Size, Flags, PAGE_READWRITE);
+
+            if (Address == IntPtr.Zero)
+            {
+                throw new InvalidOperationException();
+            }
+
+            return Address;
+        }
+
+        public static void Free(IntPtr Address)
+        {
+            VirtualFree(Address, IntPtr.Zero, MEM_RELEASE);
+        }
+
+        public unsafe static long IsRegionModified(IntPtr Address, IntPtr Size, bool Reset)
+        {
+            IntPtr[] Addresses = new IntPtr[1];
+
+            long Count = Addresses.Length;
+
+            long Granularity;
+
+            int Flags = Reset ? WRITE_WATCH_FLAG_RESET : 0;
+
+            GetWriteWatch(
+                Flags,
+                Address,
+                Size,
+                Addresses,
+                &Count,
+                &Granularity);
+
+            return Count != 0 ? Granularity : 0;
+        }
+    }
+}
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