From 923dd8b11fd2d2881ffbd36735184200fc77d4f7 Mon Sep 17 00:00:00 2001
From: pmgr <26606291+pmgr@users.noreply.github.com>
Date: Wed, 29 Apr 2020 06:42:11 +0100
Subject: [PATCH] Added WorldToScreen and a prototype for ScreenToWorld.

---
 Dalamud/Game/Internal/Gui/GameGui.cs          | 48 +++++++++++++++++++
 .../Internal/Gui/GameGuiAddressResolver.cs    |  4 ++
 2 files changed, 52 insertions(+)

diff --git a/Dalamud/Game/Internal/Gui/GameGui.cs b/Dalamud/Game/Internal/Gui/GameGui.cs
index 89f64eb2e..764b49d39 100644
--- a/Dalamud/Game/Internal/Gui/GameGui.cs
+++ b/Dalamud/Game/Internal/Gui/GameGui.cs
@@ -3,6 +3,7 @@ using System.Runtime.InteropServices;
 using Dalamud.Game.Chat.SeStringHandling.Payloads;
 using Dalamud.Hooking;
 using Serilog;
+using SharpDX;
 
 namespace Dalamud.Game.Internal.Gui {
     public sealed class GameGui : IDisposable {
@@ -34,6 +35,14 @@ namespace Dalamud.Game.Internal.Gui {
         private delegate bool OpenMapWithFlagDelegate(IntPtr UIMapObject, string flag);
         private OpenMapWithFlagDelegate openMapWithFlag;
 
+        [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
+        internal delegate IntPtr GetMatrixSingletonDelegate();
+        internal readonly GetMatrixSingletonDelegate getMatrixSingleton;
+
+        [UnmanagedFunctionPointer(CallingConvention.ThisCall)]
+        private unsafe delegate IntPtr ScreenToWorldNativeDelegate(float *camPosition, float *clipCoords, float rayDistance, float *worldCoords, float *unknown);
+        private readonly ScreenToWorldNativeDelegate screenToWorldNative;
+
         /// <summary>
         /// The item ID that is currently hovered by the player. 0 when no item is hovered.
         /// If > 1.000.000, subtract 1.000.000 and treat it as HQ
@@ -74,6 +83,12 @@ namespace Dalamud.Game.Internal.Gui {
                                                   this);
 
             this.getUIObject = Marshal.GetDelegateForFunctionPointer<GetUIObjectDelegate>(Address.GetUIObject);
+
+            this.getMatrixSingleton =
+                Marshal.GetDelegateForFunctionPointer<GetMatrixSingletonDelegate>(Address.GetMatrixSingleton);
+
+            this.screenToWorldNative =
+                Marshal.GetDelegateForFunctionPointer<ScreenToWorldNativeDelegate>(Address.ScreenToWorld);
         }
 
         private IntPtr HandleSetGlobalBgmDetour(UInt16 bgmKey, byte a2, UInt32 a3, UInt32 a4, UInt32 a5, byte a6) {
@@ -159,6 +174,39 @@ namespace Dalamud.Game.Internal.Gui {
             return this.openMapWithFlag(uiMapObjectPtr, mapLinkString);
         }
 
+        public Vector2 WorldToScreen(Vector3 worldCoords)
+        {
+            // Get base object with matrices
+            var matrixSingleton = this.getMatrixSingleton();
+
+            // Read current ViewProjectionMatrix plus game window size
+            var viewProjectionMatrix = new Matrix();
+            float width, height;
+            unsafe {
+                var rawMatrix = (float*) (matrixSingleton + 0x1b4).ToPointer();
+
+                for (var i = 0; i < 16; i++, rawMatrix += 1) {
+                    viewProjectionMatrix[i] = *rawMatrix;
+                }
+
+                width = *rawMatrix; 
+                height = *(rawMatrix + 1);
+            }
+
+            Vector3.Transform(ref worldCoords, ref viewProjectionMatrix, out Vector3 pCoords);
+
+            var normalProjCoords = new Vector2(pCoords.X / pCoords.Z, pCoords.Y / pCoords.Z);
+
+            normalProjCoords.X = 0.5f * width * (normalProjCoords.X + 1f);
+            normalProjCoords.Y = 0.5f * height * (1f - normalProjCoords.Y);
+
+            return normalProjCoords;
+        }
+
+        public Vector3 ScreenToWorld(Vector2 screenCoords) {
+            return new Vector3();
+        }
+
         public void SetBgm(ushort bgmKey) => this.setGlobalBgmHook.Original(bgmKey, 0, 0, 0, 0, 0); 
 
         public void Enable() {
diff --git a/Dalamud/Game/Internal/Gui/GameGuiAddressResolver.cs b/Dalamud/Game/Internal/Gui/GameGuiAddressResolver.cs
index 5142d0d41..0b092fdf6 100644
--- a/Dalamud/Game/Internal/Gui/GameGuiAddressResolver.cs
+++ b/Dalamud/Game/Internal/Gui/GameGuiAddressResolver.cs
@@ -12,6 +12,8 @@ namespace Dalamud.Game.Internal.Gui {
         public IntPtr HandleItemHover { get; set; }
         public IntPtr HandleItemOut { get; set; }
         public IntPtr GetUIObject { get; private set; }
+        public IntPtr GetMatrixSingleton { get; private set; }
+        public IntPtr ScreenToWorld { get; private set; }
 
         public GameGuiAddressResolver(IntPtr baseAddress) {
             BaseAddress = baseAddress;
@@ -31,6 +33,8 @@ namespace Dalamud.Game.Internal.Gui {
             HandleItemHover = sig.ScanText("E8 ?? ?? ?? ?? 48 8B 5C 24 ?? 48 89 AE ?? ?? ?? ??");
             HandleItemOut = sig.ScanText("48 89 5C 24 ?? 57 48 83 EC 20 48 8B FA 48 8B D9 4D");
             GetUIObject = sig.ScanText("E8 ?? ?? ?? ?? 48 8B C8 48 8B 10 FF 52 40 80 88 ?? ?? ?? ?? 01 E9");
+            GetMatrixSingleton = sig.ScanText("E8 ?? ?? ?? ?? 48 8D 4C 24 ?? 48 89 4c 24 ?? 4C 8D 4D ?? 4C 8D 44 24 ??");
+            ScreenToWorld = sig.ScanText("48 83 EC 48 48 8B 05 ?? ?? ?? ?? 4D 8B D1"); 
         }
     }
 }