From 1c6fc7b5b8192f66003a9a3d2d75d81bc88846be Mon Sep 17 00:00:00 2001
From: Robin Kertels <robin.kertels@gmail.com>
Date: Thu, 2 Mar 2023 02:06:02 +0100
Subject: [PATCH] [d3d9] Clamp stage and type in [G,S]etTextureStageState

This is what happens on the Nvidia D3D9 driver.
Dawn of Magic 2 calls SetTextureStageState with a
stage > 7 and expects that to succeed.
---
 src/d3d9/d3d9_device.cpp     | 21 ++++++++-------------
 src/d3d9/d3d9_stateblock.cpp |  3 +++
 2 files changed, 11 insertions(+), 13 deletions(-)

diff --git a/src/d3d9/d3d9_device.cpp b/src/d3d9/d3d9_device.cpp
index 0cf65cf0..f606c8db 100644
--- a/src/d3d9/d3d9_device.cpp
+++ b/src/d3d9/d3d9_device.cpp
@@ -2304,13 +2304,8 @@ namespace dxvk {
     if (unlikely(pValue == nullptr))
       return D3DERR_INVALIDCALL;
 
-    *pValue = 0;
-
-    if (unlikely(Stage >= caps::TextureStageCount))
-      return D3DERR_INVALIDCALL;
-
-    if (unlikely(dxvkType >= TextureStageStateCount))
-      return D3DERR_INVALIDCALL;
+    Stage = std::min(Stage, DWORD(caps::TextureStageCount - 1));
+    dxvkType = std::min(dxvkType, D3D9TextureStageStateTypes(DXVK_TSS_COUNT - 1));
 
     *pValue = m_state.textureStages[Stage][dxvkType];
 
@@ -3876,14 +3871,14 @@ namespace dxvk {
           DWORD                      Stage,
           D3D9TextureStageStateTypes Type,
           DWORD                      Value) {
+    
+    // Clamp values instead of checking and returning INVALID_CALL
+    // Matches tests + Dawn of Magic 2 relies on it.
+    Stage = std::min(Stage, DWORD(caps::TextureStageCount - 1));
+    Type = std::min(Type, D3D9TextureStageStateTypes(DXVK_TSS_COUNT - 1));
+
     D3D9DeviceLock lock = LockDevice();
 
-    if (unlikely(Stage >= caps::TextureStageCount))
-      return D3DERR_INVALIDCALL;
-
-    if (unlikely(Type >= TextureStageStateCount))
-      return D3DERR_INVALIDCALL;
-
     if (unlikely(ShouldRecord()))
       return m_recorder->SetStateTextureStageState(Stage, Type, Value);
 
diff --git a/src/d3d9/d3d9_stateblock.cpp b/src/d3d9/d3d9_stateblock.cpp
index 9c0abba1..76ab1d64 100644
--- a/src/d3d9/d3d9_stateblock.cpp
+++ b/src/d3d9/d3d9_stateblock.cpp
@@ -213,6 +213,9 @@ namespace dxvk {
           DWORD                      Stage,
           D3D9TextureStageStateTypes Type,
           DWORD                      Value) {
+    Stage = std::min(Stage, DWORD(caps::TextureStageCount - 1));
+    Type = std::min(Type, D3D9TextureStageStateTypes(DXVK_TSS_COUNT - 1));
+
     m_state.textureStages[Stage][Type] = Value;
 
     m_captures.flags.set(D3D9CapturedStateFlag::TextureStages);