From 9c6d3a2bf66d0cd52be1748d1a9b759f4f3e4aac Mon Sep 17 00:00:00 2001
From: Philip Rebohle <philip.rebohle@tu-dortmund.de>
Date: Fri, 26 Feb 2021 03:32:51 +0100
Subject: [PATCH] [d3d11] Fix RSGetViewports and RSGetScissorRects

If the output array is non-null, these functons always return the
number of valid viewports or scissors actually written to the array.

Fixes a wine test failure.
---
 src/d3d11/d3d11_context.cpp | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/src/d3d11/d3d11_context.cpp b/src/d3d11/d3d11_context.cpp
index b051b5e2..fd58b0dc 100644
--- a/src/d3d11/d3d11_context.cpp
+++ b/src/d3d11/d3d11_context.cpp
@@ -2974,8 +2974,11 @@ namespace dxvk {
           UINT*                             pNumViewports,
           D3D11_VIEWPORT*                   pViewports) {
     D3D10DeviceLock lock = LockContext();
-    
-    if (pViewports != nullptr) {
+    uint32_t numWritten = m_state.rs.numViewports;
+
+    if (pViewports) {
+      numWritten = std::min(numWritten, *pNumViewports);
+
       for (uint32_t i = 0; i < *pNumViewports; i++) {
         if (i < m_state.rs.numViewports) {
           pViewports[i] = m_state.rs.viewports[i];
@@ -2988,9 +2991,9 @@ namespace dxvk {
           pViewports[i].MaxDepth = 0.0f;
         }
       }
-    } else {
-      *pNumViewports = m_state.rs.numViewports;
     }
+
+    *pNumViewports = numWritten;
   }
   
   
@@ -2998,8 +3001,11 @@ namespace dxvk {
           UINT*                             pNumRects,
           D3D11_RECT*                       pRects) {
     D3D10DeviceLock lock = LockContext();
+    uint32_t numWritten = m_state.rs.numScissors;
     
-    if (pRects != nullptr) {
+    if (pRects) {
+      numWritten = std::min(numWritten, *pNumRects);
+
       for (uint32_t i = 0; i < *pNumRects; i++) {
         if (i < m_state.rs.numScissors) {
           pRects[i] = m_state.rs.scissors[i];
@@ -3010,9 +3016,9 @@ namespace dxvk {
           pRects[i].bottom = 0;
         }
       }
-    } else {
-      *pNumRects = m_state.rs.numScissors;
     }
+
+    *pNumRects = m_state.rs.numScissors;
   }