From 2b6cb2567581cf5d5c31c5ce6d4a35d3ae00e53f Mon Sep 17 00:00:00 2001
From: Philip Rebohle <philip.rebohle@tu-dortmund.de>
Date: Mon, 18 Dec 2017 23:24:10 +0100
Subject: [PATCH] [d3d11] Implemented D3D11_APPEND_ALIGNED_ELEMENT

---
 src/d3d11/d3d11_device.cpp | 18 +++++++++++++++---
 src/util/util_math.h       |  4 ++--
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/src/d3d11/d3d11_device.cpp b/src/d3d11/d3d11_device.cpp
index e8c08983c..e65431853 100644
--- a/src/d3d11/d3d11_device.cpp
+++ b/src/d3d11/d3d11_device.cpp
@@ -561,10 +561,22 @@ namespace dxvk {
           pInputElementDescs[i].Format).actual;
         attrib.offset   = pInputElementDescs[i].AlignedByteOffset;
         
-        // TODO implement D3D11_APPEND_ALIGNED_ELEMENT
+        // The application may choose to let the implementation
+        // generate the exact vertex layout. In that case we'll
+        // pack attributes on the same binding in the order they
+        // are declared, aligning each attribute to four bytes.
         if (attrib.offset == D3D11_APPEND_ALIGNED_ELEMENT) {
-          Logger::err("D3D11Device::CreateInputLayout: D3D11_APPEND_ALIGNED_ELEMENT not supported yet");
-          return E_INVALIDARG;
+          attrib.offset = 0;
+          
+          for (uint32_t j = 1; j <= i; j++) {
+            const DxvkVertexAttribute& prev = attributes.at(i - j);
+            
+            if (prev.binding == attrib.binding) {
+              const DxvkFormatInfo* formatInfo = imageFormatInfo(prev.format);
+              attrib.offset = align(prev.offset + formatInfo->elementSize, 4);
+              break;
+            }
+          }
         }
         
         attributes.push_back(attrib);
diff --git a/src/util/util_math.h b/src/util/util_math.h
index 7a6386a95..5705bf7f0 100644
--- a/src/util/util_math.h
+++ b/src/util/util_math.h
@@ -9,8 +9,8 @@ namespace dxvk {
     return n;
   }
   
-  template<typename T>
-  T align(T what, T to) {
+  template<typename T, typename U = T>
+  T align(T what, U to) {
     return (what + to - 1) & ~(to - 1);
   }