ANGLE: Dynamically load D3D compiler from a list or the environment

If the default compiler cannot be found, load it from a list of DLL names.
On Desktop Windows, the default compiler can be specified by an
environment variable, QT_D3DCOMPILER_DLL. This can also be set at
compile time by a define of the same name. Otherwise, the default
compiler DLL is that which is set by the Direct3D SDK.

On WinRT, the default compiler is d3dcompiler_qt, which is a
non-versioned compiler proxy provided by Qt.

Change-Id: I0d7a8a8a36cc571836f8fa59ea14513b9b19c19b
Reviewed-by: Maurice Kalinowski <maurice.kalinowski@digia.com>

1 files changed, 36 insertions, 8 deletions

diff --git a/src/3rdparty/angle/src/libGLESv2/renderer/Renderer.cpp b/src/3rdparty/angle/src/libGLESv2/renderer/Renderer.cpp
index 7ba183d250..39fd0f41f0 100644
--- a/src/3rdparty/angle/src/libGLESv2/renderer/Renderer.cpp
+++ b/src/3rdparty/angle/src/libGLESv2/renderer/Renderer.cpp
@@ -29,12 +29,12 @@
 #endif
 
 #ifndef D3DCOMPILER_DLL
-#ifndef ANGLE_OS_WINPHONE
 #define D3DCOMPILER_DLL L"d3dcompiler_43.dll" // Lowest common denominator
-#else
-#define D3DCOMPILER_DLL L"qtd3dcompiler.dll" // Placeholder DLL for phone
-#endif // ANGLE_OS_WINPHONE
-#endif // D3DCOMPILER_DLL
+#endif
+
+#ifndef QT_D3DCOMPILER_DLL
+#define QT_D3DCOMPILER_DLL D3DCOMPILER_DLL
+#endif
 
 #if defined(__MINGW32__) || defined(ANGLE_OS_WINPHONE)
 
@@ -83,12 +83,40 @@ bool Renderer::initializeCompiler()
         }
     }
 #else
-    // Load the version of the D3DCompiler DLL associated with the Direct3D version ANGLE was built with.
+    // Load the compiler DLL specified by the environment, or default to QT_D3DCOMPILER_DLL
+#if !defined(ANGLE_OS_WINRT)
+    const wchar_t *defaultCompiler = _wgetenv(L"QT_D3DCOMPILER_DLL");
+    if (!defaultCompiler)
+        defaultCompiler = QT_D3DCOMPILER_DLL;
+#else // !ANGLE_OS_WINRT
+#  ifdef _DEBUG
+    const wchar_t *defaultCompiler = L"d3dcompiler_qtd.dll";
+#  else
+    const wchar_t *defaultCompiler = L"d3dcompiler_qt.dll";
+#  endif
+#endif // ANGLE_OS_WINRT
+
+    const wchar_t *compilerDlls[] = {
+        defaultCompiler,
+        L"d3dcompiler_47.dll",
+        L"d3dcompiler_46.dll",
+        L"d3dcompiler_45.dll",
+        L"d3dcompiler_44.dll",
+        L"d3dcompiler_43.dll",
+        0
+    };
+
+    // Load the first available known compiler DLL
+    for (int i = 0; compilerDlls[i]; ++i)
+    {
 #if !defined(ANGLE_OS_WINRT)
-    mD3dCompilerModule = LoadLibrary(D3DCOMPILER_DLL);
+        mD3dCompilerModule = LoadLibrary(compilerDlls[i]);
 #else
-    mD3dCompilerModule = LoadPackagedLibrary(D3DCOMPILER_DLL, NULL);
+        mD3dCompilerModule = LoadPackagedLibrary(compilerDlls[i], NULL);
 #endif
+        if (mD3dCompilerModule)
+            break;
+    }
 #endif  // ANGLE_PRELOADED_D3DCOMPILER_MODULE_NAMES
 
     if (!mD3dCompilerModule)