On replay prefer loading the d3dcompiler we ship

* On windows 7, d3dcompiler_47.dll is too old to support SM5.1 shaders.

renderdoc/driver/shaders/dxbc/dxbc_compile.cpp

@@ -24,11 +24,19 @@
 
 #include "dxbc_compile.h"
 #include "common/common.h"
+#include "core/core.h"
 #include "os/os_specific.h"
 #include "strings/string_utils.h"
 
-// gives us an address to identify this dll with
-static int dllLocator = 0;
+static HMODULE GetLocalD3DCompiler()
+{
+  rdcstr dllFile;
+  FileIO::GetLibraryFilename(dllFile);
+
+  rdcstr dll = get_dirname(dllFile) + "/d3dcompiler_47.dll";
+
+  return LoadLibraryW(StringFormat::UTF82Wide(dll.c_str()).data());
+}
 
 HMODULE GetD3DCompiler()
 {
@@ -36,7 +44,15 @@ HMODULE GetD3DCompiler()
   if(ret != NULL)
     return ret;
 
-  // dlls to try in priority order
+  // during replay, try to load our local one to get the newest possible.
+  if(RenderDoc::Inst().IsReplayApp())
+  {
+    ret = GetLocalD3DCompiler();
+    if(ret)
+      return ret;
+  }
+
+  // now dlls to try in priority order
   const char *dlls[] = {
       "d3dcompiler_47.dll", "d3dcompiler_46.dll", "d3dcompiler_45.dll",
       "d3dcompiler_44.dll", "d3dcompiler_43.dll",
@@ -46,6 +62,8 @@ HMODULE GetD3DCompiler()
   {
     for(int d = 0; d < ARRAY_COUNT(dlls); d++)
     {
+      // first time around, try to load one that already exists. Second time around try to load it
+      // in the default search path.
       if(i == 0)
         ret = GetModuleHandleA(dlls[d]);
       else
@@ -56,15 +74,9 @@ HMODULE GetD3DCompiler()
     }
   }
 
-  // all else failed, couldn't find d3dcompiler loaded,
-  // and couldn't even loadlibrary any version!
-  // we'll have to loadlibrary the version that ships with
-  // RenderDoc.
+  // finally if we couldn't load a library anywhere from the system while capturing, load our local
+  // compiler.
+  ret = GetLocalD3DCompiler();
 
-  rdcstr dllFile;
-  FileIO::GetLibraryFilename(dllFile);
-
-  rdcstr dll = get_dirname(dllFile) + "/d3dcompiler_47.dll";
-
-  return LoadLibraryW(StringFormat::UTF82Wide(dll.c_str()).data());
+  return ret;
 }