Adapter selection for Renderer (#923)

* * Make adapter used selectable on the command line
* Added 'adapter' to Renderer::Desc with dx11, dx12, vk honoring it
* GL will check that the renderer matches, but cannot select a specific device
* Share functionality on dx adapter selection in D3DUtil

Note - that on tests that use OpenGL and the adapter doesn't match it will ignore the test (and display a message that the appropriate device couldn't be started)

* Small function name improvement.

* Variable rename to match type.

* Fix typo in Dx12 device selection.

* * Add checking if an adapter is warp
* Improve some comments

1 files changed, 13 insertions, 0 deletions

diff --git a/tools/gfx/render-gl.cpp b/tools/gfx/render-gl.cpp
index a2d379778..a3703a75b 100644
--- a/tools/gfx/render-gl.cpp
+++ b/tools/gfx/render-gl.cpp
@@ -677,6 +677,19 @@ SlangResult GLRenderer::initialize(const Desc& desc, void* inWindowHandle)
     wglMakeCurrent(m_hdc, m_glContext);
 
     auto renderer = glGetString(GL_RENDERER);
+
+    if (renderer && desc.adapter.Length() > 0)
+    {
+        String lowerAdapter = desc.adapter.ToLower();
+        String lowerRenderer = String((const char*)renderer).ToLower();
+
+        // The adapter is not available
+        if (lowerRenderer.IndexOf(lowerAdapter) == UInt(-1))
+        {
+            return SLANG_E_NOT_AVAILABLE;
+        }
+    }
+
     auto extensions = glGetString(GL_EXTENSIONS);
 
     // Load each of our extension functions by name