use rendergraph renderArea as scissor instead of viewport

viewport is used to determine aspect ratio and should be allowed to go outside of the
rendering area. The scissor is used to clip the rendered scene to a smaller visible
region and should not change any rendering with respect to the camera.

Author: john-tecplot

src/vsg/app/RenderGraph.cpp

@@ -49,7 +49,8 @@ RenderGraph::RenderGraph(ref_ptr<Window> in_window, ref_ptr<View> in_view) :
         renderArea.extent = window->extent2D();
     }
 
-    viewportState->set(renderArea.offset.x, renderArea.offset.y, renderArea.extent.width, renderArea.extent.height);
+    viewportState->scissors.resize(1);
+    viewportState->scissors[0] = _renderArea;
 
     // set up the clearValues based on the RenderPass's attachments.
     setClearValues(window->clearColor(), VkClearDepthStencilValue{0.0f, 0});
@@ -150,7 +151,8 @@ void RenderGraph::accept(RecordTraversal& recordTraversal) const
     vkCmdBeginRenderPass(vk_commandBuffer, &renderPassInfo, contents);
 
     // sync the viewportState and push
-    viewportState->set(renderArea.offset.x, renderArea.offset.y, renderArea.extent.width, renderArea.extent.height);
+    viewportState->scissors.resize(1);
+    viewportState->scissors[0] = _renderArea;
 
     if ((viewportStateHint & DYNAMIC_VIEWPORTSTATE))
     {
@@ -182,7 +184,7 @@ void RenderGraph::resized()
 
     auto extent = getExtent();
 
-    windowResizeHandler->renderArea = renderArea;
+    windowResizeHandler->renderArea = _renderArea;
     windowResizeHandler->previous_extent = previous_extent;
     windowResizeHandler->new_extent = extent;
     windowResizeHandler->visited.clear();