[D3D12] Window output

src/xenia/gpu/d3d12/shaders/edram_tile_sample_32bpp.cs.hlsl

@@ -22,7 +22,7 @@ void main(uint3 xe_group_id : SV_GroupID,
   uint4 sample_info =
       (xe_edram_tile_sample_dest_info.xxxx >> uint4(15u, 14u, 17u, 16u)) & 1u;
   uint2 edram_tile_quarter =
-      uint2(uint2(10u, 8u) <= xe_group_thread_id) * sample_info.xy;
+      uint2(uint2(10u, 8u) <= xe_group_thread_id.xy) * sample_info.xy;
   uint edram_offset = XeEDRAMOffset(
       (xe_group_id.xy << sample_info.xy) + edram_tile_quarter,
       (xe_group_thread_id.xy - edram_tile_quarter * uint2(10u, 8u)) <<

src/xenia/gpu/d3d12/shaders/fullscreen.vs.hlsl

@@ -0,0 +1,7 @@
+// A triangle covering the whole viewport.
+void main(uint xe_vertex_id : SV_VertexID, out float2 xe_texcoord : TEXCOORD,
+          out float4 xe_position : SV_Position) {
+  xe_texcoord = float2(uint2(xe_vertex_id, xe_vertex_id << 1u) & 2u);
+  xe_position =
+      float4(xe_texcoord * float2(2.0, -2.0) + float2(-1.0, 1.0), 0.0, 1.0);
+}

src/xenia/gpu/d3d12/shaders/stretch.ps.hlsl

@@ -0,0 +1,5 @@
+Texture2D<float4> xe_texture : register(t0);
+SamplerState xe_sampler : register(s0);
+float4 main(float2 xe_texcoord : TEXCOORD) : SV_Target {
+  return xe_texture.SampleLevel(xe_sampler, xe_texcoord, 0.0f);
+}