Implement HDR support for Windows (#825)

src_assets/windows/assets/shaders/directx/ScenePS_NW.hlsl

@@ -0,0 +1,22 @@
+Texture2D image : register(t0);
+
+SamplerState def_sampler : register(s0);
+
+struct PS_INPUT
+{
+    float4 pos : SV_POSITION;
+    float2 tex : TEXCOORD;
+};
+
+cbuffer SdrScaling : register(b0) {
+    float scale_factor;
+};
+
+float4 main_ps(PS_INPUT frag_in) : SV_Target
+{
+    float4 rgba = image.Sample(def_sampler, frag_in.tex, 0);
+
+    rgba.rgb = rgba.rgb * scale_factor;
+
+    return rgba;
+}