Add "Output Resampling" option (#1541)

Adds an Output Resampling option to the Video tab to allow choosing between the old Bilinear sampler and a new Area sampler. Area sampling produces a much cleaner, softer image when downscaling, and a significantly sharper image when upscaling. This can also serve as a halfway decent anti-aliasing substitute until we have a more proper implementation.

include/dusk/settings.h

@@ -15,6 +15,11 @@ enum class BloomMode : int {
     Dusk = 2,
 };
 
+enum class Resampler : int {
+    Bilinear = 0,
+    Area = 1,
+};
+
 enum class GameLanguage : u8 {
     English = OS_LANGUAGE_ENGLISH,
     German = OS_LANGUAGE_GERMAN,
@@ -47,6 +52,12 @@ struct ConfigEnumRange<BloomMode> {
     static constexpr auto max = BloomMode::Dusk;
 };
 
+template <>
+struct ConfigEnumRange<Resampler> {
+    static constexpr auto min = Resampler::Bilinear;
+    static constexpr auto max = Resampler::Area;
+};
+
 template <>
 struct ConfigEnumRange<GameLanguage> {
     static constexpr auto min = GameLanguage::English;
@@ -140,6 +151,7 @@ struct UserSettings {
         ConfigVar<FrameInterpMode> enableFrameInterpolation;
         ConfigVar<int> internalResolutionScale;
         ConfigVar<int> shadowResolutionMultiplier;
+        ConfigVar<Resampler> resampler;
         ConfigVar<bool> enableDepthOfField;
         ConfigVar<bool> enableMapBackground;
         ConfigVar<bool> disableCutscenePillarboxing;