add MMPX filter

Signed-off-by: lizzie <lizzie@eden-emu.dev>

docs/User.md

@@ -9,3 +9,21 @@ Eden will store configuration in the following directories:
 - **Linux, macOS, FreeBSD, Solaris, OpenBSD**: `$XDG_DATA_HOME`, `$XDG_CACHE_HOME`, `$XDG_CONFIG_HOME`.
 
 If a `user` directory is present in the current working directory, that will override all global configuration directories and the emulator will use that instead.
+
+# Enhancements
+
+## Filters
+
+Various graphical filters exist - each of them aimed at a specific target/image quality preset.
+
+- **Nearest**: Provides no filtering - useful for debugging.
+- **Bilinear**: Provides the hardware default filtering of the Tegra X1.
+- **Bicubic**: Provides a bicubic interpolation using a Catmull-Rom (or hardware-accelerated) implementation.
+- **Zero-Tangent, B-Spline, Mitchell**: Provides bicubic interpolation using the respective matrix weights. They're normally not hardware accelerated unless the device supports the `VK_QCOM_filter_cubic_weights` extension. The matrix weights are those matching [the specification itself](https://registry.khronos.org/vulkan/specs/latest/html/vkspec.html#VkSamplerCubicWeightsCreateInfoQCOM).
+- **Spline-1**: Bicubic interpolation (similar to Mitchell) but with a faster texel fetch method. Generally less blurry than bicubic.
+- **Gaussian**: Whole-area blur, an applied gaussian blur is done to the entire frame.
+- **Lanczos**: An implementation using `a = 3` (49 texel fetches). Provides sharper edges but blurrier artifacts.
+- **ScaleForce**: Experimental texture upscale method, see [ScaleFish](https://github.com/BreadFish64/ScaleFish).
+- **FSR**: Uses AMD FidelityFX Super Resolution to enhance image quality.
+- **Area**: Area interpolation (high kernel count).
+- **MMPX**: Nearest-neighbour filter aimed at providing higher pixel-art quality.

src/android/app/src/main/res/values/arrays.xml

@@ -260,6 +260,7 @@
         <item>@string/scaling_filter_scale_force</item>
         <item>@string/scaling_filter_fsr</item>
         <item>@string/scaling_filter_area</item>
+        <item>@string/scaling_filter_mmpx</item>
     </string-array>
 
     <integer-array name="rendererScalingFilterValues">
@@ -275,6 +276,7 @@
         <item>9</item>
         <item>10</item>
         <item>11</item>
+        <item>12</item>
     </integer-array>
 
     <string-array name="rendererAntiAliasingNames">

src/android/app/src/main/res/values/strings.xml

@@ -1017,9 +1017,10 @@
     <string name="scaling_filter_scale_force">ScaleForce</string>
     <string name="scaling_filter_fsr">AMD FidelityFX™ Super Resolution</string>
     <string name="scaling_filter_area">Area</string>
-    <string name="scaling_filter_zero_tangent">Zero-Tangent-Cardinal</string>
+    <string name="scaling_filter_zero_tangent">Zero-Tangent</string>
     <string name="scaling_filter_bspline">B-Spline</string>
-    <string name="scaling_filter_mitchell">Mitchell-Netravali</string>
+    <string name="scaling_filter_mitchell">Mitchell</string>
+    <string name="scaling_filter_mmpx">MMPX</string>
 
     <!-- Anti-Aliasing -->
     <string name="anti_aliasing_none">None</string>

src/common/settings_enums.h

@@ -143,7 +143,7 @@ ENUM(ConfirmStop, Ask_Always, Ask_Based_On_Game, Ask_Never);
 ENUM(FullscreenMode, Borderless, Exclusive);
 ENUM(NvdecEmulation, Off, Cpu, Gpu);
 ENUM(ResolutionSetup, Res1_4X, Res1_2X, Res3_4X, Res1X, Res3_2X, Res2X, Res3X, Res4X, Res5X, Res6X, Res7X, Res8X);
-ENUM(ScalingFilter, NearestNeighbor, Bilinear, Bicubic, ZeroTangent, BSpline, Mitchell, Spline1, Gaussian, Lanczos, ScaleForce, Fsr, Area, MaxEnum);
+ENUM(ScalingFilter, NearestNeighbor, Bilinear, Bicubic, ZeroTangent, BSpline, Mitchell, Spline1, Gaussian, Lanczos, ScaleForce, Fsr, Area, Mmpx, MaxEnum);
 ENUM(AntiAliasing, None, Fxaa, Smaa, MaxEnum);
 ENUM(AspectRatio, R16_9, R4_3, R21_9, R16_10, Stretch);
 ENUM(ConsoleMode, Handheld, Docked);

src/qt_common/shared_translation.cpp

@@ -554,15 +554,16 @@ std::unique_ptr<ComboboxTranslationMap> ComboboxEnumeration(QObject* parent)
                               PAIR(ScalingFilter, NearestNeighbor, tr("Nearest Neighbor")),
                               PAIR(ScalingFilter, Bilinear, tr("Bilinear")),
                               PAIR(ScalingFilter, Bicubic, tr("Bicubic")),
-                              PAIR(ScalingFilter, ZeroTangent, tr("Zero-Tangent-Cardinal")),
+                              PAIR(ScalingFilter, ZeroTangent, tr("Zero-Tangent")),
                               PAIR(ScalingFilter, BSpline, tr("B-Spline")),
-                              PAIR(ScalingFilter, Mitchell, tr("Mitchell-Netravali")),
+                              PAIR(ScalingFilter, Mitchell, tr("Mitchell")),
                               PAIR(ScalingFilter, Spline1, tr("Spline-1")),
                               PAIR(ScalingFilter, Gaussian, tr("Gaussian")),
                               PAIR(ScalingFilter, Lanczos, tr("Lanczos")),
                               PAIR(ScalingFilter, ScaleForce, tr("ScaleForce")),
                               PAIR(ScalingFilter, Fsr, tr("AMD FidelityFX™️ Super Resolution")),
                               PAIR(ScalingFilter, Area, tr("Area")),
+                              PAIR(ScalingFilter, Mmpx, tr("MMPX")),
                           }});
     translations->insert({Settings::EnumMetadata<Settings::AntiAliasing>::Index(),
                           {

src/qt_common/shared_translation.h

@@ -38,9 +38,9 @@ static const std::map<Settings::ScalingFilter, QString> scaling_filter_texts_map
     {Settings::ScalingFilter::Bilinear,
      QStringLiteral(QT_TRANSLATE_NOOP("GMainWindow", "Bilinear"))},
     {Settings::ScalingFilter::Bicubic, QStringLiteral(QT_TRANSLATE_NOOP("GMainWindow", "Bicubic"))},
-    {Settings::ScalingFilter::ZeroTangent, QStringLiteral(QT_TRANSLATE_NOOP("GMainWindow", "Zero-Tangent-Cardinal"))},
+    {Settings::ScalingFilter::ZeroTangent, QStringLiteral(QT_TRANSLATE_NOOP("GMainWindow", "Zero-Tangent"))},
     {Settings::ScalingFilter::BSpline, QStringLiteral(QT_TRANSLATE_NOOP("GMainWindow", "B-Spline"))},
-    {Settings::ScalingFilter::Mitchell, QStringLiteral(QT_TRANSLATE_NOOP("GMainWindow", "Mitchell-Netravali"))},
+    {Settings::ScalingFilter::Mitchell, QStringLiteral(QT_TRANSLATE_NOOP("GMainWindow", "Mitchell"))},
      {Settings::ScalingFilter::Spline1,
      QStringLiteral(QT_TRANSLATE_NOOP("GMainWindow", "Spline-1"))},
     {Settings::ScalingFilter::Gaussian,
@@ -51,6 +51,7 @@ static const std::map<Settings::ScalingFilter, QString> scaling_filter_texts_map
      QStringLiteral(QT_TRANSLATE_NOOP("GMainWindow", "ScaleForce"))},
     {Settings::ScalingFilter::Fsr, QStringLiteral(QT_TRANSLATE_NOOP("GMainWindow", "FSR"))},
     {Settings::ScalingFilter::Area, QStringLiteral(QT_TRANSLATE_NOOP("GMainWindow", "Area"))},
+    {Settings::ScalingFilter::Mmpx, QStringLiteral(QT_TRANSLATE_NOOP("GMainWindow", "MMPX"))},
 };
 
 static const std::map<Settings::ConsoleMode, QString> use_docked_mode_texts_map = {

src/video_core/host_shaders/CMakeLists.txt

@@ -50,6 +50,7 @@ set(SHADER_FILES
     present_gaussian.frag
     present_lanczos.frag
     present_spline1.frag
+    present_mmpx.frag
     queries_prefix_scan_sum.comp
     queries_prefix_scan_sum_nosubgroups.comp
     resolve_conditional_render.comp

src/video_core/host_shaders/present_bicubic.frag

@@ -1,3 +1,5 @@
+// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
 // SPDX-FileCopyrightText: Copyright 2021 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 #version 460 core

src/video_core/host_shaders/present_bspline.frag

@@ -1,5 +1,5 @@
-// SPDX-FileCopyrightText: Copyright 2021 yuzu Emulator Project
-// SPDX-License-Identifier: GPL-2.0-or-later
+// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
 #version 460 core
 layout (location = 0) in vec2 frag_tex_coord;
 layout (location = 0) out vec4 color;

src/video_core/host_shaders/present_mitchell.frag

@@ -1,5 +1,5 @@
-// SPDX-FileCopyrightText: Copyright 2021 yuzu Emulator Project
-// SPDX-License-Identifier: GPL-2.0-or-later
+// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
 #version 460 core
 layout (location = 0) in vec2 frag_tex_coord;
 layout (location = 0) out vec4 color;

src/video_core/host_shaders/present_mmpx.frag

@@ -0,0 +1,131 @@
+// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+// Copyright 2023 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#version 460 core
+layout(location = 0) in vec2 tex_coord;
+layout(location = 0) out vec4 frag_color;
+layout(binding = 0) uniform sampler2D tex;
+
+#define src(x, y) texture(tex, coord + vec2(x, y) * 1.0 / source_size)
+
+float luma(vec4 col) {
+    return dot(col.rgb, vec3(0.2126, 0.7152, 0.0722)) * (1.0 - col.a);
+}
+
+bool same(vec4 B, vec4 A0) {
+    return all(equal(B, A0));
+}
+
+bool notsame(vec4 B, vec4 A0) {
+    return any(notEqual(B, A0));
+}
+
+bool all_eq2(vec4 B, vec4 A0, vec4 A1) {
+    return (same(B,A0) && same(B,A1));
+}
+
+bool all_eq3(vec4 B, vec4 A0, vec4 A1, vec4 A2) {
+    return (same(B,A0) && same(B,A1) && same(B,A2));
+}
+
+bool all_eq4(vec4 B, vec4 A0, vec4 A1, vec4 A2, vec4 A3) {
+    return (same(B,A0) && same(B,A1) && same(B,A2) && same(B,A3));
+}
+
+bool any_eq3(vec4 B, vec4 A0, vec4 A1, vec4 A2) {
+    return (same(B,A0) || same(B,A1) || same(B,A2));
+}
+
+bool none_eq2(vec4 B, vec4 A0, vec4 A1) {
+    return (notsame(B,A0) && notsame(B,A1));
+}
+
+bool none_eq4(vec4 B, vec4 A0, vec4 A1, vec4 A2, vec4 A3) {
+    return (notsame(B,A0) && notsame(B,A1) && notsame(B,A2) && notsame(B,A3));
+}
+
+void main()
+{
+    vec2 source_size = vec2(textureSize(tex, 0));
+    vec2 pos = fract(tex_coord * source_size) - vec2(0.5, 0.5);
+    vec2 coord = tex_coord - pos / source_size;
+
+    vec4 E = src(0.0,0.0);
+
+    vec4 A = src(-1.0,-1.0);
+    vec4 B = src(0.0,-1.0);
+    vec4 C = src(1.0,-1.0);
+
+    vec4 D = src(-1.0,0.0);
+    vec4 F = src(1.0,0.0);
+
+    vec4 G = src(-1.0,1.0);
+    vec4 H = src(0.0,1.0);
+    vec4 I = src(1.0,1.0);
+
+    vec4 J = E;
+    vec4 K = E;
+    vec4 L = E;
+    vec4 M = E;
+
+    frag_color = E;
+
+    if(same(E,A) && same(E,B) && same(E,C) && same(E,D) && same(E,F) && same(E,G) && same(E,H) && same(E,I)) return;
+
+    vec4 P  = src(0.0,2.0);
+    vec4 Q  = src(-2.0,0.0);
+    vec4 R  = src(2.0,0.0);
+    vec4 S  = src(0.0,2.0);
+
+    float Bl = luma(B);
+    float Dl = luma(D);
+    float El = luma(E);
+    float Fl = luma(F);
+    float Hl = luma(H);
+
+    if (((same(D,B) && notsame(D,H) && notsame(D,F))) && ((El>=Dl) || same(E,A)) && any_eq3(E,A,C,G) && ((El<Dl) || notsame(A,D) || notsame(E,P) || notsame(E,Q))) J=mix(D, J, 0.5);
+    if (((same(B,F) && notsame(B,D) && notsame(B,H))) && ((El>=Bl) || same(E,C)) && any_eq3(E,A,C,I) && ((El<Bl) || notsame(C,B) || notsame(E,P) || notsame(E,R))) K=mix(B, K, 0.5);
+    if (((same(H,D) && notsame(H,F) && notsame(H,B))) && ((El>=Hl) || same(E,G)) && any_eq3(E,A,G,I) && ((El<Hl) || notsame(G,H) || notsame(E,S) || notsame(E,Q))) L=mix(H, L, 0.5);
+    if (((same(F,H) && notsame(F,B) && notsame(F,D))) && ((El>=Fl) || same(E,I)) && any_eq3(E,C,G,I) && ((El<Fl) || notsame(I,H) || notsame(E,R) || notsame(E,S))) M=mix(F, M, 0.5);
+
+    if ((notsame(E,F) && all_eq4(E,C,I,D,Q) && all_eq2(F,B,H)) && notsame(F,src(3.0,0.0))) {M=mix(M, F, 0.5); K=mix(K, M, 0.5);};
+    if ((notsame(E,D) && all_eq4(E,A,G,F,R) && all_eq2(D,B,H)) && notsame(D,src(-3.0,0.0))) {L=mix(L, D, 0.5); J=mix(J, L, 0.5);};
+    if ((notsame(E,H) && all_eq4(E,G,I,B,P) && all_eq2(H,D,F)) && notsame(H,src(0.0,3.0))) {M=mix(M, H, 0.5); L=mix(L, M, 0.5);};
+    if ((notsame(E,B) && all_eq4(E,A,C,H,S) && all_eq2(B,D,F)) && notsame(B,src(0.0,-3.0))) {K=mix(K, B, 0.5); J=mix(J, K, 0.5);};
+
+    if ((Bl<El) && all_eq4(E,G,H,I,S) && none_eq4(E,A,D,C,F)) {K=mix(K, B, 0.5); J=mix(J, K, 0.5);}
+    if ((Hl<El) && all_eq4(E,A,B,C,P) && none_eq4(E,D,G,I,F)) {M=mix(M, H, 0.5); L=mix(L, M, 0.5);}
+    if ((Fl<El) && all_eq4(E,A,D,G,Q) && none_eq4(E,B,C,I,H)) {M=mix(M, F, 0.5); K=mix(K, M, 0.5);}
+    if ((Dl<El) && all_eq4(E,C,F,I,R) && none_eq4(E,B,A,G,H)) {L=mix(L, D, 0.5); J=mix(J, L, 0.5);}
+
+    if (notsame(H,B)) {
+        if (notsame(H,A) && notsame(H,E) && notsame(H,C)) {
+            if (all_eq3(H,G,F,R) && none_eq2(H,D,src(2.0,-1.0))) L=mix(M, L, 0.5);
+            if (all_eq3(H,I,D,Q) && none_eq2(H,F,src(-2.0,-1.0))) M=mix(L, M, 0.5);
+        }
+
+        if (notsame(B,I) && notsame(B,G) && notsame(B,E)) {
+            if (all_eq3(B,A,F,R) && none_eq2(B,D,src(2.0,1.0))) J=mix(K, L, 0.5);
+            if (all_eq3(B,C,D,Q) && none_eq2(B,F,src(-2.0,1.0))) K=mix(J, K, 0.5);
+        }
+    }
+
+    if (notsame(F,D)) {
+        if (notsame(D,I) && notsame(D,E) && notsame(D,C)) {
+            if (all_eq3(D,A,H,S) && none_eq2(D,B,src(1.0,2.0))) J=mix(L, J, 0.5);
+            if (all_eq3(D,G,B,P) && none_eq2(D,H,src(1.0,2.0))) L=mix(J, L, 0.5);
+        }
+
+        if (notsame(F,E) && notsame(F,A) && notsame(F,G)) {
+            if (all_eq3(F,C,H,S) && none_eq2(F,B,src(-1.0,2.0))) K=mix(M, K, 0.5);
+            if (all_eq3(F,I,B,P) && none_eq2(F,H,src(-1.0,-2.0))) M=mix(K, M, 0.5);
+        }
+    }
+
+    vec2 a = fract(tex_coord * source_size);
+    vec4 colour = (a.x < 0.5) ? (a.y < 0.5 ? J : L) : (a.y < 0.5 ? K : M);
+    frag_color = colour;
+}

src/video_core/host_shaders/present_zero_tangent.frag

@@ -1,5 +1,5 @@
-// SPDX-FileCopyrightText: Copyright 2021 yuzu Emulator Project
-// SPDX-License-Identifier: GPL-2.0-or-later
+// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
 #version 460 core
 layout (location = 0) in vec2 frag_tex_coord;
 layout (location = 0) out vec4 color;

src/video_core/renderer_opengl/gl_blit_screen.cpp

@@ -111,6 +111,9 @@ void BlitScreen::CreateWindowAdapt() {
     case Settings::ScalingFilter::Area:
         window_adapt = MakeArea(device);
         break;
+    case Settings::ScalingFilter::Mmpx:
+        window_adapt = MakeMmpx(device);
+        break;
     case Settings::ScalingFilter::Fsr:
     case Settings::ScalingFilter::Bilinear:
     default:

src/video_core/renderer_opengl/present/filters.cpp

@@ -17,6 +17,7 @@
 #include "video_core/host_shaders/present_mitchell_frag.h"
 #include "video_core/host_shaders/present_bspline_frag.h"
 #include "video_core/host_shaders/present_zero_tangent_frag.h"
+#include "video_core/host_shaders/present_mmpx_frag.h"
 #include "video_core/renderer_opengl/present/filters.h"
 #include "video_core/renderer_opengl/present/util.h"
 
@@ -78,4 +79,9 @@ std::unique_ptr<WindowAdaptPass> MakeArea(const Device& device) {
                                              HostShaders::PRESENT_AREA_FRAG);
 }
 
+std::unique_ptr<WindowAdaptPass> MakeMmpx(const Device& device) {
+    return std::make_unique<WindowAdaptPass>(device, CreateNearestNeighborSampler(),
+                                             HostShaders::PRESENT_MMPX_FRAG);
+}
+
 } // namespace OpenGL

src/video_core/renderer_opengl/present/filters.h

@@ -25,5 +25,6 @@ std::unique_ptr<WindowAdaptPass> MakeSpline1(const Device& device);
 std::unique_ptr<WindowAdaptPass> MakeLanczos(const Device& device);
 std::unique_ptr<WindowAdaptPass> MakeScaleForce(const Device& device);
 std::unique_ptr<WindowAdaptPass> MakeArea(const Device& device);
+std::unique_ptr<WindowAdaptPass> MakeMmpx(const Device& device);
 
 } // namespace OpenGL

src/video_core/renderer_vulkan/present/filters.cpp

@@ -19,6 +19,7 @@
 #include "video_core/host_shaders/present_mitchell_frag_spv.h"
 #include "video_core/host_shaders/present_bspline_frag_spv.h"
 #include "video_core/host_shaders/present_zero_tangent_frag_spv.h"
+#include "video_core/host_shaders/present_mmpx_frag_spv.h"
 #include "video_core/host_shaders/vulkan_present_frag_spv.h"
 #include "video_core/host_shaders/vulkan_present_scaleforce_fp16_frag_spv.h"
 #include "video_core/host_shaders/vulkan_present_scaleforce_fp32_frag_spv.h"
@@ -101,4 +102,9 @@ std::unique_ptr<WindowAdaptPass> MakeArea(const Device& device, VkFormat frame_f
                                              BuildShader(device, PRESENT_AREA_FRAG_SPV));
 }
 
+std::unique_ptr<WindowAdaptPass> MakeMmpx(const Device& device, VkFormat frame_format) {
+    return std::make_unique<WindowAdaptPass>(device, frame_format, CreateNearestNeighborSampler(device),
+                                             BuildShader(device, PRESENT_MMPX_FRAG_SPV));
+}
+
 } // namespace Vulkan

src/video_core/renderer_vulkan/present/filters.h

@@ -23,5 +23,6 @@ std::unique_ptr<WindowAdaptPass> MakeGaussian(const Device& device, VkFormat fra
 std::unique_ptr<WindowAdaptPass> MakeLanczos(const Device& device, VkFormat frame_format);
 std::unique_ptr<WindowAdaptPass> MakeScaleForce(const Device& device, VkFormat frame_format);
 std::unique_ptr<WindowAdaptPass> MakeArea(const Device& device, VkFormat frame_format);
+std::unique_ptr<WindowAdaptPass> MakeMmpx(const Device& device, VkFormat frame_format);
 
 } // namespace Vulkan

src/video_core/renderer_vulkan/vk_blit_screen.cpp

@@ -68,6 +68,9 @@ void BlitScreen::SetWindowAdaptPass() {
     case Settings::ScalingFilter::Area:
         window_adapt = MakeArea(device, swapchain_view_format);
         break;
+    case Settings::ScalingFilter::Mmpx:
+        window_adapt = MakeMmpx(device, swapchain_view_format);
+        break;
     case Settings::ScalingFilter::Fsr:
     case Settings::ScalingFilter::Bilinear:
     default: