Develop

.github/workflows/build.yml

@@ -26,6 +26,9 @@ jobs:
           python -m py_compile \
             tools/patch_ndsrecomp_mph_runtime.py \
             tools/patch_ndsrecomp_mph_adaptive_capability.py \
+            tools/patch_ndsrecomp_mph_aspect_ratio_mod.py \
+            tools/patch_ndsrecomp_nearest_presentation.py \
+            tools/patch_mph_launcher_aspect_mod.py \
             tools/patch_ndsrecomp_rom_free_release.py \
             tools/patch_recomp_ui_mph_multirom.py \
             tools/ci/check_rom_free_release_sources.py \

.github/workflows/mph-multirom-static.yml

@@ -34,7 +34,11 @@ jobs:
             tools/patch_ndsrecomp_mph_runtime.py \
             tools/patch_ndsrecomp_mph_runtime_core.py \
             tools/patch_ndsrecomp_mph_widescreen.py \
+            tools/patch_ndsrecomp_mph_adaptive_capability.py \
             tools/patch_ndsrecomp_mph_widescreen_reset.py \
+            tools/patch_ndsrecomp_mph_aspect_ratio_mod.py \
+            tools/patch_ndsrecomp_nearest_presentation.py \
+            tools/patch_mph_launcher_aspect_mod.py \
             tools/promote_mph_static_coverage.py \
             tools/promote_mph_runtime_coverage.py \
             tools/probe_mph_wfc.py \
@@ -199,8 +203,11 @@ jobs:
           for file in /tmp/mph-launcher-us10/launcher_main_profile.cpp /tmp/mph-launcher-eu11/launcher_main_profile.cpp; do
             grep -q 'game.known_sha1_hex = nullptr;' "$file"
             grep -q 'game.num_known_sha1 = 0;' "$file"
-            grep -A1 'int mod_feature_count' "$file" | grep -q 'return 3;'
+            grep -A1 'int mod_feature_count' "$file" | grep -q 'return 4;'
             grep -q 'copy_text(output->id, "hd-rendering")' "$file"
+            grep -q 'copy_text(output->id, "game-aspect-ratio-patch")' "$file"
+            grep -q 'bool aspect_ratio_patch = false;' "$file"
+            grep -q -- '--mph-aspect-ratio-patch' "$file"
             grep -q -- '--firmware-state-path' "$file"
             grep -q 'bool adaptive_widescreen = true;' "$file"
             grep -q 'std::filesystem::is_regular_file(default_rom, initial_rom_error)' "$file"
@@ -234,8 +241,19 @@ jobs:
           diff -u /tmp/first.sha256 /tmp/second.sha256
           grep -q 'nds_title_patches_select_mph_runtime_profile' /tmp/ndsrecomp/runner/src/main.cpp
           grep -q 'nds_title_patches_set_mph_adaptive' /tmp/ndsrecomp/runner/src/main.cpp
+          grep -q -- '--mph-aspect-ratio-patch' /tmp/ndsrecomp/runner/src/main.cpp
           grep -q 'slirp_virtual_network_instance' /tmp/ndsrecomp/runner/src/main.cpp
           grep -q '0x02111B5Cu, 0x0211D208u, 0x02111380u' /tmp/ndsrecomp/runner/src/mph_widescreen_profiles.generated.h
+          grep -q 'SDL_SetHintWithPriority(SDL_HINT_RENDER_SCALE_QUALITY, "0"' /tmp/ndsrecomp/runner/src/frontend.cpp
+          test "$(grep -c 'SDL_SetTextureScaleMode' /tmp/ndsrecomp/runner/src/frontend.cpp)" -ge 2
+          if grep -A3 'SDL_HINT_RENDER_SCALE_QUALITY' /tmp/ndsrecomp/runner/src/frontend.cpp | grep -q '"1"'; then
+            echo 'linear SDL framebuffer scaling unexpectedly remains enabled' >&2
+            exit 1
+          fi
+          grep -q 'GL_TEXTURE_MIN_FILTER, GL_NEAREST' /tmp/ndsrecomp/runner/src/melonds_compute/ComputeHost.cpp
+          grep -q 'GL_TEXTURE_MAG_FILTER, GL_NEAREST' /tmp/ndsrecomp/runner/src/melonds_compute/ComputeHost.cpp
+          grep -q 'GL_TEXTURE_MIN_FILTER, GL_NEAREST' /tmp/ndsrecomp/runner/vendor/melonds/GPU3D_Compute.cpp
+          grep -q 'GL_TEXTURE_MAG_FILTER, GL_NEAREST' /tmp/ndsrecomp/runner/vendor/melonds/GPU3D_Compute.cpp
           ! grep -q 'kMphUs10MorphState' /tmp/ndsrecomp/runner/src/frontend.cpp
           ! grep -q 'kMphUs10AimX' /tmp/ndsrecomp/runner/src/title_patches.cpp
 

docs/WIDESCREEN_AB_TEST.md

@@ -0,0 +1,29 @@
+# Widescreen modes
+
+The launcher exposes two alternative widescreen implementations:
+
+- **Adaptive Widescreen** — the original ndsrecomp host-side 448px renderer / compositor / HUD anchoring path.
+- **Game Aspect Ratio Patch** — the MPH guest-side 21:9 projection/culling patch derived from melonPrimeDS and mphCodex.
+
+They are **mutually exclusive**. Turning either widescreen feature ON immediately turns the other one OFF. Both may be OFF for native 4:3 output, but both may not be ON at the same time.
+
+The game-side patch defaults **OFF**, so the original ndsrecomp Adaptive Widescreen implementation remains the default widescreen path.
+
+## Valid combinations
+
+| Adaptive Widescreen | Game Aspect Ratio Patch | Result |
+|---|---|---|
+| OFF | OFF | Native 4:3 / 256x192 |
+| ON | OFF | Original ndsrecomp host widescreen only |
+| OFF | ON | Guest projection/culling patch; native 256x192 top image is stretched to 448x192 only at final presentation |
+| ON | ON | **Invalid state** — the launcher automatically switches one side OFF |
+
+When only the guest patch is enabled, the DS-native render surface remains 256x192. The final 256-to-448 stretch is required because the game-side patch produces projection geometry for a 21:9 target; displaying the resulting native surface unchanged as 4:3 would make it appear horizontally compressed.
+
+Legacy `mods.ini` files from the comparison build may contain both values as `true`. The loader resolves that state while parsing and the next save writes a valid mutually-exclusive pair. The final process-launch argument construction also refuses to pass both widescreen mechanisms to the runner even if an invalid state is somehow introduced later.
+
+The runner logs the selected guest policy. Guest-side code/data writes remain fail-closed and require an authoritative supported MPH executable checksum; header-only fallback never authorizes the aspect-ratio patch.
+
+## Validation
+
+The separate host-only / guest-only presentation paths and the nearest-only Supersampling presentation fix were visually tested with MPH before mutual exclusion was enabled. The current launcher policy then passed the full ROM-free Windows/Linux build and static regression suite at head `50271f43a4d0be9fe4c02a87c278bec80f4a4a47`.

launcher/recomp-ui/CMakeLists.txt

@@ -72,10 +72,29 @@ set(MPH_PROFILE_LAUNCHER_SOURCE
     "${CMAKE_CURRENT_BINARY_DIR}/launcher_main_profile.cpp")
 file(WRITE "${MPH_PROFILE_LAUNCHER_SOURCE}" "${MPH_LAUNCHER_SOURCE}")
 
-# Configure-time regression guard for the fresh-release UX.  The generated
-# launcher must never pass a missing conventional ROM path into recomp-ui as if
-# the user had selected it.  This deliberately tests the generated TU rather
-# than the untransformed upstream-tracking source.
+# MPH display policy layer. Keep the upstream-tracking launcher source simple,
+# but expose the melonPrimeDS/mphCodex game-side projection/culling patch as a
+# separate Mods item in the generated launcher. It defaults OFF; the existing
+# Adaptive Widescreen feature remains the original host-side ndsrecomp path.
+# The two features are radio-button-like: enabling either disables the other.
+execute_process(
+    COMMAND "${Python3_EXECUTABLE}"
+        "${CMAKE_CURRENT_SOURCE_DIR}/../../tools/patch_mph_launcher_aspect_mod.py"
+        --source "${MPH_PROFILE_LAUNCHER_SOURCE}"
+    RESULT_VARIABLE _mph_aspect_mod_result
+    OUTPUT_VARIABLE _mph_aspect_mod_stdout
+    ERROR_VARIABLE _mph_aspect_mod_stderr)
+if(NOT _mph_aspect_mod_result EQUAL 0)
+    message(FATAL_ERROR
+        "Failed to add MPH launcher aspect-ratio mod:\n"
+        "${_mph_aspect_mod_stdout}${_mph_aspect_mod_stderr}")
+endif()
+message(STATUS "${_mph_aspect_mod_stdout}")
+file(READ "${MPH_PROFILE_LAUNCHER_SOURCE}" MPH_LAUNCHER_SOURCE)
+
+# Configure-time regression guards for the generated launcher. The release must
+# start without a fake ROM selection, and the two widescreen mechanisms must
+# remain separately addressable while never being enabled together.
 string(FIND "${MPH_LAUNCHER_SOURCE}"
     "std::filesystem::is_regular_file(default_rom, initial_rom_error)"
     _mph_initial_rom_exists_guard)
@@ -88,6 +107,48 @@ string(FIND "${MPH_LAUNCHER_SOURCE}"
 if(_mph_initial_rom_argument_guard EQUAL -1)
     message(FATAL_ERROR "generated launcher still passes the unconditional default ROM path")
 endif()
+string(FIND "${MPH_LAUNCHER_SOURCE}"
+    "mph-game-aspect-ratio-patch"
+    _mph_aspect_mod_feature_guard)
+if(_mph_aspect_mod_feature_guard EQUAL -1)
+    message(FATAL_ERROR "generated launcher lost the Game Aspect Ratio Patch Mods feature")
+endif()
+string(FIND "${MPH_LAUNCHER_SOURCE}"
+    "--mph-aspect-ratio-patch"
+    _mph_aspect_mod_arg_guard)
+if(_mph_aspect_mod_arg_guard EQUAL -1)
+    message(FATAL_ERROR "generated launcher does not pass the guest aspect-ratio policy to nds_runner")
+endif()
+string(FIND "${MPH_LAUNCHER_SOURCE}"
+    "bool aspect_ratio_patch = false;"
+    _mph_aspect_mod_default_guard)
+if(_mph_aspect_mod_default_guard EQUAL -1)
+    message(FATAL_ERROR "Game Aspect Ratio Patch must remain opt-in by default")
+endif()
+string(FIND "${MPH_LAUNCHER_SOURCE}"
+    "MPH_WIDESCREEN_MUTUAL_EXCLUSION"
+    _mph_widescreen_exclusion_guard)
+if(_mph_widescreen_exclusion_guard EQUAL -1)
+    message(FATAL_ERROR "generated launcher lost widescreen mutual-exclusion logic")
+endif()
+string(FIND "${MPH_LAUNCHER_SOURCE}"
+    "if (state->adaptive_widescreen) state->aspect_ratio_patch = false;"
+    _mph_adaptive_disables_guest_guard)
+if(_mph_adaptive_disables_guest_guard EQUAL -1)
+    message(FATAL_ERROR "Adaptive Widescreen no longer disables Game Aspect Ratio Patch")
+endif()
+string(FIND "${MPH_LAUNCHER_SOURCE}"
+    "if (state->aspect_ratio_patch) state->adaptive_widescreen = false;"
+    _mph_guest_disables_adaptive_guard)
+if(_mph_guest_disables_adaptive_guard EQUAL -1)
+    message(FATAL_ERROR "Game Aspect Ratio Patch no longer disables Adaptive Widescreen")
+endif()
+string(FIND "${MPH_LAUNCHER_SOURCE}"
+    "((adaptive && !mods.aspect_ratio_patch) ? L\"top\" : L\"none\")"
+    _mph_runner_exclusion_guard)
+if(_mph_runner_exclusion_guard EQUAL -1)
+    message(FATAL_ERROR "runner launch path can pass both widescreen implementations")
+endif()
 
 add_executable(mph-recomp-ui "${MPH_PROFILE_LAUNCHER_SOURCE}"
     "${NDSRECOMP_ROOT}/recompiler/support/sha1.cpp")
@@ -128,7 +189,9 @@ endif()
 enable_testing()
 add_executable(mph-mod-provider-test tests/launcher_mod_provider_test.cpp
     "${NDSRECOMP_ROOT}/recompiler/support/sha1.cpp")
-# The test #includes launcher_main.cpp whole, so it needs ndsrecomp's sha1.h.
+# The baseline provider test still covers the upstream-tracking source. The
+# generated launcher itself is compiled above and guarded for the additional
+# MPH aspect-ratio feature at configure time.
 target_include_directories(mph-mod-provider-test PRIVATE
     "${NDSRECOMP_ROOT}/recompiler/support"
     "${CMAKE_CURRENT_SOURCE_DIR}"
@@ -143,4 +206,4 @@ include("${RECOMP_UI_ROOT}/recomp_ui.cmake")
 recomp_target_launcher_ui(mph-recomp-ui CONSOLE nds
     BOXART "${CMAKE_CURRENT_SOURCE_DIR}/assets/boxart.tga")
 
-add_test(NAME mph_mod_provider_test COMMAND mph-mod-provider-test)
+add_test(NAME mph_mod_provider_test COMMAND mph-mod-provider-test)