Linux sdl port

CMakeLists.txt

@@ -22,10 +22,10 @@ endif()
 if(NOT DEFINED SNESRECOMP_ROOT)
     set(SNESRECOMP_ROOT ${CMAKE_CURRENT_SOURCE_DIR}/snesrecomp)
 endif()
-if(APPLE AND NOT DEFINED SNESRECOMP_SDL_BACKEND)
-    # The DKC1 macOS frontend currently uses SDL2's queued-audio API. Keep
-    # this project on the engine's explicit compatibility backend until its
-    # SDL3 audio-stream equivalent is implemented and validated.
+if(UNIX AND NOT DEFINED SNESRECOMP_SDL_BACKEND)
+    # The DKC1 SDL frontend currently uses SDL2's queued-audio API. Keep this
+    # project on the engine's explicit compatibility backend until its SDL3
+    # audio-stream equivalent is implemented and validated.
     set(SNESRECOMP_SDL_BACKEND "SDL2" CACHE STRING
         "Desktop SDL backend (SDL3 or SDL2)")
 endif()
@@ -85,6 +85,9 @@ target_compile_definitions(dkc1_snesrecomp_headless PRIVATE
     SNESRECOMP_REVERSE_DEBUG=0
     SNESRECOMP_EXTERNAL_RAM_ROUTINE_GUARDS=1
     SYSTEM_VOLUME_MIXER_AVAILABLE=0)
+if(UNIX)
+    target_compile_definitions(dkc1_snesrecomp_headless PRIVATE _GNU_SOURCE)
+endif()
 if(MSVC)
     # Do not use /MP here. This generated-source workload has reproduced an
     # MSVC race where cl.exe returns before every bank object is available to
@@ -147,3 +150,43 @@ if(APPLE)
         MACOSX_BUNDLE_SHORT_VERSION_STRING "${PROJECT_VERSION}"
         XCODE_ATTRIBUTE_CODE_SIGNING_ALLOWED "NO")
 endif()
+
+if(UNIX AND NOT APPLE)
+    if(NOT SNESRECOMP_SDL_BACKEND STREQUAL "SDL2")
+        message(FATAL_ERROR
+            "The DKC1 Linux frontend currently requires "
+            "-DSNESRECOMP_SDL_BACKEND=SDL2")
+    endif()
+
+    add_executable(dkc1_snesrecomp_sdl
+        ${DKC1_ENGINE_SOURCES}
+        ${DKC1_SNESRECOMP_GEN_SOURCES}
+        ${DKC1_RUNNER_SOURCES}
+        runner/headless_host.c
+        runner/dkc1_haptics.c
+        runner/dkc1_msu1.c
+        runner/sdl_host.c
+        runner/nonapple_sdl_platform.c)
+    target_include_directories(dkc1_snesrecomp_sdl PRIVATE
+        ${CMAKE_CURRENT_SOURCE_DIR}/runner
+        ${CMAKE_CURRENT_SOURCE_DIR}/recomp
+        ${SNESRECOMP_RUNNER_INCLUDE_DIRS}
+        ${SNESRECOMP_ROOT}/runner/src/desktop)
+    target_compile_definitions(dkc1_snesrecomp_sdl PRIVATE
+        _GNU_SOURCE
+        SNESRECOMP_TRACE=0
+        SNESRECOMP_REVERSE_DEBUG=0
+        SNESRECOMP_EXTERNAL_RAM_ROUTINE_GUARDS=1
+        SYSTEM_VOLUME_MIXER_AVAILABLE=0
+        DKC1_BUILD_COMMIT="${DKC1_BUILD_COMMIT}"
+        DKC1_BUILD_CONFIG="linux")
+    target_compile_options(dkc1_snesrecomp_sdl PRIVATE
+        -Wno-unused-function)
+    target_link_libraries(dkc1_snesrecomp_sdl PRIVATE
+        ${SNESRECOMP_RUNNER_LIBRARIES})
+    find_package(Threads REQUIRED)
+    target_link_libraries(dkc1_snesrecomp_sdl PRIVATE Threads::Threads)
+    snesrecomp_target_sdl(dkc1_snesrecomp_sdl)
+    set_target_properties(dkc1_snesrecomp_sdl PROPERTIES
+        OUTPUT_NAME "DKC1Recomp")
+endif()

README.md

@@ -7,7 +7,7 @@ framework — following the working [`DKC2Recomp`](https://github.com/Nicktendon
 project (same Rare engine family) as the template.
 
 **Status: playable bring-up.** The project has 100% statically generated game
-code, a headless validation host, playable Windows and native macOS hosts,
+code, a headless validation host, playable Windows, Linux SDL2, and native macOS hosts,
 continuous audio, and an opt-in 342x224 widescreen presentation path. See `docs/BRINGUP.md` for the
 chronological bring-up record and `docs/WIDESCREEN.md` for the widescreen
 architecture, ported SuperZSNES findings, validation, and limitations.
@@ -100,6 +100,33 @@ wall, black past the wall, or the earlier inward clamp. The headless validator a
 count and supports deterministic input playback and private frame/state
 captures; its environment variables are documented in `docs/BRINGUP.md`.
 
+### Linux
+
+Install a C compiler, CMake, Ninja, Python 3, Cargo, and the SDL2 development
+package. On Debian/Ubuntu:
+
+```sh
+sudo apt install build-essential cmake ninja-build python3 cargo libsdl2-dev
+```
+
+Then build both the playable SDL2 host and the headless validator. The first
+build uses the verified ROM to generate private ignored C sources; the ROM is
+never copied into the repository or executable.
+
+```sh
+git submodule update --init --recursive
+./build_linux.sh "/path/to/Donkey Kong Country (USA).sfc"
+./build/linux/DKC1Recomp
+```
+
+The Linux frontend accepts the ROM path as its first argument or through
+`DKC1_ROM`. It uses SDL2 for the window, keyboard/controller input, queued
+audio, fullscreen, and rendering. Native macOS menus and file pickers are not
+present, so Linux-only options use the existing environment variables. Keys
+match the other visible hosts: arrows, Z/X/S/A, Q/W, Return, Right Shift,
+F7/F8 pause and step, F9 export, F11/F12 quick save/load, Alt-Return
+fullscreen, and Escape to leave fullscreen or quit.
+
 ### macOS
 
 Install CMake, Ninja, and SDL2, then provide the same verified ROM the first

build_linux.sh

@@ -0,0 +1,44 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+if [[ "$(uname -s)" != "Linux" ]]; then
+  echo "error: build_linux.sh must run on Linux" >&2
+  exit 2
+fi
+
+repo_dir="$(cd "$(dirname "$0")" && pwd)"
+build_dir="$repo_dir/build/linux"
+rom_path="${1:-${DKC1_ROM:-}}"
+
+for tool in cc cmake ninja sdl2-config python3; do
+  if ! command -v "$tool" >/dev/null 2>&1; then
+    echo "error: missing required tool: $tool" >&2
+    echo "Install a C compiler, CMake, Ninja, Python 3, and SDL2 development files." >&2
+    exit 2
+  fi
+done
+
+if [[ ! -f "$repo_dir/snesrecomp/runner/runner.cmake" ]]; then
+  echo "error: snesrecomp is not initialized" >&2
+  echo "run: git submodule update --init --recursive" >&2
+  exit 2
+fi
+
+if ! compgen -G "$repo_dir/generated/snesrecomp/*.c" >/dev/null; then
+  if [[ -z "$rom_path" ]]; then
+    echo "error: private generated sources are missing" >&2
+    echo "usage: ./build_linux.sh '/path/to/Donkey Kong Country (USA).sfc'" >&2
+    exit 2
+  fi
+  python3 "$repo_dir/scripts/generate_snesrecomp.py" --rom "$rom_path"
+fi
+
+cmake -S "$repo_dir" -B "$build_dir" -G Ninja \
+  -DCMAKE_BUILD_TYPE=Release \
+  -DSNESRECOMP_SDL_BACKEND=SDL2 \
+  -DCMAKE_PREFIX_PATH="$(sdl2-config --prefix)"
+cmake --build "$build_dir" \
+  --target dkc1_snesrecomp_sdl dkc1_snesrecomp_headless --parallel
+
+echo "LINUX_BUILD_OK"
+echo "$build_dir/DKC1Recomp"

runner/nonapple_sdl_platform.c

@@ -0,0 +1,108 @@
+#include "macos_file_picker.h"
+#include "macos_metal_presenter.h"
+
+#include <stddef.h>
+
+/* The SDL frontend is shared with macOS, where these entry points provide
+ * native menus, file pickers, preferences, and display-linked Metal output.
+ * Linux deliberately keeps the command-line/environment configuration and
+ * ordinary SDL renderer path, so its platform adapters are inert. */
+
+char *Dkc1MacChooseRom(void) { return NULL; }
+char *Dkc1MacChooseBabyKongRom(void) { return NULL; }
+char *Dkc1MacSavedBabyKongRom(void) { return NULL; }
+void Dkc1MacSetBabyKongRom(const char *path) { (void)path; }
+int Dkc1MacSavedBabyKongEnabled(void) { return 0; }
+void Dkc1MacSetBabyKongEnabled(int enabled) { (void)enabled; }
+
+char *Dkc1MacChooseMsu1(void) { return NULL; }
+char *Dkc1MacSavedMsu1(void) { return NULL; }
+void Dkc1MacClearMsu1(void) {}
+
+Dkc1MacFullscreenScaling Dkc1MacSavedFullscreenScaling(void) {
+  return kDkc1MacFullscreenSharpBilinear;
+}
+
+void Dkc1MacSetFullscreenScaling(Dkc1MacFullscreenScaling scaling) {
+  (void)scaling;
+}
+
+Dkc1EdgePolicy Dkc1MacSavedWidescreenEdge(void) {
+  return kDkc1EdgeGlide;
+}
+
+void Dkc1MacSetWidescreenEdge(Dkc1EdgePolicy policy) { (void)policy; }
+
+void Dkc1MacInstallMenu(void) {}
+
+void Dkc1MacUpdateMenuState(int paused, int fullscreen,
+                            Dkc1MacFullscreenScaling fullscreen_scaling,
+                            Dkc1VideoAspect aspect, Dkc1EdgePolicy edge,
+                            unsigned char layer_mask, int provenance,
+                            int replacement_music, int baby_kong_enabled,
+                            int baby_kong_ready) {
+  (void)paused;
+  (void)fullscreen;
+  (void)fullscreen_scaling;
+  (void)aspect;
+  (void)edge;
+  (void)layer_mask;
+  (void)provenance;
+  (void)replacement_music;
+  (void)baby_kong_enabled;
+  (void)baby_kong_ready;
+}
+
+int Dkc1MacDisplayLinkStart(void *native_window, double preferred_fps) {
+  (void)native_window;
+  (void)preferred_fps;
+  return 0;
+}
+
+int Dkc1MacDisplayLinkWait(unsigned long long after_callback_number,
+                           double timeout_seconds, double *timestamp,
+                           double *target_timestamp, double *duration,
+                           unsigned long long *callback_number) {
+  (void)after_callback_number;
+  (void)timeout_seconds;
+  (void)timestamp;
+  (void)target_timestamp;
+  (void)duration;
+  (void)callback_number;
+  return 0;
+}
+
+void Dkc1MacDisplayLinkStop(void) {}
+
+int Dkc1MacMetalPresenterStart(void *native_window, double preferred_hz,
+                               Dkc1MacFullscreenScaling scaling,
+                               int fullscreen) {
+  (void)native_window;
+  (void)preferred_hz;
+  (void)scaling;
+  (void)fullscreen;
+  return 0;
+}
+
+void Dkc1MacMetalPresenterQueueFrame(
+    const uint32_t *pixels, int width, int height, int presentation_width,
+    const Dkc1MacPresentationFrameInfo *info) {
+  (void)pixels;
+  (void)width;
+  (void)height;
+  (void)presentation_width;
+  (void)info;
+}
+
+void Dkc1MacMetalPresenterSetGeometry(int presentation_width,
+                                      int fullscreen) {
+  (void)presentation_width;
+  (void)fullscreen;
+}
+
+void Dkc1MacMetalPresenterSetScaling(Dkc1MacFullscreenScaling scaling) {
+  (void)scaling;
+}
+
+void Dkc1MacMetalPresenterSetActive(int active) { (void)active; }
+void Dkc1MacMetalPresenterStop(void) {}