Play with up to 10 consoles through an in-editor relay

.github/workflows/build.yml

@@ -292,6 +292,9 @@ jobs:
       - name: Triangles the engine lost, in the Game view and Render buffers
         if: runner.os == 'Linux'
         run: LIBGL_ALWAYS_SOFTWARE=1 xvfb-run -a -s "-screen 0 1600x960x24" python3 tests/renderlostcheck.py build/splashedit
+      - name: Play with 4 consoles through the relay, grid and Network view
+        if: runner.os == 'Linux'
+        run: LIBGL_ALWAYS_SOFTWARE=1 xvfb-run -a -s "-screen 0 1600x960x24" python3 tests/relayviewcheck.py build/splashedit
       - name: Far scenery pops in, warned with its fog fix
         if: runner.os == 'Linux'
         run: LIBGL_ALWAYS_SOFTWARE=1 xvfb-run -a -s "-screen 0 1600x960x24" python3 tests/farpopcheck.py build/splashedit

CMakeLists.txt

@@ -93,6 +93,7 @@ add_library(splasheditdoc STATIC
     src/editor/lua_editor.cpp
     src/editor/play.cpp
     src/editor/linkplay.cpp
+    src/editor/relay.cpp
     src/editor/model_import.cpp
     src/editor/project.cpp
     src/editor/serial.cpp

src/editor/play.cpp

@@ -44,7 +44,11 @@ PlayTools loadPlayTools(const fs::path& file) {
         else if (key == "overlay_perf") t.overlayPerf = value == "1";
         else if (key == "overlay_rooms") t.overlayRooms = value == "1";
         else if (key == "boot_logo") t.bootLogo = value != "0";
-        else if (key == "players") t.players = value == "2" ? 2 : 1;
+        else if (key == "players") {
+            char* end = nullptr;
+            const long n = std::strtol(value.c_str(), &end, 10);
+            t.players = value.empty() || *end ? 1 : int(std::clamp<long>(n, 1, kMaxPlayers));
+        } else if (key == "relay") t.relay = value == "1";
     }
     return t;
 }
@@ -61,7 +65,8 @@ bool savePlayTools(const fs::path& file, const PlayTools& t) {
         << "overlay_perf=" << (t.overlayPerf ? 1 : 0) << "\n"
         << "overlay_rooms=" << (t.overlayRooms ? 1 : 0) << "\n"
         << "boot_logo=" << (t.bootLogo ? 1 : 0) << "\n"
-        << "players=" << (t.players == 2 ? 2 : 1) << "\n";
+        << "players=" << std::clamp(t.players, 1, kMaxPlayers) << "\n"
+        << "relay=" << (t.relay ? 1 : 0) << "\n";
     return bool(out);
 }
 

src/editor/play.hh

@@ -26,13 +26,20 @@ struct PlayTools {
     std::string port;  // Run on hardware: a serial port, or tcp:HOST:PORT
     bool overlayPerf = false, overlayRooms = false;
     bool bootLogo = true;
-    // Play boots 1 console, or 2 linked over SIO1 (editor/linkplay.hh).
+    // Play boots 1 console, or 2 to kMaxPlayers linked ones. 2 are linked
+    // to each other over SIO1 (editor/linkplay.hh) unless `relay` is on;
+    // 3 or more always go through the editor's relay (editor/relay.hh).
     int players = 1;
+    bool relay = false;
 };
+inline constexpr int kMaxPlayers = 10;
+// Whether a Play with these tools runs its consoles through the relay.
+inline bool usesRelay(const PlayTools& t) { return t.players >= 3 || (t.players == 2 && t.relay); }
 
 // key=value lines: redux=, psxsplash=, bios=, disc=, port=, overlay_perf=,
-// overlay_rooms=, boot_logo= (1 or 0), players= (1 or 2). A missing file or
-// key reads as empty or off, but boot_logo as on and players as 1.
+// overlay_rooms=, boot_logo= (1 or 0), players= (1 to kMaxPlayers, clamped),
+// relay= (1 or 0). A missing file or key reads as empty or off, but boot_logo
+// as on and players as 1 (also for a value that is not a number).
 PlayTools loadPlayTools(const std::filesystem::path& file);
 bool savePlayTools(const std::filesystem::path& file, const PlayTools& tools);