Multiplayer review and fixes, shared traffic in multiplayer cruise (0.2.0)

CMakeLists.txt

@@ -1,7 +1,7 @@
 cmake_minimum_required(VERSION 3.25...4.0)
 
 project(OpenMM2
-    VERSION 0.1.0
+    VERSION 0.2.0
     DESCRIPTION "Open source reimplementation of Midtown Madness 2"
     HOMEPAGE_URL "https://github.com/lowlevelmetal/OpenMM2"
     LANGUAGES C CXX)

cmake/Fonts.cmake

@@ -18,16 +18,22 @@ function(openmm2_fetch_archive name sha256)
     endif()
     set(archive "${OPENMM2_FONT_CACHE}/${name}.download")
     foreach(url IN LISTS ARGN)
-        file(DOWNLOAD "${url}" "${archive}" EXPECTED_HASH SHA256=${sha256} STATUS status TIMEOUT 120
-             INACTIVITY_TIMEOUT 30)
+        # The hash is checked after the download: with EXPECTED_HASH a failed
+        # download is a CMake error ("cannot compute hash on failed download"),
+        # which ends the configure before the other mirrors are tried.
+        file(DOWNLOAD "${url}" "${archive}" STATUS status TIMEOUT 120 INACTIVITY_TIMEOUT 30)
         list(GET status 0 code)
         if(code EQUAL 0)
-            file(REMOVE_RECURSE "${dir}")
-            file(ARCHIVE_EXTRACT INPUT "${archive}" DESTINATION "${dir}")
-            file(REMOVE "${archive}")
-            file(TOUCH "${dir}/.complete")
-            set(${name}_DIR "${dir}" PARENT_SCOPE)
-            return()
+            file(SHA256 "${archive}" actual)
+            if(actual STREQUAL sha256)
+                file(REMOVE_RECURSE "${dir}")
+                file(ARCHIVE_EXTRACT INPUT "${archive}" DESTINATION "${dir}")
+                file(REMOVE "${archive}")
+                file(TOUCH "${dir}/.complete")
+                set(${name}_DIR "${dir}" PARENT_SCOPE)
+                return()
+            endif()
+            set(status "SHA256 ${actual}, expected ${sha256}")
         endif()
         message(STATUS "Font download failed from ${url}: ${status}")
     endforeach()

docs/ai.md

@@ -346,7 +346,19 @@ MM2's pedestrians (build 3393, **MM2** unless marked):
 * Pedestrians are not collidable: cars drive through them (no ragdoll in
   MM2). They ignore each other and other cars.
 
-**Deviations** (marked in the code): a single player; the ground and wall
+**Players.** MM2's traffic is written for a list of players (aiMap +0x170,
+`aiMap::AddPlayer` / `RemovePlayer`, at most four): each player's room
+populates its roads with that player's bit in each road's mask
+(`aiPath::AddAmbPlayer` / `RemAmbPlayer`), a road no player keeps is emptied,
+and the goals walk the list for the first player in a car's way, keeping its
+index for `aiGoalAvoidPlayer` (aiVehicleSpline +0xe6). A single-player game
+has one; `ai::Traffic` keeps 16 slots for the shared traffic of a network
+cruise (an OpenMM2 extra), whose other players `World::setOtherPlayers`
+adds. The pedestrians stay the local player's (each machine its own, as in
+MM2's network games).
+
+**Deviations** (marked in the code): a single player (but the traffic's
+list, above); the ground and wall
 probes need the game's collision (`World::setProbe`), otherwise heights come
 from the sidewalk lines and there are no walls; the props come from the
 game (`Pedestrians::setObstacles`; inferred: the race's own props are placed

docs/frontend.md

@@ -580,8 +580,11 @@ vehicle|showcase|options|graphics|audio|control|customize|about|crashintro|
 crashlondon|crashsf|sessions|quit|message|delete>`,
 `mode:<cruise|blitz|circuit|race|crash>` and `city:<map>` (both apply the race
 defaults), `vehicle:<name>`, `go` (start the race), `result:<position>`,
-`nav:<up|down|left|right|accept|back|tab>`, `wait:<frames>`. Consecutive
-`nav:` commands need a `wait:1` between them.
+`nav:<up|down|left|right|accept|back|tab>`, `wait:<frames>`, `wait:race`
+(until a race has been driven). Consecutive `nav:` commands need a `wait:1`
+between them. The script runs once per process: after a race the menus carry
+on with the commands that followed the one that started it. The multiplayer
+commands are in docs/multiplayer.md.
 
 ## Not yet done
 

docs/gamemodes.md

@@ -274,7 +274,10 @@ player's target. When the host leaves the race everyone returns to the
 lobby (`BeDone(1)`, Quit2Lobby). A multiplayer race has no traffic,
 pedestrians, police or racers (the race modes load no AI map); multiplayer
 cruise and Cops and Robbers keep only the pedestrians
-(`mmGameMulti::Init` zeroes the traffic, cop and opponent densities).
+(`mmGameMulti::Init` zeroes the traffic, cop and opponent densities). As an
+OpenMM2 extra, a multiplayer cruise with the host's SHARED TRAFFIC option (on
+by default) has the host's traffic and police for everyone
+(docs/multiplayer.md, "Shared traffic"); off, it is MM2's.
 
 **Winning** (`mmSingleCircuit::ProgressCheck`, `mmSingleRace::ProgressCheck`):
 places 1-3 for amateurs, 1st for professionals, hard-coded; MM2 does not