Update build.sh

.gitmodules

@@ -4,3 +4,6 @@
 [submodule "libs/SDL_image"]
 	path = libs/SDL_image
 	url = https://github.com/libsdl-org/SDL_image.git
+[submodule "libs/SDL_net"]
+	path = libs/SDL_net
+	url = https://github.com/libsdl-org/SDL_net.git

build.bat

@@ -17,17 +17,17 @@ set auto_compile_flags=
 if "%asan%"=="1"      set auto_compile_flags=%auto_compile_flags% -fsanitize=address && echo [asan enabled]
 
 :: --- Compile/Link Line Definitions ------------------------------------------
-set cl_common=     /I..\src\ /I..\libs\SDL\include\ /I..\libs\SDL_image\include\ /nologo /FC /Z7 /MD /W4 /wd4244 /wd4201
-set clang_common=  -I..\src\ -I..\libs\SDL\include\ -I..\libs\SDL_image\include\ -fdiagnostics-absolute-paths -Wall -Wno-unused-variable -Wno-missing-braces -Wno-unused-function -Wno-microsoft-static-assert -Wno-c2x-extensions
+set cl_common=     /I..\src\ /I..\libs\SDL\include\ /I..\libs\SDL_image\include\ -I..\libs\SDL_net\include\ /nologo /FC /Z7 /MD /W4 /wd4244 /wd4201
+set clang_common=  -I..\src\ -I..\libs\SDL\include\ -I..\libs\SDL_image\include\ -I..\libs\SDL_net\include\ -fdiagnostics-absolute-paths -Wall -Wno-unused-variable -Wno-missing-braces -Wno-unused-function -Wno-microsoft-static-assert -Wno-c2x-extensions
 set cl_debug=      call cl /Od /Ob1 /DBUILD_DEBUG=1 %cl_common% %auto_compile_flags%
 set cl_release=    call cl /O2 /DBUILD_DEBUG=0 %cl_common% %auto_compile_flags%
-set cl_libs=       User32.lib Advapi32.lib Shell32.lib Gdi32.lib Version.lib OleAut32.lib Imm32.lib Ole32.lib Cfgmgr32.lib Setupapi.lib Winmm.lib ..\libs\SDL\build\win\Debug\SDL3-static.lib ..\libs\SDL_image\build\win\Debug\SDL3_image-static.lib
+set cl_libs=       User32.lib Advapi32.lib Shell32.lib Gdi32.lib Version.lib OleAut32.lib Imm32.lib Ole32.lib Cfgmgr32.lib Setupapi.lib Winmm.lib Ws2_32.lib Iphlpapi.lib ..\libs\SDL\build\win\Debug\SDL3-static.lib ..\libs\SDL_image\build\win\Debug\SDL3_image-static.lib ..\libs\SDL_net\build\win\Debug\SDL3_net-static.lib
 set cl_link=       /link /SUBSYSTEM:WINDOWS /MANIFEST:EMBED /INCREMENTAL:NO /pdbaltpath:%%%%_PDB%%%% %cl_libs%
 set cl_out=        /out:
 
 set clang_debug=   call clang -g -O0 -DBUILD_DEBUG=1 %clang_common% %auto_compile_flags%
 set clang_release= call clang -g -O2 -DBUILD_DEBUG=0 %clang_common% %auto_compile_flags%
-set clang_libs=    -lUser32.lib -lAdvapi32.lib -lShell32.lib -lGdi32.lib -lVersion.lib -lOleAut32.lib -lImm32.lib -lOle32.lib -lCfgmgr32.lib -lSetupapi.lib -lWinmm.lib ..\libs\SDL\build\win\Debug\SDL3-static.lib ..\libs\SDL_image\build\win\Debug\SDL3_image-static.lib
+set clang_libs=    -lUser32.lib -lAdvapi32.lib -lShell32.lib -lGdi32.lib -lVersion.lib -lOleAut32.lib -lImm32.lib -lOle32.lib -lCfgmgr32.lib -lSetupapi.lib -lWinmm.lib -lWs2_32.lib -lIphlpapi.lib ..\libs\SDL\build\win\Debug\SDL3-static.lib ..\libs\SDL_image\build\win\Debug\SDL3_image-static.lib ..\libs\SDL_net\build\win\Debug\SDL3_net-static.lib
 set clang_link=    -fuse-ld=lld -Xlinker /SUBSYSTEM:WINDOWS -Xlinker /MANIFEST:EMBED -Xlinker /pdbaltpath:%%%%_PDB%%%% %clang_libs%
 set clang_out=     -o
 
@@ -78,6 +78,9 @@ if "%sdl%"=="1" (
         pushd libs\SDL_image
         (cmake -S . -B build\win -DSDLIMAGE_VENDORED=OFF -DBUILD_SHARED_LIBS=OFF "-DSDL3_DIR=..\SDL\build\win" && cmake --build build\win) || exit /b 1
         popd
+        pushd libs\SDL_net
+        (cmake -S . -B build\win -DBUILD_SHARED_LIBS=OFF "-DSDL3_DIR=..\SDL\build\win" && cmake --build build\win) || exit /b 1
+        popd
     ) else (
         echo "SDL directory not found! Make sure to initialize git submodules."
     )

build.sh

@@ -16,15 +16,15 @@ if [ -v gcc ];       then compiler="${CC:-gcc}"; echo "[gcc compile]"; fi
 auto_compile_flags=''
 
 # --- Compile/Link Line Definitions -------------------------------------------
-clang_common='-I../src/ -I../libs/SDL/include/ -I../libs/SDL_image/include/ -g -fdiagnostics-absolute-paths -Wall -Wno-unused-variable -std=c23'
+clang_common='-I../src/ -I../libs/SDL/include/ -I../libs/SDL_image/include/ -I../libs/SDL_net/include/ -g -fdiagnostics-absolute-paths -Wall -Wno-unused-variable -std=c23'
 clang_debug="$compiler -O0 -DBUILD_DEBUG=1 ${clang_common} ${auto_compile_flags}"
 clang_release="$compiler -O2 -DBUILD_DEBUG=0 ${clang_common} ${auto_compile_flags}"
-clang_link="../libs/SDL/build/libSDL3.a ../libs/SDL_image/build/libSDL3_image.a -lm"
+clang_link="../libs/SDL/build/libSDL3.a ../libs/SDL_image/build/libSDL3_image.a ../libs/SDL_net/build/libSDL3_net.a -lm"
 clang_out="-o"
-gcc_common='-I../src/ -I../libs/SDL/include/ -I../libs/SDL_image/include/ -g -Wall -Wno-unused-variable -std=c23'
+gcc_common='-I../src/ -I../libs/SDL/include/ -I../libs/SDL_image/include/ -I../libs/SDL_net/include/ -g -Wall -Wno-unused-variable -std=c23'
 gcc_debug="$compiler -O0 -DBUILD_DEBUG=1 ${gcc_common} ${auto_compile_flags}"
 gcc_release="$compiler -O2 -DBUILD_DEBUG=0 ${gcc_common} ${auto_compile_flags}"
-gcc_link="../libs/SDL/build/libSDL3.a ../libs/SDL_image/build/libSDL3_image.a -lm"
+gcc_link="../libs/SDL/build/libSDL3.a ../libs/SDL_image/build/libSDL3_image.a ../libs/SDL_net/build/libSDL3_net.a -lm"
 gcc_out="-o"
 
 # --- Choose Compile/Link Lines -----------------------------------------------
@@ -62,6 +62,13 @@ if [ -v sdl ]; then
     else
         echo "SDL_image directory not found! Make sure to initialize git submodules."
     fi
+    if [ -d "libs/SDL_net" ]; then
+        cd libs/SDL_net
+        cmake -S . -B build -DBUILD_SHARED_LIBS=OFF "-DSDL3_DIR=..\SDL\build" && cmake --build build
+        cd ../../
+    else
+        echo "SDL_net directory not found! Make sure to initialize git submodules."
+    fi
 fi
 
 cd build

src/de_main.c

@@ -3,230 +3,6 @@
 //           and it should be isolated from platform specific
 //           stuff when it's reasonable.
 //
-static void Game_AdvanceSimulation(AppState *app)
-{
-    // update prev_p
-    ForU32(obj_id, app->object_count)
-    {
-        Object *obj = app->object_pool + obj_id;
-        obj->prev_p = obj->p;
-    }
-
-    // animate special wall
-    {
-        Object *obj = Object_Get(app, app->special_wall);
-        obj->collision_rotation = WrapF(0.f, 1.f, obj->collision_rotation + TIME_STEP);
-        obj->sprite_rotation = obj->collision_rotation;
-        Object_UpdateCollisionVerticesAndNormals(obj);
-    }
-
-    // player input
-    ForArray(player_id_index, app->player_ids)
-    {
-        Object *player = Object_PlayerFromIndex(app, player_id_index);
-
-        V2 dir = {0};
-        if (player_id_index == 0)
-        {
-            if (app->keyboard[SDL_SCANCODE_W] || app->keyboard[SDL_SCANCODE_UP])    dir.y += 1;
-            if (app->keyboard[SDL_SCANCODE_S] || app->keyboard[SDL_SCANCODE_DOWN])  dir.y -= 1;
-            if (app->keyboard[SDL_SCANCODE_A] || app->keyboard[SDL_SCANCODE_LEFT])  dir.x -= 1;
-            if (app->keyboard[SDL_SCANCODE_D] || app->keyboard[SDL_SCANCODE_RIGHT]) dir.x += 1;
-        }
-        else if (player_id_index == 1)
-        {
-            // for vim fans
-            if (app->keyboard[SDL_SCANCODE_K]) dir.y += 1;
-            if (app->keyboard[SDL_SCANCODE_J]) dir.y -= 1;
-            if (app->keyboard[SDL_SCANCODE_H]) dir.x -= 1;
-            if (app->keyboard[SDL_SCANCODE_L]) dir.x += 1;
-        }
-        dir = V2_Normalize(dir);
-
-        bool ice_skating_dlc = (player_id_index == 1);
-        if (ice_skating_dlc)
-        {
-            // @todo(mg): this is bad, we need a fixed timestep
-            float player_speed = 0.005f * TIME_STEP;
-            V2 player_ddp = V2_Scale(dir, player_speed);
-            player->dp = V2_Add(player->dp, player_ddp);
-
-            float drag = -0.999f * TIME_STEP;
-            V2 player_drag = V2_Scale(player->dp, drag);
-            player->dp = V2_Add(player->dp, player_drag);
-        }
-        else
-        {
-            float player_speed = 5.f * TIME_STEP;
-            player->dp = V2_Scale(dir, player_speed);
-        }
-    }
-
-    // movement & collision
-    ForU32(obj_id, app->object_count)
-    {
-        Object *obj = app->object_pool + obj_id;
-        obj->has_collision = false;
-    }
-    ForU32(obj_id, app->object_count)
-    {
-        Object *obj = app->object_pool + obj_id;
-        if (!(obj->flags & ObjectFlag_Move)) continue;
-
-        obj->p = V2_Add(obj->p, obj->dp);
-        Object_UpdateCollisionVerticesAndNormals(obj);
-
-        ForU32(collision_iteration, 8) // support up to 8 overlapping wall collisions
-        {
-            float closest_obstacle_separation_dist = FLT_MAX;
-            V2 closest_obstacle_wall_normal = {0};
-
-            ForU32(obstacle_id, app->object_count)
-            {
-                Object *obstacle = app->object_pool + obstacle_id;
-                if (!(obstacle->flags & ObjectFlag_Collide)) continue;
-                if (obj == obstacle) continue;
-
-                float biggest_dist = -FLT_MAX;
-                V2 wall_normal = {0};
-
-                // @info(mg) SAT algorithm needs 2 iterations
-                // from the perspective of the obj
-                // and from the perspective of the obstacle.
-                ForU32(sat_iteration, 2)
-                {
-                    Object *normal_obj;
-                    Object *projected_obstacle;
-                    CollisionProjectionResult a;
-                    CollisionProjectionResult b;
-                    if (sat_iteration == 0)
-                    {
-                        normal_obj = obj;
-                        projected_obstacle = obstacle;
-                    }
-                    else
-                    {
-                        normal_obj = obstacle;
-                        projected_obstacle = obj;
-                    }
-
-                    a = Object_CollisionProjection(normal_obj->collision_normals, normal_obj->collision_vertices); // @speed(mg) we could cache these per object
-                    b = Object_CollisionProjection(normal_obj->collision_normals, projected_obstacle->collision_vertices);
-
-                    ForArray(i, a.arr)
-                    {
-                        static_assert(ArrayCount(a.arr) == ArrayCount(obj->collision_normals.arr));
-                        V2 normal = normal_obj->collision_normals.arr[i];
-
-                        V2 obj_col = Object_GetAvgCollisionPos(normal_obj);
-                        V2 obstacle_col = Object_GetAvgCollisionPos(projected_obstacle);
-                        V2 obstacle_dir = V2_Sub(obstacle_col, obj_col);
-                        if (V2_Inner(normal, obstacle_dir) < 0)
-                        {
-                            continue;
-                        }
-
-                        float d = RngF_MaxDistance(a.arr[i], b.arr[i]);
-                        if (d > 0.f)
-                        {
-                            // @info(mg) We can exit early from checking this
-                            //     obstacle since we found an axis that has
-                            //     a separation between obj and obstacle.
-                            goto skip_this_obstacle;
-                        }
-
-                        if (d > biggest_dist)
-                        {
-                            biggest_dist = d;
-                            if (normal_obj == obj)
-                            {
-                                wall_normal = V2_Reverse(normal);
-                            }
-                            else
-                            {
-                                wall_normal = normal;
-                            }
-                        }
-                    }
-                }
-
-                if (closest_obstacle_separation_dist > biggest_dist)
-                {
-                    closest_obstacle_separation_dist = biggest_dist;
-                    closest_obstacle_wall_normal = wall_normal;
-                }
-
-                obj->has_collision |= (biggest_dist < 0.f);
-                obstacle->has_collision |= (biggest_dist < 0.f);
-
-                skip_this_obstacle:;
-            }
-
-            if (closest_obstacle_separation_dist < 0.f)
-            {
-                V2 move_out_dir = closest_obstacle_wall_normal;
-                float move_out_magnitude = -closest_obstacle_separation_dist;
-
-                V2 move_out = V2_Scale(move_out_dir, move_out_magnitude);
-                obj->p = V2_Add(obj->p, move_out);
-
-                // remove all velocity on collision axis
-                // we might want to do something different here!
-                if (move_out.x) obj->dp.x = 0;
-                if (move_out.y) obj->dp.y = 0;
-
-                Object_UpdateCollisionVerticesAndNormals(obj);
-            }
-            else
-            {
-                // Collision not found, stop iterating
-                break;
-            }
-        } // collision_iteration
-    } // obj_id
-
-
-    // animate textures
-    ForU32(obj_id, app->object_count)
-    {
-        Object *obj = app->object_pool + obj_id;
-        if (Sprite_Get(app, obj->sprite_id)->frame_count <= 1) continue;
-
-        Uint32 frame_index_map[8] =
-        {
-            0, 1, 2, 1,
-            0, 3, 4, 3
-        };
-
-        bool in_idle_frame = (0 == frame_index_map[obj->sprite_animation_index]);
-
-        float distance = V2_Length(V2_Sub(obj->p, obj->prev_p));
-        float anim_speed = (16.f * TIME_STEP);
-        anim_speed += (3200.f * distance * TIME_STEP);
-
-        if (!distance && in_idle_frame)
-        {
-            anim_speed = 0.f;
-        }
-        obj->sprite_animation_t += anim_speed;
-
-        float period = 1.f;
-        while (obj->sprite_animation_t > period)
-        {
-            obj->sprite_animation_t -= period;
-            obj->sprite_animation_index += 1;
-        }
-
-        obj->sprite_animation_index %= ArrayCount(frame_index_map);
-        obj->sprite_frame_index = frame_index_map[obj->sprite_animation_index];
-    }
-
-    // move camera
-    {
-        Object *player = Object_Get(app, app->player_ids[0]);
-        app->camera_p = player->p;
-    }
-}
 
 static void Game_VerticesCameraTransform(AppState *app, V2 verts[4], float camera_scale, V2 window_transform)
 {
@@ -243,7 +19,7 @@ static void Game_VerticesCameraTransform(AppState *app, V2 verts[4], float camer
         verts[i].y += window_transform.y;
 
         // fix y axis direction to +Y up (SDL uses +Y down, -Y up)
-        verts[i].y = app->height - verts[i].y;
+        verts[i].y = app->window_height - verts[i].y;
     }
 }
 
@@ -271,10 +47,10 @@ static void Game_IssueDrawCommands(AppState *app)
     {
         float camera_scale = 1.f;
         {
-            float wh = Max(app->width, app->height); // pick bigger window dimension
+            float wh = Max(app->window_width, app->window_height); // pick bigger window dimension
             camera_scale = wh / app->camera_range;
         }
-        V2 window_transform = (V2){app->width*0.5f, app->height*0.5f};
+        V2 window_transform = (V2){app->window_width*0.5f, app->window_height*0.5f};
 
         ForU32(object_index, app->object_count)
         {
@@ -379,6 +155,19 @@ static void Game_IssueDrawCommands(AppState *app)
         }
     }
 
+    // draw debug networking stuff
+    {
+        ColorF green = ColorF_RGB(0, 1, 0);
+        ColorF red = ColorF_RGB(1, 0, 0);
+
+        SDL_FRect rect = { 0, 0, 30, 30 };
+        if (!app->net.is_server) rect.x = 40;
+
+        ColorF color = app->net.err ? red : green;
+        SDL_SetRenderDrawColorFloat(app->renderer, color.r, color.g, color.b, color.a);
+        SDL_RenderFillRect(app->renderer, &rect);
+    }
+
     // draw mouse
     {
         static float r = 0;
@@ -399,25 +188,30 @@ static void Game_IssueDrawCommands(AppState *app)
 static void Game_Iterate(AppState *app)
 {
     {
+        app->frame_id += 1;
+
         Uint64 new_frame_time = SDL_GetTicks();
         Uint64 delta_time = new_frame_time - app->frame_time;
         app->frame_time = new_frame_time;
         app->dt = delta_time * (0.001f);
-        app->physics_time_accumulator += Min(app->dt, 1.f); // clamp dt to 1s
+        app->tick_dt_accumulator += Min(app->dt, 1.f); // clamp dt to 1s
 
         if (app->debug.fixed_dt)
         {
             app->dt = app->debug.fixed_dt;
         }
     }
 
+    Net_Iterate(app);
+
     bool run_simulation = (!app->debug.pause_on_every_frame || !app->debug.paused_frame);
     if (run_simulation)
     {
-        while (app->physics_time_accumulator > TIME_STEP)
+        while (app->tick_dt_accumulator > TIME_STEP)
         {
-            app->physics_time_accumulator -= TIME_STEP;
-            Game_AdvanceSimulation(app);
+            app->tick_id += 1;
+            app->tick_dt_accumulator -= TIME_STEP;
+            Tick_Iterate(app);
         }
     }
     Game_IssueDrawCommands(app);
@@ -432,6 +226,8 @@ static void Game_Init(AppState *app)
         app->debug.draw_collision_box = true;
     }
 
+    Net_Init(app);
+
     app->frame_time = SDL_GetTicks();
     app->object_count += 1; // reserve object under index 0 as special 'nil' value
     app->sprite_count += 1; // reserve sprite under index 0 as special 'nil' value