From e05a2bdf750f65b6a15f13fbfb1141755303300d Mon Sep 17 00:00:00 2001
From: Eric Wasylishen <ewasylishen@gmail.com>
Date: Mon, 1 Aug 2022 19:09:37 -0600
Subject: [PATCH] qbsp: "-add additional.map" feature

---
 common/bspfile.cc                   |  9 ++++++++-
 include/qbsp/qbsp.hh                |  1 +
 qbsp/map.cc                         | 30 ++++++++++++++++++++++++++++
 testmaps/q1_merge_maps_addition.map | 31 +++++++++++++++++++++++++++++
 testmaps/q1_merge_maps_base.map     | 23 +++++++++++++++++++++
 tests/test_qbsp.cc                  | 27 +++++++++++++++++++++++++
 6 files changed, 120 insertions(+), 1 deletion(-)
 create mode 100644 testmaps/q1_merge_maps_addition.map
 create mode 100644 testmaps/q1_merge_maps_base.map

diff --git a/common/bspfile.cc b/common/bspfile.cc
index e20226fd..23dd1244 100644
--- a/common/bspfile.cc
+++ b/common/bspfile.cc
@@ -688,7 +688,7 @@ public:
         return create_solid_contents();
     }
 
-    void init_filesystem(const fs::path &, const settings::common_settings &options) const override
+    void init_filesystem(const fs::path &map_or_bsp, const settings::common_settings &options) const override
     {
         // Q1-like games don't care about the local
         // filesystem.
@@ -699,6 +699,13 @@ public:
             fs::addArchive(path, true);
         }
 
+        // certain features like '-add additional.map' search relative to the map we're compiling
+        // so add the map directory to the search path
+        auto map_or_bsp_dir = map_or_bsp.parent_path();
+        if (!map_or_bsp_dir.empty()) {
+            fs::addArchive(map_or_bsp_dir);
+        }
+
         img::init_palette(this);
     }
 
diff --git a/include/qbsp/qbsp.hh b/include/qbsp/qbsp.hh
index eac457ef..5b0052d2 100644
--- a/include/qbsp/qbsp.hh
+++ b/include/qbsp/qbsp.hh
@@ -352,6 +352,7 @@ public:
     // since the max world size in Q3 is {-65536, -65536, -65536, 65536, 65536, 65536}. should we dynamically change this?
     // should we automatically turn this on if the world gets too big but leave it off for smaller worlds?
     setting_blocksize blocksize{this, "blocksize", { 0, 0, 0 }, &common_format_group, "from q3map2; split the world by x/y/z sized chunks, speeding up split decisions"};
+    setting_string add{this, "add", "", "", &common_format_group, "the given map file will be appended to the base map"};
 
     void setParameters(int argc, const char **argv) override
     {
diff --git a/qbsp/map.cc b/qbsp/map.cc
index 5d0c07ab..0266c03f 100644
--- a/qbsp/map.cc
+++ b/qbsp/map.cc
@@ -2051,6 +2051,36 @@ void LoadMapFile(void)
         map.entities.pop_back();
     }
 
+    // -add function
+    if (!qbsp_options.add.value().empty()) {
+        auto file = fs::load(qbsp_options.add.value());
+
+        if (!file) {
+            FError("Couldn't load map file \"{}\".\n", qbsp_options.add.value());
+            return;
+        }
+
+        parser_t parser(file->data(), file->size());
+
+        for (int i = 0;; i++) {
+            mapentity_t &entity = map.entities.emplace_back();
+
+            if (!ParseEntity(parser, &entity)) {
+                break;
+            }
+
+            if (entity.epairs.get("classname") == "worldspawn") {
+                // The easiest way to get the additional map's worldspawn brushes
+                // into the base map's is to rename the additional map's worldspawn classname to func_group
+                entity.epairs.set("classname", "func_group");
+            }
+        }
+        // Remove dummy entity inserted above
+        assert(!map.entities.back().epairs.size());
+        assert(map.entities.back().brushes.empty());
+        map.entities.pop_back();
+    }
+
     logging::print(logging::flag::STAT, "     {:8} faces\n", map.faces.size());
     logging::print(logging::flag::STAT, "     {:8} brushes\n", map.brushes.size());
     logging::print(logging::flag::STAT, "     {:8} entities\n", map.entities.size());
diff --git a/testmaps/q1_merge_maps_addition.map b/testmaps/q1_merge_maps_addition.map
new file mode 100644
index 00000000..ea9cac68
--- /dev/null
+++ b/testmaps/q1_merge_maps_addition.map
@@ -0,0 +1,31 @@
+// Game: Quake
+// Format: Valve
+// entity 0
+{
+"mapversion" "220"
+"classname" "worldspawn"
+"message" "merge maps addition. The worldspawn keys here should be ignored"
+"wad" "deprecated/free_wad.wad"
+// brush 0
+{
+( 0 -64 -16 ) ( 0 -63 -16 ) ( 0 -64 -15 ) bolt11 [ 0 -1 0 0 ] [ 0 0 -1 0 ] 0 1 1
+( 0 -64 -16 ) ( 0 -64 -15 ) ( 1 -64 -16 ) bolt11 [ 1 0 0 0 ] [ 0 0 -1 0 ] 0 1 1
+( 0 -64 -16 ) ( 1 -64 -16 ) ( 0 -63 -16 ) bolt11 [ -1 0 0 0 ] [ 0 -1 0 0 ] 0 1 1
+( 128 64 16 ) ( 128 65 16 ) ( 129 64 16 ) bolt11 [ 1 0 0 0 ] [ 0 -1 0 0 ] 0 1 1
+( 128 64 16 ) ( 129 64 16 ) ( 128 64 17 ) bolt11 [ -1 0 0 0 ] [ 0 0 -1 0 ] 0 1 1
+( 64 64 16 ) ( 64 64 17 ) ( 64 65 16 ) bolt11 [ 0 1 0 0 ] [ 0 0 -1 0 ] 0 1 1
+}
+}
+// entity 1
+{
+"classname" "func_wall"
+// brush 0
+{
+( 96 32 0 ) ( 96 33 0 ) ( 96 32 1 ) bolt11 [ 0 -1 0 0 ] [ 0 0 -1 -16 ] 0 1 1
+( 96 32 0 ) ( 96 32 1 ) ( 97 32 0 ) bolt11 [ 1 0 0 0 ] [ 0 0 -1 -16 ] 0 1 1
+( 96 32 0 ) ( 97 32 0 ) ( 96 33 0 ) bolt11 [ -1 0 0 0 ] [ 0 -1 0 0 ] 0 1 1
+( 128 64 16 ) ( 128 65 16 ) ( 129 64 16 ) bolt11 [ 1 0 0 0 ] [ 0 -1 0 0 ] 0 1 1
+( 128 64 16 ) ( 129 64 16 ) ( 128 64 17 ) bolt11 [ -1 0 0 0 ] [ 0 0 -1 -16 ] 0 1 1
+( 128 64 16 ) ( 128 64 17 ) ( 128 65 16 ) bolt11 [ 0 1 0 0 ] [ 0 0 -1 -16 ] 0 1 1
+}
+}
diff --git a/testmaps/q1_merge_maps_base.map b/testmaps/q1_merge_maps_base.map
new file mode 100644
index 00000000..485e0e36
--- /dev/null
+++ b/testmaps/q1_merge_maps_base.map
@@ -0,0 +1,23 @@
+// Game: Quake
+// Format: Valve
+// entity 0
+{
+"mapversion" "220"
+"classname" "worldspawn"
+"message" "merge maps base"
+"wad" "deprecated/free_wad.wad"
+// brush 0
+{
+( -64 -64 -16 ) ( -64 -63 -16 ) ( -64 -64 -15 ) bolt11 [ 0 -1 0 0 ] [ 0 0 -1 0 ] 0 1 1
+( -64 -64 -16 ) ( -64 -64 -15 ) ( -63 -64 -16 ) bolt11 [ 1 0 0 0 ] [ 0 0 -1 0 ] 0 1 1
+( -64 -64 -16 ) ( -63 -64 -16 ) ( -64 -63 -16 ) bolt11 [ -1 0 0 0 ] [ 0 -1 0 0 ] 0 1 1
+( 64 64 16 ) ( 64 65 16 ) ( 65 64 16 ) bolt11 [ 1 0 0 0 ] [ 0 -1 0 0 ] 0 1 1
+( 64 64 16 ) ( 65 64 16 ) ( 64 64 17 ) bolt11 [ -1 0 0 0 ] [ 0 0 -1 0 ] 0 1 1
+( 0 64 16 ) ( 0 64 17 ) ( 0 65 16 ) bolt11 [ 0 1 0 0 ] [ 0 0 -1 0 ] 0 1 1
+}
+}
+// entity 1
+{
+"classname" "info_player_start"
+"origin" "-16 -16 40"
+}
diff --git a/tests/test_qbsp.cc b/tests/test_qbsp.cc
index 30977e6b..c049062c 100644
--- a/tests/test_qbsp.cc
+++ b/tests/test_qbsp.cc
@@ -1766,6 +1766,33 @@ TEST_CASE("q1_wad_external", "[testmaps_q1]") {
     CHECK(bsp.dtex.textures[3].data.size() == sizeof(dmiptex_t));
 }
 
+TEST_CASE("q1_merge_maps", "[testmaps_q1]") {
+    const auto [bsp, bspx, prt] = LoadTestmapQ1("q1_merge_maps_base.map", { "-add", "q1_merge_maps_addition.map" });
+
+    CHECK(GAME_QUAKE == bsp.loadversion->game->id);
+
+    // check brushwork from the two maps is merged
+    REQUIRE(BSP_FindFaceAtPoint(&bsp, &bsp.dmodels[0], {5,0,16}, {0, 0, 1}));
+    REQUIRE(BSP_FindFaceAtPoint(&bsp, &bsp.dmodels[0], {-5,0,16}, {0, 0, 1}));
+
+    // check that the worldspawn keys from the base map are used
+    auto ents = EntData_Parse(bsp.dentdata);
+    REQUIRE(ents.size() == 3); // worldspawn, info_player_start, func_wall
+
+    REQUIRE(ents[0].get("classname") == "worldspawn");
+    CHECK(ents[0].get("message") == "merge maps base");
+
+    // check info_player_start
+    auto it = std::find_if(ents.begin(), ents.end(),
+        [](const entdict_t &dict) -> bool { return dict.get("classname") == "info_player_start"; });
+    REQUIRE(it != ents.end());
+
+    // check func_wall entity from addition map is included
+    it = std::find_if(ents.begin(), ents.end(),
+        [](const entdict_t &dict) -> bool { return dict.get("classname") == "func_wall"; });
+    REQUIRE(it != ents.end());
+}
+
 TEST_CASE("winding", "[benchmark][.releaseonly]") {
     ankerl::nanobench::Bench bench;