From 92af2ed3f7af35b5de8c7b3e910dad8618f6804f Mon Sep 17 00:00:00 2001
From: Eric Wasylishen <ewasylishen@gmail.com>
Date: Wed, 22 Jun 2022 22:37:09 -0600
Subject: [PATCH] qbsp: restore weird 1 unit bounds shrinkage Q1 needs

---
 qbsp/test_qbsp.cc | 6 +++---
 qbsp/writebsp.cc  | 6 ++++++
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/qbsp/test_qbsp.cc b/qbsp/test_qbsp.cc
index 5c0043ba..0c381790 100644
--- a/qbsp/test_qbsp.cc
+++ b/qbsp/test_qbsp.cc
@@ -974,9 +974,9 @@ TEST_CASE("q1_cube", "[testmaps_q1]")
     CHECK(cube_bounds_grown.mins() == headnode.mins);
     CHECK(cube_bounds_grown.maxs() == headnode.maxs);
 
-    // model bounds
-//    CHECK(cube_bounds_grown.mins() == bsp.dmodels[0].mins);
-//    CHECK(cube_bounds_grown.maxs() == bsp.dmodels[0].maxs);
+    // model bounds are shrunk by 1 unit on each side for some reason
+    CHECK(cube_bounds.grow(-1).mins() == bsp.dmodels[0].mins);
+    CHECK(cube_bounds.grow(-1).maxs() == bsp.dmodels[0].maxs);
 }
 
 /**
diff --git a/qbsp/writebsp.cc b/qbsp/writebsp.cc
index f1c72ebe..59d86a1a 100644
--- a/qbsp/writebsp.cc
+++ b/qbsp/writebsp.cc
@@ -272,6 +272,12 @@ void ExportDrawNodes(mapentity_t *entity, node_t *headnode, int firstface)
         dmodel.mins[i] = headnode->bounds.mins()[i] + SIDESPACE;
         dmodel.maxs[i] = headnode->bounds.maxs()[i] - SIDESPACE;
     }
+
+    // shrink the bounds in Q1 based games (Q1 engine compensates for this in Mod_LoadSubmodels)
+    if (options.target_game->id != GAME_QUAKE_II) {
+        dmodel.mins += qvec3d(1,1,1);
+        dmodel.maxs -= qvec3d(1,1,1);
+    }
 }
 
 //=============================================================================