From 221ea65efbf2c87855c945351caca259a1efae96 Mon Sep 17 00:00:00 2001
From: Eric Wasylishen <ewasylishen@gmail.com>
Date: Thu, 3 Nov 2022 23:44:18 -0600
Subject: [PATCH] light: fix -world_units_per_luxel on sloped faces

---
 common/bsputils.cc | 10 ++++++----
 light/ltface.cc    |  2 +-
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/common/bsputils.cc b/common/bsputils.cc
index 13aaeb95..3182bf50 100644
--- a/common/bsputils.cc
+++ b/common/bsputils.cc
@@ -746,6 +746,8 @@ faceextents_t::faceextents_t(const mface_t &face, const mbsp_t &bsp, float light
 }
 
 faceextents_t::faceextents_t(const mface_t &face, const mbsp_t &bsp, uint16_t lmwidth, uint16_t lmheight, texvecf world_to_lm_space) {
+    const qplane3f plane = Face_Plane(&bsp, &face);
+
     if (lmwidth > 0 && lmheight > 0) {
         lm_extents = {lmwidth - 1, lmheight - 1};
     }
@@ -755,7 +757,7 @@ faceextents_t::faceextents_t(const mface_t &face, const mbsp_t &bsp, uint16_t lm
 
     worldToLMMatrix.set_row(0, world_to_lm_space.row(0));
     worldToLMMatrix.set_row(1, world_to_lm_space.row(1));
-    worldToLMMatrix.set_row(2, {0, 0, 1, 0});
+    worldToLMMatrix.set_row(2, qvec4f(plane.normal[0], plane.normal[1], plane.normal[2], -plane.dist));
     worldToLMMatrix.set_row(3, {0, 0, 0, 1});
 
     lmToWorldMatrix = qv::inverse(worldToLMMatrix);
@@ -775,6 +777,7 @@ faceextents_t::faceextents_t(const mface_t &face, const mbsp_t &bsp, uint16_t lm
 
 faceextents_t::faceextents_t(const mface_t &face, const mbsp_t &bsp, world_units_per_luxel_t tag, float world_units_per_luxel)
 {
+    const qplane3f plane = Face_Plane(&bsp, &face);
     auto orig_normal = Face_Normal(&bsp, &face);
     size_t axis = qv::indexOfLargestMagnitudeComponent(orig_normal);
 
@@ -795,10 +798,9 @@ faceextents_t::faceextents_t(const mface_t &face, const mbsp_t &bsp, world_units
     t = t * (1/world_units_per_luxel);
     b = b * (1/world_units_per_luxel);
 
-    qmat<float, 3, 3> world_to_lm;
+    qmat<float, 2, 3> world_to_lm;
     world_to_lm.set_row(0, t);
     world_to_lm.set_row(1, b);
-    world_to_lm.set_row(2, snapped_normal);
 
     aabb2f lm_bounds;
     for (int i = 0; i < face.numedges; i++) {
@@ -817,7 +819,7 @@ faceextents_t::faceextents_t(const mface_t &face, const mbsp_t &bsp, world_units
 
     worldToLMMatrix.set_row(0, qvec4f(world_to_lm.row(0), -lm_mins[0]));
     worldToLMMatrix.set_row(1, qvec4f(world_to_lm.row(1), -lm_mins[1]));
-    worldToLMMatrix.set_row(2, qvec4f(world_to_lm.row(2), 0));
+    worldToLMMatrix.set_row(2, qvec4f(plane.normal[0], plane.normal[1], plane.normal[2], -plane.dist));
     worldToLMMatrix.set_row(3, qvec4f(0, 0, 0, 1));
 
     lmToWorldMatrix = qv::inverse(worldToLMMatrix);
diff --git a/light/ltface.cc b/light/ltface.cc
index 7844a3ad..91d95262 100644
--- a/light/ltface.cc
+++ b/light/ltface.cc
@@ -51,7 +51,7 @@ void PrintFaceInfo(const mface_t *face, const mbsp_t *bsp)
     const char *texname = Face_TextureName(bsp, face);
 
     logging::print("face {}, texture {}, {} edges; vectors:\n"
-                   "{: 3.3}\n",
+                   "{}\n",
         Face_GetNum(bsp, face), texname, face->numedges, tex->vecs);
 
     for (int i = 0; i < face->numedges; i++) {