From eb842ba165d4034ab93ebc1bcf0435bdcb2acdc9 Mon Sep 17 00:00:00 2001
From: Eric Wasylishen <ewasylishen@gmail.com>
Date: Tue, 29 Dec 2020 13:43:06 -0700
Subject: [PATCH] light: arghrad compat: preliminary sky_surface implementation

---
 include/light/light.hh | 7 +++++--
 light/surflight.cc     | 8 ++++++++
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/include/light/light.hh b/include/light/light.hh
index d2c6bddb..5d74376d 100644
--- a/include/light/light.hh
+++ b/include/light/light.hh
@@ -307,6 +307,7 @@ public:
     lockable_vec3_t sunvec;
     lockable_vec3_t sun2vec;
     lockable_vec_t sun_deviance;
+    lockable_vec3_t sky_surface;
     
     globalconfig_t() :
         scaledist {"dist", 1.0, 0.0f, 100.0f},
@@ -358,7 +359,8 @@ public:
         sunlight2_dirt  { "sunlight2_dirt", 0.0f },
         sunvec          { strings{"sunlight_mangle", "sun_mangle", "sun_angle"}, 0.0f, -90.0f, 0.0f, vec3_transformer_t::MANGLE_TO_VEC },  /* defaults to straight down */
         sun2vec         { "sun2_mangle", 0.0f, -90.0f, 0.0f, vec3_transformer_t::MANGLE_TO_VEC },  /* defaults to straight down */
-        sun_deviance    { "sunlight_penumbra", 0.0f, 0.0f, 180.0f }
+        sun_deviance    { "sunlight_penumbra", 0.0f, 0.0f, 180.0f },
+        sky_surface     { strings{"sky_surface", "sun_surface"}, 0, 0, 0} /* arghrad surface lights on sky faces */
     {}
     
     settingsdict_t settings() {
@@ -387,7 +389,8 @@ public:
             &sunlight2_dirt,
             &sunvec,
             &sun2vec,
-            &sun_deviance
+            &sun_deviance,
+            &sky_surface
         }};
     }
 };
diff --git a/light/surflight.cc b/light/surflight.cc
index f222d199..ca5dba6d 100644
--- a/light/surflight.cc
+++ b/light/surflight.cc
@@ -126,6 +126,14 @@ MakeSurfaceLightsThread(void *arg)
         VectorScale(texturecolor, 1.0f / 255.0f, texturecolor); // Convert to 0..1 range...
         VectorScale(texturecolor, info->value, texturecolor);	// Scale by light value
 
+        // Handle arghrad sky light settings http://www.bspquakeeditor.com/arghrad/sunlight.html#sky
+        if (info->flags & Q2_SURF_SKY) {
+            // FIXME: this only handles the "_sky_surface"  "red green blue" format.
+            //        There are other more complex variants we could handle documented in the link above.
+            // FIXME: we require value to be nonzero, see the check above - not sure if this matches arghrad
+            VectorCopy(*cfg.sky_surface.vec3Value(), texturecolor);
+        }
+
         // Calculate intensity...
         float intensity = 0.0f;
         for (float c : texturecolor)