light: allow .wal_json metadata to contain "light": [ r, g, b ] to override emissive color

Use this to fix the "emissive lights" test case so it can run on CI without any texture data

common/imglib.cc

@@ -565,6 +565,18 @@ std::optional<texture_meta> load_wal_json_meta(
             meta.animation = json["animation"].get<std::string>();
         }
 
+        if (json.contains("color")) {
+            auto &color = json["color"];
+
+            qvec3b color_vec = {
+                color.at(0).get<int32_t>(),
+                color.at(1).get<int32_t>(),
+                color.at(2).get<int32_t>()
+            };
+
+            meta.color_override = {color_vec};
+        }
+
         return meta;
     } catch (json::exception e) {
         logging::funcprint("{}, invalid JSON: {}\n", name, e.what());

include/common/imglib.hh

@@ -47,6 +47,10 @@ struct texture_meta
     // extension that we pulled the pixels in from.
     std::optional<ext> extension;
 
+    // so .json metadata can set an emissive color when we don't have
+    // texture data. Also useful to override the emissive color
+    std::optional<qvec3b> color_override;
+
     // Q2/WAL only
     surfflags_t flags{};
     contentflags_t contents{};

light/light.cc

@@ -1395,9 +1395,16 @@ static void AddTextureName(const std::string_view &textureName, const mbsp_t *bs
         tex.meta = std::move(texture_meta.value());
     }
 
-    tex.averageColor = img::calculate_average(tex.pixels);
-    tex.width_scale = (float)tex.width / (float)tex.meta.width;
-    tex.height_scale = (float)tex.height / (float)tex.meta.height;
+    if (tex.meta.color_override) {
+        tex.averageColor = *tex.meta.color_override;
+    } else {
+        tex.averageColor = img::calculate_average(tex.pixels);
+    }
+
+    if (tex.meta.width && tex.meta.height) {
+        tex.width_scale = (float)tex.width / (float)tex.meta.width;
+        tex.height_scale = (float)tex.height / (float)tex.meta.height;
+    }
 }
 
 // Load all of the referenced textures from the BSP texinfos into
@@ -1460,9 +1467,16 @@ static void ConvertTextures(const mbsp_t *bsp)
             continue;
         }
 
-        tex.averageColor = img::calculate_average(tex.pixels);
-        tex.width_scale = (float)tex.width / (float)tex.meta.width;
-        tex.height_scale = (float)tex.height / (float)tex.meta.height;
+        if (tex.meta.color_override) {
+            tex.averageColor = *tex.meta.color_override;
+        } else {
+            tex.averageColor = img::calculate_average(tex.pixels);
+        }
+
+        if (tex.meta.width && tex.meta.height) {
+            tex.width_scale = (float)tex.width / (float)tex.meta.width;
+            tex.height_scale = (float)tex.height / (float)tex.meta.height;
+        }
     }
 }
 

testmaps/q2_wal_metadata/textures/e1u1/baselt_5.wal_json

@@ -0,0 +1,6 @@
+{
+    "contents": ["SOLID"],
+    "flags": ["LIGHT"],
+    "value": 1000,
+    "color": [255, 128, 64]
+}

tests/test_ltface.cc

@@ -38,9 +38,11 @@ static testresults_t LoadTestmap(const std::filesystem::path &name, std::vector<
     {
         std::vector<std::string> light_args{
             "", // the exe path, which we're ignoring in this case
-            "-nodefaultpaths" // in case test_quake2_maps_dir is pointing at a real Q2 install, don't
-                              // read texture data etc. from there - we want the tests to behave the same
-                              // during development as they do on CI (which doesn't have a Q2 install).
+            "-nodefaultpaths", // in case test_quake2_maps_dir is pointing at a real Q2 install, don't
+                               // read texture data etc. from there - we want the tests to behave the same
+                               // during development as they do on CI (which doesn't have a Q2 install).
+            "-path",
+            wal_metadata_path.string()
         };
         for (auto &arg : extra_args) {
             light_args.push_back(arg);
@@ -163,7 +165,7 @@ TEST_CASE("emissive lights") {
         for (int y = 0; y < extents.height(); ++y) {
             auto sample = LM_Sample(&bsp, extents, face->lightofs, {x, y});
             INFO("sample ", x, ", ", y);
-            //CHECK(sample[0] > 0);
+            CHECK(sample[0] > 0);
         }
     }
 }