[core, ios, macos, android, node] Heatmap layer (#11046)

Co-Authored-By: Konstantin Käfer <mail@kkaefer.com>
Co-Authored-By: Anand Thakker <anandthakker@users.noreply.github.com>
Co-Authored-By: Minh Nguyễn <1ec5@users.noreply.github.com>

1 files changed, 23 insertions, 0 deletions

diff --git a/src/mbgl/style/paint_property.hpp b/src/mbgl/style/paint_property.hpp
index c4c996b3bd..195eb645a9 100644
--- a/src/mbgl/style/paint_property.hpp
+++ b/src/mbgl/style/paint_property.hpp
@@ -2,6 +2,7 @@
 
 #include <mbgl/style/properties.hpp>
 #include <mbgl/style/property_value.hpp>
+#include <mbgl/style/heatmap_color_property_value.hpp>
 #include <mbgl/style/data_driven_property_value.hpp>
 #include <mbgl/renderer/property_evaluator.hpp>
 #include <mbgl/renderer/cross_faded_property_evaluator.hpp>
@@ -48,5 +49,27 @@ public:
     static constexpr bool IsDataDriven = false;
 };
 
+/*
+ * Special-case paint property traits for heatmap-color, needed because
+ * heatmap-color values do not fit into the
+ * Undefined | Value | {Camera,Source,Composite}Function taxonomy that applies
+ * to all other paint properties.
+ *
+ * These traits are provided here--despite the fact that heatmap-color
+ * is not used like other paint properties--to allow the parameter-pack-based
+ * batch evaluation of paint properties to compile properly.
+ */
+class HeatmapColor {
+public:
+    using TransitionableType = Transitionable<HeatmapColorPropertyValue>;
+    using UnevaluatedType = Transitioning<HeatmapColorPropertyValue>;
+    using EvaluatorType = PropertyEvaluator<Color>;
+    using PossiblyEvaluatedType = Color;
+    using Type = Color;
+    static constexpr bool IsDataDriven = false;
+    
+    static Color defaultValue() { return {}; }
+};
+
 } // namespace style
 } // namespace mbgl