[ios, macos] Document DDS enumerations (#7931)

[ios, macos] Document DDS enumerations

1 files changed, 56 insertions, 4 deletions

diff --git a/platform/darwin/src/MGLStyleValue.h b/platform/darwin/src/MGLStyleValue.h
index 1ae8a67861..2ce2eae89a 100644
--- a/platform/darwin/src/MGLStyleValue.h
+++ b/platform/darwin/src/MGLStyleValue.h
@@ -6,20 +6,72 @@
 
 NS_ASSUME_NONNULL_BEGIN
 
-// TODO: API docs
+/**
+ Options for `MGLStyleFunction` objects.
+ */
 typedef NSString *MGLStyleFunctionOption NS_STRING_ENUM;
 
-// TODO: API docs
+/**
+ An `NSNumber` object containing an integer that determines the style function's 
+ exponential interpolation base.
+ 
+ The exponential interpolation base controls the rate at which the function’s 
+ output values increase. A value of 1 causes the function to increase linearly 
+ by zoom level. A higher exponential interpolation base causes the function’s 
+ output values to vary exponentially, increasing more rapidly towards the high 
+ end of the function’s range. The default value of this property is 1, for a 
+ linear curve.
+
+ This attribute corresponds to the
+ <a href="https://www.mapbox.com/mapbox-gl-js/style-spec/#function-base"><code>base</code></a>
+ function property in the Mapbox Style Specification.
+
+ This option only applies to functions that use an 
+ `MGLInterpolationModeExponential` interpolation mode that are assigned to
+ interpolatable style layer properties.
+ */
 extern MGL_EXPORT const MGLStyleFunctionOption MGLStyleFunctionOptionInterpolationBase;
 
-// TODO: API docs
+/**
+ An `MGLStyleConstantValue` object that specifies a default value that a style
+ function can use when it can't otherwise determine a value.
+
+ A default value can be used to set the value of a style layer property that
+ is not otherwise set by a function. For example, a source function with a
+ `MGLInterpolationModeCategorical` interpolation mode with stops that specify
+ color values to use based on a feature's attributes would set any feature
+ that does not have attributes that match the stop key values to this 
+ default value.
+ 
+ This option only applies to `MGLSourceStyleFunction` and
+ `MGLCompositeStyleFunction` functions.
+ */
 extern MGL_EXPORT const MGLStyleFunctionOption MGLStyleFunctionOptionDefaultValue;
 
-// TODO: API docs
+/** 
+ The modes used to interpolate property values between map zoom level changes
+ or over a range of feature attribute values.
+ */
 typedef NS_ENUM(NSUInteger, MGLInterpolationMode) {
+    /**
+     Values between two stops are interpolated exponentially or linearly if the
+     `MGLStyleFunctionOptionInterpolationBase` is 1.
+     */
     MGLInterpolationModeExponential = 0,
+    /**
+     Values between two stops are not interpolated. Instead, properties are set
+     to the value of the stop just less than the function input.
+     */
     MGLInterpolationModeInterval,
+    /**
+     Values between two stops are not interpolated. Instead, properties are set
+     to the value of the stop equal to the function input's key value.
+     */
     MGLInterpolationModeCategorical,
+    /**
+     Values between two stops are not interpolated. Instead, values are set 
+     to their input value.
+     */
     MGLInterpolationModeIdentity
 };