2 files changed, 125 insertions, 0 deletions
diff --git a/platform/darwin/src/MGLRasterStyleLayer.h b/platform/darwin/src/MGLRasterStyleLayer.h
index ff055d24f6..a74d4f7f26 100644
--- a/platform/darwin/src/MGLRasterStyleLayer.h
+++ b/platform/darwin/src/MGLRasterStyleLayer.h
@@ -7,6 +7,27 @@
 NS_ASSUME_NONNULL_BEGIN
 
 /**
+ The resampling/interpolation method to use for overscaling, also known as
+ texture magnification filter
+
+ Values of this type are used in the `MGLRasterStyleLayer.rasterResamplingMode`
+ property.
+ */
+typedef NS_ENUM(NSUInteger, MGLRasterResamplingMode) {
+    /**
+     (Bi)linear filtering interpolates point values using the weighted average
+     of the four closest original source points creating a smooth but blurry
+     look when overscaled
+     */
+    MGLRasterResamplingModeLinear,
+    /**
+     Nearest neighbor filtering interpolates point values using the nearest
+     original source point creating a sharp but pointated look when overscaled
+     */
+    MGLRasterResamplingModeNearest,
+};
+
+/**
  An `MGLRasterStyleLayer` is a style layer that renders georeferenced raster
  imagery on the map, especially raster tiles.
  
@@ -233,6 +254,40 @@ MGL_EXPORT
 @property (nonatomic) MGLTransition rasterOpacityTransition;
 
 /**
+ The resampling/interpolation method to use for overscaling, also known as
+ texture magnification filter
+ 
+ The default value of this property is an expression that evaluates to `linear`.
+ Set this property to `nil` to reset it to the default value.
+ 
+ This attribute corresponds to the <a
+ href="https://www.mapbox.com/mapbox-gl-style-spec/#paint-raster-resampling"><code>raster-resampling</code></a>
+ layout property in the Mapbox Style Specification.
+ 
+ You can set this property to an expression containing any of the following:
+ 
+ * Constant `MGLRasterResamplingMode` values
+ * Any of the following constant string values:
+   * `linear`: (Bi)linear filtering interpolates pixel values using the weighted
+ average of the four closest original source pixels creating a smooth but blurry
+ look when overscaled
+   * `nearest`: Nearest neighbor filtering interpolates pixel values using the
+ nearest original source pixel creating a sharp but pixelated look when
+ overscaled
+ * Predefined functions, including mathematical and string operators
+ * Conditional expressions
+ * Variable assignments and references to assigned variables
+ * Step functions applied to the `$zoomLevel` variable
+ 
+ This property does not support applying interpolation functions to the
+ `$zoomLevel` variable or applying interpolation or step functions to feature
+ attributes.
+ */
+@property (nonatomic, null_resettable) NSExpression *rasterResamplingMode;
+
+@property (nonatomic, null_resettable) NSExpression *rasterResampling __attribute__((unavailable("Use rasterResamplingMode instead.")));
+
+/**
  Increase or reduce the saturation of the image.
  
  The default value of this property is an expression that evaluates to the float
@@ -260,4 +315,27 @@ MGL_EXPORT
 
 @end
 
+/**
+ Methods for wrapping an enumeration value for a style layer attribute in an
+ `MGLRasterStyleLayer` object and unwrapping its raw value.
+ */
+@interface NSValue (MGLRasterStyleLayerAdditions)
+
+#pragma mark Working with Raster Style Layer Attribute Values
+
+/**
+ Creates a new value object containing the given `MGLRasterResamplingMode` enumeration.
+
+ @param rasterResamplingMode The value for the new object.
+ @return A new value object that contains the enumeration value.
+ */
++ (instancetype)valueWithMGLRasterResamplingMode:(MGLRasterResamplingMode)rasterResamplingMode;
+
+/**
+ The `MGLRasterResamplingMode` enumeration representation of the value.
+ */
+@property (readonly) MGLRasterResamplingMode MGLRasterResamplingModeValue;
+
+@end
+
 NS_ASSUME_NONNULL_END
diff --git a/platform/darwin/src/MGLRasterStyleLayer.mm b/platform/darwin/src/MGLRasterStyleLayer.mm
index 0e31512491..96ed5ab513 100644
--- a/platform/darwin/src/MGLRasterStyleLayer.mm
+++ b/platform/darwin/src/MGLRasterStyleLayer.mm
@@ -11,6 +11,15 @@
 #include <mbgl/style/transition_options.hpp>
 #include <mbgl/style/layers/raster_layer.hpp>
 
+namespace mbgl {
+
+    MBGL_DEFINE_ENUM(MGLRasterResamplingMode, {
+        { MGLRasterResamplingModeLinear, "linear" },
+        { MGLRasterResamplingModeNearest, "nearest" },
+    });
+
+}
+
 @interface MGLRasterStyleLayer ()
 
 @property (nonatomic, readonly) mbgl::style::RasterLayer *rawLayer;
@@ -252,6 +261,30 @@
     return transition;
 }
 
+- (void)setRasterResamplingMode:(NSExpression *)rasterResamplingMode {
+    MGLAssertStyleLayerIsValid();
+
+    auto mbglValue = MGLStyleValueTransformer<mbgl::style::RasterResamplingType, NSValue *, mbgl::style::RasterResamplingType, MGLRasterResamplingMode>().toPropertyValue<mbgl::style::PropertyValue<mbgl::style::RasterResamplingType>>(rasterResamplingMode);
+    self.rawLayer->setRasterResampling(mbglValue);
+}
+
+- (NSExpression *)rasterResamplingMode {
+    MGLAssertStyleLayerIsValid();
+
+    auto propertyValue = self.rawLayer->getRasterResampling();
+    if (propertyValue.isUndefined()) {
+        propertyValue = self.rawLayer->getDefaultRasterResampling();
+    }
+    return MGLStyleValueTransformer<mbgl::style::RasterResamplingType, NSValue *, mbgl::style::RasterResamplingType, MGLRasterResamplingMode>().toExpression(propertyValue);
+}
+
+- (void)setRasterResampling:(NSExpression *)rasterResampling {
+}
+
+- (NSExpression *)rasterResampling {
+    return self.rasterResamplingMode;
+}
+
 - (void)setRasterSaturation:(NSExpression *)rasterSaturation {
     MGLAssertStyleLayerIsValid();
 
@@ -288,3 +321,17 @@
 }
 
 @end
+
+@implementation NSValue (MGLRasterStyleLayerAdditions)
+
++ (NSValue *)valueWithMGLRasterResamplingMode:(MGLRasterResamplingMode)rasterResamplingMode {
+    return [NSValue value:&rasterResamplingMode withObjCType:@encode(MGLRasterResamplingMode)];
+}
+
+- (MGLRasterResamplingMode)MGLRasterResamplingModeValue {
+    MGLRasterResamplingMode rasterResamplingMode;
+    [self getValue:&rasterResamplingMode];
+    return rasterResamplingMode;
+}
+
+@end