core-plot · keltonhalbert · Oct 5, 2021 · Oct 7, 2021
diff --git a/examples/CorePlotGallery/Plot Gallery-Mac/PlotViewItem.xib b/examples/CorePlotGallery/Plot Gallery-Mac/PlotViewItem.xib
@@ -1,8 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<document type="com.apple.InterfaceBuilder3.Cocoa.XIB" version="3.0" toolsVersion="15702" targetRuntime="MacOSX.Cocoa" propertyAccessControl="none" useAutolayout="YES" customObjectInstantitationMethod="direct">
+<document type="com.apple.InterfaceBuilder3.Cocoa.XIB" version="3.0" toolsVersion="19162" targetRuntime="MacOSX.Cocoa" propertyAccessControl="none" useAutolayout="YES" customObjectInstantitationMethod="direct">
     <dependencies>
-        <deployment identifier="macosx"/>
-        <plugIn identifier="com.apple.InterfaceBuilder.CocoaPlugin" version="15702"/>
+        <plugIn identifier="com.apple.InterfaceBuilder.CocoaPlugin" version="19162"/>
         <capability name="documents saved in the Xcode 8 format" minToolsVersion="8.0"/>
     </dependencies>
     <objects>

diff --git a/framework/Source/CPTAxis.m b/framework/Source/CPTAxis.m
@@ -1034,6 +1034,10 @@ -(void)autoGenerateMajorTickLocations:(CPTNumberSet *__autoreleasing *)newMajorL
         case CPTScaleTypeLinear:
             // supported scale type
             break;
+
+        case CPTScaleTypeSkew:
+            // supported scale type
+            break;
 
         case CPTScaleTypeLog:
             // supported scale type--check range
@@ -1066,6 +1070,7 @@ -(void)autoGenerateMajorTickLocations:(CPTNumberSet *__autoreleasing *)newMajorL
     // Filter troublesome values and return empty sets
     if ((length != 0.0) && !isinf(length)) {
         switch ( scaleType ) {
+            case CPTScaleTypeSkew:
             case CPTScaleTypeLinear:
             {
                 // Determine interval value

diff --git a/framework/Source/CPTDefinitions.h b/framework/Source/CPTDefinitions.h
@@ -167,6 +167,7 @@ typedef NS_ENUM (NSInteger, CPTErrorBarType) {
  **/
 typedef NS_ENUM (NSInteger, CPTScaleType) {
     CPTScaleTypeLinear,    ///< Linear axis scale
+    CPTScaleTypeSkew,      ///< Linear axis scale that is skewed relative to orthogonal coordinate
     CPTScaleTypeLog,       ///< Logarithmic axis scale
     CPTScaleTypeAngular,   ///< Angular axis scale (not implemented)
     CPTScaleTypeDateTime,  ///< Date/time axis scale (not implemented)

diff --git a/framework/Source/CPTPlot.m b/framework/Source/CPTPlot.m
@@ -986,6 +986,7 @@ -(void)cacheNumbers:(nullable id)numbers forField:(NSUInteger)fieldEnum
     if ( numbers ) {
         switch ( [thePlotSpace scaleTypeForCoordinate:coordinate] ) {
             case CPTScaleTypeLinear:
+            case CPTScaleTypeSkew:
             case CPTScaleTypeLog:
             case CPTScaleTypeLogModulus:
             {
@@ -1082,6 +1083,7 @@ -(void)cacheNumbers:(nullable id)numbers forField:(NSUInteger)fieldEnum atRecord
 
         switch ( [thePlotSpace scaleTypeForCoordinate:coordinate] ) {
             case CPTScaleTypeLinear:
+            case CPTScaleTypeSkew:
             case CPTScaleTypeLog:
             case CPTScaleTypeLogModulus:
             {

diff --git a/framework/Source/CPTXYAxis.m b/framework/Source/CPTXYAxis.m
@@ -407,7 +407,7 @@ -(void)drawGridLinesInContext:(nonnull CGContextRef)context isMajor:(BOOL)major
 
         [self relabel];
 
-        CPTPlotSpace *thePlotSpace           = self.plotSpace;
+        CPTXYPlotSpace *thePlotSpace          = (CPTXYPlotSpace *)self.plotSpace;
         CPTNumberSet *locations              = (major ? self.majorTickLocations : self.minorTickLocations);
         CPTCoordinate selfCoordinate         = self.coordinate;
         CPTCoordinate orthogonalCoordinate   = CPTOrthogonalCoordinate(selfCoordinate);
@@ -457,7 +457,11 @@ -(void)drawGridLinesInContext:(nonnull CGContextRef)context isMajor:(BOOL)major
         for ( NSDecimalNumber *location in locations ) {
             NSDecimal locationDecimal = location.decimalValue;
 
-            if ( labeledRange && ![labeledRange contains:locationDecimal] ) {
+            // In the case of a skewed X plot space range, we will be providing the tick locations.
+            // Because of this, we don't want to mask out the tick locations without labels. Keep
+            // the labeled locations AND the skew lines that come from out of frame.
+            if ( labeledRange && ![labeledRange contains:locationDecimal] &&
+                !(thePlotSpace.xScaleType == CPTScaleTypeSkew) && !(self.coordinate == CPTCoordinateX)) {
                 continue;
             }
 
@@ -468,6 +472,15 @@ -(void)drawGridLinesInContext:(nonnull CGContextRef)context isMajor:(BOOL)major
             CGPoint startViewPoint = [thePlotSpace plotAreaViewPointForPlotPoint:startPlotPoint numberOfCoordinates:2];
             startViewPoint.x += originTransformed.x;
             startViewPoint.y += originTransformed.y;
+
+            // In the case of a skewed coordinate axis system, the Y axis lines will not connect with the origin
+            // but instead only connect to the minimum slanted X axis line. This says to connect Y axis grid lines
+            // all the way to the left hand side.
+            if (thePlotSpace.xScaleType == CPTScaleTypeSkew) {
+                if (self.coordinate == CPTCoordinateY) {
+                    startViewPoint.x = 0;
+                }
+            }
 
             // End point
             CGPoint endViewPoint = [thePlotSpace plotAreaViewPointForPlotPoint:endPlotPoint numberOfCoordinates:2];
@@ -817,6 +830,7 @@ -(nonnull NSNumber *)defaultTitleLocation
         CPTScaleType scaleType = [thePlotSpace scaleTypeForCoordinate:theCoordinate];
 
         switch ( scaleType ) {
+            case CPTScaleTypeSkew:
             case CPTScaleTypeLinear:
                 location = axisRange.midPoint;
                 break;

diff --git a/framework/Source/CPTXYPlotSpace.h b/framework/Source/CPTXYPlotSpace.h
@@ -10,6 +10,7 @@
 @property (nonatomic, readwrite, copy, nonnull) CPTPlotRange *yRange;
 @property (nonatomic, readwrite, copy, nullable) CPTPlotRange *globalXRange;
 @property (nonatomic, readwrite, copy, nullable) CPTPlotRange *globalYRange;
+@property (nonatomic, readwrite) double skewAngle;
 @property (nonatomic, readwrite, assign) CPTScaleType xScaleType;
 @property (nonatomic, readwrite, assign) CPTScaleType yScaleType;