Update a grad2.C tutorial to use TLinearGradient.

graf2d/quartz/src/QuartzFillArea.mm

@@ -369,13 +369,10 @@ void CalculateGradientPoints(const TColorGradient *extendedColor, const CGSize &
    //TODO: that's stupid, but ... radial can iherit linear to make things easier :)
    if (const TLinearGradient * const lGrad = dynamic_cast<const TLinearGradient *>(extendedColor)) {
       start = CGPointMake(lGrad->GetStartPoint().fX, lGrad->GetStartPoint().fY);
-      end.x = lGrad->GetEndPoint().fX;
-      end.y = lGrad->GetEndPoint().fY;
+      end = CGPointMake(lGrad->GetEndPoint().fX, lGrad->GetEndPoint().fY);
    } else if (const TRadialGradient * const rGrad = dynamic_cast<const TRadialGradient *>(extendedColor)) {
-      start.x = rGrad->GetStartPoint().fX;
-      start.y = rGrad->GetStartPoint().fY;
-      end.x = rGrad->GetEndPoint().fX;
-      end.y = rGrad->GetEndPoint().fY;
+      start = CGPointMake(rGrad->GetStartPoint().fX, rGrad->GetStartPoint().fY);
+      end = CGPointMake(rGrad->GetEndPoint().fX, rGrad->GetEndPoint().fY);
    }
    
    if (mode == TColorGradient::kObjectBoundingMode) {

tutorials/cocoa/grad2.C

@@ -43,15 +43,22 @@ void grad2()
 
    //   b) Gradient (from our semi-transparent red to ROOT's kOrange).
    const Double_t locations[] = {0., 1.};
-   const Color_t idx1[] = {kOrange, customRed};
-   new TColorGradient(grad1, TColorGradient::kGDVertical, 2, locations, idx1);
+   const Color_t idx1[] = {customRed, kOrange};
+   TLinearGradient * const gradFill1 = new TLinearGradient(grad1, 2, locations, idx1);
+   
+   typedef TColorGradient::GradientPoint point_type;
+   //Starting and ending points for a gradient fill (it's a vertical gradient):
+   gradFill1->SetStartEnd(point_type(0., 0.), point_type(0., 1));
 
    //   c) Custom semi-transparent green.
    new TColor(customGreen, 0., 1., 0., "green", 0.5);
 
    //   d) Gradient from ROOT's kBlue to our custom green.
-   const Color_t idx2[] = {kBlue, customGreen};
-   new TColorGradient(grad2, TColorGradient::kGDVertical, 2, locations, idx2);
+   const Color_t idx2[] = {customGreen, kBlue};
+   
+   TLinearGradient * const gradFill2 = new TLinearGradient(grad2, 2, locations, idx2);
+   //Vertical gradient fill.
+   gradFill2->SetStartEnd(point_type(0., 0), point_type(0., 1.));
 
    TH1F * hist = new TH1F("a2", "b2", 10, -2., 3.);
    TH1F * hist2 = new TH1F("c3", "d3", 10, -3., 3.);