At first i searched and found an example of a rounded corner view here:
http://iphonedevelopment.blogspot.com/2008/11/creating-transparent-uiviews-rounded.html
but i didn't succeed in implementing this in my proto minigolf.
Eventually i decided to try with a new clean project Viewbased.
I added three views in the folder classes
then i went to the interfacebuilder and took the ViewTestController.xib

I loaded this nib with 3 different views in the main view (see image) i then connected the type of the three subviews to my newly added classes, i colored the classes differently.
saved the file, returned to Xcode and compiled,
to my surprise this really simple procedure was accepted.
The roundedrect view showed up as predicted with rounded rects.
(In fact this is like overlaying ImageViews.)
My mistake was combining interfacebuilder with programmed views, and adding these views in the
/* // Implement loadView to create a view hierarchy programmatically, without using a nib. - (void)loadView {
} */
function, because it said to do so "to create a view hierarchy programmatically", which i apparently misunderstood.
I added in the rounded rect view a pentagon with this code:
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetStrokeColorWithColor(context, [UIColor greenColor].CGColor);
CGContextSetLineWidth(context, 5.0);
CGPoint five[6];
integer_t i;
for(i=0;i<6;i++)
{
five[i].x = 100 + 30* sin( i*2*3.1415/5);
five[i].y = 100 + 30* cos( i*2*3.1415/5);
NSLog(@"myPoint 4 #%f #%f", five[i].x, five[i].y);
}
CGContextAddLines ( context, five, 6 );
CGContextStrokePath(context);
[When adding an UIImageView to one of the SubViews, the image when to big spills over the view. Just set the Clip Subview check to keep the image in bounds.
Could it be possible to make this too big image scrolling? Certainly! But since i have three views inside a view it is a bit more complicated than the example here:
http://www.vimeo.com/1642150
(There must be a natural way. like the three views?) ]
from which i learned that the array CGPoint five[6] can be made without the need of a MSMutableArray, meant for NSObjects. It is like ordinary C here for once.
So slowly my C knowledge is becoming related to objective-C of Xcode