Drawing a ruler in objective c iPhone - iphone

Question

I am trying to create a dynamic ruler using code from this post of Brad Larson
NSInteger majorTickInterval = 5;
NSInteger totalTravelRangeInMicrons = 1000;
NSInteger minorTickSpacingInMicrons = 50;
CGFloat currentHeight = 100;
int leftEdgeForTicks = 10;
int majorTickLength = 15;
int minorTickLength = 10;
NSInteger minorTickCounter = majorTickInterval;
NSInteger totalNumberOfTicks = totalTravelRangeInMicrons / minorTickSpacingInMicrons;
CGFloat minorTickSpacingInPixels = currentHeight / (CGFloat)totalNumberOfTicks;
CGContextSetStrokeColorWithColor(context, [[UIColor blackColor] CGColor]);
for (NSInteger currentTickNumber = 0; currentTickNumber < totalNumberOfTicks; currentTickNumber++)
{
CGContextMoveToPoint(context, leftEdgeForTicks + 0.5, round(currentTickNumber * minorTickSpacingInPixels) + 0.5);
minorTickCounter++;
if (minorTickCounter >= majorTickInterval)
{
CGContextAddLineToPoint(context, round(leftEdgeForTicks + majorTickLength) + 7**.5, round(currentTickNumber * minorTickSpacingInPixels) + 0.5);
minorTickCounter = 0;
}
else
{
CGContextAddLineToPoint(context, round(leftEdgeForTicks + minorTickLength) + 0.5, round(currentTickNumber * minorTickSpacingInPixels) + 0.5);
}
}
CGContextStrokePath(context);
But the issue is that it is creating ticks vertically not horizontally as in below screenshot:
While I want to draw a ruler like this:
Also it is not giving me more than 25 ticks, I have played with the code but still unsuccessful.
Any guidance how can I resolve this issue.

Answer 1

Here is an implementation, from the top of my head... I think it is important to keep it readable.
CGFloat leftMargin= 10;
CGFloat topMargin = 10;
CGFloat height = 30;
CGFloat width = 200;
CGFloat minorTickSpace = 10;
int multiple = 5; // number of minor ticks per major tick
CGFloat majorTickLength = 20; // must be smaller or equal height,
CGFloat minorTickLength = 10; // must be smaller than majorTickLength
CGFloat baseY = topMargin + height;
CGFloat minorY = baseY - minorTickLength;
CGFloat majorY = baseY - majorTickLength;
CGFloat majorTickSpace = minorTickSpace * multiple;
int step = 0;
for (CGFloat x = leftMargin; x <= leftMargin + width, x += minorTickLength) {
CGContextMoveToPoint(context, x, baseY);
CGFloat endY = (step*multiple*minorTickLength == x) ? majorY : minorY;
CGContextAddLineToPoint(context, x, endY);
step++; // step contains the minorTickCount in case you want to draw labels
}
CGContextStrokePath(context);