2D Drawing in OpenGL
How to set up 2D projection in OpenGL.
How to convert an integer to a hexadecimal string in C++
int number = 42;
stringstream ss;
ss << hex << number;
// now ss.str(), which is a string, contains "2a"
Getting the UDID of an iOS device
[[UIDevice currentDevice] uniqueIdentifier]
Mac OS X Debugging Magic
Official Apple Technical Note TN2124. Very interesting document in a quite informal style.
iroundf
A few minutes ago I wrote a rounding function for myself in C. Probably not the best implementation, but it works all right. If you’re interested, check it out (I’ve put some sample values in the comments):
int iroundf(float value)
{
if(value > 0.0)
{
int unsigned cutvalue = (unsigned int)value; // 3.8234234 => 3
float remain = value - cutvalue; // 3.8234234-3 = 0.8234234
if(remain >= 0.5) // 0.8234234 >= 0.5 => TRUE
return cutvalue + 1; // iroundf(3.8234234) => 4
else
return cutvalue;
}
if(value < 0.0)
{
int cutvalue = (int)value; // -1.34 => -1 // -4.67 => -4
float remain = value - cutvalue; // -1.34-(-1) = -0.34 // -4.64-(-4) = -0.64
if(remain >= -0.5) // -0.31 >= -0.5 => TRUE // -0.61 >= -0.5 => FALSE
return cutvalue; // iroundf(-1.34) => -1
else
return cutvalue - 1; // iroundf(-4.67) => -5
}
return 0;
}
update: I just came across the following very short and elegant solution (talk about forests and trees…)
int result = (int)(float_number + 0.5);
A nice article on iPhone application internationalization
Official docs about the same topic here.
Getting filepath to the Documents folder on iPhone
To achieve the task written in the title of this post, you have to do the following:
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); NSString *documentsPath = [paths objectAtIndex:0];
Button resize causing text blur?
Today I noticed a very, very strange behaviour (bug?) in Xcode. I am creating buttons for my iPhone application with a custom image background and a text on top of it. The Interface Builder attributes window looks like this:
Usually I change the font-family and size for my text, but when I do this, the button dimensions suddenly grow pretty big. So I just head over to the Button Size tab and reset the dimension values to the originals, like so:
And here comes the crazyness: as I modify the width/height values, the text inside the button gets slightly blurred!
During my current development I realized that some button texts are not as sharp as others, but I had no idea why. Finally I managed to catch this “bug” by redoing the last few steps before the blur effect occured.
How to overcome this pesky issue? If I resize the button “by hand” in the view editor, the text keeps its sharpness. Odd.
