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How to create circle with Bézier curves?
...e using Bezier curves.
To complete the other answers : for Bezier curve with n segments the optimal distance to the control points, in the sense that the middle of the curve lies on the circle itself, is (4/3)*tan(pi/(2n)).
So for 4 points it is (4/3)*tan(pi/8) = 4*(sqrt(2)-1)/3 = 0.5522847498...
delete vs delete[] operators in C++
...r deallocates memory and calls the destructor for a single object created with new.
The delete [] operator deallocates memory and calls destructors for an array of objects created with new [].
Using delete on a pointer returned by new [] or delete [] on a pointer returned by new results in undefin...
What does the exclamation mark do before the function?
..., when we add the seemingly innocuous exclamation mark: !function foo() {} it turns it into an expression. It is now a function expression.
The ! alone doesn't invoke the function, of course, but we can now put () at the end: !function foo() {}() which has higher precedence than ! and instantly cal...
Div height 100% and expands to fit content
I have a div element on my page with its height set to 100%. The height of the body is also set to 100%. The inner div has a background and all that and is different from the body background. This works for making the div height 100% of the browser screen height, but the problem is I have content i...
C/C++ include header file order
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I don't think there's a recommended order, as long as it compiles! What's annoying is when some headers require other headers to be included first... That's a problem with the headers themselves, not with the order of includes.
My personal preference is to go from local to glob...
Determine the number of lines within a text file
Is there an easy way to programmatically determine the number of lines within a text file?
11 Answers
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Is there a way to change the environment variables of another process in Unix?
...(gdb) call putenv ("env_var_name=env_var_value")
(gdb) detach
This is quite a nasty hack and should only be done in the context of a debugging scenario, of course.
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Tab Vs Space preferences in Vim
Vim is very accommodating when it comes to tab Vs. space preferences. As I understand it, the tabstop setting indicates the width of a tab character. The shiftwidth setting specifies how many columns to increment/decrement when using the << and >> commands, whereas the softtabst...
Double not (!!) operator in PHP
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It's not the "double not operator", it's the not operator applied twice. The right ! will result in a boolean, regardless of the operand. Then the left ! will negate that boolean.
This means that for any true value (numbers...
在 App Inventor 2 中使用图像 · App Inventor 2 中文网
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Details on fixed vs. responsive sizing
In summary: What MIT App Inventor Programmers Should Do
Synopsis: App Inventor works best if you use images whose size matches the size you want them to appear on your screen. If you import larger images into your app, your app may run ou...