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## Re: [ft] what's the mean of CEIL( x )?

 From: David Turner Subject: Re: [ft] what's the mean of CEIL( x )? Date: Fri, 19 May 2006 09:18:02 +0200 User-agent: Thunderbird 1.5 (Windows/20051201)

```luoyi a écrit :
```
```sorry, but:

#define CEIL( x )   ( ( (x) + 63 ) >> 6 )

obviously doesn't do what the C language "ceil()" function do....

```
if x is a fixed-point 26.6 number, the macro returns the smallest integer that is greater
```or equal to it, so it's very comparable to ceil()

ex:

x=240 corresponds to value 3.75 CEIL(240) => 4
x=64   corresponds to value 1.0  CEIL(64) => 1
x=32  corresponds to value 0.5   CEIL(32) => 1
x =1   corresponds to value 0.015625   CEIL(1) => 1
x = 0  corresponds to value 0.  CEIL(0) => 0
x = -1 corresponds to value -0.015625   CEIL(-1) => 0
x = -32 corresponds to value -0.5  CEIL(-32) => 0
x = -64 corresponds to value -1.  CEIL(-64) => -1

etc...

Regards,

- David Turner
- The FreeType Project  (www.freetype.org)

```
```
```
```luoyi,

```
Looks like the fixed point (26.6) version of the C language "ceil( )" function. Here's a page if you're not familiar with it.
```
http://www.cplusplus.com/ref/cmath/ceil.html

```
```

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