Implemented power of two tiling.

Implemented power of two tiling.

Committed https://code.google.com/p/skia/source/detail?r=5274

[junov1, 2012-08-23 17:48:13]

https://codereview.appspot.com/6485056/diff/1/tools/PictureRenderer.cpp
File tools/PictureRenderer.cpp (right):

https://codereview.appspot.com/6485056/diff/1/tools/PictureRenderer.cpp#newco...
tools/PictureRenderer.cpp:233: // constraints are that every tile must a pixel
width that is a power of two and
"must a"?

https://codereview.appspot.com/6485056/diff/1/tools/PictureRenderer.cpp#newco...
tools/PictureRenderer.cpp:248: const SkScalar log2_conversion_value =
SkScalarLog(base);
break out a log2 func.

https://codereview.appspot.com/6485056/diff/1/tools/PictureRenderer.cpp#newco...
tools/PictureRenderer.cpp:249: SkScalar num_bits =
SkScalarCeilToScalar(SkScalarDiv(SkScalarLog(fPicture->width()),
Faster to mul inverse constant

https://codereview.appspot.com/6485056/diff/1/tools/picture_utils.cpp
File tools/picture_utils.cpp (right):

https://codereview.appspot.com/6485056/diff/1/tools/picture_utils.cpp#newcode89
tools/picture_utils.cpp:89: return ((x & (x - 1)) == 0) && (x > 0);
If this does not support negatives, why not just take an unsigned

https://codereview.appspot.com/6485056/diff/1/tools/picture_utils.h
File tools/picture_utils.h (right):

https://codereview.appspot.com/6485056/diff/1/tools/picture_utils.h#newcode39
tools/picture_utils.h:39: // Returns true if the value is an integer power of
two.
Returns true if the value is a positive integer power of two

[bsalomon, 2012-08-23 17:56:53]

https://codereview.appspot.com/6485056/diff/1/tools/picture_utils.h
File tools/picture_utils.h (right):

https://codereview.appspot.com/6485056/diff/1/tools/picture_utils.h#newcode40
tools/picture_utils.h:40: bool is_power_of_two(int value);
There already is SkIsPow2...

[keyar, 2012-08-23 18:37:47]

Applied reviewers comments.

[junov1, 2012-08-23 19:12:15]

https://codereview.appspot.com/6485056/diff/1/tools/PictureRenderer.cpp
File tools/PictureRenderer.cpp (right):

https://codereview.appspot.com/6485056/diff/1/tools/PictureRenderer.cpp#newco...
tools/PictureRenderer.cpp:233: // constraints are that every tile must a pixel
width that is a power of two and
On 2012/08/23 17:48:13, junov1 wrote:
> "must a"?
try again

https://codereview.appspot.com/6485056/diff/6001/tools/PictureRenderer.cpp
File tools/PictureRenderer.cpp (right):

https://codereview.appspot.com/6485056/diff/6001/tools/PictureRenderer.cpp#ne...
tools/PictureRenderer.cpp:248: SkScalar num_bits =
SkScalarCeilToScalar(SkScalarLog2(fPicture->width()));
SkScalar seems like an odd choice for storing a number of bits.  Why not ceil to
int?

https://codereview.appspot.com/6485056/diff/6001/tools/PictureRenderer.cpp#ne...
tools/PictureRenderer.cpp:249: int largest_possible_tile_size =
SkScalarRoundToInt(SkScalarPow(base, num_bits));
this could just be (1 << num_bits), if num_bits were an int.  Then get rid of
'base'

[keyar, 2012-08-23 19:42:09]

More fixes requested by the reviewers.

[nduca, 2012-08-23 20:15:58]

Pretty neat. LGTM! :)

[junov1, 2012-08-23 20:18:33]

On 2012/08/23 20:15:58, nduca wrote:
> Pretty neat. LGTM! :)

lgtm

[benchen, 2012-08-23 20:41:13]

On 2012/08/23 20:18:33, junov1 wrote:
> On 2012/08/23 20:15:58, nduca wrote:
> > Pretty neat. LGTM! :)
> 
> lgtm

LGTM