Fix for uninitialized memory issue on Linux

The debug gm run of "gm --debuggl" was producing assertion errors on Linux. This patch provides data back to the application in this case overwriting some uninitialized SkBitmap data.

[TomH, 2012-04-12 19:21:57]

Style nits, but no need to bikeshed: LGTM

[TomH, 2012-04-12 19:22:16]

Eh, nits shouldn't go unpublished, even if their only purpose is to spark
argument.

http://codereview.appspot.com/6012052/diff/1/src/gpu/gl/debug/GrGLCreateDebug...
File src/gpu/gl/debug/GrGLCreateDebugInterface.cpp (right):

http://codereview.appspot.com/6012052/diff/1/src/gpu/gl/debug/GrGLCreateDebug...
src/gpu/gl/debug/GrGLCreateDebugInterface.cpp:149: GrGLint l = width;  // number
of pixels in a row
Nit: Do you really need to rename this into a harder-to-read name just to get
the type from sizei to int? Or is it to avoid writing to parameters? Or ...???

http://codereview.appspot.com/6012052/diff/1/src/gpu/gl/debug/GrGLCreateDebug...
src/gpu/gl/debug/GrGLCreateDebugInterface.cpp:173: GrGLint s = 0;  // size (in
bytes) of a single component
Nit: I can't help thinking all this would be clearer if you used names like
byteAlignment and componentSize, and then could ditch the comments.

[reed1, 2012-04-12 19:24:15]

bloody chicken!

1-letter variable names are 2 shrt, i m h o.

[epoger, 2012-04-12 19:32:55]

http://codereview.appspot.com/6012052/diff/1/src/gpu/gl/debug/GrGLCreateDebug...
File src/gpu/gl/debug/GrGLCreateDebugInterface.cpp (right):

http://codereview.appspot.com/6012052/diff/1/src/gpu/gl/debug/GrGLCreateDebug...
src/gpu/gl/debug/GrGLCreateDebugInterface.cpp:173: GrGLint s = 0;  // size (in
bytes) of a single component
On 2012/04/12 19:22:16, TomH wrote:
> Nit: I can't help thinking all this would be clearer if you used names like
> byteAlignment and componentSize, and then could ditch the comments.

s/Nit/Important/

[robertphillips, 2012-04-12 19:51:15]

http://codereview.appspot.com/6012052/diff/1/src/gpu/gl/debug/GrGLCreateDebug...
File src/gpu/gl/debug/GrGLCreateDebugInterface.cpp (right):

http://codereview.appspot.com/6012052/diff/1/src/gpu/gl/debug/GrGLCreateDebug...
src/gpu/gl/debug/GrGLCreateDebugInterface.cpp:149: GrGLint l = width;  // number
of pixels in a row
In this case the caller can tell OpenGL that the rows in "pixels" are greater
than "width" wide. OpenGL then has to skip the larger width between rows. We
still need "width" below to know how many pixels actually need to be copied (vs.
skipped)

http://codereview.appspot.com/6012052/diff/1/src/gpu/gl/debug/GrGLCreateDebug...
src/gpu/gl/debug/GrGLCreateDebugInterface.cpp:173: GrGLint s = 0;  // size (in
bytes) of a single component
Yep - I was unconsciously following the spec - which spells all this out with
single character variable names.

[robertphillips, 2012-04-12 19:54:08]

committed as r3666