Fix the rendering error of SkDraw::drawVertices in gpu path for solid color

Fix the rendering error of SkDraw::drawVertices in gpu path for solid color.

If both textures and vertex-colors are NULL, drawVertices should stroke hairlines with the paint's color. 
This behavior is a useful debugging mode to visualize the mesh.

BUG=skia:2266
Committed: http://code.google.com/p/skia/source/detail?r=14985

[yunchao, 2014-05-12 05:49:37]

On 2014/03/07 13:57:25, Richard Ho wrote:

Still have some minor rendering error for vertices_80.png(vertices.png is OK).
Not sure whether this is appropriate, so I submit a CL for you to have a look
before I go ahead to fix that rendering error.

[yunchao, 2014-05-14 15:54:56]

On 2014/05/12 05:49:37, Richard Ho wrote:
> On 2014/03/07 13:57:25, Richard Ho wrote:
> 
> Still have some minor rendering error for vertices_80.png(vertices.png is OK).
> Not sure whether this is appropriate, so I submit a CL for you to have a look
> before I go ahead to fix that rendering error.

ping... Any suggestions?

[bsalomon, 2014-05-15 13:13:33]

https://codereview.chromium.org/189963004/diff/80001/gyp/common_variables.gypi
File gyp/common_variables.gypi (right):

https://codereview.chromium.org/189963004/diff/80001/gyp/common_variables.gyp...
gyp/common_variables.gypi:152: 'skia_default_gcc_optimization_level': 0, # -O3
is this an accident?

https://codereview.chromium.org/189963004/diff/80001/include/core/SkVertState.h
File include/core/SkVertState.h (right):

https://codereview.chromium.org/189963004/diff/80001/include/core/SkVertState...
include/core/SkVertState.h:13: struct VertState {
I think this class could use some documentation if it is to be moved out to its
own files. It doesn't own the indices ptr, that should be noted. Also something
about what it is used for and how it used.

[yunchao, 2014-05-15 14:15:53]

https://codereview.chromium.org/189963004/diff/80001/gyp/common_variables.gypi
File gyp/common_variables.gypi (right):

https://codereview.chromium.org/189963004/diff/80001/gyp/common_variables.gyp...
gyp/common_variables.gypi:152: 'skia_default_gcc_optimization_level': 0, # -O3
On 2014/05/15 13:13:33, bsalomon wrote:
> is this an accident?

Yeah, just for debugging... Will remove it.

https://codereview.chromium.org/189963004/diff/80001/include/core/SkVertState.h
File include/core/SkVertState.h (right):

https://codereview.chromium.org/189963004/diff/80001/include/core/SkVertState...
include/core/SkVertState.h:13: struct VertState {
On 2014/05/15 13:13:33, bsalomon wrote:
> I think this class could use some documentation if it is to be moved out to
its
> own files. It doesn't own the indices ptr, that should be noted. Also
something
> about what it is used for and how it used.

Agree. I will update the document for your reviewing.

[yunchao, 2014-05-19 07:30:02]

On 2014/05/15 14:15:53, Richard Ho wrote:
> https://codereview.chromium.org/189963004/diff/80001/gyp/common_variables.gypi
> File gyp/common_variables.gypi (right):
> 
>
https://codereview.chromium.org/189963004/diff/80001/gyp/common_variables.gyp...
> gyp/common_variables.gypi:152: 'skia_default_gcc_optimization_level': 0, # -O3
> On 2014/05/15 13:13:33, bsalomon wrote:
> > is this an accident?
> 
> Yeah, just for debugging... Will remove it.
> 
>
https://codereview.chromium.org/189963004/diff/80001/include/core/SkVertState.h
> File include/core/SkVertState.h (right):
> 
>
https://codereview.chromium.org/189963004/diff/80001/include/core/SkVertState...
> include/core/SkVertState.h:13: struct VertState {
> On 2014/05/15 13:13:33, bsalomon wrote:
> > I think this class could use some documentation if it is to be moved out to
> its
> > own files. It doesn't own the indices ptr, that should be noted. Also
> something
> > about what it is used for and how it used.
> 
> Agree. I will update the document for your reviewing.

Hi Brian, I have updated the document for VertState and fixed the small
rendering error. Please have a look.

[yunchao, 2014-05-20 15:39:59]

On 2014/05/19 07:30:02, Richard Ho wrote:
> On 2014/05/15 14:15:53, Richard Ho wrote:
> >
https://codereview.chromium.org/189963004/diff/80001/gyp/common_variables.gypi
> > File gyp/common_variables.gypi (right):
> > 
> >
>
https://codereview.chromium.org/189963004/diff/80001/gyp/common_variables.gyp...
> > gyp/common_variables.gypi:152: 'skia_default_gcc_optimization_level': 0, #
-O3
> > On 2014/05/15 13:13:33, bsalomon wrote:
> > > is this an accident?
> > 
> > Yeah, just for debugging... Will remove it.
> > 
> >
>
https://codereview.chromium.org/189963004/diff/80001/include/core/SkVertState.h
> > File include/core/SkVertState.h (right):
> > 
> >
>
https://codereview.chromium.org/189963004/diff/80001/include/core/SkVertState...
> > include/core/SkVertState.h:13: struct VertState {
> > On 2014/05/15 13:13:33, bsalomon wrote:
> > > I think this class could use some documentation if it is to be moved out
to
> > its
> > > own files. It doesn't own the indices ptr, that should be noted. Also
> > something
> > > about what it is used for and how it used.
> > 
> > Agree. I will update the document for your reviewing.
> 
> Hi Brian, I have updated the document for VertState and fixed the small
> rendering error. Please have a look.

Any suggestions?

[yunchao, 2014-05-29 13:08:01]

On 2014/05/20 15:39:59, Richard Ho wrote:
> On 2014/05/19 07:30:02, Richard Ho wrote:
> > On 2014/05/15 14:15:53, Richard Ho wrote:
> > >
> https://codereview.chromium.org/189963004/diff/80001/gyp/common_variables.gypi
> > > File gyp/common_variables.gypi (right):
> > > 
> > >
> >
>
https://codereview.chromium.org/189963004/diff/80001/gyp/common_variables.gyp...
> > > gyp/common_variables.gypi:152: 'skia_default_gcc_optimization_level': 0, #
> -O3
> > > On 2014/05/15 13:13:33, bsalomon wrote:
> > > > is this an accident?
> > > 
> > > Yeah, just for debugging... Will remove it.
> > > 
> > >
> >
>
https://codereview.chromium.org/189963004/diff/80001/include/core/SkVertState.h
> > > File include/core/SkVertState.h (right):
> > > 
> > >
> >
>
https://codereview.chromium.org/189963004/diff/80001/include/core/SkVertState...
> > > include/core/SkVertState.h:13: struct VertState {
> > > On 2014/05/15 13:13:33, bsalomon wrote:
> > > > I think this class could use some documentation if it is to be moved out
> to
> > > its
> > > > own files. It doesn't own the indices ptr, that should be noted. Also
> > > something
> > > > about what it is used for and how it used.
> > > 
> > > Agree. I will update the document for your reviewing.
> > 
> > Hi Brian, I have updated the document for VertState and fixed the small
> > rendering error. Please have a look.
> 
> Any suggestions?

ping... Brian, could you have a look when you have time. I have updated the code
according to your suggestions.

[bsalomon, 2014-05-29 18:27:03]

lgtm with some suggestions for the comments. Also, please add any affected tests
to ignored-tests.txt before landing.

https://codereview.chromium.org/189963004/diff/120001/include/core/SkVertState.h
File include/core/SkVertState.h (right):

https://codereview.chromium.org/189963004/diff/120001/include/core/SkVertStat...
include/core/SkVertState.h:14: It chooses an appropriate function to traverse
the vertices according to
This is a helper for drawVertices(). It is used to iterate over the triangles
that are to be rendered based on an SkCanvas::VertexMode and (optionally) an
index array. It does not copy the index array and the client must ensure it
remains valid for the lifetime of the VertState object.

https://codereview.chromium.org/189963004/diff/120001/include/core/SkVertStat...
include/core/SkVertState.h:26: *  Pass the indices ptr and index count to
construct VertState. Otherwise,
Construct a VertState from a vertex count, index array, and index count. If the
vertices are unindexed pass NULL for indices.

[yunchao, 2014-05-30 10:02:10]

The CQ bit was checked by yunchao.he@intel.com

[commit-bot: I haz the power, 2014-05-30 10:02:51]

CQ is trying da patch. Follow status at
 https://skia-tree-status.appspot.com/cq/yunchao.he@intel.com/189963004/160001

[commit-bot: I haz the power, 2014-05-30 10:08:32]

Change committed as 14985