Expand coverage of vertices gm

Expand coverage of vertices gm

Committed: https://skia.googlesource.com/skia/+/093779c39add14f0b35b3374fee8f05cff10c9be

[bsalomon, 2015-09-23 18:28:25]

Hey Mike, Not trying to land this yet, I'm using it to test making the xfermode
param work in GPU. I noticed that it crashes the raster backend. 

SampleApp.exe!SkFilterShader::FilterShaderContext::shadeSpan(int x, int y,
unsigned int * result, int count) Line 85	C++
SampleApp.exe!SkARGB32_Shader_Blitter::blitH(int x, int y, int width) Line
373	C++
SampleApp.exe!walk_convex_edges(SkEdge * prevHead, SkPath::FillType __formal,
SkBlitter * blitter, int start_y, int stop_y, void (SkBlitter *, int, bool) *
proc) Line 263	C++
SampleApp.exe!sk_fill_triangle(const SkPoint * pts, const SkIRect * clipRect,
SkBlitter * blitter, const SkIRect & ir) Line 678	C++
SampleApp.exe!SkScan::FillTriangle(const SkPoint * pts, const SkRasterClip &
clip, SkBlitter * blitter) Line 707	C++
SampleApp.exe!SkDraw::drawVertices(SkCanvas::VertexMode vmode, int count, const
SkPoint * vertices, const SkPoint * textures, const unsigned int * colors,
SkXfermode * xmode, const unsigned short * indices, int indexCount, const
SkPaint & paint) Line 2096	C++
SampleApp.exe!SkBitmapDevice::drawVertices(const SkDraw & draw,
SkCanvas::VertexMode vmode, int vertexCount, const SkPoint * verts, const
SkPoint * textures, const unsigned int * colors, SkXfermode * xmode, const
unsigned short * indices, int indexCount, const SkPaint & paint) Line 359	C++
SampleApp.exe!SkCanvas::onDrawVertices(SkCanvas::VertexMode vmode, int
vertexCount, const SkPoint * verts, const SkPoint * texs, const unsigned int *
colors, SkXfermode * xmode, const unsigned short * indices, int indexCount,
const SkPaint & paint) Line 2536	C++
SampleApp.exe!VerticesGM::onDraw(SkCanvas * canvas) Line 165	C++
SampleApp.exe!GMSampleView::onDrawContent(SkCanvas * canvas) Line 44	C++
SampleApp.exe!SampleView::onDraw(SkCanvas * canvas) Line 2254	C++
SampleApp.exe!SkView::draw(SkCanvas * canvas) Line 128	C++
SampleApp.exe!SampleView::draw(SkCanvas * canvas) Line 2222	C++
SampleApp.exe!SkView::draw(SkCanvas * canvas) Line 140	C++
SampleApp.exe!SampleWindow::draw(SkCanvas * canvas) Line 1011	C++
SampleApp.exe!SkWindow::update(SkIRect * updateArea) Line 128	C++
SampleApp.exe!SkOSWindow::doPaint(void * ctx) Line 194	C++
SampleApp.exe!SkOSWindow::wndProc(HWND__ * hWnd, unsigned int message, unsigned
__int64 wParam, __int64 lParam) Line 163	C++

[reed1, 2015-09-24 09:35:47]

reed@google.com changed reviewers:
+ reed@google.com

[reed1, 2015-09-24 09:35:48]

trying to repro now...

[reed1, 2015-09-24 13:47:42]

Yikes. Here is (at least part of) what is going on...

1. We install a tri-color "shader" to handle the vertex colors (if present).
2. If there was a pre-existing shader on the paint, we cleverly wrap it and the
tri-color shader with a compose-shader.
3. then we instantiate a blitter
4. as we're drawing, we wack the tri-color shader-context for each triangle,
ASSUMING it came from our tri-color shader!

The bug this CL shows, is that, in the presence of a colorfilter, the blitter
code itself may have wrapped the paint's shader with its own wrapper (in this
case, a filter-shader). Now, we we query the shader-context, it is NO LONGER
built from our tri-color shader, so the cast is invalid, and we trash memory....
crash.

I need to ponder how to fix this...

[reed1, 2016-03-08 19:34:29]

The CQ bit was checked by reed@google.com

[reed1, 2016-03-08 19:34:30]

lgtm

[commit-bot: I haz the power, 2016-03-08 19:34:38]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1361173003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1361173003/1

[commit-bot: I haz the power, 2016-03-08 19:53:33]

Description was changed from

==========
Expand coverage of vertices gm
==========

to

==========
Expand coverage of vertices gm

Committed:
https://skia.googlesource.com/skia/+/093779c39add14f0b35b3374fee8f05cff10c9be
==========

[commit-bot: I haz the power, 2016-03-08 19:53:34]

Committed patchset #1 (id:1) as
https://skia.googlesource.com/skia/+/093779c39add14f0b35b3374fee8f05cff10c9be