Implement text rendering with NVPR

Use path rendering to render the text from outlines if supported by the
GPU. Implement this in GrStencilAndCoverTextContext by copying chunks of code
from GrBitmapTextContext.

The drawing is implemented with "instanced" path drawing functions.

Moves the creation of the "main" text context from SkGpuDevice to the
GrContext::createTextContext. This is done because the decision of which text
renderer is optimal can be made only with the internal implementation-specific
information of the context.

Remove a windows assertion from SkScalerContext_GDI::getGDIGlyphPath.  The
GetGlyphOutlineW fails in fontmgr_match for the initial space char in the string
" [700] ...". According to MSDN, this is a known problem.  Just return that the
glyph has no path data in these cases.

R=jvanverth@google.com, bsalomon@google.com, mtklein@google.com

Author: kkinnunen@nvidia.com

Review URL: https://codereview.chromium.org/196133014

1 files changed, 2 insertions, 1 deletions

diff --git a/src/ports/SkFontHost_win.cpp b/src/ports/SkFontHost_win.cpp
index 5a902148bd..a6ccf4d2ee 100755
--- a/src/ports/SkFontHost_win.cpp
+++ b/src/ports/SkFontHost_win.cpp
@@ -1706,7 +1706,8 @@ DWORD SkScalerContext_GDI::getGDIGlyphPath(const SkGlyph& glyph, UINT flags,
             LogFontTypeface::EnsureAccessible(this->getTypeface());
             total_size = GetGlyphOutlineW(fDDC, glyph.fID, flags, &gm, 0, NULL, &fMat22);
             if (GDI_ERROR == total_size) {
-                SkASSERT(false);
+                // GetGlyphOutlineW is known to fail for some characters, such as spaces.
+                // In these cases, just return that the glyph does not have a shape.
                 return 0;
             }
         }