Use mixed samples internally for default coverage AA
Lays the infrastructure to use mixed samples internally, and begins
using nvpr with mixed samples on the default "gl" and "gles" configs.
In this rendition, we take the simplest approach possible re: stencil
attachments. We initially create a render target without stencil
(i.e., 0 samples). Then, any time a proxy needs a stencil buffer with
more samples than its target currently has, we create and attach a new
stencil buffer. However, we never "downgrade" a render target's
stencil attachment to one with fewer samples. So if the proxy only
needs one sample and the target has many, we leave it.
Bug: skia:
Change-Id: I8558ba799ac3dee457f349f77d4517c11413c9a9
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/224456
Commit-Queue: Chris Dalton <csmartdalton@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
diff --git a/src/gpu/GrResourceProvider.h b/src/gpu/GrResourceProvider.h
index 00bf3d2..46b4710 100644
--- a/src/gpu/GrResourceProvider.h
+++ b/src/gpu/GrResourceProvider.h
@@ -210,10 +210,10 @@
const void* data = nullptr);
/**
- * If passed in render target already has a stencil buffer, return true. Otherwise attempt to
- * attach one and return true on success.
+ * If passed in render target already has a stencil buffer with at least "numSamples" samples,
+ * return true. Otherwise attempt to attach one and return true on success.
*/
- bool attachStencilAttachment(GrRenderTarget* rt);
+ bool attachStencilAttachment(GrRenderTarget* rt, int numStencilSamples);
/**
* Wraps an existing texture with a GrRenderTarget object. This is useful when the provided