Add "sharpen" option to SkSL, to LOD bias all textures

This adds a fixed bias (-0.5) to the computed LOD of all
mip-mapped texture fetches. (Technically, to all texture
fetches, but that only matters for mip-mapped ones).

Clients can opt-in with a new GrContextOption.

Bug: skia:7541
Bug: chromium:562162
Change-Id: Ie3cd0679c4ab66f62d2dc32e7e68e5c99355115e
Reviewed-on: https://skia-review.googlesource.com/106322
Reviewed-by: Brian Salomon <bsalomon@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/gpu/gl/builders/GrGLProgramBuilder.cpp b/src/gpu/gl/builders/GrGLProgramBuilder.cpp
index 7ae63a262c..ed6386b7f3 100644
--- a/src/gpu/gl/builders/GrGLProgramBuilder.cpp
+++ b/src/gpu/gl/builders/GrGLProgramBuilder.cpp
@@ -152,6 +152,7 @@ GrGLProgram* GrGLProgramBuilder::finalize() {
     SkSL::Program::Settings settings;
     settings.fCaps = this->gpu()->glCaps().shaderCaps();
     settings.fFlipY = this->pipeline().proxy()->origin() != kTopLeft_GrSurfaceOrigin;
+    settings.fSharpenTextures = this->gpu()->getContext()->contextPriv().sharpenMipmappedTextures();
     SkSL::Program::Inputs inputs;
     SkTDArray<GrGLuint> shadersToDelete;
     bool cached = nullptr != fCached.get();