Infer sampler precision from pixel config

src/gpu/glsl/GrGLSLCaps.h

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #ifndef GrGLSLCaps_DEFINED
 #define GrGLSLCaps_DEFINED
@@ skipping 144 matching lines @@
      */
     const GrSwizzle& configTextureSwizzle(GrPixelConfig config) const {
         return fConfigTextureSwizzle[config];
     }
 
     /** Swizzle that should occur on the fragment shader outputs for a given config. */
     const GrSwizzle& configOutputSwizzle(GrPixelConfig config) const {
         return fConfigOutputSwizzle[config];
     }
 
+    /** Precision qualifier that should be used with a sampler, given its config and visibility. */
+    GrSLPrecision samplerPrecision(GrPixelConfig config, GrShaderFlags visibility) const {
+        return static_cast<GrSLPrecision>(fSamplerPrecisions[visibility][config]);
+    }
+
     GrGLSLGeneration generation() const { return fGLSLGeneration; }
 
     /**
     * Returns a string containing the caps info.
     */
     SkString dump() const override;
 
 private:
+    /** GrCaps subclasses must call this after filling in the shader precision table. */
+    void initSamplerPrecisionTable();
+
     void onApplyOptionsOverrides(const GrContextOptions& options) override;
 
     GrGLSLGeneration fGLSLGeneration;
 
     bool fDropsTileOnZeroDivide : 1;
     bool fFBFetchSupport : 1;
     bool fFBFetchNeedsCustomOutput : 1;
     bool fBindlessTextureSupport : 1;
     bool fUsesPrecisionModifiers : 1;
     bool fCanUseAnyFunctionInShader : 1;
@@ skipping 26 matching lines @@
     uint8_t fMaxVertexSamplers;
     uint8_t fMaxGeometrySamplers;
     uint8_t fMaxFragmentSamplers;
     uint8_t fMaxCombinedSamplers;
 
     AdvBlendEqInteraction fAdvBlendEqInteraction;
 
     GrSwizzle fConfigTextureSwizzle[kGrPixelConfigCnt];
     GrSwizzle fConfigOutputSwizzle[kGrPixelConfigCnt];
 
+    uint8_t fSamplerPrecisions[(1 << kGrShaderTypeCount)][kGrPixelConfigCnt];
+
     friend class GrGLCaps;  // For initialization.
     friend class GrVkCaps;
 
     typedef GrShaderCaps INHERITED;
 };
 
 #endif