added basic texturing to metal sksl backend

Bug: skia:
Change-Id: I2e70efe53f5c2fb208979cc89be9c3c841944a48
Reviewed-on: https://skia-review.googlesource.com/128844
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Timothy Liang <timliang@google.com>

1 files changed, 17 insertions, 1 deletions

diff --git a/src/sksl/SkSLMetalCodeGenerator.h b/src/sksl/SkSLMetalCodeGenerator.h
index 3eccbf0909..6f8933c381 100644
--- a/src/sksl/SkSLMetalCodeGenerator.h
+++ b/src/sksl/SkSLMetalCodeGenerator.h
@@ -77,7 +77,9 @@ public:
                       OutputStream* out)
     : INHERITED(program, errors, out)
     , fLineEnding("\n")
-    , fContext(*context) {}
+    , fContext(*context) {
+        this->setupIntrinsics();
+    }
 
     bool generateCode() override;
 
@@ -88,6 +90,16 @@ protected:
     static constexpr Requirements kOutputs_Requirement  = 1 << 1;
     static constexpr Requirements kUniforms_Requirement = 1 << 2;
 
+    enum IntrinsicKind {
+        kSpecial_IntrinsicKind
+    };
+
+    enum SpecialIntrinsic {
+        kTexture_SpecialIntrinsic,
+    };
+
+    void setupIntrinsics();
+
     void write(const char* s);
 
     void writeLine();
@@ -142,6 +154,8 @@ protected:
 
     void writeFunctionCall(const FunctionCall& c);
 
+    void writeSpecialIntrinsic(const FunctionCall& c, SpecialIntrinsic kind);
+
     void writeConstructor(const Constructor& c);
 
     void writeFieldAccess(const FieldAccess& f);
@@ -194,6 +208,8 @@ protected:
 
     Requirements requirements(const Statement& e);
 
+    typedef std::tuple<IntrinsicKind, int32_t, int32_t, int32_t, int32_t> Intrinsic;
+    std::unordered_map<String, Intrinsic> fIntrinsicMap;
     const char* fLineEnding;
     const Context& fContext;
     StringStream fHeader;