added global variable and multi-texture support to metal sksl backend

Bug: skia:
Change-Id: If676774ec0a30c5b536ccffbff2220d180b7fa59
Reviewed-on: https://skia-review.googlesource.com/129187
Commit-Queue: Timothy Liang <timliang@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/src/sksl/SkSLMetalCodeGenerator.h b/src/sksl/SkSLMetalCodeGenerator.h
index 6f8933c381..a0a0cae986 100644
--- a/src/sksl/SkSLMetalCodeGenerator.h
+++ b/src/sksl/SkSLMetalCodeGenerator.h
@@ -85,10 +85,12 @@ public:
 
 protected:
     typedef int Requirements;
+    typedef unsigned int TextureId;
     static constexpr Requirements kNo_Requirements      = 0;
     static constexpr Requirements kInputs_Requirement   = 1 << 0;
     static constexpr Requirements kOutputs_Requirement  = 1 << 1;
     static constexpr Requirements kUniforms_Requirement = 1 << 2;
+    static constexpr Requirements kGlobals_Requirement  = 1 << 3;
 
     enum IntrinsicKind {
         kSpecial_IntrinsicKind
@@ -100,6 +102,8 @@ protected:
 
     void setupIntrinsics();
 
+    TextureId nextTextureId();
+
     void write(const char* s);
 
     void writeLine();
@@ -118,6 +122,8 @@ protected:
 
     void writeOutputStruct();
 
+    void writeGlobalStruct();
+
     void writePrecisionModifier();
 
     void writeType(const Type& type);
@@ -210,6 +216,10 @@ protected:
 
     typedef std::tuple<IntrinsicKind, int32_t, int32_t, int32_t, int32_t> Intrinsic;
     std::unordered_map<String, Intrinsic> fIntrinsicMap;
+    std::vector<const VarDeclaration*> fInitNonConstGlobalVars;
+    TextureId fCurrentTextureId = 0;
+    std::unordered_map<String, TextureId> fTextureMap;
+    bool fNeedsGlobalStructInit = false;
     const char* fLineEnding;
     const Context& fContext;
     StringStream fHeader;