Revert "converted vertex shaders to device coords"

This reverts commit e7e81c15c144b8133f696d0744ed9f7e8d06e936.

Reason for revert: Chrome perf regressions

Bug: skia:
Change-Id: I17fadc97c4b8e80bfdccbf123554614a00c58473
Reviewed-on: https://skia-review.googlesource.com/99040
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>

5 files changed, 15 insertions, 109 deletions

diff --git a/src/sksl/README b/src/sksl/README
index e9e46566a8..7c2cf04551 100644
--- a/src/sksl/README
+++ b/src/sksl/README
@@ -38,8 +38,7 @@ Differences from GLSL
   'do_something_else();', depending on whether that cap is enabled or not.
 * no #version statement is required, and it will be ignored if present
 * the output color is sk_FragColor (do not declare it)
-* use sk_Position instead of gl_Position. sk_Position is in device coordinates
-  rather than normalized coordinates.
+* use sk_Position instead of gl_Position
 * use sk_PointSize instead of gl_PointSize
 * use sk_VertexID instead of gl_VertexID
 * use sk_InstanceID instead of gl_InstanceID
diff --git a/src/sksl/SkSLCompiler.cpp b/src/sksl/SkSLCompiler.cpp
index 7589da98ee..bf321c8e1e 100644
--- a/src/sksl/SkSLCompiler.cpp
+++ b/src/sksl/SkSLCompiler.cpp
@@ -200,8 +200,7 @@ Compiler::Compiler(Flags flags)
     fIRGenerator->fSymbolTable->add(skArgsName, std::unique_ptr<Symbol>(skArgs));
 
     std::vector<std::unique_ptr<ProgramElement>> ignored;
-    fIRGenerator->convertProgram(Program::kFragment_Kind, SKSL_INCLUDE, strlen(SKSL_INCLUDE),
-                                 *fTypes, &ignored);
+    fIRGenerator->convertProgram(SKSL_INCLUDE, strlen(SKSL_INCLUDE), *fTypes, &ignored);
     fIRGenerator->fSymbolTable->markAllFunctionsBuiltin();
     if (fErrorCount) {
         printf("Unexpected errors: %s\n", fErrorText.c_str());
@@ -1165,19 +1164,19 @@ std::unique_ptr<Program> Compiler::convertProgram(Program::Kind kind, String tex
     std::vector<std::unique_ptr<ProgramElement>> elements;
     switch (kind) {
         case Program::kVertex_Kind:
-            fIRGenerator->convertProgram(kind, SKSL_VERT_INCLUDE, strlen(SKSL_VERT_INCLUDE),
-                                         *fTypes, &elements);
+            fIRGenerator->convertProgram(SKSL_VERT_INCLUDE, strlen(SKSL_VERT_INCLUDE), *fTypes,
+                                         &elements);
             break;
         case Program::kFragment_Kind:
-            fIRGenerator->convertProgram(kind, SKSL_FRAG_INCLUDE, strlen(SKSL_FRAG_INCLUDE),
-                                         *fTypes, &elements);
+            fIRGenerator->convertProgram(SKSL_FRAG_INCLUDE, strlen(SKSL_FRAG_INCLUDE), *fTypes,
+                                         &elements);
             break;
         case Program::kGeometry_Kind:
-            fIRGenerator->convertProgram(kind, SKSL_GEOM_INCLUDE, strlen(SKSL_GEOM_INCLUDE),
-                                         *fTypes, &elements);
+            fIRGenerator->convertProgram(SKSL_GEOM_INCLUDE, strlen(SKSL_GEOM_INCLUDE), *fTypes,
+                                         &elements);
             break;
         case Program::kFragmentProcessor_Kind:
-            fIRGenerator->convertProgram(kind, SKSL_FP_INCLUDE, strlen(SKSL_FP_INCLUDE), *fTypes,
+            fIRGenerator->convertProgram(SKSL_FP_INCLUDE, strlen(SKSL_FP_INCLUDE), *fTypes,
                                          &elements);
             break;
     }
@@ -1189,7 +1188,7 @@ std::unique_ptr<Program> Compiler::convertProgram(Program::Kind kind, String tex
     }
     std::unique_ptr<String> textPtr(new String(std::move(text)));
     fSource = textPtr.get();
-    fIRGenerator->convertProgram(kind, textPtr->c_str(), textPtr->size(), *fTypes, &elements);
+    fIRGenerator->convertProgram(textPtr->c_str(), textPtr->size(), *fTypes, &elements);
     if (!fErrorCount) {
         for (auto& element : elements) {
             if (element->fKind == ProgramElement::kFunction_Kind) {
diff --git a/src/sksl/SkSLCompiler.h b/src/sksl/SkSLCompiler.h
index eb2fc45b51..ca39c8c659 100644
--- a/src/sksl/SkSLCompiler.h
+++ b/src/sksl/SkSLCompiler.h
@@ -45,9 +45,6 @@ class IRGenerator;
  */
 class Compiler : public ErrorReporter {
 public:
-    static constexpr const char* RTADJUST_NAME  = "sk_RTAdjust";
-    static constexpr const char* PERVERTEX_NAME = "sk_PerVertex";
-
     enum Flags {
         kNone_Flags = 0,
         // permits static if/switch statements to be used with non-constant tests. This is used when
diff --git a/src/sksl/SkSLIRGenerator.cpp b/src/sksl/SkSLIRGenerator.cpp
index 3388a4758d..019aee8eaa 100644
--- a/src/sksl/SkSLIRGenerator.cpp
+++ b/src/sksl/SkSLIRGenerator.cpp
@@ -154,9 +154,6 @@ void IRGenerator::start(const Program::Settings* settings) {
     this->pushSymbolTable();
     fInvocations = -1;
     fInputs.reset();
-    fSkPerVertex = nullptr;
-    fRTAdjust = nullptr;
-    fRTAdjustInterfaceBlock = nullptr;
 }
 
 void IRGenerator::finish() {
@@ -174,26 +171,8 @@ std::unique_ptr<Statement> IRGenerator::convertStatement(const ASTStatement& sta
             return this->convertBlock((ASTBlock&) statement);
         case ASTStatement::kVarDeclaration_Kind:
             return this->convertVarDeclarationStatement((ASTVarDeclarationStatement&) statement);
-        case ASTStatement::kExpression_Kind: {
-            std::unique_ptr<Statement> result =
-                              this->convertExpressionStatement((ASTExpressionStatement&) statement);
-            if (fRTAdjust && Program::kGeometry_Kind == fKind) {
-                ASSERT(result->fKind == Statement::kExpression_Kind);
-                Expression& expr = *((ExpressionStatement&) *result).fExpression;
-                if (expr.fKind == Expression::kFunctionCall_Kind) {
-                    FunctionCall& fc = (FunctionCall&) expr;
-                    if (fc.fFunction.fBuiltin && fc.fFunction.fName == "EmitVertex") {
-                        std::vector<std::unique_ptr<Statement>> statements;
-                        statements.push_back(getNormalizeSkPositionCode());
-                        statements.push_back(std::move(result));
-                        return std::unique_ptr<Block>(new Block(statement.fOffset,
-                                                                std::move(statements),
-                                                                fSymbolTable));
-                    }
-                }
-            }
-            return result;
-        }
+        case ASTStatement::kExpression_Kind:
+            return this->convertExpressionStatement((ASTExpressionStatement&) statement);
         case ASTStatement::kIf_Kind:
             return this->convertIf((ASTIfStatement&) statement);
         case ASTStatement::kFor_Kind:
@@ -278,11 +257,6 @@ std::unique_ptr<VarDeclarations> IRGenerator::convertVarDeclarations(const ASTVa
         }
         auto var = std::unique_ptr<Variable>(new Variable(decl.fOffset, decl.fModifiers,
                                                           varDecl.fName, *type, storage));
-        if (var->fName == Compiler::RTADJUST_NAME) {
-            ASSERT(!fRTAdjust);
-            ASSERT(var->fType == *fContext.fFloat4_Type);
-            fRTAdjust = var.get();
-        }
         std::unique_ptr<Expression> value;
         if (varDecl.fValue) {
             value = this->convertExpression(*varDecl.fValue);
@@ -498,10 +472,6 @@ std::unique_ptr<Statement> IRGenerator::convertExpressionStatement(
 
 std::unique_ptr<Statement> IRGenerator::convertReturn(const ASTReturnStatement& r) {
     ASSERT(fCurrentFunction);
-    // early returns from a vertex main function will bypass the sk_Position normalization, so
-    // assert that we aren't doing that. It is of course possible to fix this by adding a
-    // normalization before each return, but it will probably never actually be necessary.
-    ASSERT(Program::kVertex_Kind != fKind || !fRTAdjust || "main" != fCurrentFunction->fName);
     if (r.fExpression) {
         std::unique_ptr<Expression> result = this->convertExpression(*r.fExpression);
         if (!result) {
@@ -605,40 +575,6 @@ std::unique_ptr<Block> IRGenerator::applyInvocationIDWorkaround(std::unique_ptr<
     return std::unique_ptr<Block>(new Block(-1, std::move(children)));
 }
 
-std::unique_ptr<Statement> IRGenerator::getNormalizeSkPositionCode() {
-    // sk_Position = float4(sk_Position.x * rtAdjust.x + sk_Position.w * rtAdjust.y,
-    //                      sk_Position.y * rtAdjust.z + sk_Position.w * rtAdjust.w,
-    //                      0,
-    //                      sk_Position.w);
-    ASSERT(fSkPerVertex && fRTAdjust);
-    #define REF(var) std::unique_ptr<Expression>(\
-                                  new VariableReference(-1, *var, VariableReference::kRead_RefKind))
-    #define FIELD(var, idx) std::unique_ptr<Expression>(\
-                    new FieldAccess(REF(var), idx, FieldAccess::kAnonymousInterfaceBlock_OwnerKind))
-    #define POS std::unique_ptr<Expression>(new FieldAccess(REF(fSkPerVertex), 0, \
-                                                   FieldAccess::kAnonymousInterfaceBlock_OwnerKind))
-    #define ADJUST (fRTAdjustInterfaceBlock ? \
-                    FIELD(fRTAdjustInterfaceBlock, fRTAdjustFieldIndex) : \
-                    REF(fRTAdjust))
-    #define SWIZZLE(expr, field) std::unique_ptr<Expression>(new Swizzle(fContext, expr, { field }))
-    #define OP(left, op, right) std::unique_ptr<Expression>(\
-                                   new BinaryExpression(-1, left, op, right, *fContext.fFloat_Type))
-    std::vector<std::unique_ptr<Expression>> children;
-    children.push_back(OP(OP(SWIZZLE(POS, 0), Token::STAR, SWIZZLE(ADJUST, 0)),
-                          Token::PLUS,
-                          OP(SWIZZLE(POS, 3), Token::STAR, SWIZZLE(ADJUST, 1))));
-    children.push_back(OP(OP(SWIZZLE(POS, 1), Token::STAR, SWIZZLE(ADJUST, 2)),
-                          Token::PLUS,
-                          OP(SWIZZLE(POS, 3), Token::STAR, SWIZZLE(ADJUST, 3))));
-    children.push_back(std::unique_ptr<Expression>(new FloatLiteral(fContext, -1, 0.0)));
-    children.push_back(SWIZZLE(POS, 3));
-    std::unique_ptr<Expression> result = OP(POS, Token::EQ,
-                                 std::unique_ptr<Expression>(new Constructor(-1,
-                                                                             *fContext.fFloat4_Type,
-                                                                             std::move(children))));
-    return std::unique_ptr<Statement>(new ExpressionStatement(std::move(result)));
-}
-
 void IRGenerator::convertFunction(const ASTFunction& f) {
     const Type* returnType = this->convertType(*f.fReturnType);
     if (!returnType) {
@@ -755,9 +691,7 @@ void IRGenerator::convertFunction(const ASTFunction& f) {
         }
         // conservatively assume all user-defined functions have side effects
         ((Modifiers&) decl->fModifiers).fFlags |= Modifiers::kHasSideEffects_Flag;
-        if (Program::kVertex_Kind == fKind && f.fName == "main" && fRTAdjust) {
-            body->fStatements.insert(body->fStatements.end(), this->getNormalizeSkPositionCode());
-        }
+
         fProgramElements->push_back(std::unique_ptr<FunctionDefinition>(
                                         new FunctionDefinition(f.fOffset, *decl, std::move(body))));
     }
@@ -768,7 +702,6 @@ std::unique_ptr<InterfaceBlock> IRGenerator::convertInterfaceBlock(const ASTInte
     AutoSymbolTable table(this);
     std::vector<Type::Field> fields;
     bool haveRuntimeArray = false;
-    bool foundRTAdjust = false;
     for (size_t i = 0; i < intf.fDeclarations.size(); i++) {
         std::unique_ptr<VarDeclarations> decl = this->convertVarDeclarations(
                                                                          *intf.fDeclarations[i],
@@ -783,11 +716,6 @@ std::unique_ptr<InterfaceBlock> IRGenerator::convertInterfaceBlock(const ASTInte
                               "only the last entry in an interface block may be a runtime-sized "
                               "array");
             }
-            if (vd.fVar == fRTAdjust) {
-                foundRTAdjust = true;
-                ASSERT(vd.fVar->fType == *fContext.fFloat4_Type);
-                fRTAdjustFieldIndex = fields.size();
-            }
             fields.push_back(Type::Field(vd.fVar->fModifiers, vd.fVar->fName,
                                          &vd.fVar->fType));
             if (vd.fValue) {
@@ -841,9 +769,6 @@ std::unique_ptr<InterfaceBlock> IRGenerator::convertInterfaceBlock(const ASTInte
     Variable* var = new Variable(intf.fOffset, intf.fModifiers,
                                  intf.fInstanceName.fLength ? intf.fInstanceName : intf.fTypeName,
                                  *type, Variable::kGlobal_Storage);
-    if (foundRTAdjust) {
-        fRTAdjustInterfaceBlock = var;
-    }
     old->takeOwnership(var);
     if (intf.fInstanceName.fLength) {
         old->addWithoutOwnership(intf.fInstanceName, var);
@@ -853,10 +778,6 @@ std::unique_ptr<InterfaceBlock> IRGenerator::convertInterfaceBlock(const ASTInte
                                                                        (int) i)));
         }
     }
-    if (var->fName == Compiler::PERVERTEX_NAME) {
-        ASSERT(!fSkPerVertex);
-        fSkPerVertex = var;
-    }
     return std::unique_ptr<InterfaceBlock>(new InterfaceBlock(intf.fOffset,
                                                               var,
                                                               intf.fTypeName,
@@ -2106,12 +2027,10 @@ void IRGenerator::markWrittenTo(const Expression& expr, bool readWrite) {
     }
 }
 
-void IRGenerator::convertProgram(Program::Kind kind,
-                                 const char* text,
+void IRGenerator::convertProgram(const char* text,
                                  size_t length,
                                  SymbolTable& types,
                                  std::vector<std::unique_ptr<ProgramElement>>* out) {
-    fKind = kind;
     fProgramElements = out;
     Parser parser(text, length, types, fErrors);
     std::vector<std::unique_ptr<ASTDeclaration>> parsed = parser.file();
diff --git a/src/sksl/SkSLIRGenerator.h b/src/sksl/SkSLIRGenerator.h
index 327fe6fc7a..1df9b65bd0 100644
--- a/src/sksl/SkSLIRGenerator.h
+++ b/src/sksl/SkSLIRGenerator.h
@@ -62,8 +62,7 @@ public:
     IRGenerator(const Context* context, std::shared_ptr<SymbolTable> root,
                 ErrorReporter& errorReporter);
 
-    void convertProgram(Program::Kind kind,
-                        const char* text,
+    void convertProgram(const char* text,
                         size_t length,
                         SymbolTable& types,
                         std::vector<std::unique_ptr<ProgramElement>>* result);
@@ -157,15 +156,12 @@ private:
     std::unique_ptr<Statement> convertWhile(const ASTWhileStatement& w);
     void convertEnum(const ASTEnum& e);
     std::unique_ptr<Block> applyInvocationIDWorkaround(std::unique_ptr<Block> main);
-    // returns a statement which converts sk_Position from device to normalized coordinates
-    std::unique_ptr<Statement> getNormalizeSkPositionCode();
 
     void fixRectSampling(std::vector<std::unique_ptr<Expression>>& arguments);
     void checkValid(const Expression& expr);
     void markWrittenTo(const Expression& expr, bool readWrite);
     void getConstantInt(const Expression& value, int64_t* out);
 
-    Program::Kind fKind;
     const FunctionDeclaration* fCurrentFunction;
     std::unordered_map<String, Program::Settings::Value> fCapsMap;
     std::shared_ptr<SymbolTable> fRootSymbolTable;
@@ -179,10 +175,6 @@ private:
     ErrorReporter& fErrors;
     int fInvocations;
     std::vector<std::unique_ptr<ProgramElement>>* fProgramElements;
-    Variable* fSkPerVertex;
-    Variable* fRTAdjust;
-    Variable* fRTAdjustInterfaceBlock;
-    int fRTAdjustFieldIndex;
 
     friend class AutoSymbolTable;
     friend class AutoLoopLevel;