skia2/include/sksl/DSLVar.h
Ethan Nicholas fe5d6928d0 DSL var values are now specified at construction time rather than in
Declare

This solves several issues caused by the lack of ordering guarantees in
C++; it was possible for the SkSL backend to look for the value of a
variable before its Declare() call gets processed. Moving the initial
value out of Declare should fix this whole class of problems.

Change-Id: I428fe230f1c312a0128c1f00c2a36cb95f4590a6
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/380358
Reviewed-by: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
2021-03-05 21:47:28 +00:00

141 lines
3.1 KiB
C++

/*
* Copyright 2020 Google LLC
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SKSL_DSL_VAR
#define SKSL_DSL_VAR
#include "include/sksl/DSLExpression.h"
#include "include/sksl/DSLModifiers.h"
namespace SkSL {
class Variable;
namespace dsl {
class DSLType;
class DSLVar {
public:
/**
* Constructs a new variable with the specified type and name. The name is used (in mangled
* form) in the resulting shader code; it is not otherwise important. Since mangling prevents
* name conflicts and the variable's name is only important when debugging shaders, the name
* parameter is optional.
*/
DSLVar(DSLType type, const char* name = "var", DSLExpression initialValue = DSLExpression());
DSLVar(DSLType type, DSLExpression initialValue);
DSLVar(DSLModifiers modifiers, DSLType type, const char* name = "var",
DSLExpression initialValue = DSLExpression());
DSLVar(DSLModifiers modifiers, DSLType type, DSLExpression initialValue);
DSLVar(DSLVar&&) = delete;
~DSLVar();
DSLExpression x() {
return DSLExpression(*this).x();
}
DSLExpression y() {
return DSLExpression(*this).y();
}
DSLExpression z() {
return DSLExpression(*this).z();
}
DSLExpression w() {
return DSLExpression(*this).w();
}
DSLExpression r() {
return DSLExpression(*this).r();
}
DSLExpression g() {
return DSLExpression(*this).g();
}
DSLExpression b() {
return DSLExpression(*this).b();
}
DSLExpression a() {
return DSLExpression(*this).a();
}
DSLExpression field(const char* name) {
return DSLExpression(*this).field(name);
}
DSLPossibleExpression operator=(const DSLVar& var) {
return this->operator=(DSLExpression(var));
}
DSLPossibleExpression operator=(DSLExpression expr);
DSLPossibleExpression operator=(int expr) {
return this->operator=(DSLExpression(expr));
}
DSLPossibleExpression operator=(float expr) {
return this->operator=(DSLExpression(expr));
}
DSLPossibleExpression operator[](DSLExpression&& index);
DSLPossibleExpression operator++() {
return ++DSLExpression(*this);
}
DSLPossibleExpression operator++(int) {
return DSLExpression(*this)++;
}
DSLPossibleExpression operator--() {
return --DSLExpression(*this);
}
DSLPossibleExpression operator--(int) {
return DSLExpression(*this)--;
}
private:
/**
* Constructs a reference to a variable that already exists in the symbol table. This is used
* internally to reference built-in vars.
*/
DSLVar(const char* name);
const char* name() const {
return fName;
}
int fUniformHandle;
std::unique_ptr<SkSL::Statement> fDeclaration;
bool fDeclared = false;
const SkSL::Variable* fVar;
const char* fName;
friend DSLVar sk_SampleCoord();
friend class DSLCore;
friend class DSLExpression;
friend class DSLWriter;
};
} // namespace dsl
} // namespace SkSL
#endif