skia2/include/sksl/DSLVar.h
Ethan Nicholas b4f8b7a9f2 Cleaned up DSL error handling
This unifies various chunks of error handling code and makes the DSL
more gracefully handle failed object construction.

Change-Id: I4edc581c9eba276ce2ee2a17125ea7bd6057134a
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/420237
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
2021-06-23 15:22:35 +00:00

168 lines
4.2 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"
#include "include/sksl/DSLType.h"
namespace SkSL {
class IRGenerator;
class Variable;
enum class VariableStorage : int8_t;
namespace dsl {
class DSLVar {
public:
/**
* Creates an empty, unpopulated DSLVar. Can be replaced with a real DSLVar later via `swap`.
*/
DSLVar() : fType(kVoid_Type), fDeclared(true) {}
/**
* 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&&) = default;
~DSLVar();
const char* name() const {
return fName;
}
DSLModifiers modifiers() const {
return fModifiers;
}
void swap(DSLVar& other);
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=(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=(double 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);
DSLModifiers fModifiers;
// We only need to keep track of the type here so that we can create the SkSL::Variable. For
// predefined variables this field is unnecessary, so we don't bother tracking it and just set
// it to kVoid; in other words, you shouldn't generally be relying on this field to be correct.
// If you need to determine the variable's type, look at DSLWriter::Var(...).type() instead.
DSLType fType;
int fUniformHandle = -1;
std::unique_ptr<SkSL::Statement> fDeclaration;
const SkSL::Variable* fVar = nullptr;
const char* fRawName = nullptr; // for error reporting
const char* fName = nullptr;
DSLExpression fInitialValue;
VariableStorage fStorage;
bool fDeclared = false;
friend DSLVar sk_SampleCoord();
friend class DSLCore;
friend class DSLExpression;
friend class DSLFunction;
friend class DSLWriter;
friend class ::SkSL::IRGenerator;
};
} // namespace dsl
} // namespace SkSL
#endif