src/writer/pack_coord_arrayidx.h

// Copyright 2020 The Tint Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef SRC_WRITER_PACK_COORD_ARRAYIDX_H_
#define SRC_WRITER_PACK_COORD_ARRAYIDX_H_

#include <functional>

#include "src/source.h"

namespace tint {

namespace ast {
class Expression;
class TypeConstructorExpression;
}  // namespace ast

namespace writer {

/// A helper function use to generate texture intrinsic function calls for
/// backends that expect the texture coordinate and array index to be packed
/// together into a single 'coordinate' parameter.
/// PackCoordAndArrayIndex() calls the `callback` function with a vector
/// expression containing the elements of `coords` followed by the single
/// element of `array_idx` cast to the `coords` element type.
/// All types must have been assigned to the expressions and their child nodes
/// before calling.
/// @param coords the texture coordinates. May be a scalar, `vec2` or `vec3`.
/// @param array_idx the texture array index. Must be a scalar.
/// @param callback the function called with the packed result. Note that the
/// pointer argument is only valid for the duration of the call.
/// @returns the value returned by `callback` to indicate success
bool PackCoordAndArrayIndex(
    ast::Expression* coords,
    ast::Expression* array_idx,
    std::function<bool(ast::TypeConstructorExpression*)> callback);

}  // namespace writer
}  // namespace tint

#endif  // SRC_WRITER_PACK_COORD_ARRAYIDX_H_