67 lines
1.4 KiB
C++
67 lines
1.4 KiB
C++
/*
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* Copyright (c) Meta Platforms, Inc. and affiliates.
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*
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* This source code is licensed under the MIT license found in the
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* LICENSE file in the root directory of this source tree.
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*/
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#pragma once
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#include <cmath>
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#include <cstdint>
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#include <optional>
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#include <string_view>
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#include <react/utils/fnv1a.h>
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namespace facebook::react {
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/**
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* Unit for the CSS <angle> type.
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* https://www.w3.org/TR/css-values-4/#angles
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*/
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enum class CSSAngleUnit : uint8_t {
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Deg,
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Grad,
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Rad,
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Turn,
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};
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/**
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* Parses a unit from a dimension token into a CSS angle unit.
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*/
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constexpr std::optional<CSSAngleUnit> parseCSSAngleUnit(std::string_view unit) {
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switch (fnv1aLowercase(unit)) {
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case fnv1a("deg"):
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return CSSAngleUnit::Deg;
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case fnv1a("grad"):
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return CSSAngleUnit::Grad;
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case fnv1a("rad"):
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return CSSAngleUnit::Rad;
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case fnv1a("turn"):
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return CSSAngleUnit::Turn;
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default:
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return std::nullopt;
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}
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}
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/**
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* Converts a specified CSS angle to its cannonical unit (degrees)
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*/
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constexpr float canonicalize(float value, CSSAngleUnit unit) {
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switch (unit) {
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case CSSAngleUnit::Deg:
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return value;
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case CSSAngleUnit::Grad:
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return value * 0.9f;
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case CSSAngleUnit::Rad:
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return value * 57.295779513f;
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case CSSAngleUnit::Turn:
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return value * 360.0f;
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default:
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return std::numeric_limits<float>::quiet_NaN();
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}
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}
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} // namespace facebook::react
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