Flag

Functions

addFlag()

addFlag<T>(flags, …flagsToAdd): BitFlags<T>

Defined in: packages/isaacscript-common/src/functions/flag.ts:29

Helper function to add a bit flag to an existing set of bit flags.

This is a variadic function, so pass as many flags as you want to add.

Example 1:

// Give the player spectral tears
const player = Isaac.GetPlayer();
player.TearFlags = addFlag(player.TearFlags, TearFlags.TEAR_SPECTRAL);

Example 2:

// Give the player spectral and homing tears
const player = Isaac.GetPlayer();
player.TearFlags = addFlag(player.TearFlags, TearFlags.TEAR_SPECTRAL, TearFlags.TEAR_HOMING);

Type Parameters

T

T extends BitFlag | BitFlag128

Parameters

flags

T | BitFlags<T>

The existing set of bit flags.

flagsToAdd

…readonly T[]

One or more bit flags to add, each as a separate argument.

Returns

BitFlags<T>

The combined bit flags.

---

bitFlags()

bitFlags<T>(flag): BitFlags<T>

Defined in: packages/isaacscript-common/src/functions/flag.ts:55

Helper function for casting a flag enum value to a BitFlags object.

This is useful because the compiler will prevent you from assigning a specific flag to a BitFlags field. (It does this to ensure type safety, since BitFlags can represent a zero value or a composition of N flags.)

For example:

player.TearFlags = bitFlags(TearFlag.SPECTRAL);

Type Parameters

T

T extends BitFlag | BitFlag128

Parameters

flag

T

Returns

BitFlags<T>

---

getFlagName()

getFlagName<T>(flag, flagEnum): string | undefined

Defined in: packages/isaacscript-common/src/functions/flag.ts:66

Helper function to get the key associated with a particular flag.

(Since bit flags are represented by custom objects instead of normal TypeScript enums, you cannot use the reverse mapping to find the associated key of a given enum value. Use this helper function instead of indexing the enum directly.)

Type Parameters

T

T extends BitFlag | BitFlag128

Parameters

flag

BitFlag

flagEnum

ReadonlyRecord<string, T>

Returns

string | undefined

---

hasFlag()

hasFlag<T>(flags, …flagsToCheck): boolean

Defined in: packages/isaacscript-common/src/functions/flag.ts:97

Helper function to determine if a particular bit flag is set to true.

This is a variadic function, so pass as many flags as you want to check for. If passed multiple flags, it will only return true if all of the flags are set.

For example:

const player = Isaac.GetPlayer();
if (hasFlag(player.TearFlags, TearFlags.TEAR_SPECTRAL) {
  // The player currently has spectral tears
}

Type Parameters

T

T extends BitFlag | BitFlag128

Parameters

flags

T | BitFlags<T>

The existing set of bit flags.

flagsToCheck

…readonly T[]

One or more bit flags to check for, each as a separate argument.

Returns

boolean

---

isEmptyFlag()

isEmptyFlag(flag): boolean

Defined in: packages/isaacscript-common/src/functions/flag.ts:118

Helper function to check if every bit in the flag is turned off.

(This is equivalent to checking if the flag is equal to 0, but this is not possible without casting the flag to a number.)

Parameters

flag

BitFlag | BitFlag128

Returns

boolean

---

isSelfDamage()

isSelfDamage(damageFlags): boolean

Defined in: packages/isaacscript-common/src/functions/flag.ts:127

Helper function to determine whether damage to a player in the ENTITY_TAKE_DMG callback was self-inflicted. For example, damage from a Curse Room door, a Razor, or a Blood Donation Machine would count as self-inflicted damage.

Parameters

damageFlags

DamageFlagValue | BitFlags<DamageFlagValue>

Returns

boolean

---

removeFlag()

removeFlag<T>(flags, …flagsToRemove): BitFlags<T>

Defined in: packages/isaacscript-common/src/functions/flag.ts:155

Helper function to remove a bit flag from an existing set of bit flags.

This is a variadic function, so pass as many flags as you want to remove.

For example:

// Remove spectral tears from the player, if present
const player = Isaac.GetPlayer();
player.TearFlags = removeFlag(player.TearFlags, TearFlags.TEAR_SPECTRAL);

Type Parameters

T

T extends BitFlag | BitFlag128

Parameters

flags

T | BitFlags<T>

The existing set of bit flags.

flagsToRemove

…readonly T[]

One or more bit flags to remove, each as a separate argument.

Returns

BitFlags<T>

The combined bit flags.