Files
memberApp/src/utils/number-helpers.ts
Adrian Zürcher a908db4f38 first commit
2025-10-12 14:56:18 +02:00

51 lines
2.0 KiB
TypeScript

import type { Ref } from 'vue';
export function separate16BitUint(value: number): { highByte: number; lowByte: number } {
// Ensure the value is treated as a 16-bit unsigned integer
// (optional, but good for clarity and safety if 'value' might be outside 0-65535)
const normalizedValue = value & 0xffff; // Mask to ensure it's within 16 bits
// Extract the low byte (least significant 8 bits)
// This is simply the value modulo 256, or bitwise AND with 0xFF
const lowByte = normalizedValue & 0xff;
// Extract the high byte (most significant 8 bits)
// Right shift by 8 bits to move the high byte into the low byte's position,
// then mask with 0xFF to get just those 8 bits.
const highByte = (normalizedValue >> 8) & 0xff;
return { highByte, lowByte };
}
export function combineBytesTo16BitUint(highByte: number, lowByte: number): number {
// Ensure both bytes are within the 0-255 range for safety
const safeHighByte = highByte & 0xff;
const safeLowByte = lowByte & 0xff;
// Shift the high byte 8 bits to the left to place it in the higher position.
// Example: if highByte is 0xA4 (10100100), after shifting it becomes 0xA400 (1010010000000000).
const shiftedHighByte = safeHighByte << 8;
// Combine the shifted high byte with the low byte using a bitwise OR.
// Example: if shiftedHighByte is 0xA400 and lowByte is 0x78 (01111000),
// the result is 0xA478 (1010010001111000).
const combinedValue = shiftedHighByte | safeLowByte;
// Optional: Mask the result to ensure it's strictly within the 16-bit unsigned range (0 to 65535).
// This is good practice as JavaScript numbers are 64-bit floats, and this ensures
// the value wraps correctly if intermediate operations somehow exceeded 16 bits.
return combinedValue & 0xffff;
}
export function addOne(val: Ref<number>, limit: number) {
if (val.value < limit) {
val.value++;
}
}
export function substractOne(val: Ref<number>, limit: number) {
if (val.value > limit) {
val.value--;
}
}