hippofish/packages/frontend/src/components/CkFollowMouse.vue
2024-05-23 18:08:31 +00:00

81 lines
1.7 KiB
Vue

<template>
<span ref="container" :class="$style.root">
<span ref="el" :class="$style.inner" style="position: absolute">
<slot></slot>
</span>
</span>
</template>
<script lang="ts" setup>
import { onMounted, onUnmounted, shallowRef } from 'vue';
const el = shallowRef<HTMLElement>();
const container = shallowRef<HTMLElement>();
const props = defineProps({
x: {
type: Boolean,
default: true,
},
y: {
type: Boolean,
default: true,
},
speed: {
type: String,
default: '0.1s',
},
rotateByVelocity: {
type: Boolean,
default: true,
},
});
let lastX = 0;
let lastY = 0;
let oldAngle = 0;
function lerp(a, b, alpha) {
return a + alpha * (b - a);
}
const updatePosition = (mouseEvent: MouseEvent) => {
if (el.value && container.value) {
const containerRect = container.value.getBoundingClientRect();
const newX = mouseEvent.clientX - containerRect.left;
const newY = mouseEvent.clientY - containerRect.top;
let transform = `translate(calc(${props.x ? newX : 0}px - 50%), calc(${props.y ? newY : 0}px - 50%))`;
if (props.rotateByVelocity) {
const deltaX = newX - lastX;
const deltaY = newY - lastY;
const angle = lerp(
oldAngle,
Math.atan2(deltaY, deltaX) * (180 / Math.PI),
0.1,
);
transform += ` rotate(${angle}deg)`;
oldAngle = angle;
}
el.value.style.transform = transform;
el.value.style.transition = `transform ${props.speed}`;
lastX = newX;
lastY = newY;
}
};
onMounted(() => {
window.addEventListener('mousemove', updatePosition);
});
onUnmounted(() => {
window.removeEventListener('mousemove', updatePosition);
});
</script>
<style lang="scss" module>
.root {
position: relative;
display: inline-block;
}
.inner {
transform-origin: center center;
}
</style>