formula component based on katex

thanks a lot to MoshiBar for the initial implementation!

packages/frontend/src/components/MkFormula.vue

@@ -0,0 +1,33 @@
+<!--
+		 SPDX-FileCopyrightText: dakkar, MoshiBar, and other Sharkey contributors
+		 SPDX-License-Identifier: AGPL-3.0-only
+-->
+
+<template>
+	<div v-if="block" :class="$style.block" v-html="renderedFormula"></div>
+	<span v-else v-html="renderedFormula"></span>
+</template>
+
+<script lang="ts" setup>
+	import { computed } from 'vue';
+	import katex from 'katex';
+	import 'katex/dist/katex.min.css';
+
+	const props = defineProps<{
+		formula: string;
+		block: boolean;
+	}>();
+
+	const renderedFormula = computed(() =>
+		katex.renderToString(props.formula, {
+			throwOnError: false,
+			trust: false,
+			displayMode: props.block,
+		} as any));
+</script>
+
+<style lang="scss" module>
+	.block {
+		text-align: center;
+	}
+</style>

packages/frontend/src/components/global/MkMisskeyFlavoredMarkdown.ts

@@ -3,7 +3,7 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
-import { VNode, h } from 'vue';
+import { VNode, h, defineAsyncComponent } from 'vue';
 import * as mfm from '@sharkey/sfm-js';
 import * as Misskey from 'misskey-js';
 import MkUrl from '@/components/global/MkUrl.vue';
@@ -61,6 +61,8 @@ export default function(props: MfmProps) {
 
 	const useAnim = defaultStore.state.advancedMfm && defaultStore.state.animatedMfm ? true : props.isAnim ? true : false;
 
+	const MkFormula = defineAsyncComponent(() => import('@/components/MkFormula.vue'));
+
 	/**
 	 * Gen Vue Elements from MFM AST
 	 * @param ast MFM AST
@@ -410,11 +412,17 @@ export default function(props: MfmProps) {
 			}
 
 			case 'mathInline': {
-				return [h('code', token.props.formula)];
+				return [h(MkFormula, {
+					formula: token.props.formula,
+					block: false,
+				})];
 			}
 
 			case 'mathBlock': {
-				return [h('code', token.props.formula)];
+				return [h(MkFormula, {
+					formula: token.props.formula,
+					block: true,
+				})];
 			}
 
 			case 'search': {