Optimization (frontend): MkModPlayer Don't waste memory on a static pattern

Fix: Inconsistent pattern height offset.

packages/frontend/src/components/MkModPlayer.vue

@@ -7,7 +7,7 @@
 </div>
 
 <div v-else class="mod-player-enabled">
-	<div class="pattern-display" @click="togglePattern()">
+	<div class="pattern-display" @click="togglePattern()" @scroll="scrollHandler" @scrollend="scrollEndHandle">
 		<div v-if="patternHide" class="pattern-hide">
 			<b><i class="ph-eye ph-bold ph-lg"></i> Pattern Hidden</b>
 			<span>{{ i18n.ts.clickToShow }}</span>
@@ -17,6 +17,7 @@
 		<canvas ref="displayCanvas" class="pattern-canvas"></canvas>
 	</div>
 	<div class="controls">
+		<input v-if="patternScrollSliderShow" ref="patternScrollSlider" v-model="patternScrollSliderPos" class="pattern-slider" type="range" min="0" max="100" step="0.01" style=""/>
 		<button class="play" @click="playPause()">
 			<i v-if="playing" class="ph-pause ph-bold ph-lg"></i>
 			<i v-else class="ph-play ph-bold ph-lg"></i>
@@ -35,11 +36,12 @@
 </template>
 
 <script lang="ts" setup>
-import { ref, nextTick, computed } from 'vue';
+import { ref, nextTick, computed, watch } from 'vue';
 import * as Misskey from 'misskey-js';
 import { i18n } from '@/i18n.js';
 import { defaultStore } from '@/store.js';
 import { ChiptuneJsPlayer, ChiptuneJsConfig } from '@/scripts/chiptune2.js';
+import { isTouchUsing } from '@/scripts/touch.js';
 
 const colours = {
 	background: '#000000',
@@ -69,6 +71,9 @@ let playing = ref(false);
 let displayCanvas = ref<HTMLCanvasElement>();
 let progress = ref<HTMLProgressElement>();
 let position = ref(0);
+let patternScrollSlider = ref<HTMLProgressElement>();
+let patternScrollSliderShow = ref(false);
+let patternScrollSliderPos = ref(0);
 const player = ref(new ChiptuneJsPlayer(new ChiptuneJsConfig()));
 
 const maxRowNumbers = 0xFF;
@@ -179,20 +184,22 @@ function toggleVisible() {
 
 function togglePattern() {
 	patternHide.value = !patternHide.value;
-	if (!patternHide.value) {
+	handleScrollBarEnable();
+
 	if (player.value.getRow() === 0) {
 		try {
 			player.value.play(buffer);
-				display();
+			display(true);
 		} catch (err) {
 			console.warn(err);
 		}
 		player.value.stop();
-		}
+	} else {
+		display(true);
 	}
 }
 
-function DrawPattern() {
+function drawPattern() {
 	if (!displayCanvas.value) return;
 	const canvas = displayCanvas.value;
 
@@ -202,8 +209,6 @@ function DrawPattern() {
 	const halfbuf = rowBuffer / 2;
 	const minRow = row - halfbuf;
 	const maxRow = row + halfbuf;
-	const spacer = 11;
-	const space = ' ';
 
 	let rowDif = 0;
 
@@ -215,8 +220,8 @@ function DrawPattern() {
 		rowDif = row - lastDrawnRow;
 	} else {
 		alreadyDrawn = [];
-		canvas.width = 12 + 84 * nbChannels + 2;
+		if (canvas.width !== (12 + 84 * nbChannels + 2)) canvas.width = 12 + 84 * nbChannels + 2;
-		canvas.height = 12 * nbRows;
+		if (canvas.height !== (12 * nbRows)) canvas.height = 12 * nbRows;
 	}
 
 	const ctx = canvas.getContext('2d', { alpha: false }) as CanvasRenderingContext2D;
@@ -235,43 +240,9 @@ function DrawPattern() {
 		if (alreadyDrawn[rowToDraw] === true) continue;
 
 		if (rowToDraw >= 0 && rowToDraw < nbRows) {
-			let seperators = '';
-			let note = '';
-			let instr = '';
-			let volume = '';
-			let fx = '';
-			let op = '';
-			for (let channel = 0; channel < nbChannels; channel++) {
-				const part = player.value.getPatternRowChannel(pattern, rowToDraw, channel);
-
-				seperators += '|' + space.repeat( spacer + 2 );
-				note += part.substring(0, 3) + space.repeat( spacer );
-				instr += part.substring(4, 6) + space.repeat( spacer + 1 );
-				volume += part.substring(6, 9) + space.repeat( spacer );
-				fx += part.substring(10, 11) + space.repeat( spacer + 2 );
-				op += part.substring(11, 13) + space.repeat( spacer + 1 );
-			}
-
 			const baseOffset = 2 * CHAR_WIDTH;
 			const baseRowOffset = ROW_OFFSET_Y + rowToDraw * CHAR_HEIGHT;
-
+			drawRow(ctx, rowToDraw, nbChannels, pattern, baseOffset, baseRowOffset);
-			ctx.fillStyle = colours.foreground.default;
-			ctx.fillText(seperators, baseOffset, baseRowOffset);
-
-			ctx.fillStyle = colours.foreground.default;
-			ctx.fillText(note, baseOffset + CHAR_WIDTH, baseRowOffset);
-
-			ctx.fillStyle = colours.foreground.instr;
-			ctx.fillText(instr, baseOffset + CHAR_WIDTH * 5, baseRowOffset);
-
-			ctx.fillStyle = colours.foreground.volume;
-			ctx.fillText(volume, baseOffset + CHAR_WIDTH * 7, baseRowOffset);
-
-			ctx.fillStyle = colours.foreground.fx;
-			ctx.fillText(fx, baseOffset + CHAR_WIDTH * 11, baseRowOffset);
-
-			ctx.fillStyle = colours.foreground.operant;
-			ctx.fillText(op, baseOffset + CHAR_WIDTH * 12, baseRowOffset);
 
 			alreadyDrawn[rowToDraw] = true;
 		}
@@ -281,30 +252,155 @@ function DrawPattern() {
 	lastPattern = pattern;
 }
 
-function display() {
+function drawPetternPreview() {
-	if (!displayCanvas.value) {
+	if (!displayCanvas.value) return;
+	const canvas = displayCanvas.value;
+
+	const pattern = player.value.getPattern();
+	const nbRows = player.value.getPatternNumRows(pattern);
+	const row = player.value.getRow();
+	const halfbuf = rowBuffer / 2;
+
+	let nbChannels = 0;
+	if (player.value.currentPlayingNode) {
+		nbChannels = player.value.currentPlayingNode.nbChannels;
+	}
+	if (canvas.width !== (12 + 84 * nbChannels + 2)) canvas.width = 12 + 84 * nbChannels + 2;
+	if (canvas.height !== (12 * rowBuffer)) canvas.height = 12 * rowBuffer;
+
+	const ctx = canvas.getContext('2d', { alpha: false }) as CanvasRenderingContext2D;
+	ctx.font = '10px monospace';
+	ctx.imageSmoothingEnabled = false;
+	ctx.fillStyle = colours.background;
+	ctx.fillRect(0, 0, canvas.width, canvas.height);
+	ctx.drawImage( numberRowCanvas, 0, (halfbuf - row) * CHAR_HEIGHT );
+
+	ctx.fillStyle = colours.foreground.default;
+	for (let rowOffset = 0; rowOffset < rowBuffer; rowOffset++) {
+		const rowToDraw = rowOffset + row - halfbuf;
+
+		if (rowToDraw >= 0 && rowToDraw < nbRows) {
+			const baseOffset = 2 * CHAR_WIDTH;
+			const baseRowOffset = ROW_OFFSET_Y + rowOffset * CHAR_HEIGHT;
+			drawRow(ctx, rowToDraw, nbChannels, pattern, baseOffset, baseRowOffset);
+		} else if (rowToDraw >= 0) {
+			const baseRowOffset = ROW_OFFSET_Y + rowOffset * CHAR_HEIGHT;
+			ctx.fillStyle = colours.background;
+			ctx.fillRect(0, baseRowOffset - CHAR_HEIGHT, CHAR_WIDTH * 2, baseRowOffset);
+		}
+	}
+
+	lastPattern = -1;
+	lastDrawnRow = -1;
+}
+
+function drawRow(ctx: CanvasRenderingContext2D, row: number, channels: number, pattern: number, drawX = (2 * CHAR_WIDTH), drawY = ROW_OFFSET_Y) {
+	const spacer = 11;
+	const space = ' ';
+	let seperators = '';
+	let note = '';
+	let instr = '';
+	let volume = '';
+	let fx = '';
+	let op = '';
+	for (let channel = 0; channel < channels; channel++) {
+		const part = player.value.getPatternRowChannel(pattern, row, channel);
+
+		seperators += '|' + space.repeat( spacer + 2 );
+		note += part.substring(0, 3) + space.repeat( spacer );
+		instr += part.substring(4, 6) + space.repeat( spacer + 1 );
+		volume += part.substring(6, 9) + space.repeat( spacer );
+		fx += part.substring(10, 11) + space.repeat( spacer + 2 );
+		op += part.substring(11, 13) + space.repeat( spacer + 1 );
+	}
+
+	ctx.fillStyle = colours.foreground.default;
+	ctx.fillText(seperators, drawX, drawY);
+
+	ctx.fillStyle = colours.foreground.default;
+	ctx.fillText(note, drawX + CHAR_WIDTH, drawY);
+
+	ctx.fillStyle = colours.foreground.instr;
+	ctx.fillText(instr, drawX + CHAR_WIDTH * 5, drawY);
+
+	ctx.fillStyle = colours.foreground.volume;
+	ctx.fillText(volume, drawX + CHAR_WIDTH * 7, drawY);
+
+	ctx.fillStyle = colours.foreground.fx;
+	ctx.fillText(fx, drawX + CHAR_WIDTH * 11, drawY);
+
+	ctx.fillStyle = colours.foreground.operant;
+	ctx.fillText(op, drawX + CHAR_WIDTH * 12, drawY);
+}
+
+function display(skipOptimizationChecks = false) {
+	if (!displayCanvas.value || !displayCanvas.value.parentElement) {
 		stop();
 		return;
 	}
 
-	if (patternHide.value) return;
+	if (patternHide.value && !skipOptimizationChecks) return;
 
 	if (firstFrame) {
-		firstFrame = false;
+		// Changing it to false should enable pattern display by default.
-		// Change the next line to false in order to show the pattern by default.
 		patternHide.value = true;
+		handleScrollBarEnable();
+		firstFrame = false;
 	}
 
 	const row = player.value.getRow();
 	const pattern = player.value.getPattern();
 
-	if ( row === lastDrawnRow && pattern === lastPattern ) return;
+	if ( row === lastDrawnRow && pattern === lastPattern && !skipOptimizationChecks) return;
 
-	DrawPattern();
+	// Size vs speed
+	if (patternHide.value) drawPetternPreview();
+	else drawPattern();
 
-	displayCanvas.value.style.top = 'calc( 50% - ' + (row * CHAR_HEIGHT) + 'px )';
+	displayCanvas.value.style.top = !patternHide.value ? 'calc( 50% - ' + (row * CHAR_HEIGHT) + 'px )' : '0%';
 }
 
+let suppressScrollSliderWatcher = false;
+
+function scrollHandler() {
+	suppressScrollSliderWatcher = true;
+
+	if (!patternScrollSlider.value) return;
+	if (!displayCanvas.value) return;
+	if (!displayCanvas.value.parentElement) return;
+
+	patternScrollSliderPos.value = (displayCanvas.value.parentElement.scrollLeft) / (displayCanvas.value.width - displayCanvas.value.parentElement.offsetWidth) * 100;
+	patternScrollSlider.value.style.opacity = '1';
+}
+
+function scrollEndHandle() {
+	suppressScrollSliderWatcher = false;
+
+	if (!patternScrollSlider.value) return;
+	patternScrollSlider.value.style.opacity = '';
+}
+
+function handleScrollBarEnable() {
+	patternScrollSliderShow.value = (!patternHide.value && !isTouchUsing);
+	if (patternScrollSliderShow.value !== true) return;
+
+	if (!displayCanvas.value) return;
+	if (!displayCanvas.value.parentElement) return;
+	if (firstFrame) {
+		patternScrollSliderShow.value = (12 + 84 * player.value.getPatternNumRows(player.value.getPattern()) + 2 > displayCanvas.value.parentElement.offsetWidth);
+	} else {
+		patternScrollSliderShow.value = (displayCanvas.value.width > displayCanvas.value.parentElement.offsetWidth);
+	}
+}
+
+watch(patternScrollSliderPos, () => {
+	if (suppressScrollSliderWatcher) return;
+	if (!displayCanvas.value) return;
+	if (!displayCanvas.value.parentElement) return;
+
+	displayCanvas.value.parentElement.scrollLeft = (displayCanvas.value.width - displayCanvas.value.parentElement.offsetWidth) * patternScrollSliderPos.value / 100;
+});
+
 </script>
 
 <style lang="scss" scoped>
@@ -347,6 +443,12 @@ function display() {
 		text-align: center;
 		max-height: 312px; /* magic_number = CHAR_HEIGHT * rowBuffer, needs to be in px */
 
+		scrollbar-width: none;
+
+		&::-webkit-scrollbar {
+			display: none;
+		}
+
 		.pattern-canvas {
 			position: relative;
 			background-color: black;
@@ -357,36 +459,37 @@ function display() {
 
 		.patternShadowTop {
 			background: #00000080;
-			pointer-events: none;
 			width: 100%;
-			height: 50%;
+			height: calc( 50% - 14px );
 			translate: 0 -100%;
-			top: calc( 50% - 13px );
+			top: calc( 50% - 14px );
 			position: absolute;
+			pointer-events: none;
 			z-index: 2;
 		}
 
 		.patternShadowBottom {
 			background: #00000080;
-			pointer-events: none;
 			width: 100%;
-			height: calc( 50% + 12px );
+			height: calc( 50% - 12px );
 			top: calc( 50% - 1px );
 			position: absolute;
+			pointer-events: none;
 			z-index: 2;
 		}
+
 		.pattern-hide {
 			display: flex;
 			flex-direction: column;
 			justify-content: center;
 			align-items: center;
 			background: rgba(64, 64, 64, 0.3);
-			backdrop-filter: blur(2em);
+			backdrop-filter: var(--modalBgFilter);
 			color: #fff;
 			font-size: 12px;
 
 			position: absolute;
-			z-index: 3;
+			z-index: 4;
 			width: 100%;
 			height: 100%;
 
@@ -400,7 +503,7 @@ function display() {
 		display: flex;
 		width: 100%;
 		background-color: var(--bg);
-		z-index: 3;
+		z-index: 5;
 
 		> * {
 			padding: 4px 8px;
@@ -425,6 +528,18 @@ function display() {
 			margin: 4px 8px;
 			overflow-x: hidden;
 
+			&.pattern-slider {
+				position: absolute;
+				width: calc( 100% - 8px * 2 );
+				top: calc( 100% - 21px * 3 );
+				opacity: 0%;
+				transition: opacity 0.2s;
+
+				&:hover {
+					opacity: 100%;
+				}
+			}
+
 			&:focus {
 				outline: none;