优化缩略图

viewer/spine.html

@@ -1017,8 +1017,82 @@
 			+ '/' + Math.max(1, Math.round(candidate.buffer.length / 1024)) + 'kb';
 	}
 
-	// 结果画廊：逐档生成，每档一出来就填进两行四列的格子，点哪个用哪个，关掉就全部丢弃。
-	// 帧编码走 canvas.toBlob（异步），生成期间界面不会像 toDataURL 那样被卡住。
+	// 用动画 1/3 和 2/3 处的两帧估算整档体积：避开首尾信息不全的帧，按整数帧对齐。
+	async function estimateAnimatedBytes(profile, sourceFrames, size, range, options, encodeWebpFrame) {
+		const count = profileFrameCount(sourceFrames, range, profile.fps);
+		const indexes = [Math.round(count / 3), Math.round(count * 2 / 3)];
+		let total = 0;
+		for (let slot = 0; slot < indexes.length; slot++) {
+			const sourceIndex = Math.min(sourceFrames.length - 1, Math.floor(indexes[slot] * sourceFrames.length / count));
+			const pixels = scaledFramePixels(sourceFrames[sourceIndex], size, profile.size);
+			if (options.format === 'apng') {
+				total += apngEncoder.encode({
+					width: size, height: size, plays: 0, compressionLevel: 9,
+					frames: [{ rgba: pixels, delayNumerator: 100, delayDenominator: 1000 }],
+				}).length;
+			} else {
+				total += (await encodeWebpFrame(slot, pixels, profile.quality)).length;
+			}
+		}
+		return (total / indexes.length) * count;
+	}
+
+	// 沿整条路径估算体积（每点只编两帧），再按「目标体积的 0.5× ~ 2× 对数间隔」挑候选。
+	// 对数取点能让画廊里的档位从明显清晰一路铺到明显省体积，而不是全挤在目标附近；
+	// 配置允许分段（分辨率优先就是「400 系列 + 200 系列」），所以整条路径不假设单调。
+	async function pickAnimatedCandidates(searchPath, sourceFrames, size, range, options, targetBytes, count, encodeWebpFrame) {
+		// 估算点按步长抽样，避免整条路径都各编两帧；路径首尾一定纳入。
+		const stride = Math.max(1, Math.ceil(searchPath.length / 24));
+		const samples = [];
+		for (let index = 0; index < searchPath.length; index += stride) {
+			samples.push({
+				index,
+				bytes: await estimateAnimatedBytes(searchPath[index], sourceFrames, size, range, options, encodeWebpFrame),
+			});
+		}
+		const lastIndex = searchPath.length - 1;
+		if (samples[samples.length - 1].index !== lastIndex) {
+			samples.push({
+				index: lastIndex,
+				bytes: await estimateAnimatedBytes(searchPath[lastIndex], sourceFrames, size, range, options, encodeWebpFrame),
+			});
+		}
+		// 先按体积从小到大排：配置允许分段（分辨率优先的 400 / 200 两段体积曲线会重叠），
+		// 排序后再取点才能保证候选体积单调递增、也不会挑出两张几乎一样的结果。
+		samples.sort((left, right) => left.bytes - right.bytes);
+		// 体积 → 参数：在「体积相邻」的两个采样点之间插值。候选因此可以落在配置表之外，
+		// 出现 234×234@13fps/q0.22 这类值；按体积相邻插值也能跨过分段，保证候选体积递增。
+		const profileForBytes = (wantedBytes) => {
+			let upper = samples.length - 1;
+			for (let index = 0; index < samples.length; index++) {
+				if (samples[index].bytes >= wantedBytes) { upper = index; break; }
+			}
+			const lower = Math.max(0, upper - 1);
+			const before = searchPath[samples[lower].index];
+			const after = searchPath[samples[upper].index];
+			const gap = samples[upper].bytes - samples[lower].bytes;
+			const ratio = gap > 0 ? Math.max(0, Math.min(1, (wantedBytes - samples[lower].bytes) / gap)) : 0;
+			const mix = (start, end) => start + (end - start) * ratio;
+			return {
+				size: Math.max(1, Math.round(mix(before.size, after.size))),
+				fps: Math.max(1, Math.round(mix(before.fps, after.fps))),
+				quality: Math.round(mix(before.quality, after.quality) * 100) / 100,
+			};
+		};
+		// 目标区间夹在样本的实际体积范围内，免得目标远小于最小候选时空转。
+		const low = Math.log(Math.max(samples[0].bytes, targetBytes * 0.5));
+		const high = Math.log(Math.min(samples[samples.length - 1].bytes, targetBytes * 2));
+		const span = Math.max(1, count - 1);
+		const picked = [];
+		for (let slot = 0; slot < count; slot++) {
+			const wanted = Math.exp(low + (high - low) * slot / span);
+			picked.push(profileForBytes(wanted));
+		}
+		return picked;
+	}
+
+	// 结果画廊：先按目标体积定位，再逐档生成，每档一出来就填进两行五列的格子，
+	// 点哪个用哪个，关掉就全部丢弃。帧编码走 canvas.toBlob（异步），界面不会被卡住。
 	async function pickAnimatedThumbnail(sourceFrames, size, range, options) {
 		const dialog = document.getElementById('animatedPickDialog');
 		const grid = document.getElementById('animatedPickGrid');
@@ -1026,7 +1100,9 @@
 		const cancelButton = document.getElementById('animatedPickCancel');
 		const confirmButton = document.getElementById('animatedPickConfirm');
 		const targetBytes = options.maxKilobytes * 1024;
-		const profiles = animatedProfiles(options.priority);
+		// 锚点插值成更密的搜索路径，候选数量仍按锚点数量给。
+		const searchPath = animatedProfileConfig.expandAnimatedPath(options.priority);
+		const candidateCount = animatedProfiles(options.priority).length;
 		// 4 个离屏画布轮转：每帧编码互相独立，成批提交比逐帧等待快得多。
 		const pool = Array.from({ length: 4 }, () => {
 			const off = document.createElement('canvas');
@@ -1100,6 +1176,12 @@
 			document.addEventListener('keydown', keydown);
 			dialog.classList.remove('hidden');
 			(async () => {
+				// 先沿搜索路径估算体积，再按对数间隔挑出候选，最后完整生成选中的那几档，
+				// 这样画廊里的候选会围绕用户填写的体积铺开，而不是固定的那几张。
+				setStatus(t('viewer.animatedGenerating', { current: 0, total: '…' }), Infinity);
+				const profiles = await pickAnimatedCandidates(
+					searchPath, sourceFrames, size, range, options, targetBytes, candidateCount, encodeFrame,
+				);
 				for (let profileIndex = 0; profileIndex < profiles.length; profileIndex++) {
 					if (settled) return;
 					const profile = profiles[profileIndex];