From e67aab87c54563a49f493afd9e70195bc0583ee0 Mon Sep 17 00:00:00 2001
From: 134 <a134@134deMacBook-Pro.local>
Date: Wed, 8 Jul 2026 00:37:28 +0800
Subject: [PATCH] fix: rebase product lock scale composite on source

---
 app/api/canvas/local-edit/route.ts |  3 ++
 lib/canvas/generate-image.ts       | 60 +++++++++++++++++++++++++++++-
 2 files changed, 61 insertions(+), 2 deletions(-)

diff --git a/app/api/canvas/local-edit/route.ts b/app/api/canvas/local-edit/route.ts
index 69d076539..fa9893a85 100644
--- a/app/api/canvas/local-edit/route.ts
+++ b/app/api/canvas/local-edit/route.ts
@@ -5866,6 +5866,9 @@ export async function POST(request: NextRequest) {
                 scaleAdjustPatchReference?.productLockOverlayUrl as string,
               protectMaskImageUrl:
                 scaleAdjustPatchReference?.productLockProtectMaskUrl || undefined,
+              repairMaskImageUrl:
+                scaleAdjustPatchReference?.compositeClipMaskUrl || undefined,
+              sourceImageUrl,
               sourceHeight,
               sourceWidth,
             }
diff --git a/lib/canvas/generate-image.ts b/lib/canvas/generate-image.ts
index 51f07b37a..fe8b00185 100644
--- a/lib/canvas/generate-image.ts
+++ b/lib/canvas/generate-image.ts
@@ -74,6 +74,8 @@ export interface CanvasScaleAdjustPatchCompositeConfig {
 export interface CanvasScaleAdjustProductLockCompositeConfig {
   overlayImageUrl: string;
   protectMaskImageUrl?: string;
+  repairMaskImageUrl?: string;
+  sourceImageUrl?: string;
   sourceHeight: number;
   sourceWidth: number;
 }
@@ -566,6 +568,8 @@ function normalizeScaleAdjustProductLockCompositeConfig(
   const overlayImageUrl = String(value.overlayImageUrl || "").trim();
   if (!/^https?:\/\//i.test(overlayImageUrl)) return null;
   const protectMaskImageUrl = String(value.protectMaskImageUrl || "").trim();
+  const repairMaskImageUrl = String(value.repairMaskImageUrl || "").trim();
+  const sourceImageUrl = String(value.sourceImageUrl || "").trim();
   const sourceWidth = Math.round(Number(value.sourceWidth || 0));
   const sourceHeight = Math.round(Number(value.sourceHeight || 0));
   if (sourceWidth <= 0 || sourceHeight <= 0) return null;
@@ -575,6 +579,12 @@ function normalizeScaleAdjustProductLockCompositeConfig(
     ...(protectMaskImageUrl && /^https?:\/\//i.test(protectMaskImageUrl)
       ? { protectMaskImageUrl }
       : {}),
+    ...(repairMaskImageUrl && /^https?:\/\//i.test(repairMaskImageUrl)
+      ? { repairMaskImageUrl }
+      : {}),
+    ...(sourceImageUrl && /^https?:\/\//i.test(sourceImageUrl)
+      ? { sourceImageUrl }
+      : {}),
     sourceHeight,
     sourceWidth,
   };
@@ -3283,6 +3293,18 @@ async function applyScaleAdjustProductLockCompositeToImages(params: {
   const protectMaskBuffer = composite.protectMaskImageUrl
     ? await fetchImageBufferFromUrl(composite.protectMaskImageUrl)
     : null;
+  const repairMaskBuffer = composite.repairMaskImageUrl
+    ? await fetchImageBufferFromUrl(composite.repairMaskImageUrl)
+    : null;
+  const sourceBaseBuffer = composite.sourceImageUrl
+    ? await sharp(await fetchImageBufferFromUrl(composite.sourceImageUrl), {
+        failOn: "none",
+      })
+        .rotate()
+        .ensureAlpha()
+        .png({ compressionLevel: 6 })
+        .toBuffer()
+    : null;
   const overlayMetadata = await sharp(overlayBuffer, { failOn: "none" }).metadata();
   const overlayWidth = Math.round(Number(overlayMetadata.width || 0));
   const overlayHeight = Math.round(Number(overlayMetadata.height || 0));
@@ -3324,10 +3346,42 @@ async function applyScaleAdjustProductLockCompositeToImages(params: {
           width: generatedWidth,
         })
       : resizedOverlayBaseBuffer;
-    const mergedPngBuffer = await sharp(normalizedGeneratedBuffer, {
+    const baseForProductLock = sourceBaseBuffer && repairMaskBuffer
+      ? await sharp(sourceBaseBuffer, { failOn: "none" })
+          .resize(generatedWidth, generatedHeight, {
+            fit: "fill",
+            kernel: sharp.kernel.lanczos3,
+          })
+          .ensureAlpha()
+          .png({ compressionLevel: 6 })
+          .toBuffer()
+      : normalizedGeneratedBuffer;
+    const generatedRepairOverlay =
+      sourceBaseBuffer && repairMaskBuffer
+        ? await applyRawAlphaToImage({
+            alphaMaskRaw: await sharp(repairMaskBuffer, { failOn: "none" })
+              .resize(generatedWidth, generatedHeight, { fit: "fill" })
+              .removeAlpha()
+              .extractChannel(0)
+              .blur(Math.max(4, Math.round(Math.min(generatedWidth, generatedHeight) * 0.006)))
+              .raw()
+              .toBuffer(),
+            height: generatedHeight,
+            imageBuffer: normalizedGeneratedBuffer,
+            width: generatedWidth,
+          })
+        : null;
+    const mergedPngBuffer = await sharp(baseForProductLock, {
       failOn: "none",
     })
-      .composite([{ input: resizedOverlayBuffer, left: 0, top: 0 }])
+      .composite(
+        generatedRepairOverlay
+          ? [
+              { input: generatedRepairOverlay, left: 0, top: 0 },
+              { input: resizedOverlayBuffer, left: 0, top: 0 },
+            ]
+          : [{ input: resizedOverlayBuffer, left: 0, top: 0 }]
+      )
       .png({ compressionLevel: 6 })
       .toBuffer();
     const mergedBuffer = await sharp(mergedPngBuffer, { failOn: "none" })
@@ -3364,6 +3418,8 @@ async function applyScaleAdjustProductLockCompositeToImages(params: {
     overlayHeight,
     overlayWidth,
     protectMaskApplied: Boolean(protectMaskBuffer),
+    repairMaskApplied: Boolean(repairMaskBuffer && sourceBaseBuffer),
+    sourceBaseApplied: Boolean(sourceBaseBuffer),
     sourceHeight: composite.sourceHeight,
     sourceWidth: composite.sourceWidth,
   });