feat(stitch): add grid layout, alignment, border, radius, quality, and new resize modes

This commit is contained in:
Siddharth Kumar Sah
2026-04-13 11:43:16 +08:00
parent e50b0d5310
commit c4d298ac3e
2 changed files with 351 additions and 70 deletions
+226 -70
View File
@@ -12,14 +12,19 @@ import { createWorkspace } from "../../lib/workspace.js";
const MAX_CANVAS_PIXELS = 100_000_000;
const settingsSchema = z.object({
direction: z.enum(["horizontal", "vertical"]).default("horizontal"),
resize: z.enum(["fit", "original"]).default("fit"),
gap: z.number().min(0).max(100).default(0),
direction: z.enum(["horizontal", "vertical", "grid"]).default("horizontal"),
gridColumns: z.number().int().min(2).max(10).default(2),
resizeMode: z.enum(["fit", "original", "stretch", "crop"]).default("fit"),
alignment: z.enum(["start", "center", "end"]).default("center"),
gap: z.number().min(0).max(200).default(0),
border: z.number().min(0).max(50).default(0),
cornerRadius: z.number().min(0).max(50).default(0),
backgroundColor: z
.string()
.regex(/^#[0-9a-fA-F]{6}$/)
.default("#FFFFFF"),
format: z.enum(["png", "jpeg", "webp"]).default("png"),
quality: z.number().min(1).max(100).default(90),
});
function parseHexColor(hex: string): { r: number; g: number; b: number } {
@@ -30,6 +35,12 @@ function parseHexColor(hex: string): { r: number; g: number; b: number } {
};
}
interface PreparedImage {
buffer: Buffer;
width: number;
height: number;
}
export function registerStitch(app: FastifyInstance) {
app.post("/api/v1/tools/stitch", async (request, reply) => {
const files: Array<{ buffer: Buffer; filename: string }> = [];
@@ -65,7 +76,6 @@ export function registerStitch(app: FastifyInstance) {
return reply.status(400).send({ error: "At least 2 images are required for stitching" });
}
// Validate all files and decode HEIC/HEIF
for (const file of files) {
const validation = await validateImageBuffer(file.buffer);
if (!validation.valid) {
@@ -89,7 +99,6 @@ export function registerStitch(app: FastifyInstance) {
}
try {
// Read metadata for all images
const imageMetas = await Promise.all(
files.map(async (file) => {
const meta = await sharp(file.buffer).metadata();
@@ -101,85 +110,80 @@ export function registerStitch(app: FastifyInstance) {
}),
);
// Resize images if needed
const isHorizontal = settings.direction === "horizontal";
let prepared: Array<{ buffer: Buffer; width: number; height: number }>;
const isGrid = settings.direction === "grid";
if (settings.resize === "fit") {
if (isHorizontal) {
// Find min height, scale taller images down
const minHeight = Math.min(...imageMetas.map((m) => m.height));
prepared = await Promise.all(
imageMetas.map(async (img) => {
if (img.height > minHeight) {
const scaledWidth = Math.round((img.width * minHeight) / img.height);
const resized = await sharp(img.buffer).resize(scaledWidth, minHeight).toBuffer();
return { buffer: resized, width: scaledWidth, height: minHeight };
}
return img;
}),
);
} else {
// Find min width, scale wider images down
const minWidth = Math.min(...imageMetas.map((m) => m.width));
prepared = await Promise.all(
imageMetas.map(async (img) => {
if (img.width > minWidth) {
const scaledHeight = Math.round((img.height * minWidth) / img.width);
const resized = await sharp(img.buffer).resize(minWidth, scaledHeight).toBuffer();
return { buffer: resized, width: minWidth, height: scaledHeight };
}
return img;
}),
);
}
let prepared: PreparedImage[];
if (isGrid) {
prepared = await prepareForGrid(imageMetas, settings);
} else if (isHorizontal) {
prepared = await prepareForHorizontal(imageMetas, settings.resizeMode);
} else {
prepared = imageMetas;
prepared = await prepareForVertical(imageMetas, settings.resizeMode);
}
// Calculate canvas dimensions
const n = prepared.length;
let canvasWidth: number;
let canvasHeight: number;
const composites: sharp.OverlayOptions[] = [];
if (isHorizontal) {
canvasWidth = prepared.reduce((sum, img) => sum + img.width, 0) + settings.gap * (n - 1);
canvasHeight = Math.max(...prepared.map((img) => img.height));
if (isGrid) {
const cols = Math.min(settings.gridColumns, prepared.length);
const rows = Math.ceil(prepared.length / cols);
const cellWidth = Math.max(...prepared.map((img) => img.width));
const cellHeight = Math.max(...prepared.map((img) => img.height));
canvasWidth = cols * cellWidth + (cols - 1) * settings.gap + 2 * settings.border;
canvasHeight = rows * cellHeight + (rows - 1) * settings.gap + 2 * settings.border;
for (let i = 0; i < prepared.length; i++) {
const col = i % cols;
const row = Math.floor(i / cols);
const img = prepared[i];
const cellLeft = settings.border + col * (cellWidth + settings.gap);
const cellTop = settings.border + row * (cellHeight + settings.gap);
const left = cellLeft + alignOffset(cellWidth, img.width, settings.alignment);
const top = cellTop + alignOffset(cellHeight, img.height, settings.alignment);
composites.push({ input: img.buffer, left, top });
}
} else if (isHorizontal) {
const totalImgWidth = prepared.reduce((sum, img) => sum + img.width, 0);
const maxHeight = Math.max(...prepared.map((img) => img.height));
canvasWidth = totalImgWidth + (prepared.length - 1) * settings.gap + 2 * settings.border;
canvasHeight = maxHeight + 2 * settings.border;
let offset = settings.border;
for (const img of prepared) {
const top = settings.border + alignOffset(maxHeight, img.height, settings.alignment);
composites.push({ input: img.buffer, left: offset, top });
offset += img.width + settings.gap;
}
} else {
canvasWidth = Math.max(...prepared.map((img) => img.width));
canvasHeight = prepared.reduce((sum, img) => sum + img.height, 0) + settings.gap * (n - 1);
const maxWidth = Math.max(...prepared.map((img) => img.width));
const totalImgHeight = prepared.reduce((sum, img) => sum + img.height, 0);
canvasWidth = maxWidth + 2 * settings.border;
canvasHeight = totalImgHeight + (prepared.length - 1) * settings.gap + 2 * settings.border;
let offset = settings.border;
for (const img of prepared) {
const left = settings.border + alignOffset(maxWidth, img.width, settings.alignment);
composites.push({ input: img.buffer, left, top: offset });
offset += img.height + settings.gap;
}
}
// Canvas size check
if (canvasWidth * canvasHeight > MAX_CANVAS_PIXELS) {
return reply.status(422).send({
error: `Canvas too large: ${canvasWidth}x${canvasHeight} (${Math.round((canvasWidth * canvasHeight) / 1_000_000)}MP exceeds 100MP limit)`,
});
}
// Build composites
const background = parseHexColor(settings.backgroundColor);
const composites: sharp.OverlayOptions[] = [];
let offset = 0;
for (const img of prepared) {
let left: number;
let top: number;
if (isHorizontal) {
left = offset;
top = Math.round((canvasHeight - img.height) / 2);
offset += img.width + settings.gap;
} else {
left = Math.round((canvasWidth - img.width) / 2);
top = offset;
offset += img.height + settings.gap;
}
composites.push({ input: img.buffer, left, top });
}
// Create canvas and composite
let pipeline = sharp({
create: {
width: canvasWidth,
@@ -189,16 +193,41 @@ export function registerStitch(app: FastifyInstance) {
},
}).composite(composites);
// Output in requested format
if (settings.format === "jpeg") {
pipeline = pipeline.jpeg({ quality: 90 });
pipeline = pipeline.jpeg({ quality: settings.quality });
} else if (settings.format === "webp") {
pipeline = pipeline.webp({ quality: 90 });
pipeline = pipeline.webp({ quality: settings.quality });
} else {
pipeline = pipeline.png();
}
const result = await pipeline.toBuffer();
let result = await pipeline.toBuffer();
if (settings.cornerRadius > 0) {
const meta = await sharp(result).metadata();
const w = meta.width!;
const h = meta.height!;
const r = Math.min(settings.cornerRadius, Math.floor(Math.min(w, h) / 2));
const mask = Buffer.from(
`<svg width="${w}" height="${h}"><rect x="0" y="0" width="${w}" height="${h}" rx="${r}" ry="${r}" fill="white"/></svg>`,
);
result = await sharp(result)
.ensureAlpha()
.composite([{ input: mask, blend: "dest-in" }])
.png()
.toBuffer();
if (settings.format === "jpeg") {
result = await sharp(result)
.flatten({ background: { r: background.r, g: background.g, b: background.b } })
.jpeg({ quality: settings.quality })
.toBuffer();
} else if (settings.format === "webp") {
result = await sharp(result).webp({ quality: settings.quality }).toBuffer();
}
}
const jobId = randomUUID();
const workspacePath = await createWorkspace(jobId);
@@ -220,3 +249,130 @@ export function registerStitch(app: FastifyInstance) {
}
});
}
function alignOffset(containerSize: number, itemSize: number, alignment: string): number {
if (alignment === "start") return 0;
if (alignment === "end") return containerSize - itemSize;
return Math.round((containerSize - itemSize) / 2);
}
async function prepareForHorizontal(
images: PreparedImage[],
resizeMode: string,
): Promise<PreparedImage[]> {
if (resizeMode === "original") return images;
const minHeight = Math.min(...images.map((m) => m.height));
return Promise.all(
images.map(async (img) => {
if (img.height === minHeight && resizeMode === "fit") return img;
if (resizeMode === "fit") {
const scaledWidth = Math.round((img.width * minHeight) / img.height);
const resized = await sharp(img.buffer).resize(scaledWidth, minHeight).toBuffer();
return { buffer: resized, width: scaledWidth, height: minHeight };
}
if (resizeMode === "stretch") {
const resized = await sharp(img.buffer)
.resize(img.width, minHeight, { fit: "fill" })
.toBuffer();
return { buffer: resized, width: img.width, height: minHeight };
}
if (resizeMode === "crop") {
const scaledWidth = Math.round((img.width * minHeight) / img.height);
const resized = await sharp(img.buffer)
.resize(scaledWidth, minHeight, { fit: "cover" })
.toBuffer();
return { buffer: resized, width: scaledWidth, height: minHeight };
}
return img;
}),
);
}
async function prepareForVertical(
images: PreparedImage[],
resizeMode: string,
): Promise<PreparedImage[]> {
if (resizeMode === "original") return images;
const minWidth = Math.min(...images.map((m) => m.width));
return Promise.all(
images.map(async (img) => {
if (img.width === minWidth && resizeMode === "fit") return img;
if (resizeMode === "fit") {
const scaledHeight = Math.round((img.height * minWidth) / img.width);
const resized = await sharp(img.buffer).resize(minWidth, scaledHeight).toBuffer();
return { buffer: resized, width: minWidth, height: scaledHeight };
}
if (resizeMode === "stretch") {
const resized = await sharp(img.buffer)
.resize(minWidth, img.height, { fit: "fill" })
.toBuffer();
return { buffer: resized, width: minWidth, height: img.height };
}
if (resizeMode === "crop") {
const scaledHeight = Math.round((img.height * minWidth) / img.width);
const resized = await sharp(img.buffer)
.resize(minWidth, scaledHeight, { fit: "cover" })
.toBuffer();
return { buffer: resized, width: minWidth, height: scaledHeight };
}
return img;
}),
);
}
async function prepareForGrid(
images: PreparedImage[],
settings: { gridColumns: number; resizeMode: string },
): Promise<PreparedImage[]> {
if (settings.resizeMode === "original") return images;
const medianWidth = median(images.map((m) => m.width));
const medianHeight = median(images.map((m) => m.height));
return Promise.all(
images.map(async (img) => {
if (settings.resizeMode === "fit") {
const scale = Math.min(medianWidth / img.width, medianHeight / img.height);
if (scale >= 1) return img;
const newW = Math.round(img.width * scale);
const newH = Math.round(img.height * scale);
const resized = await sharp(img.buffer).resize(newW, newH).toBuffer();
return { buffer: resized, width: newW, height: newH };
}
if (settings.resizeMode === "stretch") {
const resized = await sharp(img.buffer)
.resize(medianWidth, medianHeight, { fit: "fill" })
.toBuffer();
return { buffer: resized, width: medianWidth, height: medianHeight };
}
if (settings.resizeMode === "crop") {
const resized = await sharp(img.buffer)
.resize(medianWidth, medianHeight, { fit: "cover" })
.toBuffer();
return { buffer: resized, width: medianWidth, height: medianHeight };
}
return img;
}),
);
}
function median(values: number[]): number {
const sorted = [...values].sort((a, b) => a - b);
const mid = Math.floor(sorted.length / 2);
return sorted.length % 2 === 0 ? Math.round((sorted[mid - 1] + sorted[mid]) / 2) : sorted[mid];
}
+125
View File
@@ -1754,6 +1754,131 @@ describe("POST /api/v1/tools/stitch", () => {
expect(res.statusCode).toBe(200);
});
it("stitches in grid mode with 2 columns", async () => {
const { body: payload, contentType } = createMultipartPayload([
{ name: "file", filename: "a.png", contentType: "image/png", content: PNG_200x150 },
{ name: "file", filename: "b.jpg", contentType: "image/jpeg", content: JPG_100x100 },
{ name: "file", filename: "c.png", contentType: "image/png", content: PNG_200x150 },
{ name: "file", filename: "d.jpg", contentType: "image/jpeg", content: JPG_100x100 },
{ name: "settings", content: JSON.stringify({ direction: "grid", gridColumns: 2 }) },
]);
const res = await app.inject({
method: "POST",
url: "/api/v1/tools/stitch",
headers: {
authorization: `Bearer ${adminToken}`,
"content-type": contentType,
},
body: payload,
});
expect(res.statusCode).toBe(200);
const body = JSON.parse(res.body);
expect(body.jobId).toBeDefined();
expect(body.downloadUrl).toMatch(/\/api\/v1\/download\//);
});
it("applies alignment setting", async () => {
const { body: payload, contentType } = createMultipartPayload([
{ name: "file", filename: "a.png", contentType: "image/png", content: PNG_200x150 },
{ name: "file", filename: "b.jpg", contentType: "image/jpeg", content: JPG_100x100 },
{ name: "settings", content: JSON.stringify({ alignment: "start" }) },
]);
const res = await app.inject({
method: "POST",
url: "/api/v1/tools/stitch",
headers: {
authorization: `Bearer ${adminToken}`,
"content-type": contentType,
},
body: payload,
});
expect(res.statusCode).toBe(200);
});
it("applies border and cornerRadius", async () => {
const { body: payload, contentType } = createMultipartPayload([
{ name: "file", filename: "a.png", contentType: "image/png", content: PNG_200x150 },
{ name: "file", filename: "b.png", contentType: "image/png", content: PNG_200x150 },
{ name: "settings", content: JSON.stringify({ border: 20, cornerRadius: 10 }) },
]);
const res = await app.inject({
method: "POST",
url: "/api/v1/tools/stitch",
headers: {
authorization: `Bearer ${adminToken}`,
"content-type": contentType,
},
body: payload,
});
expect(res.statusCode).toBe(200);
});
it("respects quality setting for jpeg", async () => {
const { body: payload, contentType } = createMultipartPayload([
{ name: "file", filename: "a.png", contentType: "image/png", content: PNG_200x150 },
{ name: "file", filename: "b.png", contentType: "image/png", content: PNG_200x150 },
{ name: "settings", content: JSON.stringify({ format: "jpeg", quality: 50 }) },
]);
const res = await app.inject({
method: "POST",
url: "/api/v1/tools/stitch",
headers: {
authorization: `Bearer ${adminToken}`,
"content-type": contentType,
},
body: payload,
});
expect(res.statusCode).toBe(200);
});
it("handles resizeMode stretch", async () => {
const { body: payload, contentType } = createMultipartPayload([
{ name: "file", filename: "a.png", contentType: "image/png", content: PNG_200x150 },
{ name: "file", filename: "b.jpg", contentType: "image/jpeg", content: JPG_100x100 },
{ name: "settings", content: JSON.stringify({ resizeMode: "stretch" }) },
]);
const res = await app.inject({
method: "POST",
url: "/api/v1/tools/stitch",
headers: {
authorization: `Bearer ${adminToken}`,
"content-type": contentType,
},
body: payload,
});
expect(res.statusCode).toBe(200);
});
it("handles resizeMode crop", async () => {
const { body: payload, contentType } = createMultipartPayload([
{ name: "file", filename: "a.png", contentType: "image/png", content: PNG_200x150 },
{ name: "file", filename: "b.jpg", contentType: "image/jpeg", content: JPG_100x100 },
{ name: "settings", content: JSON.stringify({ resizeMode: "crop" }) },
]);
const res = await app.inject({
method: "POST",
url: "/api/v1/tools/stitch",
headers: {
authorization: `Bearer ${adminToken}`,
"content-type": contentType,
},
body: payload,
});
expect(res.statusCode).toBe(200);
});
});
// ═══════════════════════════════════════════════════════════════════════════