{"version":3,"file":"exif-orientation.d.ts","sourceRoot":"","sources":["../../src/utils/exif-orientation.ts"],"names":[],"mappings":"AAAA,OAAO,KAAK,EAAE,eAAe,EAAE,MAAM,aAAa,CAAC;AAEnD,KAAK,MAAM,GAAG,cAAc,4BAA4B,CAAC,CAAC;AAgJ1D,wBAAgB,oBAAoB,CACnC,MAAM,EAAE,MAAM,EACd,KAAK,EAAE,eAAe,EACtB,aAAa,EAAE,UAAU,GACvB,eAAe,CAgCjB","sourcesContent":["import type { PhotonImageType } from \"./photon.js\";\n\ntype Photon = typeof import(\"@silvia-odwyer/photon-node\");\n\nfunction readOrientationFromTiff(bytes: Uint8Array, tiffStart: number): number {\n\tif (tiffStart + 8 > bytes.length) return 1;\n\n\tconst byteOrder = (bytes[tiffStart] << 8) | bytes[tiffStart + 1];\n\tconst le = byteOrder === 0x4949;\n\n\tconst read16 = (pos: number): number => {\n\t\tif (le) return bytes[pos] | (bytes[pos + 1] << 8);\n\t\treturn (bytes[pos] << 8) | bytes[pos + 1];\n\t};\n\n\tconst read32 = (pos: number): number => {\n\t\tif (le) return bytes[pos] | (bytes[pos + 1] << 8) | (bytes[pos + 2] << 16) | (bytes[pos + 3] << 24);\n\t\treturn ((bytes[pos] << 24) | (bytes[pos + 1] << 16) | (bytes[pos + 2] << 8) | bytes[pos + 3]) >>> 0;\n\t};\n\n\tconst ifdOffset = read32(tiffStart + 4);\n\tconst ifdStart = tiffStart + ifdOffset;\n\tif (ifdStart + 2 > bytes.length) return 1;\n\n\tconst entryCount = read16(ifdStart);\n\tfor (let i = 0; i < entryCount; i++) {\n\t\tconst entryPos = ifdStart + 2 + i * 12;\n\t\tif (entryPos + 12 > bytes.length) return 1;\n\n\t\tif (read16(entryPos) === 0x0112) {\n\t\t\tconst value = read16(entryPos + 8);\n\t\t\treturn value >= 1 && value <= 8 ? value : 1;\n\t\t}\n\t}\n\n\treturn 1;\n}\n\nfunction findJpegTiffOffset(bytes: Uint8Array): number {\n\tlet offset = 2;\n\twhile (offset < bytes.length - 1) {\n\t\tif (bytes[offset] !== 0xff) return -1;\n\t\tconst marker = bytes[offset + 1];\n\t\tif (marker === 0xff) {\n\t\t\toffset++;\n\t\t\tcontinue;\n\t\t}\n\n\t\tif (marker === 0xe1) {\n\t\t\tif (offset + 4 >= bytes.length) return -1;\n\t\t\tconst segmentStart = offset + 4;\n\t\t\tif (segmentStart + 6 > bytes.length) return -1;\n\t\t\tif (!hasExifHeader(bytes, segmentStart)) return -1;\n\t\t\treturn segmentStart + 6;\n\t\t}\n\n\t\tif (offset + 4 > bytes.length) return -1;\n\t\tconst length = (bytes[offset + 2] << 8) | bytes[offset + 3];\n\t\toffset += 2 + length;\n\t}\n\n\treturn -1;\n}\n\nfunction findWebpTiffOffset(bytes: Uint8Array): number {\n\tlet offset = 12;\n\twhile (offset + 8 <= bytes.length) {\n\t\tconst chunkId = String.fromCharCode(bytes[offset], bytes[offset + 1], bytes[offset + 2], bytes[offset + 3]);\n\t\tconst chunkSize =\n\t\t\tbytes[offset + 4] | (bytes[offset + 5] << 8) | (bytes[offset + 6] << 16) | (bytes[offset + 7] << 24);\n\t\tconst dataStart = offset + 8;\n\n\t\tif (chunkId === \"EXIF\") {\n\t\t\tif (dataStart + chunkSize > bytes.length) return -1;\n\t\t\t// Some WebP files have \"Exif\\0\\0\" prefix before the TIFF header\n\t\t\tconst tiffStart = chunkSize >= 6 && hasExifHeader(bytes, dataStart) ? dataStart + 6 : dataStart;\n\t\t\treturn tiffStart;\n\t\t}\n\n\t\t// RIFF chunks are padded to even size\n\t\toffset = dataStart + chunkSize + (chunkSize % 2);\n\t}\n\n\treturn -1;\n}\n\nfunction hasExifHeader(bytes: Uint8Array, offset: number): boolean {\n\treturn (\n\t\tbytes[offset] === 0x45 &&\n\t\tbytes[offset + 1] === 0x78 &&\n\t\tbytes[offset + 2] === 0x69 &&\n\t\tbytes[offset + 3] === 0x66 &&\n\t\tbytes[offset + 4] === 0x00 &&\n\t\tbytes[offset + 5] === 0x00\n\t);\n}\n\nfunction getExifOrientation(bytes: Uint8Array): number {\n\tlet tiffOffset = -1;\n\n\t// JPEG: starts with FF D8\n\tif (bytes.length >= 2 && bytes[0] === 0xff && bytes[1] === 0xd8) {\n\t\ttiffOffset = findJpegTiffOffset(bytes);\n\t}\n\t// WebP: starts with RIFF....WEBP\n\telse if (\n\t\tbytes.length >= 12 &&\n\t\tbytes[0] === 0x52 &&\n\t\tbytes[1] === 0x49 &&\n\t\tbytes[2] === 0x46 &&\n\t\tbytes[3] === 0x46 &&\n\t\tbytes[8] === 0x57 &&\n\t\tbytes[9] === 0x45 &&\n\t\tbytes[10] === 0x42 &&\n\t\tbytes[11] === 0x50\n\t) {\n\t\ttiffOffset = findWebpTiffOffset(bytes);\n\t}\n\n\tif (tiffOffset === -1) return 1;\n\treturn readOrientationFromTiff(bytes, tiffOffset);\n}\n\ntype DstIndexFn = (x: number, y: number, w: number, h: number) => number;\n\nfunction rotate90(photon: Photon, image: PhotonImageType, dstIndex: DstIndexFn): PhotonImageType {\n\tconst w = image.get_width();\n\tconst h = image.get_height();\n\tconst src = image.get_raw_pixels();\n\tconst dst = new Uint8Array(src.length);\n\n\tfor (let y = 0; y < h; y++) {\n\t\tfor (let x = 0; x < w; x++) {\n\t\t\tconst srcIdx = (y * w + x) * 4;\n\t\t\tconst dstIdx = dstIndex(x, y, w, h) * 4;\n\t\t\tdst[dstIdx] = src[srcIdx];\n\t\t\tdst[dstIdx + 1] = src[srcIdx + 1];\n\t\t\tdst[dstIdx + 2] = src[srcIdx + 2];\n\t\t\tdst[dstIdx + 3] = src[srcIdx + 3];\n\t\t}\n\t}\n\n\treturn new photon.PhotonImage(dst, h, w);\n}\n\n// Flip orientations mutate in-place. Rotations return a new image (caller must free the old one if different).\nexport function applyExifOrientation(\n\tphoton: Photon,\n\timage: PhotonImageType,\n\toriginalBytes: Uint8Array,\n): PhotonImageType {\n\tconst orientation = getExifOrientation(originalBytes);\n\tif (orientation === 1) return image;\n\n\tswitch (orientation) {\n\t\tcase 2:\n\t\t\tphoton.fliph(image);\n\t\t\treturn image;\n\t\tcase 3:\n\t\t\tphoton.fliph(image);\n\t\t\tphoton.flipv(image);\n\t\t\treturn image;\n\t\tcase 4:\n\t\t\tphoton.flipv(image);\n\t\t\treturn image;\n\t\tcase 5: {\n\t\t\tconst rotated = rotate90(photon, image, (x, y, _w, h) => x * h + (h - 1 - y));\n\t\t\tphoton.fliph(rotated);\n\t\t\treturn rotated;\n\t\t}\n\t\tcase 6:\n\t\t\treturn rotate90(photon, image, (x, y, _w, h) => x * h + (h - 1 - y));\n\t\tcase 7: {\n\t\t\tconst rotated = rotate90(photon, image, (x, y, w, h) => (w - 1 - x) * h + y);\n\t\t\tphoton.fliph(rotated);\n\t\t\treturn rotated;\n\t\t}\n\t\tcase 8:\n\t\t\treturn rotate90(photon, image, (x, y, w, h) => (w - 1 - x) * h + y);\n\t\tdefault:\n\t\t\treturn image;\n\t}\n}\n"]}