1 | pub use tiff_value::*; |
2 | |
3 | use std::{ |
4 | cmp, |
5 | collections::BTreeMap, |
6 | convert::{TryFrom, TryInto}, |
7 | io::{self, Seek, Write}, |
8 | marker::PhantomData, |
9 | mem, |
10 | num::TryFromIntError, |
11 | }; |
12 | |
13 | use crate::{ |
14 | error::TiffResult, |
15 | tags::{CompressionMethod, ResolutionUnit, Tag}, |
16 | TiffError, TiffFormatError, |
17 | }; |
18 | |
19 | pub mod colortype; |
20 | pub mod compression; |
21 | mod tiff_value; |
22 | mod writer; |
23 | |
24 | use self::colortype::*; |
25 | use self::compression::*; |
26 | use self::writer::*; |
27 | |
28 | /// Encoder for Tiff and BigTiff files. |
29 | /// |
30 | /// With this type you can get a `DirectoryEncoder` or a `ImageEncoder` |
31 | /// to encode Tiff/BigTiff ifd directories with images. |
32 | /// |
33 | /// See `DirectoryEncoder` and `ImageEncoder`. |
34 | /// |
35 | /// # Examples |
36 | /// ``` |
37 | /// # extern crate tiff; |
38 | /// # fn main() { |
39 | /// # let mut file = std::io::Cursor::new(Vec::new()); |
40 | /// # let image_data = vec![0; 100*100*3]; |
41 | /// use tiff::encoder::*; |
42 | /// |
43 | /// // create a standard Tiff file |
44 | /// let mut tiff = TiffEncoder::new(&mut file).unwrap(); |
45 | /// tiff.write_image::<colortype::RGB8>(100, 100, &image_data).unwrap(); |
46 | /// |
47 | /// // create a BigTiff file |
48 | /// let mut bigtiff = TiffEncoder::new_big(&mut file).unwrap(); |
49 | /// bigtiff.write_image::<colortype::RGB8>(100, 100, &image_data).unwrap(); |
50 | /// |
51 | /// # } |
52 | /// ``` |
53 | pub struct TiffEncoder<W, K: TiffKind = TiffKindStandard> { |
54 | writer: TiffWriter<W>, |
55 | kind: PhantomData<K>, |
56 | } |
57 | |
58 | /// Constructor functions to create standard Tiff files. |
59 | impl<W: Write + Seek> TiffEncoder<W> { |
60 | /// Creates a new encoder for standard Tiff files. |
61 | /// |
62 | /// To create BigTiff files, use [`new_big`][TiffEncoder::new_big] or |
63 | /// [`new_generic`][TiffEncoder::new_generic]. |
64 | pub fn new(writer: W) -> TiffResult<TiffEncoder<W, TiffKindStandard>> { |
65 | TiffEncoder::new_generic(writer) |
66 | } |
67 | } |
68 | |
69 | /// Constructor functions to create BigTiff files. |
70 | impl<W: Write + Seek> TiffEncoder<W, TiffKindBig> { |
71 | /// Creates a new encoder for BigTiff files. |
72 | /// |
73 | /// To create standard Tiff files, use [`new`][TiffEncoder::new] or |
74 | /// [`new_generic`][TiffEncoder::new_generic]. |
75 | pub fn new_big(writer: W) -> TiffResult<Self> { |
76 | TiffEncoder::new_generic(writer) |
77 | } |
78 | } |
79 | |
80 | /// Generic functions that are available for both Tiff and BigTiff encoders. |
81 | impl<W: Write + Seek, K: TiffKind> TiffEncoder<W, K> { |
82 | /// Creates a new Tiff or BigTiff encoder, inferred from the return type. |
83 | pub fn new_generic(writer: W) -> TiffResult<Self> { |
84 | let mut encoder = TiffEncoder { |
85 | writer: TiffWriter::new(writer), |
86 | kind: PhantomData, |
87 | }; |
88 | |
89 | K::write_header(&mut encoder.writer)?; |
90 | |
91 | Ok(encoder) |
92 | } |
93 | |
94 | /// Create a [`DirectoryEncoder`] to encode an ifd directory. |
95 | pub fn new_directory(&mut self) -> TiffResult<DirectoryEncoder<W, K>> { |
96 | DirectoryEncoder::new(&mut self.writer) |
97 | } |
98 | |
99 | /// Create an [`ImageEncoder`] to encode an image one slice at a time. |
100 | pub fn new_image<C: ColorType>( |
101 | &mut self, |
102 | width: u32, |
103 | height: u32, |
104 | ) -> TiffResult<ImageEncoder<W, C, K, Uncompressed>> { |
105 | let encoder = DirectoryEncoder::new(&mut self.writer)?; |
106 | ImageEncoder::new(encoder, width, height) |
107 | } |
108 | |
109 | /// Create an [`ImageEncoder`] to encode an image one slice at a time. |
110 | pub fn new_image_with_compression<C: ColorType, D: Compression>( |
111 | &mut self, |
112 | width: u32, |
113 | height: u32, |
114 | compression: D, |
115 | ) -> TiffResult<ImageEncoder<W, C, K, D>> { |
116 | let encoder = DirectoryEncoder::new(&mut self.writer)?; |
117 | ImageEncoder::with_compression(encoder, width, height, compression) |
118 | } |
119 | |
120 | /// Convenience function to write an entire image from memory. |
121 | pub fn write_image<C: ColorType>( |
122 | &mut self, |
123 | width: u32, |
124 | height: u32, |
125 | data: &[C::Inner], |
126 | ) -> TiffResult<()> |
127 | where |
128 | [C::Inner]: TiffValue, |
129 | { |
130 | let encoder = DirectoryEncoder::new(&mut self.writer)?; |
131 | let image: ImageEncoder<W, C, K> = ImageEncoder::new(encoder, width, height)?; |
132 | image.write_data(data) |
133 | } |
134 | |
135 | /// Convenience function to write an entire image from memory with a given compression. |
136 | pub fn write_image_with_compression<C: ColorType, D: Compression>( |
137 | &mut self, |
138 | width: u32, |
139 | height: u32, |
140 | compression: D, |
141 | data: &[C::Inner], |
142 | ) -> TiffResult<()> |
143 | where |
144 | [C::Inner]: TiffValue, |
145 | { |
146 | let encoder = DirectoryEncoder::new(&mut self.writer)?; |
147 | let image: ImageEncoder<W, C, K, D> = |
148 | ImageEncoder::with_compression(encoder, width, height, compression)?; |
149 | image.write_data(data) |
150 | } |
151 | } |
152 | |
153 | /// Low level interface to encode ifd directories. |
154 | /// |
155 | /// You should call `finish` on this when you are finished with it. |
156 | /// Encoding can silently fail while this is dropping. |
157 | pub struct DirectoryEncoder<'a, W: 'a + Write + Seek, K: TiffKind> { |
158 | writer: &'a mut TiffWriter<W>, |
159 | dropped: bool, |
160 | // We use BTreeMap to make sure tags are written in correct order |
161 | ifd_pointer_pos: u64, |
162 | ifd: BTreeMap<u16, DirectoryEntry<K::OffsetType>>, |
163 | } |
164 | |
165 | impl<'a, W: 'a + Write + Seek, K: TiffKind> DirectoryEncoder<'a, W, K> { |
166 | fn new(writer: &'a mut TiffWriter<W>) -> TiffResult<Self> { |
167 | // the previous word is the IFD offset position |
168 | let ifd_pointer_pos = writer.offset() - mem::size_of::<K::OffsetType>() as u64; |
169 | writer.pad_word_boundary()?; // TODO: Do we need to adjust this for BigTiff? |
170 | Ok(DirectoryEncoder { |
171 | writer, |
172 | dropped: false, |
173 | ifd_pointer_pos, |
174 | ifd: BTreeMap::new(), |
175 | }) |
176 | } |
177 | |
178 | /// Write a single ifd tag. |
179 | pub fn write_tag<T: TiffValue>(&mut self, tag: Tag, value: T) -> TiffResult<()> { |
180 | let mut bytes = Vec::with_capacity(value.bytes()); |
181 | { |
182 | let mut writer = TiffWriter::new(&mut bytes); |
183 | value.write(&mut writer)?; |
184 | } |
185 | |
186 | self.ifd.insert( |
187 | tag.to_u16(), |
188 | DirectoryEntry { |
189 | data_type: <T>::FIELD_TYPE.to_u16(), |
190 | count: value.count().try_into()?, |
191 | data: bytes, |
192 | }, |
193 | ); |
194 | |
195 | Ok(()) |
196 | } |
197 | |
198 | fn write_directory(&mut self) -> TiffResult<u64> { |
199 | // Start by writing out all values |
200 | for &mut DirectoryEntry { |
201 | data: ref mut bytes, |
202 | .. |
203 | } in self.ifd.values_mut() |
204 | { |
205 | let data_bytes = mem::size_of::<K::OffsetType>(); |
206 | |
207 | if bytes.len() > data_bytes { |
208 | let offset = self.writer.offset(); |
209 | self.writer.write_bytes(bytes)?; |
210 | *bytes = vec![0; data_bytes]; |
211 | let mut writer = TiffWriter::new(bytes as &mut [u8]); |
212 | K::write_offset(&mut writer, offset)?; |
213 | } else { |
214 | while bytes.len() < data_bytes { |
215 | bytes.push(0); |
216 | } |
217 | } |
218 | } |
219 | |
220 | let offset = self.writer.offset(); |
221 | |
222 | K::write_entry_count(self.writer, self.ifd.len())?; |
223 | for ( |
224 | tag, |
225 | DirectoryEntry { |
226 | data_type: field_type, |
227 | count, |
228 | data: offset, |
229 | }, |
230 | ) in self.ifd.iter() |
231 | { |
232 | self.writer.write_u16(*tag)?; |
233 | self.writer.write_u16(*field_type)?; |
234 | (*count).write(self.writer)?; |
235 | self.writer.write_bytes(offset)?; |
236 | } |
237 | |
238 | Ok(offset) |
239 | } |
240 | |
241 | /// Write some data to the tiff file, the offset of the data is returned. |
242 | /// |
243 | /// This could be used to write tiff strips. |
244 | pub fn write_data<T: TiffValue>(&mut self, value: T) -> TiffResult<u64> { |
245 | let offset = self.writer.offset(); |
246 | value.write(self.writer)?; |
247 | Ok(offset) |
248 | } |
249 | |
250 | /// Provides the number of bytes written by the underlying TiffWriter during the last call. |
251 | fn last_written(&self) -> u64 { |
252 | self.writer.last_written() |
253 | } |
254 | |
255 | fn finish_internal(&mut self) -> TiffResult<()> { |
256 | let ifd_pointer = self.write_directory()?; |
257 | let curr_pos = self.writer.offset(); |
258 | |
259 | self.writer.goto_offset(self.ifd_pointer_pos)?; |
260 | K::write_offset(self.writer, ifd_pointer)?; |
261 | self.writer.goto_offset(curr_pos)?; |
262 | K::write_offset(self.writer, 0)?; |
263 | |
264 | self.dropped = true; |
265 | |
266 | Ok(()) |
267 | } |
268 | |
269 | /// Write out the ifd directory. |
270 | pub fn finish(mut self) -> TiffResult<()> { |
271 | self.finish_internal() |
272 | } |
273 | } |
274 | |
275 | impl<'a, W: Write + Seek, K: TiffKind> Drop for DirectoryEncoder<'a, W, K> { |
276 | fn drop(&mut self) { |
277 | if !self.dropped { |
278 | let _ = self.finish_internal(); |
279 | } |
280 | } |
281 | } |
282 | |
283 | /// Type to encode images strip by strip. |
284 | /// |
285 | /// You should call `finish` on this when you are finished with it. |
286 | /// Encoding can silently fail while this is dropping. |
287 | /// |
288 | /// # Examples |
289 | /// ``` |
290 | /// # extern crate tiff; |
291 | /// # fn main() { |
292 | /// # let mut file = std::io::Cursor::new(Vec::new()); |
293 | /// # let image_data = vec![0; 100*100*3]; |
294 | /// use tiff::encoder::*; |
295 | /// use tiff::tags::Tag; |
296 | /// |
297 | /// let mut tiff = TiffEncoder::new(&mut file).unwrap(); |
298 | /// let mut image = tiff.new_image::<colortype::RGB8>(100, 100).unwrap(); |
299 | /// |
300 | /// // You can encode tags here |
301 | /// image.encoder().write_tag(Tag::Artist, "Image-tiff" ).unwrap(); |
302 | /// |
303 | /// // Strip size can be configured before writing data |
304 | /// image.rows_per_strip(2).unwrap(); |
305 | /// |
306 | /// let mut idx = 0; |
307 | /// while image.next_strip_sample_count() > 0 { |
308 | /// let sample_count = image.next_strip_sample_count() as usize; |
309 | /// image.write_strip(&image_data[idx..idx+sample_count]).unwrap(); |
310 | /// idx += sample_count; |
311 | /// } |
312 | /// image.finish().unwrap(); |
313 | /// # } |
314 | /// ``` |
315 | /// You can also call write_data function wich will encode by strip and finish |
316 | pub struct ImageEncoder< |
317 | 'a, |
318 | W: 'a + Write + Seek, |
319 | C: ColorType, |
320 | K: TiffKind, |
321 | D: Compression = Uncompressed, |
322 | > { |
323 | encoder: DirectoryEncoder<'a, W, K>, |
324 | strip_idx: u64, |
325 | strip_count: u64, |
326 | row_samples: u64, |
327 | width: u32, |
328 | height: u32, |
329 | rows_per_strip: u64, |
330 | strip_offsets: Vec<K::OffsetType>, |
331 | strip_byte_count: Vec<K::OffsetType>, |
332 | dropped: bool, |
333 | compression: D, |
334 | _phantom: ::std::marker::PhantomData<C>, |
335 | } |
336 | |
337 | impl<'a, W: 'a + Write + Seek, T: ColorType, K: TiffKind, D: Compression> |
338 | ImageEncoder<'a, W, T, K, D> |
339 | { |
340 | fn new(encoder: DirectoryEncoder<'a, W, K>, width: u32, height: u32) -> TiffResult<Self> |
341 | where |
342 | D: Default, |
343 | { |
344 | Self::with_compression(encoder, width, height, D::default()) |
345 | } |
346 | |
347 | fn with_compression( |
348 | mut encoder: DirectoryEncoder<'a, W, K>, |
349 | width: u32, |
350 | height: u32, |
351 | compression: D, |
352 | ) -> TiffResult<Self> { |
353 | if width == 0 || height == 0 { |
354 | return Err(TiffError::FormatError(TiffFormatError::InvalidDimensions( |
355 | width, height, |
356 | ))); |
357 | } |
358 | |
359 | let row_samples = u64::from(width) * u64::try_from(<T>::BITS_PER_SAMPLE.len())?; |
360 | let row_bytes = row_samples * u64::from(<T::Inner>::BYTE_LEN); |
361 | |
362 | // Limit the strip size to prevent potential memory and security issues. |
363 | // Also keep the multiple strip handling 'oiled' |
364 | let rows_per_strip = { |
365 | match D::COMPRESSION_METHOD { |
366 | CompressionMethod::PackBits => 1, // Each row must be packed separately. Do not compress across row boundaries |
367 | _ => (1_000_000 + row_bytes - 1) / row_bytes, |
368 | } |
369 | }; |
370 | |
371 | let strip_count = (u64::from(height) + rows_per_strip - 1) / rows_per_strip; |
372 | |
373 | encoder.write_tag(Tag::ImageWidth, width)?; |
374 | encoder.write_tag(Tag::ImageLength, height)?; |
375 | encoder.write_tag(Tag::Compression, D::COMPRESSION_METHOD.to_u16())?; |
376 | |
377 | encoder.write_tag(Tag::BitsPerSample, <T>::BITS_PER_SAMPLE)?; |
378 | let sample_format: Vec<_> = <T>::SAMPLE_FORMAT.iter().map(|s| s.to_u16()).collect(); |
379 | encoder.write_tag(Tag::SampleFormat, &sample_format[..])?; |
380 | encoder.write_tag(Tag::PhotometricInterpretation, <T>::TIFF_VALUE.to_u16())?; |
381 | |
382 | encoder.write_tag(Tag::RowsPerStrip, u32::try_from(rows_per_strip)?)?; |
383 | |
384 | encoder.write_tag( |
385 | Tag::SamplesPerPixel, |
386 | u16::try_from(<T>::BITS_PER_SAMPLE.len())?, |
387 | )?; |
388 | encoder.write_tag(Tag::XResolution, Rational { n: 1, d: 1 })?; |
389 | encoder.write_tag(Tag::YResolution, Rational { n: 1, d: 1 })?; |
390 | encoder.write_tag(Tag::ResolutionUnit, ResolutionUnit::None.to_u16())?; |
391 | |
392 | Ok(ImageEncoder { |
393 | encoder, |
394 | strip_count, |
395 | strip_idx: 0, |
396 | row_samples, |
397 | rows_per_strip, |
398 | width, |
399 | height, |
400 | strip_offsets: Vec::new(), |
401 | strip_byte_count: Vec::new(), |
402 | dropped: false, |
403 | compression, |
404 | _phantom: ::std::marker::PhantomData, |
405 | }) |
406 | } |
407 | |
408 | /// Number of samples the next strip should have. |
409 | pub fn next_strip_sample_count(&self) -> u64 { |
410 | if self.strip_idx >= self.strip_count { |
411 | return 0; |
412 | } |
413 | |
414 | let raw_start_row = self.strip_idx * self.rows_per_strip; |
415 | let start_row = cmp::min(u64::from(self.height), raw_start_row); |
416 | let end_row = cmp::min(u64::from(self.height), raw_start_row + self.rows_per_strip); |
417 | |
418 | (end_row - start_row) * self.row_samples |
419 | } |
420 | |
421 | /// Write a single strip. |
422 | pub fn write_strip(&mut self, value: &[T::Inner]) -> TiffResult<()> |
423 | where |
424 | [T::Inner]: TiffValue, |
425 | { |
426 | let samples = self.next_strip_sample_count(); |
427 | if u64::try_from(value.len())? != samples { |
428 | return Err(io::Error::new( |
429 | io::ErrorKind::InvalidData, |
430 | "Slice is wrong size for strip" , |
431 | ) |
432 | .into()); |
433 | } |
434 | |
435 | // Write the (possible compressed) data to the encoder. |
436 | let offset = self.encoder.write_data(value)?; |
437 | let byte_count = self.encoder.last_written() as usize; |
438 | |
439 | self.strip_offsets.push(K::convert_offset(offset)?); |
440 | self.strip_byte_count.push(byte_count.try_into()?); |
441 | |
442 | self.strip_idx += 1; |
443 | Ok(()) |
444 | } |
445 | |
446 | /// Write strips from data |
447 | pub fn write_data(mut self, data: &[T::Inner]) -> TiffResult<()> |
448 | where |
449 | [T::Inner]: TiffValue, |
450 | { |
451 | let num_pix = usize::try_from(self.width)? |
452 | .checked_mul(usize::try_from(self.height)?) |
453 | .ok_or_else(|| { |
454 | io::Error::new( |
455 | io::ErrorKind::InvalidInput, |
456 | "Image width * height exceeds usize" , |
457 | ) |
458 | })?; |
459 | if data.len() < num_pix { |
460 | return Err(io::Error::new( |
461 | io::ErrorKind::InvalidData, |
462 | "Input data slice is undersized for provided dimensions" , |
463 | ) |
464 | .into()); |
465 | } |
466 | |
467 | self.encoder |
468 | .writer |
469 | .set_compression(self.compression.get_algorithm()); |
470 | |
471 | let mut idx = 0; |
472 | while self.next_strip_sample_count() > 0 { |
473 | let sample_count = usize::try_from(self.next_strip_sample_count())?; |
474 | self.write_strip(&data[idx..idx + sample_count])?; |
475 | idx += sample_count; |
476 | } |
477 | |
478 | self.encoder.writer.reset_compression(); |
479 | self.finish()?; |
480 | Ok(()) |
481 | } |
482 | |
483 | /// Set image resolution |
484 | pub fn resolution(&mut self, unit: ResolutionUnit, value: Rational) { |
485 | self.encoder |
486 | .write_tag(Tag::ResolutionUnit, unit.to_u16()) |
487 | .unwrap(); |
488 | self.encoder |
489 | .write_tag(Tag::XResolution, value.clone()) |
490 | .unwrap(); |
491 | self.encoder.write_tag(Tag::YResolution, value).unwrap(); |
492 | } |
493 | |
494 | /// Set image resolution unit |
495 | pub fn resolution_unit(&mut self, unit: ResolutionUnit) { |
496 | self.encoder |
497 | .write_tag(Tag::ResolutionUnit, unit.to_u16()) |
498 | .unwrap(); |
499 | } |
500 | |
501 | /// Set image x-resolution |
502 | pub fn x_resolution(&mut self, value: Rational) { |
503 | self.encoder.write_tag(Tag::XResolution, value).unwrap(); |
504 | } |
505 | |
506 | /// Set image y-resolution |
507 | pub fn y_resolution(&mut self, value: Rational) { |
508 | self.encoder.write_tag(Tag::YResolution, value).unwrap(); |
509 | } |
510 | |
511 | /// Set image number of lines per strip |
512 | /// |
513 | /// This function needs to be called before any calls to `write_data` or |
514 | /// `write_strip` and will return an error otherwise. |
515 | pub fn rows_per_strip(&mut self, value: u32) -> TiffResult<()> { |
516 | if self.strip_idx != 0 { |
517 | return Err(io::Error::new( |
518 | io::ErrorKind::InvalidInput, |
519 | "Cannot change strip size after data was written" , |
520 | ) |
521 | .into()); |
522 | } |
523 | // Write tag as 32 bits |
524 | self.encoder.write_tag(Tag::RowsPerStrip, value)?; |
525 | |
526 | let value: u64 = value as u64; |
527 | self.strip_count = (self.height as u64 + value - 1) / value; |
528 | self.rows_per_strip = value; |
529 | |
530 | Ok(()) |
531 | } |
532 | |
533 | fn finish_internal(&mut self) -> TiffResult<()> { |
534 | self.encoder |
535 | .write_tag(Tag::StripOffsets, K::convert_slice(&self.strip_offsets))?; |
536 | self.encoder.write_tag( |
537 | Tag::StripByteCounts, |
538 | K::convert_slice(&self.strip_byte_count), |
539 | )?; |
540 | self.dropped = true; |
541 | |
542 | self.encoder.finish_internal() |
543 | } |
544 | |
545 | /// Get a reference of the underlying `DirectoryEncoder` |
546 | pub fn encoder(&mut self) -> &mut DirectoryEncoder<'a, W, K> { |
547 | &mut self.encoder |
548 | } |
549 | |
550 | /// Write out image and ifd directory. |
551 | pub fn finish(mut self) -> TiffResult<()> { |
552 | self.finish_internal() |
553 | } |
554 | } |
555 | |
556 | impl<'a, W: Write + Seek, C: ColorType, K: TiffKind, D: Compression> Drop |
557 | for ImageEncoder<'a, W, C, K, D> |
558 | { |
559 | fn drop(&mut self) { |
560 | if !self.dropped { |
561 | let _ = self.finish_internal(); |
562 | } |
563 | } |
564 | } |
565 | |
566 | struct DirectoryEntry<S> { |
567 | data_type: u16, |
568 | count: S, |
569 | data: Vec<u8>, |
570 | } |
571 | |
572 | /// Trait to abstract over Tiff/BigTiff differences. |
573 | /// |
574 | /// Implemented for [`TiffKindStandard`] and [`TiffKindBig`]. |
575 | pub trait TiffKind { |
576 | /// The type of offset fields, `u32` for normal Tiff, `u64` for BigTiff. |
577 | type OffsetType: TryFrom<usize, Error = TryFromIntError> + Into<u64> + TiffValue; |
578 | |
579 | /// Needed for the `convert_slice` method. |
580 | type OffsetArrayType: ?Sized + TiffValue; |
581 | |
582 | /// Write the (Big)Tiff header. |
583 | fn write_header<W: Write>(writer: &mut TiffWriter<W>) -> TiffResult<()>; |
584 | |
585 | /// Convert a file offset to `Self::OffsetType`. |
586 | /// |
587 | /// This returns an error for normal Tiff if the offset is larger than `u32::MAX`. |
588 | fn convert_offset(offset: u64) -> TiffResult<Self::OffsetType>; |
589 | |
590 | /// Write an offset value to the given writer. |
591 | /// |
592 | /// Like `convert_offset`, this errors if `offset > u32::MAX` for normal Tiff. |
593 | fn write_offset<W: Write>(writer: &mut TiffWriter<W>, offset: u64) -> TiffResult<()>; |
594 | |
595 | /// Write the IFD entry count field with the given `count` value. |
596 | /// |
597 | /// The entry count field is an `u16` for normal Tiff and `u64` for BigTiff. Errors |
598 | /// if the given `usize` is larger than the representable values. |
599 | fn write_entry_count<W: Write>(writer: &mut TiffWriter<W>, count: usize) -> TiffResult<()>; |
600 | |
601 | /// Internal helper method for satisfying Rust's type checker. |
602 | /// |
603 | /// The `TiffValue` trait is implemented for both primitive values (e.g. `u8`, `u32`) and |
604 | /// slices of primitive values (e.g. `[u8]`, `[u32]`). However, this is not represented in |
605 | /// the type system, so there is no guarantee that that for all `T: TiffValue` there is also |
606 | /// an implementation of `TiffValue` for `[T]`. This method works around that problem by |
607 | /// providing a conversion from `[T]` to some value that implements `TiffValue`, thereby |
608 | /// making all slices of `OffsetType` usable with `write_tag` and similar methods. |
609 | /// |
610 | /// Implementations of this trait should always set `OffsetArrayType` to `[OffsetType]`. |
611 | fn convert_slice(slice: &[Self::OffsetType]) -> &Self::OffsetArrayType; |
612 | } |
613 | |
614 | /// Create a standard Tiff file. |
615 | pub struct TiffKindStandard; |
616 | |
617 | impl TiffKind for TiffKindStandard { |
618 | type OffsetType = u32; |
619 | type OffsetArrayType = [u32]; |
620 | |
621 | fn write_header<W: Write>(writer: &mut TiffWriter<W>) -> TiffResult<()> { |
622 | write_tiff_header(writer)?; |
623 | // blank the IFD offset location |
624 | writer.write_u32(0)?; |
625 | |
626 | Ok(()) |
627 | } |
628 | |
629 | fn convert_offset(offset: u64) -> TiffResult<Self::OffsetType> { |
630 | Ok(Self::OffsetType::try_from(offset)?) |
631 | } |
632 | |
633 | fn write_offset<W: Write>(writer: &mut TiffWriter<W>, offset: u64) -> TiffResult<()> { |
634 | writer.write_u32(u32::try_from(offset)?)?; |
635 | Ok(()) |
636 | } |
637 | |
638 | fn write_entry_count<W: Write>(writer: &mut TiffWriter<W>, count: usize) -> TiffResult<()> { |
639 | writer.write_u16(u16::try_from(count)?)?; |
640 | |
641 | Ok(()) |
642 | } |
643 | |
644 | fn convert_slice(slice: &[Self::OffsetType]) -> &Self::OffsetArrayType { |
645 | slice |
646 | } |
647 | } |
648 | |
649 | /// Create a BigTiff file. |
650 | pub struct TiffKindBig; |
651 | |
652 | impl TiffKind for TiffKindBig { |
653 | type OffsetType = u64; |
654 | type OffsetArrayType = [u64]; |
655 | |
656 | fn write_header<W: Write>(writer: &mut TiffWriter<W>) -> TiffResult<()> { |
657 | write_bigtiff_header(writer)?; |
658 | // blank the IFD offset location |
659 | writer.write_u64(0)?; |
660 | |
661 | Ok(()) |
662 | } |
663 | |
664 | fn convert_offset(offset: u64) -> TiffResult<Self::OffsetType> { |
665 | Ok(offset) |
666 | } |
667 | |
668 | fn write_offset<W: Write>(writer: &mut TiffWriter<W>, offset: u64) -> TiffResult<()> { |
669 | writer.write_u64(offset)?; |
670 | Ok(()) |
671 | } |
672 | |
673 | fn write_entry_count<W: Write>(writer: &mut TiffWriter<W>, count: usize) -> TiffResult<()> { |
674 | writer.write_u64(u64::try_from(count)?)?; |
675 | Ok(()) |
676 | } |
677 | |
678 | fn convert_slice(slice: &[Self::OffsetType]) -> &Self::OffsetArrayType { |
679 | slice |
680 | } |
681 | } |
682 | |