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Refactoring to simplify expand_strip function

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Jonathan Behrens committed 2021-04-10 15:02:16 -04:00
1 parent 91fe529859
commit 7641dcbd3f
1 file changed
+63 -112
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src/decoder/mod.rs
+63 -112
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@@ -889,12 +889,28 @@ impl<R: Read + Seek> Decoder<R> {
/// Returns the number of bytes read.
fn expand_strip<'a>(
&mut self,
buffer: DecodingBuffer<'a>,
mut buffer: DecodingBuffer<'a>,
offset: u64,
length: u64,
strip_sample_count: usize,
) -> TiffResult<usize> {
// Validate that the provided buffer is of the expected type.
let color_type = self.colortype()?;
match (color_type, &buffer) {
(ColorType::RGB(n), _)
| (ColorType::RGBA(n), _)
| (ColorType::CMYK(n), _)
| (ColorType::Gray(n), _)
if usize::from(n) == buffer.byte_len() * 8 => {}
(ColorType::Gray(n), DecodingBuffer::U8(_)) if n <= 8 => {}
(type_, _) => {
return Err(TiffError::UnsupportedError(
TiffUnsupportedError::UnsupportedColorType(type_),
))
}
}
// Construct necessary reader to perform decompression.
self.goto_offset_u64(offset)?;
let (bytes, mut reader): (usize, Box<dyn EndianReader>) = match self.compression_method {
CompressionMethod::None => {
@@ -940,146 +956,81 @@ impl<R: Read + Seek> Decoder<R> {
));
}
Ok(match (color_type, buffer) {
(ColorType::RGB(8), DecodingBuffer::U8(ref mut buffer))
| (ColorType::RGBA(8), DecodingBuffer::U8(ref mut buffer))
| (ColorType::CMYK(8), DecodingBuffer::U8(ref mut buffer)) => {
reader.read_exact(&mut buffer[..bytes])?;
bytes
// Read into the output buffer.
let samples = bytes / buffer.byte_len();
match buffer {
DecodingBuffer::U8(ref mut buffer) => {
reader.read_exact(&mut buffer[..samples])?
}
(ColorType::RGBA(16), DecodingBuffer::U16(ref mut buffer))
| (ColorType::RGB(16), DecodingBuffer::U16(ref mut buffer))
| (ColorType::CMYK(16), DecodingBuffer::U16(ref mut buffer)) => {
reader.read_u16_into(&mut buffer[..bytes / 2])?;
bytes / 2
DecodingBuffer::U16(ref mut buffer) => {
reader.read_u16_into(&mut buffer[..samples])?
}
(ColorType::RGBA(32), DecodingBuffer::U32(ref mut buffer))
| (ColorType::RGB(32), DecodingBuffer::U32(ref mut buffer))
| (ColorType::CMYK(32), DecodingBuffer::U32(ref mut buffer)) => {
reader.read_u32_into(&mut buffer[..bytes / 4])?;
bytes / 4
DecodingBuffer::U32(ref mut buffer) => {
reader.read_u32_into(&mut buffer[..samples])?
}
(ColorType::RGBA(32), DecodingBuffer::F32(ref mut buffer))
| (ColorType::RGB(32), DecodingBuffer::F32(ref mut buffer))
| (ColorType::CMYK(32), DecodingBuffer::F32(ref mut buffer)) => {
reader.read_f32_into(&mut buffer[..bytes / 4])?;
bytes / 4
DecodingBuffer::U64(ref mut buffer) => {
reader.read_u64_into(&mut buffer[..samples])?
}
(ColorType::RGBA(64), DecodingBuffer::F64(ref mut buffer))
| (ColorType::RGB(64), DecodingBuffer::F64(ref mut buffer))
| (ColorType::CMYK(64), DecodingBuffer::F64(ref mut buffer)) => {
reader.read_f64_into(&mut buffer[..bytes / 8])?;
bytes / 8
DecodingBuffer::I8(ref mut buffer) => {
reader.read_i8_into(&mut buffer[..samples])?
}
(ColorType::RGBA(64), DecodingBuffer::U64(ref mut buffer))
| (ColorType::RGB(64), DecodingBuffer::U64(ref mut buffer))
| (ColorType::CMYK(64), DecodingBuffer::U64(ref mut buffer)) => {
reader.read_u64_into(&mut buffer[..bytes / 8])?;
bytes / 8
DecodingBuffer::I16(ref mut buffer) => {
reader.read_i16_into(&mut buffer[..samples])?
}
(ColorType::RGBA(8), DecodingBuffer::I8(ref mut buffer))
| (ColorType::RGB(8), DecodingBuffer::I8(ref mut buffer))
| (ColorType::CMYK(8), DecodingBuffer::I8(ref mut buffer)) => {
reader.read_i8_into(&mut buffer[..bytes])?;
bytes
DecodingBuffer::I32(ref mut buffer) => {
reader.read_i32_into(&mut buffer[..samples])?
}
(ColorType::RGBA(16), DecodingBuffer::I16(ref mut buffer))
| (ColorType::RGB(16), DecodingBuffer::I16(ref mut buffer))
| (ColorType::CMYK(16), DecodingBuffer::I16(ref mut buffer)) => {
reader.read_i16_into(&mut buffer[..bytes / 2])?;
bytes / 2
DecodingBuffer::I64(ref mut buffer) => {
reader.read_i64_into(&mut buffer[..samples])?
}
DecodingBuffer::F32(ref mut buffer) => {
reader.read_f32_into(&mut buffer[..samples])?
}
DecodingBuffer::F64(ref mut buffer) => {
reader.read_f64_into(&mut buffer[..samples])?
}
}
(ColorType::Gray(64), DecodingBuffer::U64(ref mut buffer)) => {
reader.read_u64_into(&mut buffer[..bytes / 8])?;
if self.photometric_interpretation == PhotometricInterpretation::WhiteIsZero {
for datum in buffer[..bytes / 8].iter_mut() {
// Invert colors if necessary.
if self.photometric_interpretation == PhotometricInterpretation::WhiteIsZero {
match (color_type, buffer) {
(ColorType::Gray(64), DecodingBuffer::U64(ref mut buffer)) => {
for datum in buffer[..samples].iter_mut() {
*datum = 0xffff_ffff_ffff_ffff - *datum
}
}
bytes / 8
}
(ColorType::Gray(64), DecodingBuffer::I64(ref mut buffer)) => {
reader.read_i64_into(&mut buffer[..bytes / 8])?;
bytes / 8
}
(ColorType::Gray(32), DecodingBuffer::U32(ref mut buffer)) => {
reader.read_u32_into(&mut buffer[..bytes / 4])?;
if self.photometric_interpretation == PhotometricInterpretation::WhiteIsZero {
for datum in buffer[..bytes / 4].iter_mut() {
(ColorType::Gray(32), DecodingBuffer::U32(ref mut buffer)) => {
for datum in buffer[..samples].iter_mut() {
*datum = 0xffff_ffff - *datum
}
}
bytes / 4
}
(ColorType::Gray(32), DecodingBuffer::I32(ref mut buffer)) => {
reader.read_i32_into(&mut buffer[..bytes / 4])?;
bytes / 4
}
(ColorType::Gray(16), DecodingBuffer::U16(ref mut buffer)) => {
reader.read_u16_into(&mut buffer[..bytes / 2])?;
if self.photometric_interpretation == PhotometricInterpretation::WhiteIsZero {
for datum in buffer[..bytes / 2].iter_mut() {
(ColorType::Gray(16), DecodingBuffer::U16(ref mut buffer)) => {
for datum in buffer[..samples].iter_mut() {
*datum = 0xffff - *datum
}
}
bytes / 2
}
(ColorType::Gray(8), DecodingBuffer::I8(ref mut buffer)) => {
reader.read_i8_into(&mut buffer[..bytes])?;
if self.photometric_interpretation == PhotometricInterpretation::WhiteIsZero {
for datum in buffer[..bytes].iter_mut() {
*datum = !*datum;
(ColorType::Gray(n), DecodingBuffer::U8(ref mut buffer)) if n <= 8 => {
for byte in buffer[..samples].iter_mut() {
*byte = 0xff - *byte
}
}
bytes
}
// The following conversions interpret the image as in libtiff.
// In particular, MIN is white and MAX is black and not Zero as the name would imply.
(ColorType::Gray(16), DecodingBuffer::I16(ref mut buffer)) => {
reader.read_i16_into(&mut buffer[..bytes / 2])?;
if self.photometric_interpretation == PhotometricInterpretation::WhiteIsZero {
for datum in buffer[..bytes / 2].iter_mut() {
*datum = !*datum;
}
}
bytes / 2
}
(ColorType::Gray(n), DecodingBuffer::U8(ref mut buffer)) if n <= 8 => {
reader.read_exact(&mut buffer[..bytes])?;
if self.photometric_interpretation == PhotometricInterpretation::WhiteIsZero {
for byte in buffer[..bytes].iter_mut() {
*byte = !*byte;
}
}
bytes
}
(ColorType::Gray(32), DecodingBuffer::F32(ref mut buffer)) => {
reader.read_f32_into(&mut buffer[..bytes / 4])?;
if self.photometric_interpretation == PhotometricInterpretation::WhiteIsZero {
for datum in buffer[..bytes / 4].iter_mut() {
(ColorType::Gray(32), DecodingBuffer::F32(ref mut buffer)) => {
for datum in buffer[..samples].iter_mut() {
// FIXME: assumes [0, 1) range for floats
*datum = 1.0 - *datum
}
}
bytes / 4
}
(ColorType::Gray(64), DecodingBuffer::F64(ref mut buffer)) => {
reader.read_f64_into(&mut buffer[..bytes / 8])?;
if self.photometric_interpretation == PhotometricInterpretation::WhiteIsZero {
for datum in buffer[..bytes / 8].iter_mut() {
(ColorType::Gray(64), DecodingBuffer::F64(ref mut buffer)) => {
for datum in buffer[..samples].iter_mut() {
// FIXME: assumes [0, 1) range for floats
*datum = 1.0 - *datum
}
}
bytes / 8
_ => {}
}
(type_, _) => {
return Err(TiffError::UnsupportedError(
TiffUnsupportedError::UnsupportedColorType(type_),
))
}
})
}
Ok(samples)
}
/// Number of strips in image