Initial vendor packages

Signed-off-by: Valentin Popov <valentin@popov.link>

4 files changed, 884 insertions, 0 deletions

diff --git a/vendor/image/src/codecs/tga/decoder.rs b/vendor/image/src/codecs/tga/decoder.rs
new file mode 100644
index 0000000..16243ce
--- /dev/null
+++ b/vendor/image/src/codecs/tga/decoder.rs
@@ -0,0 +1,502 @@
+use super::header::{Header, ImageType, ALPHA_BIT_MASK, SCREEN_ORIGIN_BIT_MASK};
+use crate::{
+    color::{ColorType, ExtendedColorType},
+    error::{
+        ImageError, ImageResult, LimitError, LimitErrorKind, UnsupportedError, UnsupportedErrorKind,
+    },
+    image::{ImageDecoder, ImageFormat, ImageReadBuffer},
+};
+use byteorder::ReadBytesExt;
+use std::{
+    convert::TryFrom,
+    io::{self, Read, Seek},
+    mem,
+};
+
+struct ColorMap {
+    /// sizes in bytes
+    start_offset: usize,
+    entry_size: usize,
+    bytes: Vec<u8>,
+}
+
+impl ColorMap {
+    pub(crate) fn from_reader(
+        r: &mut dyn Read,
+        start_offset: u16,
+        num_entries: u16,
+        bits_per_entry: u8,
+    ) -> ImageResult<ColorMap> {
+        let bytes_per_entry = (bits_per_entry as usize + 7) / 8;
+
+        let mut bytes = vec![0; bytes_per_entry * num_entries as usize];
+        r.read_exact(&mut bytes)?;
+
+        Ok(ColorMap {
+            entry_size: bytes_per_entry,
+            start_offset: start_offset as usize,
+            bytes,
+        })
+    }
+
+    /// Get one entry from the color map
+    pub(crate) fn get(&self, index: usize) -> Option<&[u8]> {
+        let entry = self.start_offset + self.entry_size * index;
+        self.bytes.get(entry..entry + self.entry_size)
+    }
+}
+
+/// The representation of a TGA decoder
+pub struct TgaDecoder<R> {
+    r: R,
+
+    width: usize,
+    height: usize,
+    bytes_per_pixel: usize,
+    has_loaded_metadata: bool,
+
+    image_type: ImageType,
+    color_type: ColorType,
+    original_color_type: Option<ExtendedColorType>,
+
+    header: Header,
+    color_map: Option<ColorMap>,
+
+    // Used in read_scanline
+    line_read: Option<usize>,
+    line_remain_buff: Vec<u8>,
+}
+
+impl<R: Read + Seek> TgaDecoder<R> {
+    /// Create a new decoder that decodes from the stream `r`
+    pub fn new(r: R) -> ImageResult<TgaDecoder<R>> {
+        let mut decoder = TgaDecoder {
+            r,
+
+            width: 0,
+            height: 0,
+            bytes_per_pixel: 0,
+            has_loaded_metadata: false,
+
+            image_type: ImageType::Unknown,
+            color_type: ColorType::L8,
+            original_color_type: None,
+
+            header: Header::default(),
+            color_map: None,
+
+            line_read: None,
+            line_remain_buff: Vec::new(),
+        };
+        decoder.read_metadata()?;
+        Ok(decoder)
+    }
+
+    fn read_header(&mut self) -> ImageResult<()> {
+        self.header = Header::from_reader(&mut self.r)?;
+        self.image_type = ImageType::new(self.header.image_type);
+        self.width = self.header.image_width as usize;
+        self.height = self.header.image_height as usize;
+        self.bytes_per_pixel = (self.header.pixel_depth as usize + 7) / 8;
+        Ok(())
+    }
+
+    fn read_metadata(&mut self) -> ImageResult<()> {
+        if !self.has_loaded_metadata {
+            self.read_header()?;
+            self.read_image_id()?;
+            self.read_color_map()?;
+            self.read_color_information()?;
+            self.has_loaded_metadata = true;
+        }
+        Ok(())
+    }
+
+    /// Loads the color information for the decoder
+    ///
+    /// To keep things simple, we won't handle bit depths that aren't divisible
+    /// by 8 and are larger than 32.
+    fn read_color_information(&mut self) -> ImageResult<()> {
+        if self.header.pixel_depth % 8 != 0 || self.header.pixel_depth > 32 {
+            // Bit depth must be divisible by 8, and must be less than or equal
+            // to 32.
+            return Err(ImageError::Unsupported(
+                UnsupportedError::from_format_and_kind(
+                    ImageFormat::Tga.into(),
+                    UnsupportedErrorKind::Color(ExtendedColorType::Unknown(
+                        self.header.pixel_depth,
+                    )),
+                ),
+            ));
+        }
+
+        let num_alpha_bits = self.header.image_desc & ALPHA_BIT_MASK;
+
+        let other_channel_bits = if self.header.map_type != 0 {
+            self.header.map_entry_size
+        } else {
+            if num_alpha_bits > self.header.pixel_depth {
+                return Err(ImageError::Unsupported(
+                    UnsupportedError::from_format_and_kind(
+                        ImageFormat::Tga.into(),
+                        UnsupportedErrorKind::Color(ExtendedColorType::Unknown(
+                            self.header.pixel_depth,
+                        )),
+                    ),
+                ));
+            }
+
+            self.header.pixel_depth - num_alpha_bits
+        };
+        let color = self.image_type.is_color();
+
+        match (num_alpha_bits, other_channel_bits, color) {
+            // really, the encoding is BGR and BGRA, this is fixed
+            // up with `TgaDecoder::reverse_encoding`.
+            (0, 32, true) => self.color_type = ColorType::Rgba8,
+            (8, 24, true) => self.color_type = ColorType::Rgba8,
+            (0, 24, true) => self.color_type = ColorType::Rgb8,
+            (8, 8, false) => self.color_type = ColorType::La8,
+            (0, 8, false) => self.color_type = ColorType::L8,
+            (8, 0, false) => {
+                // alpha-only image is treated as L8
+                self.color_type = ColorType::L8;
+                self.original_color_type = Some(ExtendedColorType::A8);
+            }
+            _ => {
+                return Err(ImageError::Unsupported(
+                    UnsupportedError::from_format_and_kind(
+                        ImageFormat::Tga.into(),
+                        UnsupportedErrorKind::Color(ExtendedColorType::Unknown(
+                            self.header.pixel_depth,
+                        )),
+                    ),
+                ))
+            }
+        }
+        Ok(())
+    }
+
+    /// Read the image id field
+    ///
+    /// We're not interested in this field, so this function skips it if it
+    /// is present
+    fn read_image_id(&mut self) -> ImageResult<()> {
+        self.r
+            .seek(io::SeekFrom::Current(i64::from(self.header.id_length)))?;
+        Ok(())
+    }
+
+    fn read_color_map(&mut self) -> ImageResult<()> {
+        if self.header.map_type == 1 {
+            // FIXME: we could reverse the map entries, which avoids having to reverse all pixels
+            // in the final output individually.
+            self.color_map = Some(ColorMap::from_reader(
+                &mut self.r,
+                self.header.map_origin,
+                self.header.map_length,
+                self.header.map_entry_size,
+            )?);
+        }
+        Ok(())
+    }
+
+    /// Expands indices into its mapped color
+    fn expand_color_map(&self, pixel_data: &[u8]) -> io::Result<Vec<u8>> {
+        #[inline]
+        fn bytes_to_index(bytes: &[u8]) -> usize {
+            let mut result = 0usize;
+            for byte in bytes.iter() {
+                result = result << 8 | *byte as usize;
+            }
+            result
+        }
+
+        let bytes_per_entry = (self.header.map_entry_size as usize + 7) / 8;
+        let mut result = Vec::with_capacity(self.width * self.height * bytes_per_entry);
+
+        if self.bytes_per_pixel == 0 {
+            return Err(io::ErrorKind::Other.into());
+        }
+
+        let color_map = self
+            .color_map
+            .as_ref()
+            .ok_or_else(|| io::Error::from(io::ErrorKind::Other))?;
+
+        for chunk in pixel_data.chunks(self.bytes_per_pixel) {
+            let index = bytes_to_index(chunk);
+            if let Some(color) = color_map.get(index) {
+                result.extend_from_slice(color);
+            } else {
+                return Err(io::ErrorKind::Other.into());
+            }
+        }
+
+        Ok(result)
+    }
+
+    /// Reads a run length encoded data for given number of bytes
+    fn read_encoded_data(&mut self, num_bytes: usize) -> io::Result<Vec<u8>> {
+        let mut pixel_data = Vec::with_capacity(num_bytes);
+        let mut repeat_buf = Vec::with_capacity(self.bytes_per_pixel);
+
+        while pixel_data.len() < num_bytes {
+            let run_packet = self.r.read_u8()?;
+            // If the highest bit in `run_packet` is set, then we repeat pixels
+            //
+            // Note: the TGA format adds 1 to both counts because having a count
+            // of 0 would be pointless.
+            if (run_packet & 0x80) != 0 {
+                // high bit set, so we will repeat the data
+                let repeat_count = ((run_packet & !0x80) + 1) as usize;
+                self.r
+                    .by_ref()
+                    .take(self.bytes_per_pixel as u64)
+                    .read_to_end(&mut repeat_buf)?;
+
+                // get the repeating pixels from the bytes of the pixel stored in `repeat_buf`
+                let data = repeat_buf
+                    .iter()
+                    .cycle()
+                    .take(repeat_count * self.bytes_per_pixel);
+                pixel_data.extend(data);
+                repeat_buf.clear();
+            } else {
+                // not set, so `run_packet+1` is the number of non-encoded pixels
+                let num_raw_bytes = (run_packet + 1) as usize * self.bytes_per_pixel;
+                self.r
+                    .by_ref()
+                    .take(num_raw_bytes as u64)
+                    .read_to_end(&mut pixel_data)?;
+            }
+        }
+
+        if pixel_data.len() > num_bytes {
+            // FIXME: the last packet contained more data than we asked for!
+            // This is at least a warning. We truncate the data since some methods rely on the
+            // length to be accurate in the success case.
+            pixel_data.truncate(num_bytes);
+        }
+
+        Ok(pixel_data)
+    }
+
+    /// Reads a run length encoded packet
+    fn read_all_encoded_data(&mut self) -> ImageResult<Vec<u8>> {
+        let num_bytes = self.width * self.height * self.bytes_per_pixel;
+
+        Ok(self.read_encoded_data(num_bytes)?)
+    }
+
+    /// Reads a run length encoded line
+    fn read_encoded_line(&mut self) -> io::Result<Vec<u8>> {
+        let line_num_bytes = self.width * self.bytes_per_pixel;
+        let remain_len = self.line_remain_buff.len();
+
+        if remain_len >= line_num_bytes {
+            // `Vec::split_to` if std had it
+            let bytes = {
+                let bytes_after = self.line_remain_buff.split_off(line_num_bytes);
+                mem::replace(&mut self.line_remain_buff, bytes_after)
+            };
+
+            return Ok(bytes);
+        }
+
+        let num_bytes = line_num_bytes - remain_len;
+
+        let line_data = self.read_encoded_data(num_bytes)?;
+
+        let mut pixel_data = Vec::with_capacity(line_num_bytes);
+        pixel_data.append(&mut self.line_remain_buff);
+        pixel_data.extend_from_slice(&line_data[..num_bytes]);
+
+        // put the remain data to line_remain_buff.
+        // expects `self.line_remain_buff` to be empty from
+        // the above `pixel_data.append` call
+        debug_assert!(self.line_remain_buff.is_empty());
+        self.line_remain_buff
+            .extend_from_slice(&line_data[num_bytes..]);
+
+        Ok(pixel_data)
+    }
+
+    /// Reverse from BGR encoding to RGB encoding
+    ///
+    /// TGA files are stored in the BGRA encoding. This function swaps
+    /// the blue and red bytes in the `pixels` array.
+    fn reverse_encoding_in_output(&mut self, pixels: &mut [u8]) {
+        // We only need to reverse the encoding of color images
+        match self.color_type {
+            ColorType::Rgb8 | ColorType::Rgba8 => {
+                for chunk in pixels.chunks_mut(self.color_type.bytes_per_pixel().into()) {
+                    chunk.swap(0, 2);
+                }
+            }
+            _ => {}
+        }
+    }
+
+    /// Flip the image vertically depending on the screen origin bit
+    ///
+    /// The bit in position 5 of the image descriptor byte is the screen origin bit.
+    /// If it's 1, the origin is in the top left corner.
+    /// If it's 0, the origin is in the bottom left corner.
+    /// This function checks the bit, and if it's 0, flips the image vertically.
+    fn flip_vertically(&mut self, pixels: &mut [u8]) {
+        if self.is_flipped_vertically() {
+            if self.height == 0 {
+                return;
+            }
+
+            let num_bytes = pixels.len();
+
+            let width_bytes = num_bytes / self.height;
+
+            // Flip the image vertically.
+            for vertical_index in 0..(self.height / 2) {
+                let vertical_target = (self.height - vertical_index) * width_bytes - width_bytes;
+
+                for horizontal_index in 0..width_bytes {
+                    let source = vertical_index * width_bytes + horizontal_index;
+                    let target = vertical_target + horizontal_index;
+
+                    pixels.swap(target, source);
+                }
+            }
+        }
+    }
+
+    /// Check whether the image is vertically flipped
+    ///
+    /// The bit in position 5 of the image descriptor byte is the screen origin bit.
+    /// If it's 1, the origin is in the top left corner.
+    /// If it's 0, the origin is in the bottom left corner.
+    /// This function checks the bit, and if it's 0, flips the image vertically.
+    fn is_flipped_vertically(&self) -> bool {
+        let screen_origin_bit = SCREEN_ORIGIN_BIT_MASK & self.header.image_desc != 0;
+        !screen_origin_bit
+    }
+
+    fn read_scanline(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        if let Some(line_read) = self.line_read {
+            if line_read == self.height {
+                return Ok(0);
+            }
+        }
+
+        // read the pixels from the data region
+        let mut pixel_data = if self.image_type.is_encoded() {
+            self.read_encoded_line()?
+        } else {
+            let num_raw_bytes = self.width * self.bytes_per_pixel;
+            let mut buf = vec![0; num_raw_bytes];
+            self.r.by_ref().read_exact(&mut buf)?;
+            buf
+        };
+
+        // expand the indices using the color map if necessary
+        if self.image_type.is_color_mapped() {
+            pixel_data = self.expand_color_map(&pixel_data)?;
+        }
+        self.reverse_encoding_in_output(&mut pixel_data);
+
+        // copy to the output buffer
+        buf[..pixel_data.len()].copy_from_slice(&pixel_data);
+
+        self.line_read = Some(self.line_read.unwrap_or(0) + 1);
+
+        Ok(pixel_data.len())
+    }
+}
+
+impl<'a, R: 'a + Read + Seek> ImageDecoder<'a> for TgaDecoder<R> {
+    type Reader = TGAReader<R>;
+
+    fn dimensions(&self) -> (u32, u32) {
+        (self.width as u32, self.height as u32)
+    }
+
+    fn color_type(&self) -> ColorType {
+        self.color_type
+    }
+
+    fn original_color_type(&self) -> ExtendedColorType {
+        self.original_color_type
+            .unwrap_or_else(|| self.color_type().into())
+    }
+
+    fn scanline_bytes(&self) -> u64 {
+        // This cannot overflow because TGA has a maximum width of u16::MAX_VALUE and
+        // `bytes_per_pixel` is a u8.
+        u64::from(self.color_type.bytes_per_pixel()) * self.width as u64
+    }
+
+    fn into_reader(self) -> ImageResult<Self::Reader> {
+        Ok(TGAReader {
+            buffer: ImageReadBuffer::new(self.scanline_bytes(), self.total_bytes()),
+            decoder: self,
+        })
+    }
+
+    fn read_image(mut self, buf: &mut [u8]) -> ImageResult<()> {
+        assert_eq!(u64::try_from(buf.len()), Ok(self.total_bytes()));
+
+        // In indexed images, we might need more bytes than pixels to read them. That's nonsensical
+        // to encode but we'll not want to crash.
+        let mut fallback_buf = vec![];
+        // read the pixels from the data region
+        let rawbuf = if self.image_type.is_encoded() {
+            let pixel_data = self.read_all_encoded_data()?;
+            if self.bytes_per_pixel <= usize::from(self.color_type.bytes_per_pixel()) {
+                buf[..pixel_data.len()].copy_from_slice(&pixel_data);
+                &buf[..pixel_data.len()]
+            } else {
+                fallback_buf = pixel_data;
+                &fallback_buf[..]
+            }
+        } else {
+            let num_raw_bytes = self.width * self.height * self.bytes_per_pixel;
+            if self.bytes_per_pixel <= usize::from(self.color_type.bytes_per_pixel()) {
+                self.r.by_ref().read_exact(&mut buf[..num_raw_bytes])?;
+                &buf[..num_raw_bytes]
+            } else {
+                fallback_buf.resize(num_raw_bytes, 0u8);
+                self.r
+                    .by_ref()
+                    .read_exact(&mut fallback_buf[..num_raw_bytes])?;
+                &fallback_buf[..num_raw_bytes]
+            }
+        };
+
+        // expand the indices using the color map if necessary
+        if self.image_type.is_color_mapped() {
+            let pixel_data = self.expand_color_map(rawbuf)?;
+            // not enough data to fill the buffer, or would overflow the buffer
+            if pixel_data.len() != buf.len() {
+                return Err(ImageError::Limits(LimitError::from_kind(
+                    LimitErrorKind::DimensionError,
+                )));
+            }
+            buf.copy_from_slice(&pixel_data);
+        }
+
+        self.reverse_encoding_in_output(buf);
+
+        self.flip_vertically(buf);
+
+        Ok(())
+    }
+}
+
+pub struct TGAReader<R> {
+    buffer: ImageReadBuffer,
+    decoder: TgaDecoder<R>,
+}
+impl<R: Read + Seek> Read for TGAReader<R> {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        let decoder = &mut self.decoder;
+        self.buffer.read(buf, |buf| decoder.read_scanline(buf))
+    }
+}
diff --git a/vendor/image/src/codecs/tga/encoder.rs b/vendor/image/src/codecs/tga/encoder.rs
new file mode 100644
index 0000000..cf34984
--- /dev/null
+++ b/vendor/image/src/codecs/tga/encoder.rs
@@ -0,0 +1,215 @@
+use super::header::Header;
+use crate::{error::EncodingError, ColorType, ImageEncoder, ImageError, ImageFormat, ImageResult};
+use std::{convert::TryFrom, error, fmt, io::Write};
+
+/// Errors that can occur during encoding and saving of a TGA image.
+#[derive(Debug, Copy, Clone, Hash, PartialEq, Eq, PartialOrd, Ord)]
+enum EncoderError {
+    /// Invalid TGA width.
+    WidthInvalid(u32),
+
+    /// Invalid TGA height.
+    HeightInvalid(u32),
+}
+
+impl fmt::Display for EncoderError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            EncoderError::WidthInvalid(s) => f.write_fmt(format_args!("Invalid TGA width: {}", s)),
+            EncoderError::HeightInvalid(s) => {
+                f.write_fmt(format_args!("Invalid TGA height: {}", s))
+            }
+        }
+    }
+}
+
+impl From<EncoderError> for ImageError {
+    fn from(e: EncoderError) -> ImageError {
+        ImageError::Encoding(EncodingError::new(ImageFormat::Tga.into(), e))
+    }
+}
+
+impl error::Error for EncoderError {}
+
+/// TGA encoder.
+pub struct TgaEncoder<W: Write> {
+    writer: W,
+}
+
+impl<W: Write> TgaEncoder<W> {
+    /// Create a new encoder that writes its output to ```w```.
+    pub fn new(w: W) -> TgaEncoder<W> {
+        TgaEncoder { writer: w }
+    }
+
+    /// Encodes the image ```buf``` that has dimensions ```width```
+    /// and ```height``` and ```ColorType``` ```color_type```.
+    ///
+    /// The dimensions of the image must be between 0 and 65535 (inclusive) or
+    /// an error will be returned.
+    pub fn encode(
+        mut self,
+        buf: &[u8],
+        width: u32,
+        height: u32,
+        color_type: ColorType,
+    ) -> ImageResult<()> {
+        // Validate dimensions.
+        let width = u16::try_from(width)
+            .map_err(|_| ImageError::from(EncoderError::WidthInvalid(width)))?;
+
+        let height = u16::try_from(height)
+            .map_err(|_| ImageError::from(EncoderError::HeightInvalid(height)))?;
+
+        // Write out TGA header.
+        let header = Header::from_pixel_info(color_type, width, height)?;
+        header.write_to(&mut self.writer)?;
+
+        // Write out Bgr(a)8 or L(a)8 image data.
+        match color_type {
+            ColorType::Rgb8 | ColorType::Rgba8 => {
+                let mut image = Vec::from(buf);
+
+                for chunk in image.chunks_mut(usize::from(color_type.bytes_per_pixel())) {
+                    chunk.swap(0, 2);
+                }
+
+                self.writer.write_all(&image)?;
+            }
+            _ => {
+                self.writer.write_all(buf)?;
+            }
+        }
+
+        Ok(())
+    }
+}
+
+impl<W: Write> ImageEncoder for TgaEncoder<W> {
+    fn write_image(
+        self,
+        buf: &[u8],
+        width: u32,
+        height: u32,
+        color_type: ColorType,
+    ) -> ImageResult<()> {
+        self.encode(buf, width, height, color_type)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{EncoderError, TgaEncoder};
+    use crate::{codecs::tga::TgaDecoder, ColorType, ImageDecoder, ImageError};
+    use std::{error::Error, io::Cursor};
+
+    fn round_trip_image(image: &[u8], width: u32, height: u32, c: ColorType) -> Vec<u8> {
+        let mut encoded_data = Vec::new();
+        {
+            let encoder = TgaEncoder::new(&mut encoded_data);
+            encoder
+                .encode(&image, width, height, c)
+                .expect("could not encode image");
+        }
+
+        let decoder = TgaDecoder::new(Cursor::new(&encoded_data)).expect("failed to decode");
+
+        let mut buf = vec![0; decoder.total_bytes() as usize];
+        decoder.read_image(&mut buf).expect("failed to decode");
+        buf
+    }
+
+    #[test]
+    fn test_image_width_too_large() {
+        // TGA cannot encode images larger than 65,535×65,535
+        // create a 65,536×1 8-bit black image buffer
+        let size = usize::from(u16::MAX) + 1;
+        let dimension = size as u32;
+        let img = vec![0u8; size];
+        // Try to encode an image that is too large
+        let mut encoded = Vec::new();
+        let encoder = TgaEncoder::new(&mut encoded);
+        let result = encoder.encode(&img, dimension, 1, ColorType::L8);
+        match result {
+            Err(ImageError::Encoding(err)) => {
+                let err = err
+                    .source()
+                    .unwrap()
+                    .downcast_ref::<EncoderError>()
+                    .unwrap();
+                assert_eq!(*err, EncoderError::WidthInvalid(dimension));
+            }
+            other => panic!(
+                "Encoding an image that is too wide should return a InvalidWidth \
+                it returned {:?} instead",
+                other
+            ),
+        }
+    }
+
+    #[test]
+    fn test_image_height_too_large() {
+        // TGA cannot encode images larger than 65,535×65,535
+        // create a 65,536×1 8-bit black image buffer
+        let size = usize::from(u16::MAX) + 1;
+        let dimension = size as u32;
+        let img = vec![0u8; size];
+        // Try to encode an image that is too large
+        let mut encoded = Vec::new();
+        let encoder = TgaEncoder::new(&mut encoded);
+        let result = encoder.encode(&img, 1, dimension, ColorType::L8);
+        match result {
+            Err(ImageError::Encoding(err)) => {
+                let err = err
+                    .source()
+                    .unwrap()
+                    .downcast_ref::<EncoderError>()
+                    .unwrap();
+                assert_eq!(*err, EncoderError::HeightInvalid(dimension));
+            }
+            other => panic!(
+                "Encoding an image that is too tall should return a InvalidHeight \
+                it returned {:?} instead",
+                other
+            ),
+        }
+    }
+
+    #[test]
+    fn round_trip_single_pixel_rgb() {
+        let image = [0, 1, 2];
+        let decoded = round_trip_image(&image, 1, 1, ColorType::Rgb8);
+        assert_eq!(decoded.len(), image.len());
+        assert_eq!(decoded.as_slice(), image);
+    }
+
+    #[test]
+    fn round_trip_single_pixel_rgba() {
+        let image = [0, 1, 2, 3];
+        let decoded = round_trip_image(&image, 1, 1, ColorType::Rgba8);
+        assert_eq!(decoded.len(), image.len());
+        assert_eq!(decoded.as_slice(), image);
+    }
+
+    #[test]
+    fn round_trip_gray() {
+        let image = [0, 1, 2];
+        let decoded = round_trip_image(&image, 3, 1, ColorType::L8);
+        assert_eq!(decoded.len(), image.len());
+        assert_eq!(decoded.as_slice(), image);
+    }
+
+    #[test]
+    fn round_trip_graya() {
+        let image = [0, 1, 2, 3, 4, 5];
+        let decoded = round_trip_image(&image, 1, 3, ColorType::La8);
+        assert_eq!(decoded.len(), image.len());
+        assert_eq!(decoded.as_slice(), image);
+    }
+
+    #[test]
+    fn round_trip_3px_rgb() {
+        let image = [0; 3 * 3 * 3]; // 3x3 pixels, 3 bytes per pixel
+        let _decoded = round_trip_image(&image, 3, 3, ColorType::Rgb8);
+    }
+}
diff --git a/vendor/image/src/codecs/tga/header.rs b/vendor/image/src/codecs/tga/header.rs
new file mode 100644
index 0000000..83ba7a3
--- /dev/null
+++ b/vendor/image/src/codecs/tga/header.rs
@@ -0,0 +1,150 @@
+use crate::{
+    error::{UnsupportedError, UnsupportedErrorKind},
+    ColorType, ImageError, ImageFormat, ImageResult,
+};
+use byteorder::{LittleEndian, ReadBytesExt, WriteBytesExt};
+use std::io::{Read, Write};
+
+pub(crate) const ALPHA_BIT_MASK: u8 = 0b1111;
+pub(crate) const SCREEN_ORIGIN_BIT_MASK: u8 = 0b10_0000;
+
+pub(crate) enum ImageType {
+    NoImageData = 0,
+    /// Uncompressed images.
+    RawColorMap = 1,
+    RawTrueColor = 2,
+    RawGrayScale = 3,
+    /// Run length encoded images.
+    RunColorMap = 9,
+    RunTrueColor = 10,
+    RunGrayScale = 11,
+    Unknown,
+}
+
+impl ImageType {
+    /// Create a new image type from a u8.
+    pub(crate) fn new(img_type: u8) -> ImageType {
+        match img_type {
+            0 => ImageType::NoImageData,
+
+            1 => ImageType::RawColorMap,
+            2 => ImageType::RawTrueColor,
+            3 => ImageType::RawGrayScale,
+
+            9 => ImageType::RunColorMap,
+            10 => ImageType::RunTrueColor,
+            11 => ImageType::RunGrayScale,
+
+            _ => ImageType::Unknown,
+        }
+    }
+
+    /// Check if the image format uses colors as opposed to gray scale.
+    pub(crate) fn is_color(&self) -> bool {
+        matches! { *self,
+            ImageType::RawColorMap
+            | ImageType::RawTrueColor
+            | ImageType::RunTrueColor
+            | ImageType::RunColorMap
+        }
+    }
+
+    /// Does the image use a color map.
+    pub(crate) fn is_color_mapped(&self) -> bool {
+        matches! { *self, ImageType::RawColorMap | ImageType::RunColorMap }
+    }
+
+    /// Is the image run length encoded.
+    pub(crate) fn is_encoded(&self) -> bool {
+        matches! {*self, ImageType::RunColorMap | ImageType::RunTrueColor | ImageType::RunGrayScale }
+    }
+}
+
+/// Header used by TGA image files.
+#[derive(Debug, Default)]
+pub(crate) struct Header {
+    pub(crate) id_length: u8,      // length of ID string
+    pub(crate) map_type: u8,       // color map type
+    pub(crate) image_type: u8,     // image type code
+    pub(crate) map_origin: u16,    // starting index of map
+    pub(crate) map_length: u16,    // length of map
+    pub(crate) map_entry_size: u8, // size of map entries in bits
+    pub(crate) x_origin: u16,      // x-origin of image
+    pub(crate) y_origin: u16,      // y-origin of image
+    pub(crate) image_width: u16,   // width of image
+    pub(crate) image_height: u16,  // height of image
+    pub(crate) pixel_depth: u8,    // bits per pixel
+    pub(crate) image_desc: u8,     // image descriptor
+}
+
+impl Header {
+    /// Load the header with values from pixel information.
+    pub(crate) fn from_pixel_info(
+        color_type: ColorType,
+        width: u16,
+        height: u16,
+    ) -> ImageResult<Self> {
+        let mut header = Self::default();
+
+        if width > 0 && height > 0 {
+            let (num_alpha_bits, other_channel_bits, image_type) = match color_type {
+                ColorType::Rgba8 => (8, 24, ImageType::RawTrueColor),
+                ColorType::Rgb8 => (0, 24, ImageType::RawTrueColor),
+                ColorType::La8 => (8, 8, ImageType::RawGrayScale),
+                ColorType::L8 => (0, 8, ImageType::RawGrayScale),
+                _ => {
+                    return Err(ImageError::Unsupported(
+                        UnsupportedError::from_format_and_kind(
+                            ImageFormat::Tga.into(),
+                            UnsupportedErrorKind::Color(color_type.into()),
+                        ),
+                    ))
+                }
+            };
+
+            header.image_type = image_type as u8;
+            header.image_width = width;
+            header.image_height = height;
+            header.pixel_depth = num_alpha_bits + other_channel_bits;
+            header.image_desc = num_alpha_bits & ALPHA_BIT_MASK;
+            header.image_desc |= SCREEN_ORIGIN_BIT_MASK; // Upper left origin.
+        }
+
+        Ok(header)
+    }
+
+    /// Load the header with values from the reader.
+    pub(crate) fn from_reader(r: &mut dyn Read) -> ImageResult<Self> {
+        Ok(Self {
+            id_length: r.read_u8()?,
+            map_type: r.read_u8()?,
+            image_type: r.read_u8()?,
+            map_origin: r.read_u16::<LittleEndian>()?,
+            map_length: r.read_u16::<LittleEndian>()?,
+            map_entry_size: r.read_u8()?,
+            x_origin: r.read_u16::<LittleEndian>()?,
+            y_origin: r.read_u16::<LittleEndian>()?,
+            image_width: r.read_u16::<LittleEndian>()?,
+            image_height: r.read_u16::<LittleEndian>()?,
+            pixel_depth: r.read_u8()?,
+            image_desc: r.read_u8()?,
+        })
+    }
+
+    /// Write out the header values.
+    pub(crate) fn write_to(&self, w: &mut dyn Write) -> ImageResult<()> {
+        w.write_u8(self.id_length)?;
+        w.write_u8(self.map_type)?;
+        w.write_u8(self.image_type)?;
+        w.write_u16::<LittleEndian>(self.map_origin)?;
+        w.write_u16::<LittleEndian>(self.map_length)?;
+        w.write_u8(self.map_entry_size)?;
+        w.write_u16::<LittleEndian>(self.x_origin)?;
+        w.write_u16::<LittleEndian>(self.y_origin)?;
+        w.write_u16::<LittleEndian>(self.image_width)?;
+        w.write_u16::<LittleEndian>(self.image_height)?;
+        w.write_u8(self.pixel_depth)?;
+        w.write_u8(self.image_desc)?;
+        Ok(())
+    }
+}
diff --git a/vendor/image/src/codecs/tga/mod.rs b/vendor/image/src/codecs/tga/mod.rs
new file mode 100644
index 0000000..fdc2f0c
--- /dev/null
+++ b/vendor/image/src/codecs/tga/mod.rs
@@ -0,0 +1,17 @@
+//! Decoding of TGA Images
+//!
+//! # Related Links
+//! <http://googlesites.inequation.org/tgautilities>
+
+/// A decoder for TGA images
+///
+/// Currently this decoder does not support 8, 15 and 16 bit color images.
+pub use self::decoder::TgaDecoder;
+
+//TODO add 8, 15, 16 bit color support
+
+pub use self::encoder::TgaEncoder;
+
+mod decoder;
+mod encoder;
+mod header;