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Diffstat (limited to 'vendor/gif/src/common.rs')
| -rw-r--r-- | vendor/gif/src/common.rs | 346 |
1 files changed, 0 insertions, 346 deletions
diff --git a/vendor/gif/src/common.rs b/vendor/gif/src/common.rs deleted file mode 100644 index 20ba99b..0000000 --- a/vendor/gif/src/common.rs +++ /dev/null @@ -1,346 +0,0 @@ -use std::borrow::Cow; -use std::collections::HashMap; -use std::collections::HashSet; - -/// Disposal method -#[derive(Debug, Copy, Clone, PartialEq, Eq)] -#[repr(u8)] -pub enum DisposalMethod { - /// StreamingDecoder is not required to take any action. - Any = 0, - /// Do not dispose. - Keep = 1, - /// Restore to background color. - Background = 2, - /// Restore to previous. - Previous = 3, -} - -impl DisposalMethod { - /// Converts `u8` to `Option<Self>` - pub fn from_u8(n: u8) -> Option<DisposalMethod> { - match n { - 0 => Some(DisposalMethod::Any), - 1 => Some(DisposalMethod::Keep), - 2 => Some(DisposalMethod::Background), - 3 => Some(DisposalMethod::Previous), - _ => None - } - } -} - -/// Known GIF block labels. -/// -/// Note that the block uniquely specifies the layout of bytes that follow and how they are -/// framed. For example, the header always has a fixed length but is followed by a variable amount -/// of additional data. An image descriptor may be followed by a local color table depending on -/// information read in it. Therefore, it doesn't make sense to continue parsing after encountering -/// an unknown block as the semantics of following bytes are unclear. -/// -/// The extension block provides a common framing for an arbitrary amount of application specific -/// data which may be ignored. -#[derive(Debug, Copy, Clone, PartialEq, Eq)] -#[repr(u8)] -pub enum Block { - /// Image block. - Image = 0x2C, - /// Extension block. - Extension = 0x21, - /// Image trailer. - Trailer = 0x3B, -} - -impl Block { - /// Converts `u8` to `Option<Self>` - pub fn from_u8(n: u8) -> Option<Block> { - match n { - 0x2C => Some(Block::Image), - 0x21 => Some(Block::Extension), - 0x3B => Some(Block::Trailer), - _ => None - } - } -} - -/// A newtype wrapper around an arbitrary extension ID. -/// -/// An extension is some amount of byte data organized in sub-blocks so that one can skip over it -/// without knowing the semantics. Though technically you likely want to use a `Application` -/// extension, the library tries to stay flexible here. -/// -/// This allows us to customize the set of impls compared to a raw `u8`. It also clarifies the -/// intent and gives some inherent methods for interoperability with known extension types. -#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)] -pub struct AnyExtension(pub u8); - -/// Known GIF extension labels. -/// -/// These are extensions which may be interpreted by the library and to which a specification with -/// the internal data layout is known. -#[derive(Debug, Copy, Clone, PartialEq, Eq)] -#[repr(u8)] -pub enum Extension { - /// Plain Text extension. - /// - /// This instructs the decoder to render a text as characters in a grid of cells, in a - /// mono-spaced font of its choosing. This is seldom actually implemented and ignored by - /// ImageMagick. The color is always taken from the global table which further complicates any - /// use. No real information on the frame sequencing of this block is available in the - /// standard. - Text = 0x01, - /// Control extension. - Control = 0xF9, - /// Comment extension. - Comment = 0xFE, - /// Application extension. - /// - /// See [ImageMagick] for an idea of commonly recognized extensions. - /// - /// [ImageMagick]: https://github.com/ImageMagick/ImageMagick/blob/b0b58c6303195928060f55f9c3ca8233ab7f7733/coders/gif.c#L1128 - Application = 0xFF, -} - -impl AnyExtension { - /// Decode the label as a known extension. - pub fn into_known(self) -> Option<Extension> { - Extension::from_u8(self.0) - } -} - -impl From<Extension> for AnyExtension { - fn from(ext: Extension) -> Self { - AnyExtension(ext as u8) - } -} - -impl Extension { - /// Converts `u8` to a `Extension` if it is known. - pub fn from_u8(n: u8) -> Option<Extension> { - match n { - 0x01 => Some(Extension::Text), - 0xF9 => Some(Extension::Control), - 0xFE => Some(Extension::Comment), - 0xFF => Some(Extension::Application), - _ => None - } - } -} - -/// A GIF frame -#[derive(Debug, Clone)] -pub struct Frame<'a> { - /// Frame delay in units of 10 ms. - pub delay: u16, - /// Disposal method. - pub dispose: DisposalMethod, - /// Transparent index (if available). - pub transparent: Option<u8>, - /// True if the frame needs user input to be displayed. - pub needs_user_input: bool, - /// Offset from the top border of the canvas. - pub top: u16, - /// Offset from the left border of the canvas. - pub left: u16, - /// Width of the frame. - pub width: u16, - /// Height of the frame. - pub height: u16, - /// True if the image is interlaced. - pub interlaced: bool, - /// Frame local color palette if available. - pub palette: Option<Vec<u8>>, - /// Buffer containing the image data. - /// Only indices unless configured differently. - pub buffer: Cow<'a, [u8]> -} - -impl<'a> Default for Frame<'a> { - fn default() -> Frame<'a> { - Frame { - delay: 0, - dispose: DisposalMethod::Keep, - transparent: None, - needs_user_input: false, - top: 0, - left: 0, - width: 0, - height: 0, - interlaced: false, - palette: None, - buffer: Cow::Borrowed(&[]) - } - } -} - -impl Frame<'static> { - /// Creates a frame from pixels in RGBA format. - /// - /// This is a lossy method. The `gif` format does not support arbitrary alpha but only a 1-bit - /// transparency mask per pixel. Any non-zero alpha value will be interpreted as a fully opaque - /// pixel. Additionally, only 256 colors can appear in a single frame. The palette will be - /// reduced by the NeuQuant algorithm if necessary. Different frames have independent palettes. - /// - /// *Note: This method is not optimized for speed.* - /// - /// # Panics: - /// * If the length of pixels does not equal `width * height * 4`. - #[cfg(feature = "color_quant")] - pub fn from_rgba(width: u16, height: u16, pixels: &mut [u8]) -> Frame<'static> { - Frame::from_rgba_speed(width, height, pixels, 1) - } - - /// Creates a frame from pixels in RGBA format. - /// - /// `speed` is a value in the range [1, 30]. - /// The higher the value the faster it runs at the cost of image quality. - /// A `speed` of 10 is a good compromise between speed and quality. - /// - /// This is a lossy method. The `gif` format does not support arbitrary alpha but only a 1-bit - /// transparency mask per pixel. Any non-zero alpha value will be interpreted as a fully opaque - /// pixel. Additionally, only 256 colors can appear in a single frame. The palette will be - /// reduced by the NeuQuant algorithm if necessary. Different frames have independent palettes. - /// - /// # Panics: - /// * If the length of pixels does not equal `width * height * 4`. - /// * If `speed < 1` or `speed > 30` - #[cfg(feature = "color_quant")] - pub fn from_rgba_speed(width: u16, height: u16, pixels: &mut [u8], speed: i32) -> Frame<'static> { - assert_eq!(width as usize * height as usize * 4, pixels.len(), "Too much or too little pixel data for the given width and height to create a GIF Frame"); - assert!(speed >= 1 && speed <= 30, "speed needs to be in the range [1, 30]"); - let mut transparent = None; - for pix in pixels.chunks_exact_mut(4) { - if pix[3] != 0 { - pix[3] = 0xFF; - } else { - transparent = Some([pix[0], pix[1], pix[2], pix[3]]) - } - } - - // Attempt to build a palette of all colors. If we go over 256 colors, - // switch to the NeuQuant algorithm. - let mut colors: HashSet<(u8, u8, u8, u8)> = HashSet::new(); - for pixel in pixels.chunks_exact(4) { - if colors.insert((pixel[0], pixel[1], pixel[2], pixel[3])) && colors.len() > 256 { - // > 256 colours, let's use NeuQuant. - let nq = color_quant::NeuQuant::new(speed, 256, pixels); - - return Frame { - width, - height, - buffer: Cow::Owned(pixels.chunks_exact(4).map(|pix| nq.index_of(pix) as u8).collect()), - palette: Some(nq.color_map_rgb()), - transparent: transparent.map(|t| nq.index_of(&t) as u8), - ..Frame::default() - }; - } - } - - // Palette size <= 256 elements, we can build an exact palette. - let mut colors_vec: Vec<(u8, u8, u8, u8)> = colors.into_iter().collect(); - colors_vec.sort(); - let palette = colors_vec.iter().flat_map(|&(r, g, b, _a)| [r, g, b]).collect(); - let colors_lookup: HashMap<(u8, u8, u8, u8), u8> = colors_vec.into_iter().zip(0..=255).collect(); - - let index_of = | pixel: &[u8] | - *colors_lookup.get(&(pixel[0], pixel[1], pixel[2], pixel[3])).unwrap(); - - return Frame { - width, - height, - buffer: Cow::Owned(pixels.chunks_exact(4).map(|pix| index_of(pix)).collect()), - palette: Some(palette), - transparent: transparent.map(|t| index_of(&t)), - ..Frame::default() - } - } - - /// Creates a frame from a palette and indexed pixels. - /// - /// # Panics: - /// * If the length of pixels does not equal `width * height`. - /// * If the length of palette > `256 * 3`. - pub fn from_palette_pixels(width: u16, height: u16, pixels: &[u8], palette: &[u8], transparent: Option<u8>) -> Frame<'static> { - assert_eq!(width as usize * height as usize, pixels.len(), "Too many or too little pixels for the given width and height to create a GIF Frame"); - assert!(palette.len() <= 256*3, "Too many palette values to create a GIF Frame"); - - Frame { - width, - height, - buffer: Cow::Owned(pixels.to_vec()), - palette: Some(palette.to_vec()), - transparent, - ..Frame::default() - } - } - - /// Creates a frame from indexed pixels in the global palette. - /// - /// # Panics: - /// * If the length of pixels does not equal `width * height`. - pub fn from_indexed_pixels(width: u16, height: u16, pixels: &[u8], transparent: Option<u8>) -> Frame<'static> { - assert_eq!(width as usize * height as usize, pixels.len(), "Too many or too little pixels for the given width and height to create a GIF Frame"); - - Frame { - width, - height, - buffer: Cow::Owned(pixels.to_vec()), - palette: None, - transparent, - ..Frame::default() - } - } - - /// Creates a frame from pixels in RGB format. - /// - /// This is a lossy method. In the `gif` format only 256 colors can appear in a single frame. - /// The palette will be reduced by the NeuQuant algorithm if necessary. Different frames have - /// independent palettes. - /// - /// *Note: This method is not optimized for speed.* - /// - /// # Panics: - /// * If the length of pixels does not equal `width * height * 3`. - #[cfg(feature = "color_quant")] - pub fn from_rgb(width: u16, height: u16, pixels: &[u8]) -> Frame<'static> { - Frame::from_rgb_speed(width, height, pixels, 1) - } - - /// Creates a frame from pixels in RGB format. - /// - /// `speed` is a value in the range [1, 30]. - /// - /// This is a lossy method. In the `gif` format only 256 colors can appear in a single frame. - /// The palette will be reduced by the NeuQuant algorithm if necessary. Different frames have - /// independent palettes. - /// - /// The higher the value the faster it runs at the cost of image quality. - /// A `speed` of 10 is a good compromise between speed and quality. - /// - /// # Panics: - /// * If the length of pixels does not equal `width * height * 3`. - /// * If `speed < 1` or `speed > 30` - #[cfg(feature = "color_quant")] - pub fn from_rgb_speed(width: u16, height: u16, pixels: &[u8], speed: i32) -> Frame<'static> { - assert_eq!(width as usize * height as usize * 3, pixels.len(), "Too much or too little pixel data for the given width and height to create a GIF Frame"); - let mut vec: Vec<u8> = Vec::with_capacity(pixels.len() + width as usize * height as usize); - for v in pixels.chunks_exact(3) { - vec.extend_from_slice(&[v[0], v[1], v[2], 0xFF]) - } - Frame::from_rgba_speed(width, height, &mut vec, speed) - } - - pub(crate) fn required_bytes(&self) -> usize { - usize::from(self.width) * usize::from(self.height) - } -} - -#[test] -#[cfg(feature = "color_quant")] -// Creating the `colors_lookup` hashmap in Frame::from_rgba_speed panics due to -// overflow while bypassing NeuQuant and zipping a RangeFrom with 256 colors. -// Changing .zip(0_u8..) to .zip(0_u8..=255) fixes this issue. -fn rgba_speed_avoid_panic_256_colors() { - let side = 16; - let pixel_data: Vec<u8> = (0..=255).map(|a| vec![a, a, a]).flatten().collect(); - Frame::from_rgb(side, side, &pixel_data); -} |