<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/home/sangenya/.cargo/registry/src/github.com-1ecc6299db9ec823/gif-0.9.2/src/common.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>common.rs - source</title><link rel="stylesheet" type="text/css" href="../../normalize.css"><link rel="stylesheet" type="text/css" href="../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" type="text/css" href="../../light.css" id="themeStyle"><link rel="stylesheet" type="text/css" href="../../dark.css" disabled ><link rel="stylesheet" type="text/css" href="../../ayu.css" disabled ><script id="default-settings"></script><script src="../../storage.js"></script><script src="../../crates.js"></script><noscript><link rel="stylesheet" href="../../noscript.css"></noscript><link rel="icon" type="image/svg+xml" href="../../favicon.svg">
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</pre><pre class="rust">
<span class="doccomment">//! Common common used both by decoder and encoder</span>
<span class="kw">extern</span> <span class="kw">crate</span> <span class="ident">color_quant</span>;
<span class="kw">use</span> <span class="ident">std::mem</span>;
<span class="kw">use</span> <span class="ident">std::borrow::Cow</span>;
<span class="doccomment">/// Disposal method</span>
<span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Debug</span>, <span class="ident">Copy</span>, <span class="ident">Clone</span>, <span class="ident">PartialEq</span>, <span class="ident">Eq</span>)]</span>
<span class="attribute">#[<span class="ident">repr</span>(<span class="ident">u8</span>)]</span>
<span class="kw">pub</span> <span class="kw">enum</span> <span class="ident">DisposalMethod</span> {
<span class="doccomment">/// StreamingDecoder is not required to take any action.</span>
<span class="ident">Any</span> <span class="op">=</span> <span class="number">0</span>,
<span class="doccomment">/// Do not dispose.</span>
<span class="ident">Keep</span> <span class="op">=</span> <span class="number">1</span>,
<span class="doccomment">/// Restore to background color.</span>
<span class="ident">Background</span> <span class="op">=</span> <span class="number">2</span>,
<span class="doccomment">/// Restore to previous.</span>
<span class="ident">Previous</span> <span class="op">=</span> <span class="number">3</span>,
}
<span class="kw">impl</span> <span class="ident">DisposalMethod</span> {
<span class="doccomment">/// Converts `u8` to `Option<Self>`</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">from_u8</span>(<span class="ident">n</span>: <span class="ident">u8</span>) <span class="op">-</span><span class="op">></span> <span class="prelude-ty">Option</span><span class="op"><</span><span class="ident">DisposalMethod</span><span class="op">></span> {
<span class="kw">if</span> <span class="ident">n</span> <span class="op"><</span><span class="op">=</span> <span class="number">3</span> {
<span class="prelude-val">Some</span>(<span class="kw">unsafe</span> { <span class="ident">mem::transmute</span>(<span class="ident">n</span>) })
} <span class="kw">else</span> {
<span class="prelude-val">None</span>
}
}
}
<span class="doccomment">/// Known GIF block types</span>
<span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Debug</span>, <span class="ident">Copy</span>, <span class="ident">Clone</span>, <span class="ident">PartialEq</span>, <span class="ident">Eq</span>)]</span>
<span class="attribute">#[<span class="ident">repr</span>(<span class="ident">u8</span>)]</span>
<span class="kw">pub</span> <span class="kw">enum</span> <span class="ident">Block</span> {
<span class="doccomment">/// Image block.</span>
<span class="ident">Image</span> <span class="op">=</span> <span class="number">0x2C</span>,
<span class="doccomment">/// Extension block.</span>
<span class="ident">Extension</span> <span class="op">=</span> <span class="number">0x21</span>,
<span class="doccomment">/// Image trailer.</span>
<span class="ident">Trailer</span> <span class="op">=</span> <span class="number">0x3B</span>
}
<span class="kw">impl</span> <span class="ident">Block</span> {
<span class="doccomment">/// Converts `u8` to `Option<Self>`</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">from_u8</span>(<span class="ident">n</span>: <span class="ident">u8</span>) <span class="op">-</span><span class="op">></span> <span class="prelude-ty">Option</span><span class="op"><</span><span class="ident">Block</span><span class="op">></span> {
<span class="kw">match</span> <span class="ident">n</span> {
<span class="number">0x2C</span> <span class="op">|</span> <span class="number">0x21</span> <span class="op">|</span> <span class="number">0x3B</span> <span class="op">=</span><span class="op">></span> {
<span class="prelude-val">Some</span>(<span class="kw">unsafe</span> { <span class="ident">mem::transmute</span>(<span class="ident">n</span>) })
}
<span class="kw">_</span> <span class="op">=</span><span class="op">></span> <span class="prelude-val">None</span>
}
}
}
<span class="doccomment">/// Known GIF extensions</span>
<span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Debug</span>, <span class="ident">Copy</span>, <span class="ident">Clone</span>, <span class="ident">PartialEq</span>, <span class="ident">Eq</span>)]</span>
<span class="attribute">#[<span class="ident">repr</span>(<span class="ident">u8</span>)]</span>
<span class="kw">pub</span> <span class="kw">enum</span> <span class="ident">Extension</span> {
<span class="doccomment">/// Text extension.</span>
<span class="ident">Text</span> <span class="op">=</span> <span class="number">0x01</span>,
<span class="doccomment">/// Control extension.</span>
<span class="ident">Control</span> <span class="op">=</span> <span class="number">0xF9</span>,
<span class="doccomment">/// Comment extension.</span>
<span class="ident">Comment</span> <span class="op">=</span> <span class="number">0xFE</span>,
<span class="doccomment">/// Application extension.</span>
<span class="ident">Application</span> <span class="op">=</span> <span class="number">0xFF</span>
}
<span class="kw">impl</span> <span class="ident">Extension</span> {
<span class="doccomment">/// Converts `u8` to `Option<Self>`</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">from_u8</span>(<span class="ident">n</span>: <span class="ident">u8</span>) <span class="op">-</span><span class="op">></span> <span class="prelude-ty">Option</span><span class="op"><</span><span class="ident">Extension</span><span class="op">></span> {
<span class="kw">match</span> <span class="ident">n</span> {
<span class="number">0x01</span> <span class="op">|</span> <span class="number">0xF9</span> <span class="op">|</span> <span class="number">0xFE</span> <span class="op">|</span> <span class="number">0xFF</span> <span class="op">=</span><span class="op">></span> {
<span class="prelude-val">Some</span>(<span class="kw">unsafe</span> { <span class="ident">mem::transmute</span>(<span class="ident">n</span>) })
}
<span class="kw">_</span> <span class="op">=</span><span class="op">></span> <span class="prelude-val">None</span>
}
}
}
<span class="doccomment">/// A GIF frame</span>
<span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Debug</span>, <span class="ident">Clone</span>)]</span>
<span class="kw">pub</span> <span class="kw">struct</span> <span class="ident">Frame</span><span class="op"><</span><span class="lifetime">'a</span><span class="op">></span> {
<span class="doccomment">/// Frame delay in units of 10 ms.</span>
<span class="kw">pub</span> <span class="ident">delay</span>: <span class="ident">u16</span>,
<span class="doccomment">/// Disposal method.</span>
<span class="kw">pub</span> <span class="ident">dispose</span>: <span class="ident">DisposalMethod</span>,
<span class="doccomment">/// Transparent index (if available).</span>
<span class="kw">pub</span> <span class="ident">transparent</span>: <span class="prelude-ty">Option</span><span class="op"><</span><span class="ident">u8</span><span class="op">></span>,
<span class="doccomment">/// True if the frame needs user input do be displayed.</span>
<span class="kw">pub</span> <span class="ident">needs_user_input</span>: <span class="ident">bool</span>,
<span class="doccomment">/// Offset from the top border of the canvas.</span>
<span class="kw">pub</span> <span class="ident">top</span>: <span class="ident">u16</span>,
<span class="doccomment">/// Offset from the left border of the canvas.</span>
<span class="kw">pub</span> <span class="ident">left</span>: <span class="ident">u16</span>,
<span class="doccomment">/// Width of the frame.</span>
<span class="kw">pub</span> <span class="ident">width</span>: <span class="ident">u16</span>,
<span class="doccomment">/// Height of the frame.</span>
<span class="kw">pub</span> <span class="ident">height</span>: <span class="ident">u16</span>,
<span class="doccomment">/// True if the image is interlaced.</span>
<span class="kw">pub</span> <span class="ident">interlaced</span>: <span class="ident">bool</span>,
<span class="doccomment">/// Frame local color palette if available.</span>
<span class="kw">pub</span> <span class="ident">palette</span>: <span class="prelude-ty">Option</span><span class="op"><</span><span class="ident">Vec</span><span class="op"><</span><span class="ident">u8</span><span class="op">></span><span class="op">></span>,
<span class="doccomment">/// Buffer containing the image data.</span>
<span class="doccomment">/// Only indices unless configured differently.</span>
<span class="kw">pub</span> <span class="ident">buffer</span>: <span class="ident">Cow</span><span class="op"><</span><span class="lifetime">'a</span>, [<span class="ident">u8</span>]<span class="op">></span>
}
<span class="kw">impl</span><span class="op"><</span><span class="lifetime">'a</span><span class="op">></span> <span class="ident">Default</span> <span class="kw">for</span> <span class="ident">Frame</span><span class="op"><</span><span class="lifetime">'a</span><span class="op">></span> {
<span class="kw">fn</span> <span class="ident">default</span>() <span class="op">-</span><span class="op">></span> <span class="ident">Frame</span><span class="op"><</span><span class="lifetime">'a</span><span class="op">></span> {
<span class="ident">Frame</span> {
<span class="ident">delay</span>: <span class="number">0</span>,
<span class="ident">dispose</span>: <span class="ident">DisposalMethod::Keep</span>,
<span class="ident">transparent</span>: <span class="prelude-val">None</span>,
<span class="ident">needs_user_input</span>: <span class="bool-val">false</span>,
<span class="ident">top</span>: <span class="number">0</span>,
<span class="ident">left</span>: <span class="number">0</span>,
<span class="ident">width</span>: <span class="number">0</span>,
<span class="ident">height</span>: <span class="number">0</span>,
<span class="ident">interlaced</span>: <span class="bool-val">false</span>,
<span class="ident">palette</span>: <span class="prelude-val">None</span>,
<span class="ident">buffer</span>: <span class="ident">Cow::Borrowed</span>(<span class="kw-2">&</span>[])
}
}
}
<span class="kw">impl</span> <span class="ident">Frame</span><span class="op"><</span><span class="lifetime">'static</span><span class="op">></span> {
<span class="doccomment">/// Creates a frame from pixels in RGBA format.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// *Note: This method is not optimized for speed.*</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">from_rgba</span>(<span class="ident">width</span>: <span class="ident">u16</span>, <span class="ident">height</span>: <span class="ident">u16</span>, <span class="ident">pixels</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> [<span class="ident">u8</span>]) <span class="op">-</span><span class="op">></span> <span class="ident">Frame</span><span class="op"><</span><span class="lifetime">'static</span><span class="op">></span> {
<span class="macro">assert_eq!</span>(<span class="ident">width</span> <span class="kw">as</span> <span class="ident">usize</span> <span class="op">*</span> <span class="ident">height</span> <span class="kw">as</span> <span class="ident">usize</span> <span class="op">*</span> <span class="number">4</span>, <span class="ident">pixels</span>.<span class="ident">len</span>());
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">frame</span> <span class="op">=</span> <span class="ident">Frame::default</span>();
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">transparent</span> <span class="op">=</span> <span class="prelude-val">None</span>;
<span class="kw">for</span> <span class="ident">pix</span> <span class="kw">in</span> <span class="ident">pixels</span>.<span class="ident">chunks_mut</span>(<span class="number">4</span>) {
<span class="kw">if</span> <span class="ident">pix</span>[<span class="number">3</span>] <span class="op">!</span><span class="op">=</span> <span class="number">0</span> {
<span class="ident">pix</span>[<span class="number">3</span>] <span class="op">=</span> <span class="number">0xFF</span>;
} <span class="kw">else</span> {
<span class="ident">transparent</span> <span class="op">=</span> <span class="prelude-val">Some</span>([<span class="ident">pix</span>[<span class="number">0</span>], <span class="ident">pix</span>[<span class="number">1</span>], <span class="ident">pix</span>[<span class="number">2</span>], <span class="ident">pix</span>[<span class="number">3</span>]])
}
}
<span class="ident">frame</span>.<span class="ident">width</span> <span class="op">=</span> <span class="ident">width</span>;
<span class="ident">frame</span>.<span class="ident">height</span> <span class="op">=</span> <span class="ident">height</span>;
<span class="kw">let</span> <span class="ident">nq</span> <span class="op">=</span> <span class="ident">color_quant::NeuQuant::new</span>(<span class="number">1</span>, <span class="number">256</span>, <span class="ident">pixels</span>);
<span class="ident">frame</span>.<span class="ident">buffer</span> <span class="op">=</span> <span class="ident">Cow::Owned</span>(<span class="ident">pixels</span>.<span class="ident">chunks</span>(<span class="number">4</span>).<span class="ident">map</span>(<span class="op">|</span><span class="ident">pix</span><span class="op">|</span> <span class="ident">nq</span>.<span class="ident">index_of</span>(<span class="ident">pix</span>) <span class="kw">as</span> <span class="ident">u8</span>).<span class="ident">collect</span>());
<span class="ident">frame</span>.<span class="ident">palette</span> <span class="op">=</span> <span class="prelude-val">Some</span>(<span class="ident">nq</span>.<span class="ident">color_map_rgb</span>());
<span class="ident">frame</span>.<span class="ident">transparent</span> <span class="op">=</span> <span class="kw">if</span> <span class="kw">let</span> <span class="prelude-val">Some</span>(<span class="ident">t</span>) <span class="op">=</span> <span class="ident">transparent</span> {
<span class="prelude-val">Some</span>(<span class="ident">nq</span>.<span class="ident">index_of</span>(<span class="kw-2">&</span><span class="ident">t</span>) <span class="kw">as</span> <span class="ident">u8</span>)
} <span class="kw">else</span> {
<span class="prelude-val">None</span>
};
<span class="ident">frame</span>
}
<span class="doccomment">/// Creates a frame from pixels in RGB format.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// *Note: This method is not optimized for speed.*</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">from_rgb</span>(<span class="ident">width</span>: <span class="ident">u16</span>, <span class="ident">height</span>: <span class="ident">u16</span>, <span class="ident">pixels</span>: <span class="kw-2">&</span>[<span class="ident">u8</span>]) <span class="op">-</span><span class="op">></span> <span class="ident">Frame</span><span class="op"><</span><span class="lifetime">'static</span><span class="op">></span> {
<span class="macro">assert_eq!</span>(<span class="ident">width</span> <span class="kw">as</span> <span class="ident">usize</span> <span class="op">*</span> <span class="ident">height</span> <span class="kw">as</span> <span class="ident">usize</span> <span class="op">*</span> <span class="number">3</span>, <span class="ident">pixels</span>.<span class="ident">len</span>());
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">vec</span>: <span class="ident">Vec</span><span class="op"><</span><span class="ident">u8</span><span class="op">></span> <span class="op">=</span> <span class="ident">Vec::with_capacity</span>(<span class="ident">pixels</span>.<span class="ident">len</span>() <span class="op">+</span> <span class="ident">width</span> <span class="kw">as</span> <span class="ident">usize</span> <span class="op">*</span> <span class="ident">height</span> <span class="kw">as</span> <span class="ident">usize</span>);
<span class="kw">for</span> <span class="ident">v</span> <span class="kw">in</span> <span class="ident">pixels</span>.<span class="ident">chunks</span>(<span class="number">3</span>) {
<span class="ident">vec</span>.<span class="ident">extend</span>([<span class="ident">v</span>[<span class="number">0</span>], <span class="ident">v</span>[<span class="number">1</span>], <span class="ident">v</span>[<span class="number">2</span>], <span class="number">0xFF</span>].<span class="ident">iter</span>().<span class="ident">cloned</span>())
}
<span class="ident">Frame::from_rgba</span>(<span class="ident">width</span>, <span class="ident">height</span>, <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">vec</span>)
}
}</pre></div>
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