A simple solution for generating .ico and .icns icons. This crate serves as IconWriter CLI's internal library.
This crate's API revolves around the concept of binding source images to a set of sizes and resampling configurations. The following example demonstrates this principle:
rust
use iconwriter::prelude::*;
const N_ENTRIES: usize = 1;
fn main() {
// Creating the icon
let mut icon = Icon::ico(n_entries);
// Importing the source image
let src_image = SourceImage::from_file("img.jpg").unwrap();
// Configuring the entry
let opts = IconOptions::new(
vec![(32, 32), (64, 64)] /* 32x32 and 64x64 sizes */,
ResamplingFilter::Linear /* Interpolate the image */,
Crop::Square /* Square image */
);
// Adding the entry
icon.add_entry(opts, &src_image).unwrap();
}
Note that the capacity argument in the Icon::ico, Icon::icns, Icon::png_sequence and Icon::new methods specifies the expected number of entries in a given Icon, not the number of sizes (since a single entry can contain multiple sizes).
Let's say you want to customize your icon so that the smaller versions of it are less detailed. IconWriter helps you achieve this result by allowing to sample from multiple sources.
You can simply combine separate source images by specifying to which entry they should be assigned:
```rust use iconwriter::prelude::*; const N_ENTRIES: usize = 2;
fn main() { let option = IconOptions::new; let mut icon = Icon::ico(nentries); // Importing the source images let small = SourceImage::fromfile("small.jpg").unwrap(); let large = SourceImage::fromfile("small.png").unwrap(); // Configuring the entries let filter = ResamplingFilter::Nearest; let crop = Crop::Square; let smallopt = option(vec![(16, 16)], filter, crop); let largeopt = option(vec![(32, 32)], filter, crop); // Adding the entries icon.addentry(smallopt, &small).unwrap(); icon.addentry(large_opt, &large).unwrap(); } ```
Note that different IconOption do not need to share the same rasampling options (namely the filter and crop fields) and can even share a common source field.
However, different entries cannot share a common Size in there sizes field. For example, the following program will panic at second call of icon.add_entry():
```rust use iconwriter::prelude::*; const NENTRIES: usize = 2; fn main() { let option = IconOptions::new; let mut icon = Icon::ico(nentries);
// Importing the source images
let src1 = SourceImage::from_file("src1.jpg").unwrap();
let src2 = SourceImage::from_file("src2.png").unwrap();
// Configuring the entries
let filter = ResamplingFilter::Nearest;
let crop = Crop::Square;
let src1_opt = option(vec![(16, 16)], filter, crop);
let src2_opt = option(vec![(16, 16)], filter, crop);
// Adding the entries
icon.add_entry(src1_opt, &src1).expect("Returns `Ok(())`");
icon.add_entry(src2_opt, &src2)
.expect("Returns `Err(Error::SizeAlreadyIncluded((16, 16))))`");
} ```
Writing to files can be easily done by calling the Icon::write method:
```rust use iconwriter::prelude::; use std::fs::File; / Const declarations */ fn main() { let mut icon = Icon::ico(N_ENTRIES);
/* Process the icon */
if let Ok(&file) = File::create("myfile.ico") {
match icon.write(file) {
Ok(()) => println!("File 'myfile.ico' saved!"),
Err(_) => println!("An error occurred ;-;")
}
}
} ```
| Format | Decoding |
| ------ | -------------------------------------------------- |
| PNG | All supported color types |
| JPEG | Baseline and progressive |
| GIF | Yes |
| BMP | Yes |
| ICO | Yes |
| TIFF | Baseline(no fax support), LZW, PackBits |
| WEBP | Lossy(Luma channel only) |
| PNM | PBM, PGM, PPM, standard PAM |
| SVG | Limited(flat filled shapes only) |
There are two main limitations in this crate: both ICNS and SVG are not fully supported. Due to the use of external depencies, this crate is not able to fully support the formal specifications of those two file formats.
However, the coverage provided by these external dependencies should be more than enought for most use cases.
Icon Writer uses the icns crate for generating .icns files. The supported icon types are specified by the creators of such crate as follows:
| OSType | Description | Supported? |
|--------|-----------------------------------------|------------|
| ICON | 32×32 1-bit icon | No |
| ICN# | 32×32 1-bit icon with 1-bit mask | No |
| icm# | 16×12 1-bit icon with 1-bit mask | No |
| icm4 | 16×12 4-bit icon | No |
| icm8 | 16×12 8-bit icon | No |
| ics# | 16×16 1-bit mask | No |
| ics4 | 16×16 4-bit icon | No |
| ics8 | 16x16 8-bit icon | No |
| is32 | 16×16 24-bit icon | Yes |
| s8mk | 16x16 8-bit mask | Yes |
| icl4 | 32×32 4-bit icon | No |
| icl8 | 32×32 8-bit icon | No |
| il32 | 32x32 24-bit icon | Yes |
| l8mk | 32×32 8-bit mask | Yes |
| ich# | 48×48 1-bit mask | No |
| ich4 | 48×48 4-bit icon | No |
| ich8 | 48×48 8-bit icon | No |
| ih32 | 48×48 24-bit icon | Yes |
| h8mk | 48×48 8-bit mask | Yes |
| it32 | 128×128 24-bit icon | Yes |
| t8mk | 128×128 8-bit mask | Yes |
| icp4 | 16x16 32-bit PNG/JP2 icon | PNG only |
| icp5 | 32x32 32-bit PNG/JP2 icon | PNG only |
| icp6 | 64x64 32-bit PNG/JP2 icon | PNG only |
| ic07 | 128x128 32-bit PNG/JP2 icon | PNG only |
| ic08 | 256×256 32-bit PNG/JP2 icon | PNG only |
| ic09 | 512×512 32-bit PNG/JP2 icon | PNG only |
| ic10 | 512x512@2x "retina" 32-bit PNG/JP2 icon | PNG only |
| ic11 | 16x16@2x "retina" 32-bit PNG/JP2 icon | PNG only |
| ic12 | 32x32@2x "retina" 32-bit PNG/JP2 icon | PNG only |
| ic13 | 128x128@2x "retina" 32-bit PNG/JP2 icon | PNG only |
| ic14 | 256x256@2x "retina" 32-bit PNG/JP2 icon | PNG only |
IconWriter uses the nsvg crate for rasterizing .svg files. According to the authors of the crate:
Like NanoSVG, the rasteriser only renders flat filled shapes. It is not particularly fast or accurate, but it is a simple way to bake vector graphics into textures.
The author of iconwriter is inclined to search for alternatives to nsvg if inquired to. Help would be appreciated.