前言
本文是使用rust库resvg来将svg图片转为png图片。
环境配置
系统:windows
平台:visual studio code
语言:rust
库:resvg
resvg是一个基于rust的svg渲染库,其官方地址:
An SVG rendering library
resvg库的核心是svg的渲染,但本文暂且不关注如何渲染svg,本文关注如何将svg转为png格式,官方有提供演示代码。
本文参考官方示例,将代码稍作修改,并结合rust的文件库rfd,编写一个简单的程序,可以导入svg图片,然后转为png图片,并保存。
首先看一下核心的转换代码:
官方代码:
fn main() {
let args: Vec<String> = std::env::args().collect();
if args.len() != 3 {
println!("Usage:\n\tminimal " );
return;
}
let tree = {
let mut opt = usvg::Options::default();
// Get file's absolute directory.
opt.resources_dir = std::fs::canonicalize(&args[1])
.ok()
.and_then(|p| p.parent().map(|p| p.to_path_buf()));
opt.fontdb_mut().load_system_fonts();
let svg_data = std::fs::read(&args[1]).unwrap();
usvg::Tree::from_data(&svg_data, &opt).unwrap()
};
let pixmap_size = tree.size().to_int_size();
let mut pixmap = tiny_skia::Pixmap::new(pixmap_size.width(), pixmap_size.height()).unwrap();
resvg::render(&tree, tiny_skia::Transform::default(), &mut pixmap.as_mut());
pixmap.save_png(&args[2]).unwrap();
}
本地使用时,简单封装成一个函数,如下:
///
/// svg转png
///
pub fn svgtopng(
svgpath: &str,
destimgpath: &str,
)
{
let mut opt=resvg::usvg::Options::default();
opt.resources_dir=std::fs::canonicalize(svgpath)
.ok()
.and_then(|p| p.parent().map(|p| p.to_path_buf()));
opt.fontdb_mut().load_system_fonts();
let svgdata=std::fs::read(svgpath).unwrap();
let tree=resvg::usvg::Tree::from_data(&svgdata,&opt).unwrap();
let pixmap_size = tree.size().to_int_size();
let mut pixmap = resvg::tiny_skia::Pixmap::new(pixmap_size.width(), pixmap_size.height()).unwrap();
resvg::render(&tree, resvg::tiny_skia::Transform::default(), &mut pixmap.as_mut());
pixmap.save_png(destimgpath).unwrap();
}
转换的程序就好了,然后我们结合rust的GUI库iced来编写一个简单的带UI的转换程序,所以,我们还需要添加iced库,看一下toml文件:
[package]
name = "gui-serial"
version = "0.1.0"
edition = "2021"
[dependencies]
iced={version="0.12.1"}
iced_widget={version="0.12.3",features=[]}
serialport="4.3.0"
clap="4.5.7"
image="0.25.1"
resvg={version="0.42.0",features=[]}
关于iced以及rfd库的使用,此处不再赘述,可以参考本人的另外的博文:
Rust UI开发(三):iced如何打开图片(对话框)并在窗口显示图片?
我直接把主程序的代码贴在这:
use std::{io::{self,Write}, process::CommandArgs};
use eximg::codecs::png;
use imgtoicon::image_to_icon;
use resvg::usvg::filter::Merge;
use serialport::{DataBits,StopBits,Parity};
//use clap::{value_parser, Arg, ArgAction, Command};
mod ser;
mod imgtoicon;
mod resvgpro;
use iced::{Application, Command, Element, Font, Renderer, Settings, Subscription};
use iced_widget::{container,button,text,column,row,svg,image};
use rfd::FileDialog;
extern crate resvg;
extern crate image as eximg;
#[derive(Debug,Clone)]
enum Message{
Cvt,
Open,
Save,
}
struct Serial{
portname:String,
baudrate:u32,
databits:DataBits,
stopbits:StopBits,
parity:Parity,
timeout:u64,
openfile:String,
destfile:String,
}
fn main() ->iced::Result {
let myicon=imgtoicon::image_to_icon("..\\gui-serial\\img\\mainicon4.png");
let myfont="微软雅黑";
Serial::run(Settings{
id:Some("mw".to_string()),
window:iced::window::Settings{
size:iced::Size{width:800.0,height:600.0},
min_size:Some(iced::Size { width: 200.0, height: 200.0 }),
max_size:Some(iced::Size { width: 1000.0, height: 800.0 }),
position:iced::window::Position::Specific(iced::Point::new(100.0,100.0)),
icon:Some(myicon),
level:iced::window::Level::Normal,
..Default::default()
},
default_font:Font::with_name(myfont),
..Default::default()
})
}
impl Application for Serial{
type Executor = iced::executor::Default;
type Message = Message;
type Flags = ();
type Theme = iced::Theme;
fn new(flags: Self::Flags) -> (Self, Command<Self::Message>) {
(Self{
portname:String::from("COM1"),
baudrate:9600,
databits:DataBits::Eight,
stopbits:StopBits::One,
parity:Parity::None,
timeout:1000,
openfile:String::from(""),
destfile:String::from(""),
},
Command::none())
}
fn title(&self) -> String {
String::from("串口调试工具-rs")
}
fn update(&mut self, message: Self::Message) -> Command<Self::Message> {
match message{
Message::Cvt=>{
resvgpro::svgtopng(&self.openfile,
&self.destfile)
}
Message::Open=>{
if let Some(file)=FileDialog::new()
.set_title("打开文件")
.add_filter("svg", &["svg"])
.pick_file(){
self.openfile=file.display().to_string();
}
else{
println!("打开文件失败")
};
}
Message::Save=>{
if let Some(file)=FileDialog::new()
.set_title("保存文件")
.add_filter("png", &["png"])
.save_file(){
let filestr=file.display().to_string();
resvgpro::svgtopng(&self.openfile, &filestr);
self.destfile=filestr;
}
else{
println!("保存文件失败")
};
}
}
Command::none()
}
fn subscription(&self) -> Subscription<Self::Message> {
Subscription::none()
}
fn view(&self) -> Element<'_, Self::Message, Self::Theme, crate::Renderer> {
//let btn1=button("转换").on_press(Message::Cvt);
let btn2=button("打开").on_press(Message::Open);
let btn3=button("转换并保存").on_press(Message::Save);
let svghandle=svg::Handle::from_path(&self.openfile);
let pnghandle=image::Handle::from_path(&self.destfile);
let col1=column![
btn2,
text(format!("打开文件路径:{}",&self.openfile)).size(15),
btn3,
text(format!("保存文件路径:{}",&self.destfile)).size(15),
//btn1,
row![
svg(svghandle).content_fit(iced::ContentFit::Contain).width(300),
image(pnghandle).content_fit(iced::ContentFit::Contain).width(300),
].padding(5).spacing(20),
].padding(5).spacing(5);
let cont=container(col1).padding(5);
cont.into()
}
}
实例演示: