feat: 截图功能验证。

截图需要 700 ms，转换成 webp 3 s。

src-tauri/src/main.rs

@@ -0,0 +1,82 @@
+#![cfg_attr(
+    all(not(debug_assertions), target_os = "windows"),
+    windows_subsystem = "windows"
+)]
+
+use bmp::{Image, Pixel};
+use scrap::{Capturer, Display};
+use std::io::ErrorKind::WouldBlock;
+use std::path::Path;
+use std::thread;
+use std::time::Duration;
+use std::{fs, time::Instant};
+
+// Learn more about Tauri commands at https://tauri.app/v1/guides/features/command
+#[tauri::command]
+fn greet(name: &str) -> String {
+    format!("Hello, {}! You've been greeted from Rust!", name)
+}
+
+#[tauri::command]
+fn take_snapshot() -> String {
+    let one_second = Duration::new(1, 0);
+    let one_frame = one_second / 60;
+
+    let display = Display::primary().expect("Couldn't find primary display.");
+    let mut capturer = Capturer::new(display).expect("Couldn't begin capture.");
+    let (w, h) = (capturer.width(), capturer.height());
+
+    loop {
+        // Wait until there's a frame.
+
+        let start = Instant::now();
+        let buffer = match capturer.frame() {
+            Ok(buffer) => buffer,
+            Err(error) => {
+                if error.kind() == WouldBlock {
+                    // Keep spinning.
+                    thread::sleep(one_frame);
+                    continue;
+                } else {
+                    panic!("Error: {}", error);
+                }
+            }
+        };
+
+        println!("Captured! Saving...");
+
+        // Flip the ARGB image into a BGRA image.
+
+        let mut bitflipped = Vec::with_capacity(w * h * 3);
+        let stride = buffer.len() / h;
+
+        let mut img = Image::new(w as u32, h as u32);
+
+        for y in 0..h {
+            for x in 0..w {
+                let i = stride * y + 4 * x;
+                bitflipped.extend_from_slice(&[buffer[i + 2], buffer[i + 1], buffer[i]]);
+                // img.set_pixel(
+                //     x as u32,
+                //     y as u32,
+                //     Pixel::new(buffer[i + 2], buffer[i + 1], buffer[i]),
+                // );
+            }
+        }
+
+        let webp_memory =
+            webp::Encoder::from_rgb(bitflipped.as_slice(), w as u32, h as u32).encode(100.0);
+        let encode_text = base64::encode(&*webp_memory);
+        // let output_path = Path::new("assets").join("lake").with_extension("webp");
+        // std::fs::write(&output_path, &*webp_memory).unwrap();
+        println!("运行耗时: {:?}", start.elapsed());
+        return encode_text;
+    }
+}
+
+fn main() {
+    tauri::Builder::default()
+        .invoke_handler(tauri::generate_handler![greet, take_snapshot])
+        .run(tauri::generate_context!())
+        .expect("error while running tauri application");
+}