correct sprite cropping

src-tauri/src/services/petpet/mod.rs

@@ -2,24 +2,67 @@ use crate::models::dolls::DollDto;
 use crate::services::sprite_recolor;
 use image::{imageops::FilterType, RgbaImage};
 use petpet::{encode_gif, generate};
+use rand::prelude::IndexedRandom;
+
+const SPRITE_SIZE: u32 = 32;
+const SPRITE_FRAMES: &[(u32, u32)] = &[
+    (160, 125),
+    (32, 125),
+    (192, 0),
+    (224, 0),
+    (32, 0),
+    (0, 0),
+    (0, 127),
+    (32, 127),
+    (224, 126),
+    (224, 96),
+    (224, 64),
+    (160, 0),
+    (160, 127),
+    (160, 126),
+    (224, 0),
+    (224, 127),
+    (32, 126),
+    (32, 125),
+    (0, 126),
+    (0, 125),
+    (160, 0),
+    (160, 127),
+    (192, 127),
+    (192, 126),
+    (224, 125),
+    (32, 126),
+    (192, 125),
+    (224, 127),
+    (160, 126),
+    (160, 125),
+    (224, 0),
+    (224, 127),
+];
+
+fn crop_random_sprite(img: &RgbaImage) -> RgbaImage {
+    let mut rng = rand::rng();
+    let &(coord_x, coord_y) = SPRITE_FRAMES
+        .choose(&mut rng)
+        .expect("SPRITE_FRAMES must not be empty");
+    image::imageops::crop_imm(img, coord_x, coord_y, SPRITE_SIZE, SPRITE_SIZE).to_image()
+}
 
 pub fn encode_pet_doll_gif_base64(doll: DollDto) -> Result<String, String> {
     let body_color = &doll.configuration.color_scheme.body;
     let outline_color = &doll.configuration.color_scheme.outline;
 
-    // Get recolored image
     let img: RgbaImage = sprite_recolor::get_recolored_image(body_color, outline_color)
         .map_err(|e| format!("Failed to recolor image: {}", e))?;
 
-    // Generate petpet frames
-    let frames = generate(img, FilterType::Lanczos3, None)
+    let random_sprite = crop_random_sprite(&img);
+
+    let frames = generate(random_sprite, FilterType::Lanczos3, None)
         .map_err(|e| format!("Failed to generate petpet frames: {}", e))?;
 
-    // Encode to GIF
     let mut output = Vec::new();
     encode_gif(frames, &mut output, 10).map_err(|e| format!("Failed to encode GIF: {}", e))?;
 
-    // Base64
     use base64::{engine::general_purpose, Engine as _};
     Ok(general_purpose::STANDARD.encode(&output))
 }