1 files changed, 103 insertions, 0 deletions
diff --git a/import/fallback_generator/src/lib.rs b/import/fallback_generator/src/lib.rs
new file mode 100644
index 0000000..efb6579
--- /dev/null
+++ b/import/fallback_generator/src/lib.rs
@@ -0,0 +1,103 @@
+#![feature(random, string_remove_matches)]
+use ab_glyph::{FontRef, PxScale};
+use anyhow::Result;
+use image::{DynamicImage, ImageBuffer, ImageEncoder, Rgba, codecs::qoi::QoiEncoder};
+use imageproc::drawing::{draw_text_mut, text_size};
+use std::{
+    hash::{Hash, Hasher},
+    io::Write,
+};
+
+pub fn generate_fallback(name: &str, output: &mut dyn Write) -> Result<()> {
+    let width = 1024;
+    let height = (width * 1000) / 707;
+
+    let mut image = ImageBuffer::<Rgba<f32>, Vec<f32>>::new(width, height);
+
+    let text = name;
+    let bg = random_accent(text, 0.4);
+    image.pixels_mut().for_each(|p| *p = bg);
+
+    let font = FontRef::try_from_slice(include_bytes!(
+        "/usr/share/fonts/cantarell/Cantarell-VF.otf"
+    ))
+    .unwrap();
+    let font_bold = FontRef::try_from_slice(include_bytes!(
+        "/usr/share/fonts/TTF/OpenSans-CondensedExtraBold.ttf"
+    ))
+    .unwrap();
+
+    let mut bgtext = text.to_string();
+    bgtext.remove_matches(&[',', ' ']);
+    let bgtext = bgtext.repeat(3);
+    let scale = PxScale { x: 1000., y: 1000. };
+    let (w, h) = text_size(scale, &font, &bgtext);
+    for i in -1..4 {
+        draw_text_mut(
+            &mut image,
+            random_accent(&text, 0.6),
+            width as i32 / 2 - w as i32 / 2 + i * h as i32,
+            i * h as i32 * 2 / 3,
+            scale,
+            &font_bold,
+            &bgtext,
+        );
+    }
+
+    image.enumerate_pixels_mut().for_each(|(_x, y, p)| {
+        let f = 1. - (y as f32 / height as f32) * 0.5;
+        p.0[0] *= f;
+        p.0[1] *= f;
+        p.0[2] *= f;
+    });
+
+    let scale = PxScale { x: 200., y: 200. };
+    let (w, _h) = text_size(scale, &font, text);
+    draw_text_mut(
+        &mut image,
+        Rgba([1., 1., 1., 1.]),
+        width as i32 / 2 - w as i32 / 2,
+        height as i32 * 3 / 4,
+        scale,
+        &font,
+        text,
+    );
+
+    let image = DynamicImage::from(image).to_rgb8();
+
+    QoiEncoder::new(output).write_image(
+        image.as_raw(),
+        image.width(),
+        image.height(),
+        image::ExtendedColorType::Rgb8,
+    )?;
+    Ok(())
+}
+
+struct XorshiftHasher(u64);
+impl Hasher for XorshiftHasher {
+    fn finish(&self) -> u64 {
+        self.0
+    }
+    fn write(&mut self, bytes: &[u8]) {
+        for b in bytes {
+            self.0 = self
+                .0
+                .wrapping_add((*b as u64).wrapping_shl(24) + (*b as u64).wrapping_shl(56));
+            self.0 ^= self.0.wrapping_shl(13);
+            self.0 ^= self.0.wrapping_shr(7);
+            self.0 ^= self.0.wrapping_shl(17);
+        }
+    }
+}
+
+fn random_accent(text: &str, y: f32) -> Rgba<f32> {
+    let mut hasher = XorshiftHasher(0);
+    text.hash(&mut hasher);
+    let h = hasher.finish();
+    let mut u = (h >> 32) as u32 as f32 / u32::MAX as f32;
+    let mut v = (h) as u32 as f32 / u32::MAX as f32;
+    u *= 0.2;
+    v *= 0.2;
+    Rgba([y - u * 0.5 - v * 0.5, y + v, y + u, 1.])
+}