Merge pull request #62 from picture-pro/25-thumbnail-watermark

25 thumbnail watermark

crates/bl/src/upload.rs → crates/bl/src/upload/mod.rs

@@ -1,3 +1,6 @@
+#[cfg(feature = "ssr")]
+mod watermark;
+
 use std::collections::HashMap;
 
 #[cfg(feature = "ssr")]
@@ -169,11 +172,13 @@ async fn create_photo(img: image::DynamicImage) -> Result<PhotoRecordId> {
   let thumbnail_size = thumbnail_size(aspect_ratio);
 
   // create thumbnail
-  let thumbnail_image = img.resize_exact(
+  let mut thumbnail_image = img.resize_exact(
     thumbnail_size.0,
     thumbnail_size.1,
     image::imageops::FilterType::Lanczos3,
   );
+  // apply watermark
+  watermark::apply_watermark(&mut thumbnail_image);
 
   // encode thumbnail image as jpeg
   let mut thumbnail_bytes = Vec::new();

crates/bl/src/upload/watermark.rs

@@ -0,0 +1,44 @@
+use image::{DynamicImage, GenericImageView};
+
+fn create_watermark(width: u32, height: u32) -> image::DynamicImage {
+  // load the watermark image from bytes which is a transparent 200x200 pixels
+  // image
+  let watermark_bytes = include_bytes!("../../assets/watermark.png");
+  let watermark = image::load_from_memory(watermark_bytes).unwrap();
+
+  // center the watermark inside an image of the correct size, or if it's too
+  // large, scale it down
+  let (w, h) = watermark.dimensions();
+  let (w, h) = if w > width || h > height {
+    let scale = (width as f32 / w as f32).min(height as f32 / h as f32);
+    (w as f32 * scale, h as f32 * scale)
+  } else {
+    (w as f32, h as f32)
+  };
+  let watermark = watermark.resize_exact(
+    w as u32,
+    h as u32,
+    image::imageops::FilterType::Lanczos3,
+  );
+  // center the watermark
+  let x = (width - w as u32) / 2;
+  let y = (height - h as u32) / 2;
+  let mut final_watermark = image::RgbaImage::new(width, height);
+  image::imageops::overlay(
+    &mut final_watermark,
+    &watermark.to_rgba8(),
+    x.into(),
+    y.into(),
+  );
+
+  DynamicImage::ImageRgba8(final_watermark)
+}
+
+pub fn apply_watermark(target: &mut DynamicImage) {
+  // create the watermark image
+  let (width, height) = target.dimensions();
+  let watermark = create_watermark(width, height);
+
+  // blend the watermark onto the target image
+  image::imageops::overlay(target, &watermark, 0, 0);
+}