Cargoify servo

components/net/image/base.rs

@@ -0,0 +1,67 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use std::iter::range_step;
+use stb_image = stb_image::image;
+use png;
+
+// FIXME: Images must not be copied every frame. Instead we should atomically
+// reference count them.
+pub type Image = png::Image;
+
+
+static TEST_IMAGE: &'static [u8] = include_bin!("test.jpeg");
+
+pub fn test_image_bin() -> Vec<u8> {
+    TEST_IMAGE.iter().map(|&x| x).collect()
+}
+
+// TODO(pcwalton): Speed up with SIMD, or better yet, find some way to not do this.
+fn byte_swap(data: &mut [u8]) {
+    let length = data.len();
+    for i in range_step(0, length, 4) {
+        let r = data[i + 2];
+        data[i + 2] = data[i + 0];
+        data[i + 0] = r;
+    }
+}
+
+pub fn load_from_memory(buffer: &[u8]) -> Option<Image> {
+    if buffer.len() == 0 {
+        return None;
+    }
+
+    if png::is_png(buffer) {
+        match png::load_png_from_memory(buffer) {
+            Ok(mut png_image) => {
+                match png_image.pixels {
+                    png::RGB8(ref mut data) | png::RGBA8(ref mut data) => {
+                        byte_swap(data.as_mut_slice());
+                    }
+                    _ => {}
+                }
+                Some(png_image)
+            }
+            Err(_err) => None,
+        }
+    } else {
+        // For non-png images, we use stb_image
+        // Can't remember why we do this. Maybe it's what cairo wants
+        static FORCE_DEPTH: uint = 4;
+
+        match stb_image::load_from_memory_with_depth(buffer, FORCE_DEPTH, true) {
+            stb_image::ImageU8(mut image) => {
+                assert!(image.depth == 4);
+                byte_swap(image.data.as_mut_slice());
+                Some(png::Image {
+                    width: image.width as u32,
+                    height: image.height as u32,
+                    pixels: png::RGBA8(image.data)
+                })
+            }
+            stb_image::ImageF32(_image) => fail!("HDR images not implemented"),
+            stb_image::Error(_) => None
+        }
+    }
+}