1 files changed, 62 insertions, 0 deletions
diff --git a/mtree-test/src/decode.rs b/mtree-test/src/decode.rs
new file mode 100644
index 0000000..9c29717
--- /dev/null
+++ b/mtree-test/src/decode.rs
@@ -0,0 +1,62 @@
+use crate::{BLOCK_SIZE, Frame, LastFrames, frame_to_frame_rect_copy};
+use framework::BitstreamFilter;
+use glam::{I16Vec2, i16vec2};
+use std::collections::VecDeque;
+
+pub struct Dec {
+    res: I16Vec2,
+    last: LastFrames,
+}
+impl BitstreamFilter for Dec {
+    const INPUT_CODEC_ID: &str = "V_VCEMTREE";
+    const OUTPUT_CODEC_ID: &str = "V_UNCOMPRESSED";
+
+    fn new(width: u32, height: u32) -> Self {
+        Self {
+            res: i16vec2(width as i16, height as i16),
+            last: LastFrames {
+                frame_offset: 0,
+                frames: VecDeque::new(),
+            },
+        }
+    }
+    fn process_block(&mut self, a: Vec<u8>) -> Vec<u8> {
+        let mut a = a.as_slice();
+        let mut frame = Frame::new(self.res);
+
+        for bx in 0..self.res.x / BLOCK_SIZE {
+            for by in 0..self.res.y / BLOCK_SIZE {
+                let boff = i16vec2(bx * BLOCK_SIZE, by * BLOCK_SIZE);
+                let brect = boff..boff + I16Vec2::splat(BLOCK_SIZE);
+                let kind = a[0];
+                a = &a[1..];
+                if kind == 0 {
+                    let size = frame.import_rect(self.res, brect, &a);
+                    a = &a[size..];
+                } else {
+                    let rframeindex =
+                        u64::from_le_bytes([a[0], a[1], a[2], a[3], a[4], a[5], a[6], a[7]]);
+                    a = &a[8..];
+                    let offx = i16::from_le_bytes([a[0], a[1]]);
+                    a = &a[2..];
+                    let offy = i16::from_le_bytes([a[0], a[1]]);
+                    a = &a[2..];
+
+                    let rframe = &self.last.frames[(rframeindex - self.last.frame_offset) as usize];
+                    frame_to_frame_rect_copy(
+                        self.res,
+                        &mut frame,
+                        rframe,
+                        I16Vec2::splat(BLOCK_SIZE),
+                        boff,
+                        i16vec2(offx, offy),
+                    );
+                }
+            }
+        }
+
+        self.last.frames.push_back(frame.clone());
+
+        frame.0
+    }
+}