lbmp support

wie_backend/src/canvas.rs

@@ -1,3 +1,5 @@
+mod lbmp;
+
 use core::mem::size_of;
 
 use ab_glyph::{Font, FontRef, ScaleFont};
@@ -7,6 +9,8 @@ use num_traits::{Num, Zero};
 
 use wie_util::{Result, WieError};
 
+use self::lbmp::decode_lbmp;
+
 lazy_static::lazy_static! {
     static ref FONT: FontRef<'static> = FontRef::try_from_slice(include_bytes!("../../fonts/neodgm.ttf")).unwrap();
 }
@@ -56,6 +60,33 @@ pub trait PixelType: Send {
     fn to_color(raw: Self::DataType) -> Color;
 }
 
+pub struct Rgb332Pixel;
+
+impl PixelType for Rgb332Pixel {
+    type DataType = u8;
+
+    fn from_color(color: Color) -> Self::DataType {
+        let r = (color.r * 7 + 127) / 255;
+        let g = (color.g * 7 + 127) / 255;
+        let b = (color.b * 3 + 127) / 255;
+
+        (r << 5) | (g << 2) | b
+    }
+
+    fn to_color(raw: Self::DataType) -> Color {
+        let r = (raw >> 5) & 0x7;
+        let g = (raw >> 2) & 0x7;
+        let b = raw & 0x3;
+
+        Color {
+            a: 0xff,
+            r: r * 36,
+            g: g * 36,
+            b: b * 85,
+        }
+    }
+}
+
 pub struct Rgb565Pixel;
 
 impl PixelType for Rgb565Pixel {
@@ -433,6 +464,10 @@ impl Clip {
 pub fn decode_image(data: &[u8]) -> Result<Box<dyn Image>> {
     use std::io::Cursor;
 
+    if data[0] == b'L' && data[1] == b'B' && data[2] == b'M' && data[3] == b'P' {
+        return decode_lbmp(data);
+    }
+
     let image = ImageReader::new(Cursor::new(&data))
         .with_guessed_format()
         .map_err(|x| WieError::FatalError(x.to_string()))?

wie_backend/src/canvas/lbmp.rs

@@ -0,0 +1,40 @@
+use bytemuck::{cast_vec, from_bytes, Pod, Zeroable};
+
+use wie_util::{Result, WieError};
+
+use crate::canvas::{Image, Rgb332Pixel, Rgb565Pixel, VecImageBuffer};
+
+// lcd bitmap file format for skvm
+
+#[repr(C)]
+#[derive(Clone, Copy, Pod, Zeroable)]
+struct LbmpHeader {
+    descriptor: u32,
+    r#type: u32,
+    width: u32,
+    height: u32,
+    size: u32,
+    mask: u32,
+}
+
+pub fn decode_lbmp(data: &[u8]) -> Result<Box<dyn Image>> {
+    let header: &LbmpHeader = from_bytes(&data[0..24]);
+    let data = &data[24..];
+
+    if header.r#type == 2 || header.r#type == 3 {
+        // unsupported grayscale
+        return Err(WieError::Unimplemented(format!("Unsupported grayscale type {}", header.r#type)));
+    }
+
+    Ok(if header.r#type == 8 {
+        Box::new(VecImageBuffer::<Rgb332Pixel>::from_raw(header.width, header.height, data.to_vec()))
+    } else if header.r#type == 16 {
+        Box::new(VecImageBuffer::<Rgb565Pixel>::from_raw(
+            header.width,
+            header.height,
+            cast_vec(data.to_vec()),
+        ))
+    } else {
+        return Err(WieError::Unimplemented(format!("Unsupported type {}", header.r#type)));
+    })
+}

wie_midp/src/classes/javax/microedition/lcdui/image.rs

@@ -11,7 +11,7 @@ use jvm::{
     Array, ClassInstanceRef, Jvm, Result as JvmResult,
 };
 
-use wie_backend::canvas::{decode_image, ArgbPixel, Canvas, Image as BackendImage, ImageBufferCanvas, Rgb565Pixel, VecImageBuffer};
+use wie_backend::canvas::{decode_image, ArgbPixel, Canvas, Image as BackendImage, ImageBufferCanvas, Rgb332Pixel, Rgb565Pixel, VecImageBuffer};
 use wie_jvm_support::{WieJavaClassProto, WieJvmContext};
 
 use crate::classes::javax::microedition::lcdui::Graphics;
@@ -199,6 +199,7 @@ impl Image {
         let bytes_per_pixel = bpl / width;
 
         Ok(match bytes_per_pixel {
+            1 => Box::new(VecImageBuffer::<Rgb332Pixel>::from_raw(width as _, height as _, pod_collect_to_vec(&buf))) as Box<_>,
             2 => Box::new(VecImageBuffer::<Rgb565Pixel>::from_raw(width as _, height as _, pod_collect_to_vec(&buf))) as Box<_>,
             4 => Box::new(VecImageBuffer::<ArgbPixel>::from_raw(width as _, height as _, pod_collect_to_vec(&buf))) as Box<_>,
             _ => unimplemented!("Unsupported pixel format: {}", bytes_per_pixel),