make the default cga font easier to unpack.

Cargo.toml

@@ -8,7 +8,7 @@ license = "Zlib OR Apache-2.0 OR MIT"
 
 [dependencies]
 bitfrob = "0.2.3"
-voladdress = "1.0.2"
+voladdress = { version = "1.1", features = ["experimental_volregion"] }
 
 [profile.dev]
 opt-level = 3

examples/hello.rs

@@ -63,7 +63,7 @@ extern "C" fn main() -> ! {
 
   {
     // get our tile data into memory.
-    Cga8x8Thick.bitunpack_4bpp(CHARBLOCK0_4BPP, 0);
+    Cga8x8Thick.bitunpack_4bpp(CHARBLOCK0_4BPP.as_region().sub_slice(..256), 0);
   }
 
   {

src/builtin_art/cga_8x8_thick.rs

@@ -1,10 +1,10 @@
 use core::mem::size_of_val;
 
-use voladdress::{Safe, VolBlock};
+use voladdress::{Safe, VolRegion};
 
 use crate::{
   bios::{BitUnPack, BitUnpackInfo},
-  video::Tile4,
+  video::{Tile4, Tile8},
 };
 
 /// The CGA [Code Page 437][cp437] type face, with thick lines.
@@ -135,10 +135,14 @@ impl Cga8x8Thick {
   ///
   /// * `offset_and_touch_zero`: Works like the [`BitUnpackInfo`] field. By
   ///   default you should usually pass 0 here.
+  ///
+  /// ## Panics
+  /// * Requires at least 256 elements of space within the region.
   #[inline]
   pub fn bitunpack_4bpp(
-    self, b: VolBlock<Tile4, Safe, Safe, 512>, offset_and_touch_zero: u32,
+    self, b: VolRegion<Tile4, Safe, Safe>, offset_and_touch_zero: u32,
   ) {
+    assert!(b.len() >= 256);
     let src = CGA_8X8_THICK.as_ptr();
     let dest = b.index(0).as_usize() as *mut u32;
     let info = BitUnpackInfo {
@@ -149,4 +153,27 @@ impl Cga8x8Thick {
     };
     unsafe { BitUnPack(src.cast(), dest, &info) };
   }
+
+  /// Bit unpacks the data (8bpp depth) to the location given.
+  ///
+  /// * `offset_and_touch_zero`: Works like the [`BitUnpackInfo`] field. By
+  ///   default you should usually pass 0 here.
+  ///
+  /// ## Panics
+  /// * Requires at least 256 elements of space within the region.
+  #[inline]
+  pub fn bitunpack_8bpp(
+    self, b: VolRegion<Tile8, Safe, Safe>, offset_and_touch_zero: u32,
+  ) {
+    assert!(b.len() >= 256);
+    let src = CGA_8X8_THICK.as_ptr();
+    let dest = b.index(0).as_usize() as *mut u32;
+    let info = BitUnpackInfo {
+      src_byte_len: size_of_val(&CGA_8X8_THICK) as u16,
+      src_elem_width: 1,
+      dest_elem_width: 8,
+      offset_and_touch_zero,
+    };
+    unsafe { BitUnPack(src.cast(), dest, &info) };
+  }
 }