refactor(graphics): use fixed-size slices in to_64x64_ycbcr_tile

In theory, this could help the compiler to unroll loops.. doesn't seem
to be the case though.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

Author: elmarco

crates/ironrdp-graphics/src/color_conversion.rs

@@ -135,15 +135,12 @@ pub fn to_64x64_ycbcr_tile(
     height: usize,
     stride: usize,
     format: PixelFormat,
-    y: &mut [i16],
-    cb: &mut [i16],
-    cr: &mut [i16],
+    y: &mut [i16; 64 * 64],
+    cb: &mut [i16; 64 * 64],
+    cr: &mut [i16; 64 * 64],
 ) {
     assert!(width <= 64);
     assert!(height <= 64);
-    assert_eq!(y.len(), 64 * 64);
-    assert_eq!(cb.len(), 64 * 64);
-    assert_eq!(cr.len(), 64 * 64);
 
     let to_rgb = pixel_format_to_rgb_fn(format);
     let bpp = format.bytes_per_pixel() as usize;

crates/ironrdp-testsuite-core/tests/graphics/color_conversion.rs

@@ -4,9 +4,9 @@ use ironrdp_graphics::{color_conversion::*, image_processing::PixelFormat};
 fn to_64x64_ycbcr() {
     let input = [0u8; 4];
 
-    let mut y = vec![0; 4096];
-    let mut cb = vec![0; 4096];
-    let mut cr = vec![0; 4096];
+    let mut y = [0; 64 * 64];
+    let mut cb = [0; 64 * 64];
+    let mut cr = [0; 64 * 64];
     to_64x64_ycbcr_tile(&input, 1, 1, 4, PixelFormat::ABgr32, &mut y, &mut cb, &mut cr);
 }