Kernel video - Faster bootvideo

Kernel/Core/metadevs/video/bootvideo.rs

@@ -196,31 +196,29 @@ impl super::Framebuffer for Framebuffer
 		let bpp = output_fmt.bytes_per_pixel();
 		// Iterate across destination row nums and source rows
 		//for (row,src) in Iterator::zip( dst.top() .. dst.bottom(), buf.chunks(src_pitch) )
-		for (row,src) in ::lib::ExactZip::new( dst.top() .. dst.bottom(), buf.chunks(src_pitch) )
+		match output_fmt
 		{
-			let seg = self.buffer.scanline_slice(row as usize, dst.left() as usize, dst.right() as usize);
-			match output_fmt
+		VideoFormat::X8R8G8B8 => {
+			assert!(bpp == 4);
+			// This mode corresponds to the internal format, so can use fast operations (raw byte copy)
+			for (row,src) in ::lib::ExactZip::new( dst.top() .. dst.bottom(), buf.chunks(src_pitch) )
 			{
-			VideoFormat::X8R8G8B8 => {
-				// TODO: Find a faster way of bliting.
-				for (px,&col) in ::lib::ExactZip::new( seg.chunks_mut(bpp), src.iter() )
-				{
-					px[0] = ((col >>  0) & 0xFF) as u8;
-					px[1] = ((col >>  8) & 0xFF) as u8;
-					px[2] = ((col >> 16) & 0xFF) as u8;
-					//px[3] = ((col >> 24) & 0xFF) as u8;
-				}
-				},
-			VideoFormat::R5G6B5 => {
+				let seg = self.buffer.scanline_slice(row as usize, dst.left() as usize, dst.right() as usize);
+				seg.copy_from_slice( ::lib::as_byte_slice(src) );
+			}
+			},
+		VideoFormat::R5G6B5 =>
+			for (row,src) in ::lib::ExactZip::new( dst.top() .. dst.bottom(), buf.chunks(src_pitch) )
+			{
+				let seg = self.buffer.scanline_slice(row as usize, dst.left() as usize, dst.right() as usize);
 				for (px,&col) in ::lib::ExactZip::new( seg.chunks_mut(bpp), src.iter() )
 				{
 					let col16 = output_fmt.col_from_xrgb(col);
 					px[0] = ((col16 >>  0) & 0xFF) as u8;
 					px[1] = ((col16 >>  8) & 0xFF) as u8;
 				}
-				},
-			fmt @ _ => todo!("Framebuffer::blit_buf - {:?}", fmt),
-			}
+			},
+		fmt @ _ => todo!("Framebuffer::blit_buf - {:?}", fmt),
 		}
 
 		if redraw_cursor {