Function draw_cursor 

pub fn draw_cursor(
    buf: &mut [u8],
    stride: usize,
    buf_width: usize,
    buf_height: usize,
    cx: i32,
    cy: i32,
)

Draw the cursor sprite onto a pixel buffer.

Arguments

• buf: Pixel buffer (BGRA format, 4 bytes/pixel).
• stride: Buffer stride in bytes.
• buf_width: Buffer width in pixels.
• buf_height: Buffer height in pixels.
• cx, cy: Cursor position (top-left of sprite).