add depth screenshot. I have an idea

src/bin/platformer/main.rs

@@ -300,6 +300,8 @@ async fn main () -> Result <()> {
 	let mut next_upf_print = 60;
 	let mut last_upf_instant = Instant::now ();
 	
+	let mut depth_buffer = vec! [0u32; 320 * 2 * 240 * 2];
+	
 	'running: loop {
 		let _frames_to_do = time_step.step ();
 		let mut player_gamepad = virtual_gamepad::VirtualGamepad::default ();
@@ -313,6 +315,16 @@ async fn main () -> Result <()> {
 				Event::KeyDown { keycode: Some (Keycode::R), .. } => {
 					game_state.logic.reset_level (&level);
 				},
+				Event::KeyDown { keycode: Some (Keycode::F12), .. } => {
+					let depth_bytes: Vec <u8> = depth_buffer.iter ()
+					.map (|x| (x >> 16) as u16)
+					.map (|x| x.to_le_bytes ())
+					.flatten ()
+					.collect ();
+					
+					let mut f = std::fs::File::create ("screenshot.data")?;
+					f.write_all (&depth_bytes)?;
+				},
 				Event::KeyDown { scancode: Some (Scancode::Space), repeat: false, .. } => {
 					player_gamepad.jump.pressed = true;
 				},
@@ -385,6 +397,10 @@ async fn main () -> Result <()> {
 		
 		window.gl_swap_window ();
 		
+		unsafe {
+			gl::ReadPixels (0, 0, 320 * 2, 240 * 2, gl::DEPTH_COMPONENT, gl::UNSIGNED_INT, &mut depth_buffer [0] as *mut u32 as *mut std::ffi::c_void);
+		}
+		
 		tokio::time::sleep (Duration::from_millis (10)).await;
 	}
 	

src/prelude.rs

@@ -4,6 +4,7 @@ pub use std::{
 		CString,
 		c_void,
 	},
+	io::Write,
 	time::Duration,
 };