Add arrow key spinnies

src/main.rs

@@ -6,8 +6,7 @@ use nom::{
 };
 
 use sdl2::event::Event;
-use sdl2::keyboard::Keycode;
+use sdl2::keyboard::{Keycode, Scancode};
-
 use std::collections::HashMap;
 use std::convert::TryInto;
 use std::ffi::{c_void, CStr, CString};
@@ -622,6 +621,10 @@ fn main () {
 	let mut last_frame_time = Instant::now ();
 	let mut frame = 0;
 	let mut timestep_accum = Duration::from_millis (0);
+	let mut azimuth: f32 = 0.0;
+	let mut altitude: f32 = 0.0;
+	let mut spin_speed: i32 = 0;
+	const SPIN_RAMP_TIME: i32 = 30;
 	
 	//println! ("Entering main loop");
 	
@@ -637,10 +640,34 @@ fn main () {
 		
 		timestep_accum += (frame_time - last_frame_time).mul_f32 (fps_num);
 		
+		let keyboard_state = event_pump.keyboard_state ();
+		
 		for _ in 0..4 {
 			if timestep_accum > Duration::from_millis (fps_den) {
 				frame += 1;
 				timestep_accum -= Duration::from_millis (fps_den);
+				
+				let spin_f = 4.0 * spin_speed as f32 / SPIN_RAMP_TIME as f32;
+				
+				if keyboard_state.is_scancode_pressed (Scancode::Left) {
+					spin_speed = std::cmp::min (spin_speed + 1, SPIN_RAMP_TIME);
+					azimuth += spin_f;
+				}
+				else if keyboard_state.is_scancode_pressed (Scancode::Right) {
+					spin_speed = std::cmp::min (spin_speed + 1, SPIN_RAMP_TIME);
+					azimuth -= spin_f;
+				}
+				else if keyboard_state.is_scancode_pressed (Scancode::Up) {
+					spin_speed = std::cmp::min (spin_speed + 1, SPIN_RAMP_TIME);
+					altitude = f32::min (90.0, altitude + spin_f);
+				}
+				else if keyboard_state.is_scancode_pressed (Scancode::Down) {
+					spin_speed = std::cmp::min (spin_speed + 1, SPIN_RAMP_TIME);
+					altitude = f32::max (-90.0, altitude - spin_f);
+				}
+				else {
+					spin_speed = 0;
+				}
 			}
 			else {
 				break;
@@ -663,8 +690,10 @@ fn main () {
 		
 		window.gl_make_current (&gl_ctx).unwrap ();
 		
-		let longitude = (frame as f32).to_radians ();
+		//let longitude = (frame as f32).to_radians ();
-		let latitude = (frame as f32 / 5.0).to_radians ().sin () * -40.0f32.to_radians () - 75.0f32.to_radians ();
+		let longitude = azimuth.to_radians ();
+		let latitude = (altitude - 90.0).to_radians ();
+		//let latitude = (frame as f32 / 5.0).to_radians ().sin () * -40.0f32.to_radians () - 75.0f32.to_radians ();
 		
 		let proj_mat = Mat4::perspective_rh_gl (30.0f32.to_radians (), 1280.0 / 720.0, 0.5, 500.0);