examples

commit 9636e425c8ecf42cd00f574ced88656a5d528ac2
parent 81027f9fa9973e5b56e10200396492372a294d0f
Author: Henry Wilson <henry@henryandlizzy.uk>
Date:   Thu, 28 Apr 2022 19:38:44 +0100

gl-asteroids: Factor coord_from_rotation

Diffstat:
M
src/gl-asteroids.cpp
 | 
12
+++++++-----

1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/src/gl-asteroids.cpp b/src/gl-asteroids.cpp
@@ -176,6 +176,11 @@ coord rotate(coord o, float a)
 	return {o.x*c + o.y*s, o.y*c - o.x*s};
 }
 
+coord coord_from_rotation(float a)
+{
+	return {(float)sin(a), (float)cos(a)};
+}
+
 struct physics
 {
 	coord pos, vel;
@@ -479,7 +484,7 @@ int main(int argc, char* argv[])
 
 			b.ang_mom = 0;
 			b.scale /= 1.25;
-			auto vel = coord{(float)sin(b.rot), (float)cos(b.rot)} * bullet_speed;
+			auto vel = coord_from_rotation(b.rot) * bullet_speed;
 			b.vel += vel;
 			ship_phys.vel -= vel * .05f;
 		}
@@ -497,10 +502,7 @@ int main(int argc, char* argv[])
 		up = is_pressed(GLFW_KEY_UP);
 
 		if (up)
-		{
-			float sr = sin(ship_phys.rot), cr = cos(ship_phys.rot);
-			ship_phys.vel += coord{sr, cr} * dt;
-		}
+			ship_phys.vel += coord_from_rotation(ship_phys.rot) * dt;
 
 		// resolve motion