examples

commit ff494da64cb87734b2a98880e423546b093ab569
parent 3917a91f68f8dceb8155bf59c92df22f8152d23e
Author: Henry Wilson <henry@henryandlizzy.uk>
Date:   Mon,  9 May 2022 23:47:05 +0100

gl-asteroids: Add variation to particle ttl

Diffstat:
M
src/gl-asteroids.cpp
 | 
32
++++++++++++++++++++------------

1 file changed, 20 insertions(+), 12 deletions(-)
diff --git a/src/gl-asteroids.cpp b/src/gl-asteroids.cpp
@@ -12,6 +12,8 @@
 #include <optional>
 #include <functional>
 
+/// SOUNDS
+
 using sample = std::span<short>;
 
 std::mutex queued_sounds_mutex;
@@ -58,6 +60,10 @@ void sound_routine(std::stop_token token)
 	snd_pcm_close(handle);
 }
 
+std::jthread sound(sound_routine);
+
+/// GRAPHICS
+
 struct coord
 {
 	coord() = default;
@@ -170,6 +176,8 @@ coord& operator *=(coord& lhs, coord rhs)
 	return lhs;
 }
 
+/// PHYSICS
+
 coord rotate(coord o, float a)
 {
 	float s = sin(a), c = cos(a);
@@ -270,13 +278,17 @@ static bool left_arena(entity const& e)
 	return e.phys.left_arena();
 }
 
+std::random_device rd;
+std::default_random_engine gen(rd());
+
 struct particle : entity
 {
 	float ttl;
 
 	static particle& make_particle(entity e, float ttl)
 	{
-		return particles.emplace_back(e, ttl);
+		static std::uniform_real_distribution<float> d(.5, 1);
+		return particles.emplace_back(e, ttl * d(gen));
 	}
 	static void move_all(float dt)
 	{
@@ -370,15 +382,10 @@ int main(int argc, char* argv[])
 	unsigned ammo = 10;
 	float firerate = 2, bullet_speed = 1;
 
-	std::random_device rd;
-	std::default_random_engine gen(rd());
 	std::uniform_real_distribution<float> dis_p(-1,1);
 	std::uniform_real_distribution<float> dis_s(0.05,0.25);
-	std::uniform_real_distribution<float> dis_ds(0.005,0.025);
 	std::uniform_real_distribution<float> dis_v(0.02,0.05);
-	std::uniform_real_distribution<float> dis_z(.3,.6);
 	std::uniform_int_distribution<int> dis_d(0,7);
-	std::uniform_real_distribution<float> dis_a(-3,3);
 
 	std::array<short, 2 * 512> tone;
 	for (unsigned i = 0; i < tone.size(); ++i)
@@ -413,8 +420,6 @@ int main(int argc, char* argv[])
 	for (auto& c : starsv)
 		c.x = dis_p(gen), c.y = dis_p(gen);
 
-	std::jthread sound(sound_routine);
-
 	while (!glfwWindowShouldClose(w) && not is_pressed(GLFW_KEY_ESCAPE))
 	{
 		float t = glfwGetTime();
@@ -442,7 +447,8 @@ int main(int argc, char* argv[])
 				std::swap(v.x, v.y);
 			}
 
-			rocks.emplace_back(random_rock_visual(), physics{p, v, 0, dis_a(gen), scale});
+			static std::uniform_real_distribution<float> ang(-3,3);
+			rocks.emplace_back(random_rock_visual(), physics{p, v, 0, ang(gen), scale});
 		}
 
 		if (powerup_time < t)
@@ -543,12 +549,13 @@ int main(int argc, char* argv[])
 					play_sample(square);
 					for (unsigned j = 0; j < 7; ++j)
 					{
+						static std::uniform_real_distribution<float> scale(0.005,0.025);
 						entity debris = *r;
 						debris.vis = &random_rock_visual();
 						debris.phys.vel.x += .3 * dis_p(gen);
 						debris.phys.vel.y += .3 * dis_p(gen);
-						debris.phys.scale = dis_ds(gen);
-						particle::make_particle(debris, .7);
+						debris.phys.scale = scale(gen);
+						particle::make_particle(debris, 1);
 					}
 
 					if (r->phys.scale > .13f)
@@ -557,6 +564,7 @@ int main(int argc, char* argv[])
 
 						auto nr = *r;
 
+						static std::uniform_real_distribution<float> dis_z(.3,.6);
 						float sf = dis_z(gen);
 
 						r->phys.scale *= sf;
@@ -601,7 +609,7 @@ int main(int argc, char* argv[])
 					debris.phys.vel.x += .3 * dis_p(gen);
 					debris.phys.vel.y += .3 * dis_p(gen);
 					debris.phys.scale *= 1.5 * dis_s(gen);
-					particle::make_particle(debris, .7);
+					particle::make_particle(debris, 2);
 				}
 				powerups.reset();
 				score -= 10;