7 files changed, 129 insertions, 1 deletions

diff --git a/src/audio.cpp b/src/audio.cpp
index 2f70fee..af6d24b 100644
--- a/src/audio.cpp
+++ b/src/audio.cpp
@@ -20,6 +20,7 @@ along with Minitrem.  If not, see <http://www.gnu.org/licenses/>.
 namespace audio {
 
 static std::list<sf::Sound> playing_sounds;
+static std::list<ambient_t*> ambient_sounds;
 
 void clean_sounds(void)
 {
@@ -41,4 +42,32 @@ void sound_t::play(void)
 	sound->play();
 }
 
+void ambient_t::load(const char *path)
+{
+	printf("load %s\n", path);
+	sound.openFromFile(path);
+	sound.setLoop(true);
+	ambient_sounds.push_back(this);
+}
+
+void update_ambience(bool playing)
+{
+	for (ambient_t *ambient : ambient_sounds) {
+		if (!playing) {
+			if (ambient->playing) {
+				ambient->sound.stop();
+				ambient->playing = false;
+			}
+			continue;
+		}
+
+		if (!ambient->playing) {
+			ambient->sound.play();
+			ambient->playing = true;
+		}
+
+		ambient->sound.setVolume(ambient->weight * 100.0f);
+	}
+}
+
 } // namespace audio
diff --git a/src/common.hpp b/src/common.hpp
index 181139f..6042e08 100644
--- a/src/common.hpp
+++ b/src/common.hpp
@@ -260,6 +260,7 @@ namespace game {
 		void start(void);
 		void stop(void);
 		void tick(ntime_t time);
+		void compute_ambience(render::state_t *render);
 		void pause(void);
 		void resume(void);
 
@@ -389,11 +390,14 @@ namespace render {
 		void render_line(v2f_t x0, v2f_t x1, sf::Color color);
 
 		void debug_path(v2f_t x, std::list<v2f_t> *path);
+
+		rectf_t window_in_world_space(void);
 	};
 }
 
 namespace audio {
 	void clean_sounds(void);
+	void update_ambience(bool playing);
 
 	class sound_t {
 		sf::SoundBuffer buffer;
@@ -402,6 +406,15 @@ namespace audio {
 		void load(const char *path);
 		void play(void);
 	};
+
+	class ambient_t {
+	public:
+		sf::Music sound;
+		bool playing = false;
+		float weight = 0.0f;
+
+		void load(const char *path);
+	};
 }
 
 extern render::state_t *debug_render;
@@ -429,6 +442,23 @@ T lerp(T a, T b, T x)
 	return a * (1 - x) + b * x;
 }
 
+// Linear map between intervals.
+template <typename T>
+T remap(T am, T ap, T bm, T bp, T x)
+{
+	return (x - am) * (bp - bm) / (ap - am) + bm;
+}
+
+template <typename T>
+T clamp(T x, T m, T p)
+{
+	if (x < m)
+		return m;
+	if (x > p)
+		return p;
+	return x;
+}
+
 // Bilinear interpolation.
 template <typename T>
 T bilerp(T a, T b, T c, T d, T x, T y)
diff --git a/src/game/assets.cpp b/src/game/assets.cpp
index ef7be9b..96199a6 100644
--- a/src/game/assets.cpp
+++ b/src/game/assets.cpp
@@ -24,6 +24,7 @@ spider_assets_t spider;
 nest_assets_t nest;
 fx_assets_t fx;
 deco_assets_t deco;
+ambience_assets_t ambience;
 
 render::animated_texture_t unit_selected;
 render::animated_texture_t unit_selected_halo;
@@ -73,6 +74,13 @@ void load(void)
 	render::register_tile(TILE_WATER, "assets/tiles/water.png", NULL, 0.0f);
 	world::register_tile(TILE_GRAVEL, 0);
 	render::register_tile(TILE_GRAVEL, "assets/tiles/gravel.png", NULL, 0.0f);
+
+	ambience.nexus.load("assets/ambience/nexus.ogg");
+	ambience.chasm.load("assets/ambience/chasm.ogg");
+	ambience.wind.load("assets/ambience/wind.ogg");
+	ambience.water.load("assets/ambience/water.ogg");
+
+	ambience.nexus.weight = 1.0f;
 }
 
 } // namespace game::assets
diff --git a/src/game/game.cpp b/src/game/game.cpp
index 44ea95d..58b2c9d 100644
--- a/src/game/game.cpp
+++ b/src/game/game.cpp
@@ -194,7 +194,6 @@ void state_t::resume(void)
 	paused = false;
 }
 
-
 #define TIME_DELTA ((ntime_t)1000000000 / 60)
 
 void state_t::tick(ntime_t time_)
@@ -234,6 +233,55 @@ void state_t::tick(ntime_t time_)
 	}
 }
 
+void state_t::compute_ambience(render::state_t *render)
+{
+	rectf_t area;
+	size_t plains = 0, cave = 0, water = 0, weird = 0;
+	float scale, volume;
+
+	area = render->window_in_world_space();
+
+	// resolution chosen arbitrarily
+	for (size_t y = 0; y < 5; y++)
+	for (size_t x = 0; x < 5; x++) {
+		v2f_t point;
+		world::tile_t *tile;
+
+		point[0] = lerp(area[0][0], area[1][0], y / 4.0f);
+		point[1] = lerp(area[0][1], area[1][1], x / 4.0f);
+
+		tile = world.get_tile(world::tile_index_t(point), world::SECTOR_FULL);
+
+		switch (tile->type) {
+		case TILE_DIRT:
+			plains++;
+			break;
+
+		case TILE_GRAVEL:
+		case TILE_STONE:
+			cave++;
+			break;
+
+		case TILE_WATER:
+			water++;
+			break;
+
+		case TILE_DIRT_RED:
+		case TILE_STONE_RED:
+			weird++;
+			break;
+		}
+	}
+
+	scale = 1.0f / area.dims().len();
+	volume = clamp(remap(0.002f, 0.08f, 0.0f, 1.0f, scale), 0.0f, 1.0f);
+
+	assets::ambience.wind.weight = plains / 25.0f * volume;
+	assets::ambience.chasm.weight = cave / 25.0f * volume;
+	assets::ambience.water.weight = water / 25.0f * volume;
+	assets::ambience.nexus.weight = weird / 25.0f * volume;
+}
+
 die_t::die_t(size_t sides_)
 {
 	sides = sides_;
diff --git a/src/game/game.hpp b/src/game/game.hpp
index 85e3849..8486412 100644
--- a/src/game/game.hpp
+++ b/src/game/game.hpp
@@ -77,11 +77,16 @@ namespace game {
 			render::animated_texture_t wart;
 		} deco_assets_t;
 
+		typedef struct {
+			audio::ambient_t nexus, chasm, wind, water;
+		} ambience_assets_t;
+
 		extern soldier_assets_t soldier;
 		extern spider_assets_t spider;
 		extern nest_assets_t nest;
 		extern fx_assets_t fx;
 		extern deco_assets_t deco;
+		extern ambience_assets_t ambience;
 		extern render::animated_texture_t unit_selected; 
 		extern render::animated_texture_t unit_selected_halo;
 		extern render::animated_texture_t move_marker;
diff --git a/src/main.cpp b/src/main.cpp
index ea0092d..20110e5 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -68,8 +68,10 @@ int main()
 		window.clear();
 		render.begin_frame(now, dt);
 		render.render(&game);
+		game.compute_ambience(&render);
 		interface.render_to(&render);
 		audio::clean_sounds();
+		audio::update_ambience(!game.paused);
 		render.end_frame();
 	}
 
diff --git a/src/render.cpp b/src/render.cpp
index 7a798ab..8d4949b 100644
--- a/src/render.cpp
+++ b/src/render.cpp
@@ -194,6 +194,12 @@ static rectf_t window_bounds(sf::RenderWindow *window)
 	return bounds;
 }
 
+// NOTE: this includes the margin
+rectf_t state_t::window_in_world_space(void)
+{
+	return window_bounds(window);
+}
+
 void state_t::render(game::state_t *game)
 {
 	rectf_t bounds;