Basic music and sound.

1 files changed, 105 insertions, 0 deletions

diff --git a/sound.c b/sound.c
new file mode 100644
index 0000000..611bca9
--- /dev/null
+++ b/sound.c
@@ -0,0 +1,105 @@
+#include "config.h"
+#include "sound.h"
+
+#if DEBUG
+#include "error.h"
+#include "platform.h"
+#endif
+
+typedef struct {
+	int pitch;
+	int length;
+} Beep;
+
+static struct {
+	unsigned t;
+	Song song;
+	Beep beeps[max_beeps];
+	int beep_count;
+} sys;
+
+typedef unsigned char (*Song_Func)(unsigned t);
+
+static unsigned char menu_song(unsigned t) {
+	return 0;
+}
+
+static unsigned char main_song(unsigned t) {
+	/* From tejeez 2011-10-05
+	 * I didn't have time to make my own music PepeHands */
+	return (~t>>2)*((127&t*(7&t>>10))<(245&t*(2+(5&t>>14))));
+}
+
+static unsigned char dead_song(unsigned t) {
+	return 0;
+}
+
+static unsigned char win_song(unsigned t) {
+	return 0;
+}
+
+void init_sound() {
+	sys.t = 0;
+	sys.song = song_menu;
+}
+
+void set_song(Song song) {
+	sys.song = song;
+	sys.t = 0;
+}
+
+Song_Func get_current_song_f() {
+	switch (sys.song) {
+		case song_menu:
+			return menu_song;
+		case song_main:
+			return main_song;
+		case song_win:
+			return win_song;
+		case song_dead:
+			return dead_song;
+	}
+	return 0;
+}
+
+void play_beep(int pitch, int length) {
+	Beep* beep;
+
+#if DEBUG
+	if (sys.beep_count >= max_beeps) {
+		platform_err("Too many beeps.\n");
+		platform_abort(error_sound_error);
+	}
+#endif
+
+	beep = &sys.beeps[sys.beep_count++];
+	beep->pitch = pitch;
+	beep->length = length;
+}
+
+void sound_mix(unsigned char* stream, int len) {
+	int i, j;
+	Song_Func f;
+	Beep* beep;
+
+	f = get_current_song_f();
+
+	for (i = 0; i < len; i++) {
+/*		stream[i] = sys.t % 50;*/
+		stream[i] = 0;
+		stream[i] = f(sys.t) / 2;
+		for (j = sys.beep_count - 1; j >= 0; j--) {
+			beep = &sys.beeps[j];
+			stream[i] |= (sys.t % beep->pitch) * 5;
+			beep->length--;
+
+			if (beep->length <= 0) {
+				if (sys.beep_count > 1) {
+					*beep = sys.beeps[sys.beep_count - 1];
+				}
+				sys.beep_count--;
+			}
+		}
+		sys.t++;
+	}
+}