backporting...

[dosdemo] / src / audio.h

diff --git a/src/audio.h b/src/audio.h
new file mode 100644 (file)
index 0000000..f362781
--- /dev/null
+++ b/src/audio.h
@@ -0,0 +1,54 @@
+#ifndef AUDIO_H_
+#define AUDIO_H_
+
+enum { AU_STOPPED, AU_PLAYING };
+
+enum {
+       AU_CUR = 0x7000,
+       AU_VOLUP = 0x7100,
+       AU_VOLDN = 0x7200
+};
+
+struct au_module {
+       char *name;
+       void *impl;
+};
+
+int au_init(void);
+void au_shutdown(void);
+
+struct au_module *au_load_module(const char *fname);
+void au_free_module(struct au_module *mod);
+
+int au_play_module(struct au_module *mod);
+void au_update(void);
+int au_stop_module(struct au_module *mod);
+int au_module_state(struct au_module *mod);
+
+int au_volume(int vol);
+int au_sfx_volume(int vol);
+int au_music_volume(int vol);
+
+/* pay no attention to the man behind the curtain */
+#define AU_VOLADJ(vol, newvol) \
+       do { \
+               int d; \
+               switch(newvol & 0xff00) { \
+               case AU_CUR: \
+                       return (vol); \
+               case AU_VOLUP: \
+                       d = newvol & 0xff; \
+                       (newvol) = (vol) + (d ? d : 16); \
+                       if((newvol) >= 256) (newvol) = 255; \
+                       break; \
+               case AU_VOLDN: \
+                       d = newvol & 0xff; \
+                       (newvol) = (vol) - (d ? d : 16); \
+                       if((newvol) < 0) (newvol) = 0; \
+                       break; \
+               default: \
+                       break; \
+               } \
+       } while(0)
+
+#endif /* AUDIO_H_ */