Merge pull request #12 from SethBarberee/master

Merge work from SethBarberee/pmd-red into pret.

1 files changed, 241 insertions, 0 deletions

diff --git a/src/music_pre.c b/src/music_pre.c
new file mode 100644
index 0000000..292f0a8
--- /dev/null
+++ b/src/music_pre.c
@@ -0,0 +1,241 @@
+#include "global.h"
+#include "gba/io_reg.h"
+#include "m4a.h"
+
+extern void nullsub_19(void);
+extern void nullsub_20(u16 songIndex);
+extern bool8 EnableInterrupts(void);
+extern bool8 DisableInterrupts(void);
+extern bool8 IsBGSong(u32);
+
+extern void sub_800C298(u16 r0);
+extern u16 sub_800CAE0(u16);
+
+extern u32 gUnknown_202D5F0[];
+extern u16 gUnknown_202D688;
+extern u16 gUnknown_202D68A;
+extern u16 gUnknown_202D68C;
+extern u16 gUnknown_202D68E;
+extern u16 gUnknown_202D690;
+extern u16 gUnknown_202D692;
+extern u8 gUnknown_202D694;
+
+struct unkStruct_3000FD8
+{
+    u16 unk0;
+    u16 unk2;
+    u16 unk4;
+    u8 unk6;
+    u8 padding;
+};
+
+extern struct unkStruct_3000FD8 gUnknown_3000FD8[8];
+
+void sub_800BF80(void);
+
+// Some kind of initializer for music?
+void sub_800BD08(void)
+{
+    s32 counter;
+    u16 zero;
+    u16 zero2;
+
+    struct unkStruct_3000FD8 *preload;
+
+    DmaStop(0);
+    DmaStop(1);
+    DmaStop(2);
+    DmaStop(3);
+
+    m4aSoundInit();
+
+    gUnknown_202D688 = 0;
+    gUnknown_202D68A = 0x3e7;
+    gUnknown_202D68C = 0x3e7;
+    gUnknown_202D68E = 0x3e5;
+    gUnknown_202D690 = 0;
+    gUnknown_202D692 = 0;
+    gUnknown_202D694 = 0;
+
+    // Kinda hacky but makes things match
+    preload = gUnknown_3000FD8;
+    zero = 0;
+    zero2 = 0;
+    counter = 7;
+
+    while(counter >= 0)
+    {
+        preload->unk0 = zero2;
+        preload->unk2 = 0x3e5;
+        preload->unk4 = zero2;
+        preload->unk6 = zero;
+        counter--;
+        preload++;
+    }
+    nullsub_19();
+}
+
+void sub_800BDDC(void)
+{
+    sub_800BF80();
+    sub_800C298(0x3e6);
+    sub_800C298(0x3e5);
+}
+
+
+void sub_800BDFC(u16 songIndex)
+{
+    bool8 interrupt_flag;
+    u16 temp_store;
+
+    if(!IsBGSong(songIndex))
+        return;
+    if(songIndex == 0x3e7)
+        return;
+    if(songIndex == gUnknown_202D68A)
+    {
+        temp_store = gUnknown_202D688 - 1;
+        if(temp_store <= 1)
+            return;
+    }
+    if(sub_800CAE0(songIndex))
+    {
+        nullsub_20(songIndex);
+        return;
+    }
+    interrupt_flag = DisableInterrupts();
+    gUnknown_202D68A = songIndex;
+    gUnknown_202D694 = 1;
+
+    if(gUnknown_202D690 == 0)
+    {
+        gUnknown_202D688 = 1;
+        m4aSongNumStart(songIndex);
+    }
+    if(interrupt_flag)
+        EnableInterrupts();
+}
+
+void FadeInNewBGM(u16 SongIndex, u16 speed)
+{
+    bool8 interrupt_flag;
+    u16 temp_store;
+
+    if(!IsBGSong(SongIndex))
+        return;
+    if(SongIndex == 0x3e7)
+        return;
+    if(SongIndex == gUnknown_202D68A)
+    {
+        temp_store = gUnknown_202D688 - 1;
+        if((temp_store) <= 1)
+            return;
+    }
+
+    if((speed > 256))
+    {
+        speed = 16;
+
+    }
+    else
+    {
+        if((speed >>= 4) == 0)
+        {
+            speed = 1;
+        }
+    }
+
+    interrupt_flag = DisableInterrupts();
+    gUnknown_202D68A = SongIndex;
+    gUnknown_202D694 = 1;
+
+    if(gUnknown_202D690 == 0)
+    {
+        gUnknown_202D688 = 1;
+        m4aSongNumStart(SongIndex);
+        m4aMPlayImmInit(&gUnknown_20008F0);
+        m4aMPlayVolumeControl(&gUnknown_20008F0, 0xFF, 0);
+        m4aSongNumStop(SongIndex);
+        m4aMPlayFadeIn(&gUnknown_20008F0, speed);
+    }
+    if(interrupt_flag)
+        EnableInterrupts();
+}
+
+void sub_800BF48(u16 SongIndex)
+{
+    u16 preload  = gUnknown_202D68A;
+    if(preload == 0x3e7)
+    {
+        sub_800BDFC(SongIndex);
+        gUnknown_202D68C = preload;
+        return;
+    }
+    gUnknown_202D68C = SongIndex;
+}
+
+void sub_800BF80(void)
+{
+    bool8 interrupt_flag = DisableInterrupts();
+    if(gUnknown_202D690 == 0)
+    {
+        if(gUnknown_202D68A != 0x3e7)
+        {
+            m4aMPlayStop(&gUnknown_20008F0);
+        }
+    }
+    gUnknown_202D68A = 0x3e7;
+    gUnknown_202D68C = 0x3e7;
+    if(interrupt_flag)
+        EnableInterrupts();
+}
+
+void sub_800BFD0(u16 speed)
+{
+
+    u32 comparison;
+    bool8 interrupt_flag;
+
+    // TODO clean this comparison up
+    comparison = 0x80 << 17; // 16777216
+    if((speed * 65536) > comparison)
+    {
+        speed = 16;
+    }
+    else
+    {
+        if((speed >>= 4) == 0)
+        {
+            speed = 1;
+        }
+    }
+    interrupt_flag = DisableInterrupts();
+    if(gUnknown_202D690 == 0)
+    {
+        if(gUnknown_202D68A != 0x3e7)
+        {
+            if(gUnknown_202D688 == 2)
+            {
+                gUnknown_202D688 = 3;
+                m4aMPlayFadeOut(&gUnknown_20008F0, speed);
+            }
+            else
+            {
+                gUnknown_202D68A = 0x3e7;
+                m4aMPlayStop(&gUnknown_20008F0);
+            }
+        }
+    }
+    else
+    {
+        gUnknown_202D68A = 0x3e7;
+    }
+    gUnknown_202D68C = 0x3e7;
+    if(interrupt_flag)
+        EnableInterrupts();
+}
+
+u16 sub_800C068(void)
+{
+    return gUnknown_202D68A;
+}