decompile field_camera.c (#103)

* start decompiling field_camera.c

* can't get CameraUpdate to match

* finish decompiling

1 files changed, 516 insertions, 0 deletions

diff --git a/src/field_camera.c b/src/field_camera.c
new file mode 100644
index 000000000..02db33bf2
--- /dev/null
+++ b/src/field_camera.c
@@ -0,0 +1,516 @@
+#include "global.h"
+#include "fieldmap.h"
+#include "sprite.h"
+#include "text.h"
+
+extern u16 gBGTilemapBuffers[4][0x400];
+
+
+//ToDo: argument types
+extern u8 MapGridGetMetatileLayerTypeAt();
+extern u8 player_get_direction_upper_nybble(void);
+extern void ResetBerryTreeSparkleFlags(void);
+extern void RotatingGatePuzzleCameraUpdate(s16, s16);
+extern int MapGridGetMetatileIdAt(int, int);
+extern int CameraMove(int, int);
+
+extern u8 gUnknown_0202E854;
+
+
+struct UnknownStruct
+{
+    u8 unk0;
+    u8 unk1;
+    u8 unk2;
+    u8 unk3;
+    bool8 unk4;
+};
+
+extern struct UnknownStruct gUnknown_03000590;
+extern u16 gUnknown_03000598;
+extern s16 gUnknown_0300059A;
+extern u8 gUnknown_0300059C;
+extern void (*gUnknown_030005A0)(void);
+
+struct CameraSomething
+{
+    void (*callback)(struct CameraSomething *);
+    u32 unk4;
+    s32 unk8;
+    s32 unkC;
+    s32 unk10;
+    s32 unk14;
+};
+
+extern struct CameraSomething gUnknown_03004880;
+extern u16 gUnknown_03004898;
+extern u16 gUnknown_0300489C;
+
+static void RedrawMapSliceNorth(struct UnknownStruct *a, struct MapData *mapData);
+static void RedrawMapSliceSouth(struct UnknownStruct *a, struct MapData *mapData);
+static void RedrawMapSliceEast(struct UnknownStruct *a, struct MapData *mapData);
+static void RedrawMapSliceWest(struct UnknownStruct *a, struct MapData *mapData);
+static s32 MapPosToBgTilemapOffset(struct UnknownStruct *a, s32 x, s32 y);
+void CameraUpdate(void);
+
+static void DrawWholeMapViewInternal(int x, int y, struct MapData *mapData);
+static void DrawMetatileAt(struct MapData *mapData, u16, int, int);
+static void DrawMetatile(s32 a, u16 *b, u16 c);
+u8 AddCameraObject(u8);
+void UpdateFieldObjectsForCameraUpdate(s16, s16);
+static void CameraPanningCB_PanAhead(void);
+
+static void move_tilemap_camera_to_upper_left_corner_(struct UnknownStruct *a)
+{
+    a->unk2 = 0;
+    a->unk3 = 0;
+    a->unk0 = 0;
+    a->unk1 = 0;
+    a->unk4 = TRUE;
+}
+
+static void tilemap_move_something(struct UnknownStruct *a, u32 b, u32 c)
+{
+    a->unk2 += b;
+    a->unk2 %= 32;
+    a->unk3 += c;
+    a->unk3 %= 32;
+}
+
+static void coords8_add(struct UnknownStruct *a, u32 b, u32 c)
+{
+    a->unk0 += b;
+    a->unk1 += c;
+}
+
+void move_tilemap_camera_to_upper_left_corner(void)
+{
+    move_tilemap_camera_to_upper_left_corner_(&gUnknown_03000590);
+    CpuFill16(0, gBGTilemapBuffers[2], 0x800);
+    CpuFill16(0, gBGTilemapBuffers[1], 0x800);
+    CpuFill16(0x3014, gBGTilemapBuffers[3], 0x800);
+}
+
+void sub_8057A58(void)
+{
+    *gBGHOffsetRegs[1] = gUnknown_03000590.unk0 + gUnknown_03000598;
+    *gBGVOffsetRegs[1] = gUnknown_03000590.unk1 + gUnknown_0300059A + 8;
+    *gBGHOffsetRegs[2] = gUnknown_03000590.unk0 + gUnknown_03000598;
+    *gBGVOffsetRegs[2] = gUnknown_03000590.unk1 + gUnknown_0300059A + 8;
+    *gBGHOffsetRegs[3] = gUnknown_03000590.unk0 + gUnknown_03000598;
+    *gBGVOffsetRegs[3] = gUnknown_03000590.unk1 + gUnknown_0300059A + 8;
+    
+    if(gUnknown_03000590.unk4)
+    {
+        DmaCopy16(3, gBGTilemapBuffers[1], (void *)(VRAM + 0xE800), 0x800);
+        DmaCopy16(3, gBGTilemapBuffers[2], (void *)(VRAM + 0xE000), 0x800);
+        DmaCopy16(3, gBGTilemapBuffers[3], (void *)(VRAM + 0xF000), 0x800);
+        gUnknown_03000590.unk4 = FALSE;
+    }
+}
+
+void sub_8057B14(u16 *a, u16 *b)
+{
+    *a = gUnknown_03000590.unk0 + gUnknown_03000598;
+    *b = gUnknown_03000590.unk1 + gUnknown_0300059A + 8;
+}
+
+void DrawWholeMapView(void)
+{
+    DrawWholeMapViewInternal(gSaveBlock1.pos.x, gSaveBlock1.pos.y, gMapHeader.mapData);
+    gUnknown_03000590.unk4 = TRUE;
+}
+
+static void DrawWholeMapViewInternal(int x, int y, struct MapData *mapData)
+{
+    u8 i;
+    u8 j;
+    u32 r6;
+    u8 temp;
+    
+    for(i = 0; i < 32; i += 2)
+    {
+        temp = gUnknown_03000590.unk3 + i;
+        if(temp >= 32)
+            temp -= 32;
+        r6 = temp * 32;
+        for(j = 0; j < 32; j += 2)
+        {
+            temp = gUnknown_03000590.unk2 + j;
+            if(temp >= 32)
+                temp -= 32;
+            DrawMetatileAt(mapData, r6 + temp, x + j / 2, y + i / 2);
+        }
+    }
+}
+
+static void RedrawMapSlicesForCameraUpdate(struct UnknownStruct *a, int x, int y)
+{
+    struct MapData *mapData = gMapHeader.mapData;
+    
+    if(x > 0)
+        RedrawMapSliceWest(a, mapData);
+    if(x < 0)
+        RedrawMapSliceEast(a, mapData);
+    if(y > 0)
+        RedrawMapSliceNorth(a, mapData);
+    if(y < 0)
+        RedrawMapSliceSouth(a, mapData);
+    a->unk4 = TRUE;
+}
+
+static void RedrawMapSliceNorth(struct UnknownStruct *a, struct MapData *mapData)
+{
+    u8 i;
+    u8 temp;
+    u32 r7;
+    
+    temp = a->unk3 + 28;
+    if(temp >= 32)
+        temp -= 32;
+    r7 = temp * 32;
+    for(i = 0; i < 32; i += 2)
+    {
+        temp = a->unk2 + i;
+        if(temp >= 32)
+            temp -= 32;
+        DrawMetatileAt(mapData, r7 + temp, gSaveBlock1.pos.x + i / 2, gSaveBlock1.pos.y + 14);
+    }
+}
+
+static void RedrawMapSliceSouth(struct UnknownStruct *a, struct MapData *mapData)
+{
+    u8 i;
+    u8 temp;
+    u32 r7 = a->unk3 * 32;
+    
+    for(i = 0; i < 32; i += 2)
+    {
+        temp = a->unk2 + i;
+        if(temp >= 32)
+            temp -= 32;
+        DrawMetatileAt(mapData, r7 + temp, gSaveBlock1.pos.x + i / 2, gSaveBlock1.pos.y);
+    }
+}
+
+static void RedrawMapSliceEast(struct UnknownStruct *a, struct MapData *mapData)
+{
+    u8 i;
+    u8 temp;
+    u32 r6 = a->unk2;
+    
+    for(i = 0; i < 32; i += 2)
+    {
+        temp = a->unk3 + i;
+        if(temp >= 32)
+            temp -= 32;
+        DrawMetatileAt(mapData, temp * 32 + r6, gSaveBlock1.pos.x, gSaveBlock1.pos.y + i / 2);
+    }
+}
+
+static void RedrawMapSliceWest(struct UnknownStruct *a, struct MapData *mapData)
+{
+    u8 i;
+    u8 temp;
+    u8 r5 = a->unk2 + 28;
+    
+    if(r5 >= 32)
+        r5 -= 32;
+    for(i = 0; i < 32; i += 2)
+    {
+        temp = a->unk3 + i;
+        if(temp >= 32)
+            temp -= 32;
+        DrawMetatileAt(mapData, temp * 32 + r5, gSaveBlock1.pos.x + 14, gSaveBlock1.pos.y + i / 2);
+    }
+}
+
+void CurrentMapDrawMetatileAt(int a, int b)
+{
+    int offset = MapPosToBgTilemapOffset(&gUnknown_03000590, a, b);
+    
+    if(offset >= 0)
+    {
+        DrawMetatileAt(gMapHeader.mapData, offset, a, b);
+        gUnknown_03000590.unk4 = TRUE;
+    }
+}
+
+void DrawDoorMetatileAt(int x, int y, u16 *arr)
+{
+    int offset = MapPosToBgTilemapOffset(&gUnknown_03000590, x, y);
+    
+    if(offset >= 0)
+    {
+        DrawMetatile(1, arr, offset);
+        gUnknown_03000590.unk4 = TRUE;
+    }
+}
+
+static void DrawMetatileAt(struct MapData *mapData, u16 b, int c, int d)
+{
+    u16 metatileId = MapGridGetMetatileIdAt(c, d);
+    u16 *metatiles;
+    
+    if(metatileId > 1024)
+        metatileId = 0;
+    if(metatileId < 512)
+        metatiles = mapData->primaryTileset->metatiles;
+    else
+    {
+        metatiles = mapData->secondaryTileset->metatiles;
+        metatileId -= 512;
+    }
+    DrawMetatile(MapGridGetMetatileLayerTypeAt(c, d), metatiles + metatileId * 8, b);
+}
+
+static void DrawMetatile(s32 a, u16 *b, u16 c)
+{
+    switch(a)
+    {
+        case 2:
+            gBGTilemapBuffers[3][c] = b[0];
+            gBGTilemapBuffers[3][c + 1] = b[1];
+            gBGTilemapBuffers[3][c + 0x20] = b[2];
+            gBGTilemapBuffers[3][c + 0x21] = b[3];
+            
+            gBGTilemapBuffers[2][c] = 0;
+            gBGTilemapBuffers[2][c + 1] = 0;
+            gBGTilemapBuffers[2][c + 0x20] = 0;
+            gBGTilemapBuffers[2][c + 0x21] = 0;
+            
+            gBGTilemapBuffers[1][c] = b[4];
+            gBGTilemapBuffers[1][c + 1] = b[5];
+            gBGTilemapBuffers[1][c + 0x20] = b[6];
+            gBGTilemapBuffers[1][c + 0x21] = b[7];
+            break;
+        case 1:
+            gBGTilemapBuffers[3][c] = b[0];
+            gBGTilemapBuffers[3][c + 1] = b[1];
+            gBGTilemapBuffers[3][c + 0x20] = b[2];
+            gBGTilemapBuffers[3][c + 0x21] = b[3];
+            
+            gBGTilemapBuffers[2][c] = b[4];
+            gBGTilemapBuffers[2][c + 1] = b[5];
+            gBGTilemapBuffers[2][c + 0x20] = b[6];
+            gBGTilemapBuffers[2][c + 0x21] = b[7];
+            
+            gBGTilemapBuffers[1][c] = 0;
+            gBGTilemapBuffers[1][c + 1] = 0;
+            gBGTilemapBuffers[1][c + 0x20] = 0;
+            gBGTilemapBuffers[1][c + 0x21] = 0;
+            break;
+        case 0:
+            gBGTilemapBuffers[3][c] = 0x3014;
+            gBGTilemapBuffers[3][c + 1] = 0x3014;
+            gBGTilemapBuffers[3][c + 0x20] = 0x3014;
+            gBGTilemapBuffers[3][c + 0x21] = 0x3014;
+            
+            gBGTilemapBuffers[2][c] = b[0];
+            gBGTilemapBuffers[2][c + 1] = b[1];
+            gBGTilemapBuffers[2][c + 0x20] = b[2];
+            gBGTilemapBuffers[2][c + 0x21] = b[3];
+            
+            gBGTilemapBuffers[1][c] = b[4];
+            gBGTilemapBuffers[1][c + 1] = b[5];
+            gBGTilemapBuffers[1][c + 0x20] = b[6];
+            gBGTilemapBuffers[1][c + 0x21] = b[7];
+            break;
+    }
+}
+
+static s32 MapPosToBgTilemapOffset(struct UnknownStruct *a, s32 x, s32 y)
+{
+    x -= gSaveBlock1.pos.x;
+    x *= 2;
+    if(x >= 32 || x < 0)
+        return -1;
+    x = x + a->unk2;
+    if(x >= 32)
+        x -= 32;
+    
+    y = (y - gSaveBlock1.pos.y) * 2;
+    if(y >= 32 || y < 0)
+        return -1;
+    y = y + a->unk3;
+    if(y >= 32)
+        y -= 32;
+    
+    return y * 32 + x;
+}
+
+static void CameraUpdateCallback(struct CameraSomething *a)
+{
+    if(a->unk4 != 0)
+    {
+        a->unk8 = gSprites[a->unk4].data2;
+        a->unkC = gSprites[a->unk4].data3;
+    }
+}
+
+void ResetCameraUpdateInfo(void)
+{
+    gUnknown_03004880.unk8 = 0;
+    gUnknown_03004880.unkC = 0;
+    gUnknown_03004880.unk10 = 0;
+    gUnknown_03004880.unk14 = 0;
+    gUnknown_03004880.unk4 = 0;
+    gUnknown_03004880.callback = NULL;
+}
+
+u32 InitCameraUpdateCallback(u8 a)
+{
+    if(gUnknown_03004880.unk4 != 0)
+        DestroySprite(&gSprites[gUnknown_03004880.unk4]);
+    gUnknown_03004880.unk4 = AddCameraObject(a);
+    gUnknown_03004880.callback = CameraUpdateCallback;
+    return 0;
+}
+
+void CameraUpdate(void)
+{
+    int deltaX;
+    int deltaY;
+    int r0;
+    int r1;
+    int r7;
+    int r8;
+    
+    if(gUnknown_03004880.callback != NULL)
+        gUnknown_03004880.callback(&gUnknown_03004880);
+    r7 = gUnknown_03004880.unk8;
+    r8 = gUnknown_03004880.unkC;
+    deltaX = 0;
+    deltaY = 0;
+    r1 = gUnknown_03004880.unk10;
+    r0 = gUnknown_03004880.unk14;
+    
+    
+    if(r1 == 0 && r7 != 0)
+    {
+        if(r7 > 0)
+            deltaX = 1;
+        else
+            deltaX = -1;
+    }
+    if(r0 == 0 && r8 != 0)
+    {
+        if(r8 > 0)
+            deltaY = 1;
+        else
+            deltaY = -1;
+    }
+    if(r1 != 0 && r1 == -r7)
+    {
+        if(r7 > 0)
+            deltaX = 1;
+        else
+            deltaX = -1;
+    }
+    if(r0 != 0 && r0 == -r8)
+    {
+        if(r8 > 0)
+            deltaX = 1;
+        else
+            deltaX = -1;
+    }
+    
+    gUnknown_03004880.unk10 += r7;
+    gUnknown_03004880.unk10 = gUnknown_03004880.unk10 - 16 * (gUnknown_03004880.unk10 / 16);    
+    gUnknown_03004880.unk14 += r8;
+    gUnknown_03004880.unk14 = gUnknown_03004880.unk14 - 16 * (gUnknown_03004880.unk14 / 16);
+    
+    if(deltaX != 0 || deltaY != 0)
+    {
+        CameraMove(deltaX, deltaY);
+        UpdateFieldObjectsForCameraUpdate(deltaX, deltaY);
+        RotatingGatePuzzleCameraUpdate(deltaX, deltaY);
+        ResetBerryTreeSparkleFlags();
+        tilemap_move_something(&gUnknown_03000590, deltaX * 2, deltaY * 2);
+        RedrawMapSlicesForCameraUpdate(&gUnknown_03000590, deltaX * 2, deltaY * 2);
+    }
+    
+    coords8_add(&gUnknown_03000590, r7, r8);
+    gUnknown_0300489C -= r7;
+    gUnknown_03004898 -= r8;
+}
+
+static void camera_move_and_redraw(int a, int b)
+{
+    CameraMove(a, b);
+    UpdateFieldObjectsForCameraUpdate(a, b);
+    DrawWholeMapView();
+    gUnknown_0300489C -= a * 16;
+    gUnknown_03004898 -= b * 16;
+}
+
+void SetCameraPanningCallback(void (*a)(void))
+{
+    gUnknown_030005A0 = a;
+}
+
+void SetCameraPanning(s16 a, s16 b)
+{
+    gUnknown_03000598 = a;
+    gUnknown_0300059A = b + 32;
+}
+
+void InstallCameraPanAheadCallback(void)
+{
+    gUnknown_030005A0 = CameraPanningCB_PanAhead;
+    gUnknown_0300059C = 0;
+    gUnknown_03000598 = 0;
+    gUnknown_0300059A = 32;
+}
+
+void UpdateCameraPanning(void)
+{
+    if (gUnknown_030005A0 != NULL)
+        gUnknown_030005A0();
+    //Update sprite offset of overworld objects
+    gSpriteCoordOffsetX = gUnknown_0300489C - gUnknown_03000598;
+    gSpriteCoordOffsetY = gUnknown_03004898 - gUnknown_0300059A - 8;
+}
+
+static void CameraPanningCB_PanAhead(void)
+{
+    u8 var;
+    
+    if (gUnknown_0202E854 == 0)
+    {
+        InstallCameraPanAheadCallback();
+    }
+    else
+    {
+        if (gPlayerAvatar.running1 == 1)
+        {
+            gUnknown_0300059C ^= 1;
+            if (gUnknown_0300059C == 0)
+                return;
+        }
+        else
+        {
+            gUnknown_0300059C = 0;
+        }
+        
+        var = player_get_direction_upper_nybble();
+        if (var == 2)
+        {
+            if (gUnknown_0300059A > -8)
+                gUnknown_0300059A -= 2;
+        }
+        else if (var == 1)
+        {
+            if (gUnknown_0300059A < 72)
+                gUnknown_0300059A += 2;
+        }
+        else if (gUnknown_0300059A < 32)
+        {
+            gUnknown_0300059A += 2;
+        }
+        else if (gUnknown_0300059A > 32)
+        {
+            gUnknown_0300059A -= 2;
+        }
+    }
+}