## Custom Battle Mugshots

This feature lets us use any trainer for the elite four mugshot battle intro:

<a href="https://imgur.com/T47I2js"><img src="https://i.imgur.com/T47I2js.gif" title="source: imgur.com" /></a>

### First, lets move the mugshot IDs to a constants 
- Open [include/battle_transition.h](../blob/master/include/battle_transitions.h)
- Add `#include "constants/battle_transition.h` to the top
- remove the following:
```
enum // TRANSITION_MUGSHOT
{
    MUGSHOT_SIDNEY,
    MUGSHOT_PHOEBE,
    MUGSHOT_GLACIA,
    MUGSHOT_DRAKE,
    MUGSHOT_CHAMPION,
    MUGSHOTS_COUNT
};
```
- create a new file, `include/constants/battle_transition.h`
```c
#ifndef GUARD_CONSTANTS_BATTLE_TRANSITION_H
#define GUARD_CONSTANTS_BATTLE_TRANSITION_H

#define MUGSHOT_SIDNEY      0
#define MUGSHOT_PHOEBE      1
#define MUGSHOT_GLACIA      2
#define MUGSHOT_DRAKE       3
#define MUGSHOT_CHAMPION    4

#define MUGSHOTS_COUNT      5

#endif //GUARD_CONSTANTS_BATTLE_TRANSITION_H
```

### Allow scripts to recognize these constants
- Open [data/event_scripts.s](../blob/master/data/event_scripts.s)
- Add `#include "constants/battle_transition.h"` somewhere at the top

Now you can use `MUGSHOT_##` in scripts. This will be relevant later.

### Define a new mugshot Id
- Let's define a new mugshot for our trainer. I will use May as an example.
- Inside the new `constants/battle_transition.h`, define a new ID (and increase `MUGSHOT_COUNT`)
```c
#define MUGSHOT_MAY    5
#define MUGSHOT_COUNT  6
```

### Define a new mugshot type
At the bottom of `include/battle_transition.h`, replace `B_TRANSITION_COUNT` with:
```
#define B_TRANSITION_MUGSHOT                                   42
#define B_TRANSITION_COUNT                                     43
```

Now we just need a way to load the appropriate mugshot for this transition type. We'll use a variable that we can set before battles.

### Define a variable to load the mugshot ID
Inside `include/constants/vars.h`, replace an unused variable or add your own: `VAR_MUGSHOT_ID`

### Allow trainers to have custom battle transitions
- Open [include/data.h](../blob/master/include/data.h)
- Add the following to `struct Trainer`:
```c
    u8 transition:7;
    u8 hasCustomTransition:1;
```
- Open [src/battle_setup.c](../blob/master/src/battle_setup.c). Find the function `GetTrainerBattleTransition`
- Add the following code above Line 816: `if (gTrainers[gTrainerBattleOpponent_A].trainerClass == TRAINER_CLASS_ELITE_FOUR)`
```c
    if (gTrainers[gTrainerBattleOpponent_A].hasCustomTransition)
        return gTrainers[gTrainerBattleOpponent_A].transition;
```
- In [src/data.c](../blob/master/src/data.c), we need to add `#include "battle_transition.h"` to the top as well.

### Lets add the actual mugshot loading code
- Open [src/battle_transition.c](../blob/master/src/battle_transition.c)
- Add `#include "event_data.h"` to the top. 
- Add `static void Phase2Task_Mugshot(u8 taskId);` in the function declarations. For example, above `static void Phase2Task_Sidney(u8 taskId);`
- Add the new transition to `sPhase2_Tasks` by adding `[B_TRANSITION_MUGSHOT] = Phase2Task_Mugshot,` to the array.
- Somewhere in the file, add our new function:
```c
static void Phase2Task_Mugshot(u8 taskId)
{
    gTasks[taskId].tMugshotId = VarGet(VAR_MUGSHOT_ID);
    Phase2Task_MugShotTransition(taskId);
}
```

### Add Mugshot Id graphics
For each mugshot we've added, we need to add an element to the following:
- `sMugshotsTrainerPicIDsTable`
- `sMugshotsOpponentRotationScales`: ({0x200, 0x200} should be fine, but dealer's choice)
- `sMugshotsOpponentCoords`: ({0, 0} should be fine, but again its case-dependent)
- `sOpponentMugshotsPals`

For example:
```diff
static const u8 sMugshotsTrainerPicIDsTable[MUGSHOTS_COUNT] =
static const u8 sMugshotsTrainerPicIDsTable[MUGSHOTS_COUNT] =
{
+    [MUGSHOT_MAY]    = TRAINER_PIC_MAY,
    [MUGSHOT_SIDNEY] = TRAINER_PIC_ELITE_FOUR_SIDNEY,
    [MUGSHOT_PHOEBE] = TRAINER_PIC_ELITE_FOUR_PHOEBE,
    [MUGSHOT_GLACIA] = TRAINER_PIC_ELITE_FOUR_GLACIA,
    [MUGSHOT_DRAKE] = TRAINER_PIC_ELITE_FOUR_DRAKE,
    [MUGSHOT_CHAMPION] = TRAINER_PIC_CHAMPION_WALLACE,
};
static const s16 sMugshotsOpponentRotationScales[MUGSHOTS_COUNT][2] =
{
+    [MUGSHOT_MAY]    =   {0x200, 0x200},
    [MUGSHOT_SIDNEY] =   {0x200, 0x200},
    [MUGSHOT_PHOEBE] =   {0x200, 0x200},
    [MUGSHOT_GLACIA] =   {0x1B0, 0x1B0},
    [MUGSHOT_DRAKE] =    {0x1A0, 0x1A0},
    [MUGSHOT_CHAMPION] = {0x188, 0x188},
};
static const s16 sMugshotsOpponentCoords[MUGSHOTS_COUNT][2] =
{
+    [MUGSHOT_MAY]      = {0,     0},
    [MUGSHOT_SIDNEY] =   {0,     0},
    [MUGSHOT_PHOEBE] =   {0,     0},
    [MUGSHOT_GLACIA] =   {-4,    4},
    [MUGSHOT_DRAKE] =    {0,     5},
    [MUGSHOT_CHAMPION] = {-8,    7},
};
static const u16 *const sOpponentMugshotsPals[MUGSHOTS_COUNT] =
{
+    [MUGSHOT_MAY]    = sMugshotPal_Glacia,
    [MUGSHOT_SIDNEY] = sMugshotPal_Sidney,
    [MUGSHOT_PHOEBE] = sMugshotPal_Phoebe,
    [MUGSHOT_GLACIA] = sMugshotPal_Glacia,
    [MUGSHOT_DRAKE] = sMugshotPal_Drake,
    [MUGSHOT_CHAMPION] = sMugshotPal_Champion
};
```

### Change Relevant Trainer Data
- Open [src/data/trainers.h](../blob/master/src/data/trainers.h)
- Add the following to any trainer you want to give a mugshot
```c
        .hasCustomTransition = TRUE,
        .transition = B_TRANSITION_MUGSHOT,
```

### Set the variable
We must define `VAR_MUGSHOT_ID` before our trainerbattle, and it should work!

For example:
```c
EventScript_BattleMay::
    lockall
    faceplayer
    msgbox sText_SomeIntro, MSGBOX_DEFAULT
    setvar VAR_MUGSHOT_ID, MUGSHOT_MAY
    trainerbattle_no_intro TRAINER_MAY_ROUTE_103_TORCHIC, sText_MayLose
```