Yal's Monster Collector Engine

I think the easiest way to add this would be having a new global array of "mega evolutions data" which has three items per row: base monster, mega monster, and held item needed for the transformation.

• When generating the Moves menu, check each row of the mega evolutions data and if both the base monster and held item matches this monster's data, add a fifth option for mega evolution (unless you've already mega'd another monster in this battle, which you'd keep track of in a separate variable), picking this option will change that monster's species to the mega monster.

• All mega IDs should be at the very end of the monster data, perhaps even beyond MONSTER_MAX so the data won't e.g. get added to the dex.

• At the end of battle, go through the mega evolutions array again and if any of the player's party monster has a mega species, change it back to the regular species.

I'm thinking something like this:

• The item should be itemvalid_FIELDONLY so you can't use it in battle and have a new use_script itemuse_teachmove where the use_arg is the ID of the move.
• The new use script should first attempt to learn it with amp_learn_move_instantly, this function returns "false" if the monster already has a full movelist and if so you'll need to create a menu. You can copy this code from obj_battlecontrol's Step Event case 32 (but in the itemusescript the AMP ID will be argument0 and the move ID will be argument1 rather than "exp_monster" and "nm").
  
• Instead of using mev_monster_learnmove_spawnmenu directly, make a copy of it that, in turn, uses a copy of mev_monster_learnmove_confirm to confirm moves. This copy of the function doesn't destroy ALL parent_menu objects (we want the inventory menu and main menu to remain) but only the intermediate steps, and it also removes 1 copy of the TM (assuming you want them to be consumable and not reusable like in XY onwards). Likewise the copy of mev_monster_learnmove_cancel also lets the main and inventory menus remain.

Overworld sprites should "just work", draw_sprite_gridbased uses a percentage of the sprite asset's size so the only thing that matters is that it's a 4x4 grid.

For the tiles, change the TILESIZE macro-constant to 32 (it's set in init_constants) and then also update the settings of tileset_indoors and tileset_outdoors to be 32 (the underlying sprites also need to be resized to 640x512 for the information about how many columns of tiles are in the sets to be accurate. 

Changing the sizes should be safe (I use the TILESIZE constant everywhere) except I don't know what Game Maker will do with pre-existing tile layers when you change the tilesize. It's probably best to make a backup of your project (File --> Export Project --> YYZ) before you do this.

The error is because there's no player in the room. One way around it is to use with loops instead which does nothing if there's no object that matches it, try replacing the line with this:

with(obj_player){
    sprite_index = spr_player;
}

For priority, I would add a new parameter to init_move for move priority (which is 0 for all moves that doesn't have a priority) and then when you action_slate the move, add some big number times the move's priority to the speed-priority parameter. There's three places move-actions are slated: mev_battle_attack_select, mev_battle_attack_select_target, and obj_battlecontrol's step event. (There's already cases where actions are slated with higher priority, like when using a consumable item in battle, so the only thing that's missing is a bonus priority value from the move data)

For "attack heals for a percentage of damage" I would add a new side-effect type called "movespfx_LIFESTEAL" and give to those moves, special effects are handled in obj_battlecontrol's step event (search for "mvd_SIDEEFFECT_TYPE" to find where it's processed) and this is where you'd add the logic to heal the user based on how much damage the target took (the user's ID is in a_user). You can access the amount of damage dealt through n.my_dmg (the obj_damageapply created in the Damage block) though you'd probably want to save it in its own variable that's always initialized to 0 (in case the damage block gets skipped due to the move having 0 power n.my_dmg does not exist which will lead to a game crash if you try accessing it).

For multiple buffs/debuffs i would do something similar, add new side effect types for multiple buff/debuffs, and for these the mvd_SIDEEFFECT_SUBTYPE slot of the movedata would be an array:

[50,    movespfx_MULTIDEBUFF,        [stat_DEF,stat_RES],        1]

Applying these would be very similar to the current buff/debuff code but you loop over the "stat" value (since it's an array).

...actually, you could probably just turn the regular buff/debuff cases into loops in case an array is passed into them (use is_array to check), and avoid the extra work of having separate multibuff/debuff values.

Are you spawning the virtual keys offscreen perhaps? All of the menus draw themselves in the Draw GUI event (GUI layer) to avoid having to think about that, be careful not to use the x / y position of menu objects (which is not used) but instead check the coordinates of the GGUI frames / GGUI elements, which are in GUI coordinates.

(Also, are you using the Game Maker virtual keys system or making your own?)

Not really, adding more features also makes it more complicated to use. (Though if you check the comments I have suggested implementations for a lot of commonly requested features)

I think the easiest way to figure out how to implement abilities would be running a search (Ctrl+Shift+F) for itemvalidflag_AUTO_, this should bring up all the places where items are automatically triggered (e.g. the Spiked Shell being triggered on damage to deal a counter attack... you'd want a similar check for abilities being triggered on damage at basically the same place, for things like Flash Fire, Sturdy and so on; other abilities might trigger on each turn, or when attacking, etc)

You'll also need to actually give abilities to monsters (so init_monster needs to take a new argument for ability, the global.monster_data array be extended so it can fit this new data in, and the giant setup in init_monsters should provide it of course)

To show the ability, mev_pause_monsters_status is the script that builds the status screen. You'd read out the abl_NAME field here and create a ggui_element_text to display it somewhere.

1) Savefiles are found in AppData/Local/<name you saved the GM project under>, monster_save0 is the first file, monster_save1 the second and so on. It's a hidden folder so the easiest way to find it is to type in %LOCALAPPDATA% in the file explorer path and hit enter.

2) The important part is setting global.player_side_monsters and global.enemy_side_monsters to 2 (that's what controls how many monsters each side is allowed to have at once). The easiest way to inject this would be to copy obj_npc_trainer and cc_battlestart_trainer to new obj_npc_doublebattletrainer/cc_battlestart_doublebattletrainer which are mostly identical but sets these to 2 instead of 1 before the fight starts. (Also note that cc_battlestart_trainer actually can take an array of trainer data, global.encounter_trainer_data has one entry per trainer, so if you want a double battle against specifically two different trainers (instead of an entity like 'twins') you could populate this twice with different monster, dialogue etc data for each trainer.

3) Use an obj_encounterzoneselector, place one in the room and stretch it out over the area you want the battles in and then select the ects_* script with that room's settings (there's two more ects_* scripts with the first town / Driftwood Forest encounter data). They're tied to these markers so you can make things more granular (e.g. have different encounters in different terrain)

Badge status is handled by the array global.player_badges. The first badge is badge 0, the second badge 1 and so on.

You can check cis_leader1 and cis_leader1_beat for an example how this is done:

• in cis_leader1 there's different dialogue depending on if you have the badge or not (and you only trigger the battle if you don't have the badge). Also it sets up the post-battle script (global.after_battle_event) which is what triggers the cutscene after the battle.
• in cis_leader1_beat (the script set up to run when you win the battle) you actually get the badge thanks to the line that reads
  csc_enqueue(cc_obtainbadge,0)
  so for a second badge, you'd instead obtain badge 1 in the same way.

-12341 is the value of the NONE constant (one of the reasons I picked that number was to make it instantly recognizable). You need to set global.load_room to the current room before changing to the evolution room (and also the global.load_x, load_y and load_direction variables to the player's current x / y / drawdir respectively) otherwise it doesn't know where to put you back - and that's exactly what's happening right now.

(For an example of how to do this, check out player_step_fill which handles the "steps in tall grass to the next random battle" counter, and which sets these before changing to the battle room if an encounter is triggered - side note, this function would also be where you put things like "monsters in daycare gets EXP" and "countdown to eggs hatching" happening)

Since there's only one boss in the demo Fielder might as well be the champion. 😉

Total is the actual number of stat points, it gets subdivided proportionally over the stats (so the mhp-atk-def-mag-res-spd values are relative - e.g. if ATK is twice as high as DEF, the final stat will also be twice as high, but the actual value that gets stored in the end is TOTAL x ATK/(sum of all 6 stats), not ATK as-is).

The reason for why it's this convoluted is so it's easy to balance monsters - if two monsters has the same stat total, they should theoretically have the same power. (You can see this in Pokémon where there's tiers like "pseudolegendary" (600 stat total), the games never draw attention to this but competitive play communities does and that's where I got the idea originally)

Hello!

I don't really do commissions, I'm afraid - I barely have time to bring my own ideas to life :P But if you're stuck on anything with the engine, leave a question in the comments and I'll reply to it within 24 hours.

Of course you can! It's even mentioned in the store page description. The only thing you're not allowed to do is resell it as an asset pack, anything else is fair game, commercial or otherwise.

(And just for the record you are allowed to use all of the sprites/music that comes bundled with the code in a commercial game as well, though since a lot of it are placeholder-ish I can see why you'd wanna replace them :P)

You can find the code for it in the mev_intro_starterselect_confirm script:

var amp = amp_get_new_party_id();
amp_generate_monster(amp,MONSTER_SPECIES,LEVEL)

If you wanna add it to the box instead, use amp_get_new_box_id to get the first free box slot instead of the first free party slot.

I'll look into it, probably it can be fixed by manually altering the "active" variable so the menu ignores keypresses during the fadeout.

I consider it complete (unless there's a game-breaking bug).

function msh_botsmith_spawn_monsterpurchse_list(argument0) {

//mev_pause_moncyclopedia()

//Make sure statistics are up-to-date

msh_recompute_seencaught()

//Find max monster

var maxmon = 0, c;

for(c = MONSTER_MAX-1; c >= 0; c--){

if(global.monsters_seen[c]){

maxmon = c // maxmon is arraylength

break

}

}

    show_debug_message(global.monster_data)

with(instance_create_depth(x,y,depth - 1,obj_gguimenu)){

ggui_menu_preallocate(1,maxmon +1)

//Left pane: monster list (scrollable)

ggui_frame(0,0,VIEW_W*0.4,VIEW_H,spr_messagebox)

ggui_frame_set_scrolling(false,true,1,10,false,true)

var cmax = 10, yy, hh, vev;

ggui_element_text_settings(font_mainmsg,c_white,0,1)

for(c = 0;c < cmax;c++){

vev= c

yy = lerp(0.05,0.95,c/cmax)

hh = lerp(0.05,0.95,(c+1)/cmax) - yy

ggui_element_text_scrollable(0.1,yy+hh*0.5,0,vev)

}

//Add meta data as well, based on how much info the player has about the monster.

var d, mev, it;

draw_set_font(font_n)//Needed by string_wrap

for(d = 0; d <= maxmon; d++){

vev= d

yy = lerp(0.05,0.95,d/cmax)

hh = lerp(0.05,0.95,(d+1)/cmax) - yy

// ggui_menu_region(0,vev,mev,0.05,yy,0.95,yy+hh)

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

if(global.monsters_caught[d]){ 

//Wrap flavor text so it fits the box we add below

mev = argument0

it  =  global.monsters_seen[d]     //global.monsters_caught[d]

ggui_fill_meta(0,d,global.monster_data[d,mond_SPRITE_BATTLE],0,global.monster_data[d,mond_NAME],string_wrap(global.monster_data[d,mond_CRAFT_SLOT_SOUL_STRING],VIEW_W*0.6*0.8))

var soul = global.monster_data[d,mond_CRAFT_SLOT_SOUL] 

shop_item  = it

shop_cost  = soul

}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

else if(global.monsters_seen[d]){

mev = NONE

ggui_fill_meta(0,d,global.monster_data[d,mond_SPRITE_BATTLE],0,global.monster_data[d,mond_NAME],"???")

shop_item[d] = NONE

shop_cost[d] = 0

}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

else{

mev = NONE

ggui_fill_meta(0,d,spr_unknownmonster,0,"???","???")

shop_item[d] = NONE

shop_cost[d] = 0

}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

ggui_menu_region(0,vev,mev,0.05,yy,0.95,yy+hh)

}

//Upper right pane: monster sprite + name

ggui_frame(VIEW_W*0.4,0,VIEW_W*0.6,VIEW_H*0.5,spr_messagebox)

ggui_element_sprite_current(0.5,0.8)

ggui_element_text_settings(font_mainmsg,c_white,1,0)

ggui_element_text_current(0.5,0.8)

//Lower right pane: flavor text

ggui_frame(VIEW_W*0.4,VIEW_H*0.5,VIEW_W*0.6,VIEW_H*0.4,spr_messagebox)

ggui_element_text_settings(font_n,c_white,0,0)

ggui_element_desc_current(0.1,0.1)

//Lowest right pane: total statistics

ggui_frame(VIEW_W*0.4,VIEW_H*0.9,VIEW_W*0.6,VIEW_H*0.1,spr_messagebox)

ggui_element_text_settings(font_nfat,c_white,1,1)

ggui_element_text(0.5,0.5,tsprintf("Species Witnessed: %          Species Possessed: %",global.monsters_seen_total,global.monsters_caught_total))

ggui_element_text(0.5,0.8,tsprintf("Required Parts: %",global.monster_data[d,mond_CRAFT_SLOT_SOUL_STRING]))

}

}

I tested most of my engines with 2023.8 to make sure nothing had broken, I only found a single issue (a missing sprite_exists check in the open world 3D engine). array_length_1d is deprecated but trivial to replace (array_length does the exact same thing) so I figured there's no rush, there's currently no easy way to find a list of all deprecated functions in use in a project so I'd probably just miss something, think the project is safe and then run into a massive tech support nightmare when a new GM update drops anyway.

As for the for loop variable name, I'm just using "c" because there's a programming language called "C++" so writing "c++" as the increment operation is funny. That's the whole reason :P

Anything declared with "var" only exists in the piece of code it belongs to, so c's in different scripts will not affect each other. And with multiple loops in the same script, you reset the variable to 0 at the start of the for loop, so it doesn't matter it's reused. (The exception being when you have a loop inside a loop  - then you need separate variables so the inner loop won't mess with the outer loop).

1: There's a 'user' field for enqueued actions, for instance the a_user variable in the ctst_TURNQUEUE state in obj_battlecontrol's step event. (this state is probably when you want to consume the points, since it's when the action actually happens). This "user" field is a battlemonster object ID so simply check its side variable: if it's equal to side_ENEMY it's an enemy and shouldn't consume points.

2: Correct, enemies just pick a random move this way (add all valid actions to a list, shuffle it, pick the first option). If you want something priority-based you could rework what happens in the bcontrolstate_ACTIONSELECT_ENEMY segment to use a priority queue instead (ds_priority functions), where you insert things and they're automatically sorted so you can pick the highest priority value - it's pretty much analoguous to how ds_lists work and the only hard part is figuring out how to compute the priorities - you might want to add some new fields to the move database for storing base priority and priority increase per turn to make this easier to control on a case-by-case basis, and maybe rework target selection a bit to account for type matchups (i.e., add every possible move-target combination to the list but multiply the regular priority with the type multiplier for that target)

(Also you might want to still add a little bit of randomness to the priorities, so the AI doesn't become completely predictable and the player can exploit it)

Oh yeah, might need to have a look into that. I know even the released version of Pokémon Colosseum had a bug which let you duplicate items if you used an item as the first party member and then reordered items on the second party member's turn (so you could get infinite Master Balls that way) so it seems this kind of stuff is tricky to get right.

The code you posted seems to make sense. The interesting thing here is how you compute sheildcheck, and you didn't include that bit of code...

Also, just to get the obvious out of the way: obj_damageapply still does HP damage and not shield damage, right? (So you didn't accidentally change that one as well when you changed all the variables)

(Also note that your two sheildcheck checks are >0 and <1 so both of them will occur for values between zero and one! Is this intentional?)

trg here is the target monster object and we've already checked that it's alive, so you really only need to check if amp_read_var(trg.amp_id,amp_SHIELDHP) is greater than zero: if so, deal shield damage, else deal regular damage.