RPG Maker Forums

/*:
 * @plugindesc v1.1 Use percentages for special shop prices
 * @author Patrick Tietz <ptietz.official[at]gmail.com>
 *
 * @param rounding method
 * @desc how to round results
 * (round, floor, ceil)
 * @type select
 * @option round
 * @option floor
 * @option ceil
 * @default round
 *
 * @param treat as discount
 * @desc treat input percentages as discount
 * @type boolean
 * @default false
 *
 * @param use variables
 * @desc use price input as variable index
 * @type boolean
 * @default false
 *
 * @param overall variable
 * @desc apply to all prices
 * @type variable
 * @default 0
 *
 *
 * @help
 *
 * ######################################
 * # Welcome                            #
 * ######################################
 *
 * Thank you for using ShopPercentages.
 *
 * This Plugin treats special prices in the shop processing
 * as percentages rather than absolute prices.
 *
 * This way, you won't have to go over all the NPCs
 * that sell a particular item, whenever you change
 * and balance its price.
 *
 * Have fun making games! :)
 *
 *
 * ######################################
 * # General Instructions               #
 * ######################################
 *
 * This plugin is plug & play and will perfectly work
 * from the moment you install and enable it
 * from within the plugin manager.
 *
 * Please, keep in mind that this plugin
 * overrides the defaul shop behavior for special prices.
 * Installing this plugin midway through your project
 * will probably have a significant impact on
 * already set special prices in your game.
 * This might ruin your financial balance
 * and you will have to edit every shop again.
 *
 * The plugin does not add any plugin commands.
 *
 *
 * ######################################
 * # Parameters                         #
 * ######################################
 *
 * rounding method
 * ===============
 * You can define how you want float number results
 * to be rounded. Methods are "round", "ceil" and "floor".
 *
 *   Example:
 *   Let's assume we have an item for sale that costs 210 by default.
 *   We want to have it sold by 90% of its original value.
 *   That would give us a total of 189.81 which is not
 *   possible in RPG Maker MV. Therefore we must round.
 *
 *
 * treat as discount
 * =================
 * If enabled, you special price inputs will be treated
 * as discount rather than total percentage values.
 * This affects variables as well.
 *
 * This parameter's behavior adjusts to your
 * "treat as discount" setting.
 *
 *   Example:
 *   Usually, when you have an item of 200 value
 *   sold for 180, you would have to enter "90"
 *   as 180 is 90% of 200.
 *   With this parameter enabled, you would now
 *   have to enter "10" as 180 is a 10% discount
 *   of the original 200.
 *
 *
 * use variables
 * =============
 * If you enable "use variables", your special prices will no longer
 * be treated as direct percentage inputs but as variable indizes.
 *
 *   Example:
 *   Maybe, you want a 10% discount on all swords.
 *   To get there, you would have to set a value
 *   for a variable, depending on your "treat as discount" setting.
 *   Then you would write the index of that variable
 *   as a special price on each shop's swords.
 *   Of course, there are many other use cases thinkable.
 *
 *
 * overall variable
 * ================
 * Here, you can specify a variable whose value is applied to
 * all shop prices (even default ones).
 *
 * Be aware that this variable is applied AFTER
 * everything else. This means, that even an item
 * that already has a special price, will still
 * be affected by this setting.
 *
 * This parameter's behavior adjusts to your
 * "treat as discount" setting.
 *
 *   Example:
 *   Let's say your player has some sort of bargaining skill
 *   which affects all shop prices.
 *   This can be achieved by writing the current discount,
 *   calculated by the particular skill, into a variable
 *   and then specifying that variable in this plugin.
 *
 *
 * ######################################
 * # Terms of use                       #
 * ######################################
 *
 * You may freely use, copy and modify this script
 * in any commercial or non-commercial game.
 *
 * Re-distribution of the source code as is, is prohibited.
 * You may link to the source, you got it from, though.
 * The distribution of your modified code is allowed,
 * as long as the original author is kept visible.
 *
 * Crediting the author in the game, however,
 * is not required, although much appreciated.
 *
 * Screenshots packed with this plugin are for
 * demonstrational purpose only.
 *
 * Credits for the original software
 * "RPG Maker MV" go to
 * Copyright (c) 2015 KADOKAWA CORPORATION / YOJI OJIMA
 */

// get parameters
PT_ShopPercentages_ParamsRaw = {
    roundingMethod: String( PluginManager.parameters( 'PT_ShopPercentages' )[ 'rounding method' ] ),
    treatAsDiscount: String( PluginManager.parameters( 'PT_ShopPercentages' )[ 'treat as discount' ] ),
    useVars: String( PluginManager.parameters( 'PT_ShopPercentages' )[ 'use variables' ] ),
    overallVariable: parseInt( PluginManager.parameters( 'PT_ShopPercentages' )[ 'overall variable' ] ),
};

// validate parameters
PT_ShopPercentages_Params = {
    roundingMethod      : PT_ShopPercentages_ParamsRaw.roundingMethod === 'ceil'
                            || PT_ShopPercentages_ParamsRaw.roundingMethod === 'floor'
                            ? PT_ShopPercentages_ParamsRaw.roundingMethod
                            : 'round',
    treatAsDiscount     : PT_ShopPercentages_ParamsRaw.treatAsDiscount === 'true'
                            || PT_ShopPercentages_ParamsRaw.treatAsDiscount === '1'
                            || PT_ShopPercentages_ParamsRaw.treatAsDiscount === 'yes'
                            ? true
                            : false,
    useVars: PT_ShopPercentages_ParamsRaw.useVars === 'true'
                            || PT_ShopPercentages_ParamsRaw.useVars === '1'
                            || PT_ShopPercentages_ParamsRaw.useVars === 'yes'
                            ? true
                            : false,
    overallVariable: PT_ShopPercentages_ParamsRaw.overallVariable
};


/**
 * Calculate item price
 *
 * @param {number} origItemPrice original item price (from database)
 * @param {number} rawPriceInput raw price input from shop window, optional
 * @param {boolean} isOverall for internal use only
 * @returns {number}
 */
Window_ShopBuy.prototype.calcItemPrice = function( origItemPrice, rawPriceInput, isOverall = false )
{
    var result = origItemPrice;
   
    if ( arguments.length > 1 && typeof rawPriceInput !== 'undefined' )
    {
        // get price modifier depending "use variables" setting
        var input = !isOverall && PT_ShopPercentages_Params.useVars
            ? parseInt( $gameVariables.value( rawPriceInput ) )
            : rawPriceInput;
           
        // calculate price depending on "treatAsDiscount" setting
        var percentage = PT_ShopPercentages_Params.treatAsDiscount
            ? origItemPrice - origItemPrice * input / 100
            : origItemPrice * ( input / 100 );
           
        // round price depending on "rounding message" setting
        result = parseInt( Math[ PT_ShopPercentages_Params.roundingMethod ]( percentage ) );
    }
   
    // if "overall variable" is set
    if ( !isOverall && PT_ShopPercentages_Params.overallVariable > 0 )
    {
        // redo the whole thing
        result = this.calcItemPrice(
            result,
            $gameVariables.value( PT_ShopPercentages_Params.overallVariable ),
            true
        );
    }
   
    // return result
    return result;
};


/**
 * Make item list for buying window
 *
 * @override
 * @returns {undefined}
 */
Window_ShopBuy.prototype.makeItemList = function()
{
    this._data = [];
    this._price = [];
   
    this._shopGoods.forEach( function( goods )
    {
        var item = null;
       
        switch ( goods[0] )
        {
            case 0:
                item = $dataItems[ goods[1] ];
                break;
            case 1:
                item = $dataWeapons[ goods[1] ];
                break;
            case 2:
                item = $dataArmors[ goods[1] ];
                break;
        }
       
        if ( item )
        {
            this._data.push( item );
            this._price.push(
                goods[2] === 0
                ? this.calcItemPrice( item.price )
                : this.calcItemPrice( item.price, goods[3] )
            );
        }
       
    }, this );
   
};