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[MagmaMcFry]

Code: (Pseudocode) [Select]

Color interpolateColor(Color[] colorList, float[] weightList, int numColors) {
  float totalWeight = 0f;
  for (int i = 0..numColors-1) {
    totalWeight += weightList[i];
  }
  Color returnColor = new Color(0f, 0f, 0f);
  if (totalWeight == 0f) return returnColor;
  for (int i = 0..numColors-1) {
    returnColor.r += colorList[i].r * weightList[i];
    returnColor.g += colorList[i].g * weightList[i];
    returnColor.b += colorList[i].b * weightList[i];
  }
  returnColor.r /= totalWeight;
  returnColor.g /= totalWeight;
  returnColor.b /= totalWeight;
  return returnColor;
}


[DrKillPatient]

I'm trying to write a program in C++ that reads external data files for monsters in a roguelike, formatted like so...

Code: [Select]

wolf
    desc = A slavering wolf. Beware!
    health = 100
    attacks
        bites = 5-10 pierce
        claws = 2-5 slash

I have some idea as to how I'd organize this, that is, with a series of nested key/value pairs, where the value can either be a string or another (list of) key/value pairs. But I don't know exactly how I'd implement this in C++. I'd like the result to be that I can just call some kind of 'fromFile' function and return a list of such value trees (e.g. "wolf", "troll", "goblin"), then step through them one by one and query values like "health". Another problem is how to return a list like "attacks", though. (Maybe there's a better way of doing this.)

Any ideas? I'm stumped entirely with this one.

[Mego]

Quick attempt at a solution:

Code: [Select]

#include <string>
#include <fstream>
#include <map>
#include <sstream>
#include <cstdlib>

using namespace std;

class Attack {
string name;
int minDamage, maxDamage;
string type;
public:
Attack(string n, int mind, int maxd, string t) : name(n), minDamage(mind), maxDamage(maxd) type(t) {}
string getName() { return name; }
int getMinDamage() { return minDamage; }
int getMaxDamage() { return maxDamage; }
string getType() { return type; }
};

class Monster {
string desc;
int health;
map<string, Attack> attacks;
public:
Monster(string d, int h, map<string, Attack> a) : desc(d), health(h), attacks(a) {}
string getDesc() { return desc; }
Attack getAttack(string s) { return attacks.at(s); }
};

map<string, Monster> monsters;

/*
wolf
    desc = A slavering wolf. Beware!
    health = 100
    attacks
        bites = 5-10 pierce
        claws = 2-5 slash
*/

void processMonster(stringstream data) {
string name, desc, healthstr;
int health;
map<string, Attack> attacks;
getline(data, name);
getline(data, desc);
desc = desc.substr(desc.find(" = "+4));
getline(data, healthstr);
healthstr = healthstr.substr(healthstr.find(" = "+4));
health = atoi(healthstr.c_str());
data.getline(); // discard the "attacks" line
string temp;
while(getline(data, temp)) {
string atkname = temp.substr(0, temp.find(" = "));
string dmg = temp.substr(temp.find(" = ")+4, temp.find(" ", temp.find(" = ")+4));
string type = temp.substr(temp.find(" ", temp.find(" = ")+4)+1);
int mindmg, maxdmg;
if(dmg.find("-") != string::npos) { // variable damage
mindmg = atoi(dmg.substr(0, dmg.find("-")).c_str());
maxdmg = atoi(dmg.substr(dmg.find("-")+1).c_str());
}
else { // static damage
mindmg = maxdmg = atoi(dmg.c_str());
}
attacks[atkname] = Attack(atkname, mindmg, maxdmg, type);
}
monsters[name] = Monster(name, desc, health, attacks);
}

void readFile(string fname) {
string line;
ifstream f(fname);
stringstream lines;
bool newMonsterFlag = true;
while(getline(f, line)) {
if(line.at(0) != " " && line.at(0) != "\t") {
processMonster(lines);
lines.str("");
}
lines << line << endl;
}
}


[Skyrunner]

I'd suggest doing it like so:

Code: [Select]

#include <map>
#include <vector>
using namespace std;

enum ATTRIBUTES {HP = 1, MP, INITIATIVE /*so on so forth*/ }

struct attackInfo
{
string name;
int min;
int max;
};

class monster
{
/*other values */

string monsterName;
string description;
map<int, double> attributes;
vector<attackInfo> attacks;

/* other stuff */
};
So when you read things from the file...

Code: (file) [Select]

wolf
    desc = A slavering wolf. Beware!
    health = 100
    attacks
        bites = 5-10 pierce
        claws = 2-5 slash

you would put "wolf" in the monster::monsterName, put everything after the desc = into monster::description, put everything that comes after desc but isn't attacks into the attributes map (The format would be attributes.insert(pair<int, double>(ENUMNAME, VALUE);, where the ENUMNAME is the enumerated name in the ATTRIBUTES enum. For example. attributes.insert(pair<int, double>(HP, 100); would make the monster have an HP of 100.). Put everything after "attacks" into a attackInfo variable, which is pushed onto monster.attacks. The attackInfo struct has minimum, maximum, and the attack name. o_O

Aaand I think I made the paragraph really complicated >_< Sorry. I guess I'm not good at explaining my ideas ;_; The "monster" struct would be to make a instance of a monster that can be used. If you put it in a map that's part of a constant class, it could be used as a lookup table.

[Mego]

I think Java has ruined me to the point where I can't effectively code using anything except OOP. Curses be to you, Sun/Oracle/whoever the hell you are.

Also Skyrunner, programming languages and traditional languages don't mix very cleanly.

[Skyrunner]

What's bad about OOP?

Also, do you have any comments on my code? >.> I'm actually using something similar to that in my own simulator: a single generic class, where each object is differentiated from others solely by its attributes. That means that instead of having a superclass "Plant", from where "Base Herb", "Snowberry bush", and "Apple" inherit from, I have a single class "Herb", which has various variables which include things like "Name", "Growth Period", "Effect" ...
If it's a bad method, I should try and change it early on than later. I do think it's a sort of Object Factory design pattern.

[Putnam]

I think Mego is complaining about inability to write programs that aren't OOP, as opposed to complaining about OOP itself.

[DrKillPatient]

I've found some source code that's similar to what I want to do, but it's in C# and I think I'm missing something when looking at the code. I've tried to write a simple version of the IndentationTree class with the Parse function in C++, but it doesn't seem to be working in the same way that the C# version does (only the root node is returned, totally empty). My understanding of the C# version is that it will take a series of lines, create a root node, and for each indent level, add those lines to the root node as new nodes, subnodes under those, etc. Does anyone here know enough C# to see what I'm misunderstanding?

https://bitbucket.org/munificent/bramble/src/5e40302278e4/Bramble.Core/IndentationTree.cs?at=default

EDIT: Here's my C++ version:

Spoiler (click to show/hide)

Code: (.h) [Select]

#ifndef _INDENTATIONTREE_H_
#define _INDENTATIONTREE_H_

#include <string>
#include <vector>

class IndentationTree {
public:
    IndentationTree(int indent, std::string text) : _indent(indent), _text(text) {};
    IndentationTree parse(std::vector<std::string>);
    int indent() { return _indent; };
    std::string text () { return _text; };
    std::vector<IndentationTree> childTrees;
private:
    void normalizeIndents(int currentIndent);
    int _indent;
    std::string _text;
};

#endif


Code: (.cpp) [Select]

#include "IndentationTree.h"
#include <stack>

IndentationTree IndentationTree::parse(std::vector<std::string> lines) {
    if (lines.empty())
        throw "Lines empty.";

    std::stack<IndentationTree> stack;
    IndentationTree root = IndentationTree(-1, "");
    stack.push(root);

    for (int i = 0; i < lines.size(); ++i) {
        // Create new branch
        int ind = (lines[i].find_first_not_of(' '));
        std::string txt = lines[i];

        IndentationTree tree = IndentationTree(ind, txt);

        // Insert it in the tree
        if (ind >= stack.top().indent()) {
            // Indented less or equal; pop until we reach the right level
            // (If not, skip this and push new tree)
            while (stack.top().indent() >= ind)
                stack.pop();
        }
       
        stack.top().childTrees.push_back(tree);
        stack.push(tree);
    }

    root.normalizeIndents(-1);
    return root;
}

void IndentationTree::normalizeIndents(int currentIndent) {
    _indent = currentIndent;
    for (int i = 0; i < childTrees.size(); ++i)
        childTrees[i].normalizeIndents(currentIndent + 1);
}


[olemars]

Code: [Select]

IndentationTree root = IndentationTree(-1, "");Your root is local and is destroyed as the function returns.

Either have the function return a pointer to an IndentationTree

Code: [Select]

IndentationTree *root = new IndentationTree(-1, "");or have the function take a pointer or reference to an IndentationTree in its parameter list instead of returning it. In either case the Parse function is probably meant to be static (either that or rewrite it to be recursive).

Edit: Also, since your stack (oh, and don't name an object the same as a class) works on IndentationTree objects, the root is copied as you push it on the stack and isn't the same as the one you return.

[Mego]

I think Mego is complaining about inability to write programs that aren't OOP, as opposed to complaining about OOP itself.

This. OOP is a wonderful design, but isn't necessary for everything. Unfortunately, when learning Java, it gets drilled into your head to the point that structural and procedural programming fall out.

[MorleyDev]

Of course a lot of OOP code has the problem of overusing inheritance. One of the reasons the Java standard library sucks from a design perspective is the flagrant abuse of inheritance in situations where it would be much cleaner to use composition.

[Putnam]

Okay, so that I stop throwing code at the wall and seeing what sticks, I'm just going to ask here:

How would I set up a program, preferably with a for loop, so that it would take a chunk of text, copy that, replace all instances of a certain word with a different one, then do that multiple times with a different word each time.

[RulerOfNothing]

Depends. What language are you using?

[Putnam]

C++.

[Mego]

Combining string::replace and string::find will probably be your best bet, if you're only using the standard library.