Tutorium #2

Softwareentwicklung Praktikum

Gruppe 4 – Michael Schwarz prog-tutor-michael@iicm.tugraz.at
Gruppe 5 – Anja Karl prog-tutor-anja@iicm.tugraz.at
Gruppe 8 – Thomas Neff prog-tutor-thomas@iicm.tugraz.at

Ablauf des Tutoriums

• STL - Standard Template Library
• Vektoren
• Strings
• Maps
• Makefiles
• Ass1

STL - Standard Template Library

• Generische Datentypen für unterschiedliche Einsatzzwecke (z.B. std::vector<int> oder std::vector<std::string>)
• Automatisches Speichermanagement
• Iteratoren zum Durchlaufen der Container, unabhängig von der Datenstruktur
• Vorgefertigte Algorithmen (copy, sort, transform, etc.)

Vector

std::vector<int> int_vector;
int_vector.push_back(42);
int_vector.push_back(13);
int_vector.push_back(37);

int i;
for(i = 0; i < int_vector.size(); i++)
  std::cout << int_vector[i] << std::endl;

for(vector<int>::iterator it = int_vector.begin(); it != int_vector.end(); it++)
  std::cout << *it << std::endl;

...oder mit C++2011

for(auto it = int_vector.begin(); it != int_vector.end(); it++)
  std::cout << *it << std::endl;

Schreiben auf stdout

#include <iostream>
	   
int main()
{
  std::cout << "Hallo Welt!\n";
  return 0;
}

std::cout << "The answer to life, the universe and everything is " << 42 << std::endl;

std::cout << "string1 is " << string1 << ", it's length is " << string1.length() << std::endl;

int value = 32;
std::cout << value << " = 0x" << std::hex 
          << value << std::endl; 

Prädikate testen

• Testet, ob eine Eigenschaft auf ein (std::any_of), alle (std::all_of) oder kein (std::none_of) Element eines Containers zutrifft.

• Beispiel: Test, ob eine durch 5 teilbare Zahl in einem Vector vorkommt

#include <iostream>
#include <vector>
#include <algorithm>

bool is_div5(int x) { return (x % 5 == 0); }

int main() {
  std::vector<int> numbers {1, 3, 5, 7, 9, 11, 13};
  
  if(std::any_of(numbers.begin(), numbers.end(), is_div5)) {
    std::cout << "Durch 5 teilbare Zahl gefunden" << std::endl;
  }
}

Einfache Klasse II (ball.h)

#ifndef BALL_H_INCLUDED
#define BALL_H_INCLUDED

#include <string>

class Ball
{
private:
  float x_, y_, speed_;
  int direction_;
  std::string name_;

public:
  Ball(float x, float y, float speed, int direction,
       std::string name);
  
  void move();
  
  float getSpeed();
  void setSpeed(float speed);
  std::string getName();
  void setDirection(float direction);
  float getDirection();
};

#endif

Konstruktor und move (ball.cpp)

#include <math.h>
#include "ball.h"

Ball::Ball(float x, float y, float speed, int dir, 
      std::string name) : x_(x), y_(y), speed_(speed)
{
  direction_ = dir * M_PI / 180.0;
  name_ = "Ball '" + name + "'";
}

void Ball::move()
{
  x_ = x_ + cos(direction_) * speed_;
  y_ = y_ + sin(direction_) * speed_;  
  if(x_ < 0 || x_ > 800) 
    direction_ = atan2(sin(direction_), -cos(direction_));
  if(y_ < 0 || y_ > 600)
    direction_ = atan2(-sin(direction_), cos(direction_));
}

Getter und Setter

float Ball::getSpeed()
{
  return speed_;
}

void Ball::setSpeed(float speed)
{
  speed_ = speed;
}

std::string Ball::getName()
{
  return name_;
}

float Ball::getDirection()
{
  return direction_;
}

void Ball::setDirection(float direction)
{
  direction_ = direction;
}

• Neuer Getter getName() liefert Namen des Balls zurück
• Neuer Getter getDirection() und Setter setDirection() für die Richtung des Balls

Das main-Programm

#include <vector> #include "ball.h" int main() { std::vector<Ball> balls; Ball b1(200, 225, 5, 10, "#1"); balls.push_back(b1); while(1) { int i; for(i = 0; i < balls.size(); i++) { if(balls[i].getName().compare("Ball #2") == 0) balls[i].setDirection(balls[i].getDirection() + 1); balls[i].move(); } drawWindow(); // some magic... } }

Ball Starten

Gruppenfindung

Exkurs Makefile

Ziel: Abhängigkeit1 (Abhängigkeit2 ...) <tab> (Befehl 1) <tab> (Befehl 2) ...

all: ass1 ass1: ass1.cpp g++ ass1.cpp -Wall -o ass1

Exkurs Makefile - Ass1

EXECUTABLE = ass1 OBJECT_DIR = objects SOURCES = $(wildcard *.cpp) OBJECTS = $(patsubst %, $(OBJECT_DIR)/%,${SOURCES:.cpp=.o}) all: $(EXECUTABLE) $(OBJECT_DIR)/%.o: %.cpp $(CC) $(CCFLAGS) $@ $< -MMD -MF ./$@.d $(EXECUTABLE) : $(OBJECTS) $(CC) -o $@ $^ $(LDFLAGS) clean: rm -f $(OBJECT_DIR)/*.o $(OBJECT_DIR)/*.o.d rm -f $(EXECUTABLE)

Exkurs Makefile

all: ass1 objects/Tower.o: Tower.cpp g++ -Wall -g -c -o Tower.o Tower.cpp -MMD -MF ./Tower.o.d [...] objects/main.o: main.cpp g++ -Wall -g -c -o main.o main.cpp -MMD -MF ./main.o.d ass1 : objects/Tower.o objects/main.o [...] g++ -o ass1 objects/Tower.o objects/main.o [...] clean: rm -f objects/Tower.o objects/main.o [...] objects/Tower.o.d [...] rm -f ass1

# ass1 erstellen
make
# ass1 und alle *.o löschen
make clean

Ass1

• Grundlage für "Tower Defense"
• main.cpp wird vorgegeben
• 3 Klassen zu schreiben: SpeedRatio, Tower& Monster

Ass1 - SpeedRatio

Ass1 - Tower

Ass1 - Monster

Freiwillige Übung

Viel Glück für Ass1

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