Unmaintained Introduction to coding - 12. Adding a merchant and building

Adding a merchant and building​

Adding the castle​

We will add a small castle at the bottom left of the window. We load its texture and create its sprite:

sf::Texture castleTex;
castleTex.loadFromFile("resources/castle.png");

sf::Sprite castle;
castle.setTexture(castleTex);
castle.setScale(4, 4);
castle.setPosition(40, 460);

We handle the collisions between the character and the castle:

if(player.getGlobalBounds().intersects(castle.getGlobalBounds()))
    player.setPosition(player.getPosition().x-trans.x, player.getPosition().y-trans.y);

We draw the castle:

win.draw(castle);

View attachment 621

Adding the merchant​

In front of the castle, there will be a merchant selling health potions in exchange of gold. Here, we load its texture and create its sprite:

sf::Texture merchantTex;
merchantTex.loadFromFile("resources/merchant.png");

sf::Sprite merchant;
merchant.setTexture(merchantTex);
merchant.setScale(3, 3);
merchant.setPosition(77, 415);

Handle the collisions between the merchant and the player:

if(player.getGlobalBounds().intersects(merchant.getGlobalBounds()))
    player.setPosition(player.getPosition().x-trans.x, player.getPosition().y-trans.y);

And we draw the merchant:

win.draw(merchant);

View attachment 622

​

Displaying a text when the player is near the merchant​

When the character is close to the merchant, we will display a text indicating that the player can buy a potion by pressing the key B.

To detect if the player is near the merchant, we will employ the same technique we used to check if the player was in the range of attack of a monster.

We create the sf::Text object representing the text to display:

sf::Text buyPotionText;    buyPotionText.setFont(font);
buyPotionText.setString("Press B to buy a potion.");
buyPotionText.setFillColor(sf::Color::White);
buyPotionText.setCharacterSize(30);
 buyPotionText.setPosition((800 - (buyPotionText.getGlobalBounds().width)) / 2, (600 - (buyPotionText.getGlobalBounds().height)) / 2);

We define a variable indicating whether the player is near the merchant or not:

bool isPlayerNearMerchant = false;

We draw the text only if the player is close to the merchant:

if(isPlayerNearMerchant)
    win.draw(buyPotionText);

We check if the player is around the merchant, in the range where he can buy potions, and we set the variable 'isPlayerNearMerchant' accordingly.

sf::FloatRect nearMerchantRect(merchant.getGlobalBounds());
nearMerchantRect.left -= nearMerchantRect.width;
nearMerchantRect.top -= nearMerchantRect.height;
nearMerchantRect.width *= 3;
nearMerchantRect.height *= 3;

if(player.getGlobalBounds().intersects(nearMerchantRect))
    isPlayerNearMerchant = true;
else
    isPlayerNearMerchant = false;

View attachment 623

The code of the game so far​

#include <SFML/Graphics.hpp>

int main()
{
    sf::RenderWindow win(sf::VideoMode(800, 600), "Introduction to coding", sf::Style::Close);

    // Grass

    sf::Texture grassTex;
    grassTex.loadFromFile("resources/grass.png");
    grassTex.setRepeated(true);

    sf::Sprite grass;
    grass.setTexture(grassTex);
    grass.setScale(5, 5);
    grass.setTextureRect(sf::IntRect(0,0,160,120));

    // Dirt tiles

    sf::Texture dirtTex;
    dirtTex.loadFromFile("resources/dirt.png");

    sf::Sprite dirtTiles[10];
    dirtTiles[0].setPosition(300, 60);
    dirtTiles[1].setPosition(660, 300);
    dirtTiles[2].setPosition(390, 480);
    dirtTiles[3].setPosition(660, 60);
    dirtTiles[4].setPosition(720, 420);
    dirtTiles[5].setPosition(180, 300);
    dirtTiles[6].setPosition(60, 180);
    dirtTiles[7].setPosition(60, 420);
    dirtTiles[8].setPosition(240, 420);
    dirtTiles[9].setPosition(480, 120);

    for(int c = 0; c < 10; c++)
    {
        dirtTiles[c].setTexture(dirtTex);
        dirtTiles[c].setScale(5, 5);
    }

    // Trees

    sf::Texture treeTex;
    treeTex.loadFromFile("resources/tree.png");

    sf::Sprite trees[8];
    trees[0].setPosition(50, 60);
    trees[1].setPosition(600, 150);
    trees[2].setPosition(630, 456);
    trees[3].setPosition(300, 600);
    trees[4].setPosition(720, 40);
    trees[5].setPosition(460, 500);
    trees[6].setPosition(20, 370);
    trees[7].setPosition(340, 240);

    for(int c = 0; c < 8; c++)
    {
        trees[c].setTexture(treeTex);
                trees[c].setScale(3, 3);
    }

    // Stones

    sf::Texture stoneTex;
    stoneTex.loadFromFile("resources/stone.png");

    sf::Sprite stones[3];
    stones[0].setPosition(304, 64);
    stones[1].setPosition(664, 304);
    stones[2].setPosition(180, 300);

    for(int c = 0; c < 3; c++)
    {
        stones[c].setTexture(stoneTex);
        stones[c].setScale(3, 3);
    }

    // Player

    sf::Texture playerTex;
    playerTex.loadFromFile("resources/player.png");
    sf::Texture playerAttackingTex;
    playerAttackingTex.loadFromFile("resources/playerAttacking.png");

    sf::Sprite player;
    player.setTexture(playerTex);
    player.setPosition(400, 300);
    player.setScale(3, 3);

    float playerMovementSpeed = 200.0;
    sf::Clock playerMovementClock;
    sf::Clock playerAttackClock;

    int playerGoldAmount = 0, playerPotionAmount = 0, playerHealthAmount = 3;

    // Monsters

    sf::Texture monsterTexs[3];
    monsterTexs[0].loadFromFile("resources/monster1.png");
    monsterTexs[1].loadFromFile("resources/monster2.png");
    monsterTexs[2].loadFromFile("resources/monster3.png");

    sf::Sprite monsters[4];
    monsters[0].setPosition(500, 40);
    monsters[1].setPosition(100, 170);
    monsters[2].setPosition(400, 450);
    monsters[3].setPosition(690, 160);

    bool monstersDead[4];

    for(int c = 0; c < 4; c++)
    {
        monsters[c].setTexture(monsterTexs[0]);
        monsters[c].setScale(3, 3);
        monstersDead[c] = false;
    }

    sf::Clock monstersAnimationClock;
    sf::Clock monsterRespawnClocks[4];
    sf::Clock monsterAttackClock;
    bool isPlayerNearMonster = false;

    // Gold

    sf::Texture goldTex;
    goldTex.loadFromFile("resources/gold.png");

    sf::Sprite gold;
    gold.setTexture(goldTex);
    gold.setScale(2, 2);
    gold.setPosition(15, 10);

    sf::Font font;
    font.loadFromFile("resources/LinuxBiolinum.ttf");

    sf::Text goldAmountText;
    goldAmountText.setFont(font);
    goldAmountText.setString("0");
    goldAmountText.setFillColor(sf::Color::White);
    goldAmountText.setCharacterSize(24);
    goldAmountText.setPosition(60, 10);

    // Potions

    sf::Texture healthPotionTex;
    healthPotionTex.loadFromFile("resources/healthPotion.png");
    sf::Texture emptyVialTex;
    emptyVialTex.loadFromFile("resources/emptyVial.png");

    sf::Sprite potion;
    potion.setTexture(emptyVialTex);
    potion.setScale(2, 2);
    potion.setPosition(350, 10);

    sf::Text potionAmountText;
    potionAmountText.setFont(font);
    potionAmountText.setString("0");
    potionAmountText.setFillColor(sf::Color::White);
    potionAmountText.setCharacterSize(24);
    potionAmountText.setPosition(395, 10);

    // Health of the player

    sf::Texture heartTex;
    heartTex.loadFromFile("resources/heart.png");
    sf::Texture emptyHeartTex;
    emptyHeartTex.loadFromFile("resources/emptyHeart.png");

    sf::Sprite hearts[3];
    hearts[0].setPosition(800 - 130, 10);
    hearts[1].setPosition(800 - 90, 10);
    hearts[2].setPosition(800 - 50, 10);

    for(int c = 0; c < 3; c++)
    {
        hearts[c].setTexture(heartTex);
        hearts[c].setScale(2, 2);
    }

    // Castle

    sf::Texture castleTex;
    castleTex.loadFromFile("resources/castle.png");

    sf::Sprite castle;
    castle.setTexture(castleTex);
    castle.setScale(4, 4);
    castle.setPosition(40, 460);

    // Merchant

    sf::Texture merchantTex;
    merchantTex.loadFromFile("resources/merchant.png");

    sf::Sprite merchant;
    merchant.setTexture(merchantTex);
    merchant.setScale(3, 3);
    merchant.setPosition(77, 415);

    sf::Text buyPotionText;
    buyPotionText.setFont(font);
    buyPotionText.setString("Press B to buy a potion.");
    buyPotionText.setFillColor(sf::Color::White);
    buyPotionText.setCharacterSize(30);
    buyPotionText.setPosition((800 - (buyPotionText.getGlobalBounds().width)) / 2, (600 - (buyPotionText.getGlobalBounds().height)) / 2);

    bool isPlayerNearMerchant = false;

    // Game loop

    sf::Event event;

    while(win.isOpen())
    {
        while(win.pollEvent(event))
        {
            if(event.type == sf::Event::Closed)
                win.close();
        }

        // Player movements

         sf::Vector2f trans;
        float mouv = playerMovementClock.getElapsedTime().asSeconds() * playerMovementSpeed;

        if(sf:⌨️:isKeyPressed(sf:⌨️:W))
            trans.y -= mouv;
        if(sf:⌨️:isKeyPressed(sf:⌨️:S))
            trans.y += mouv;
        if(sf:⌨️:isKeyPressed(sf:⌨️:A))
            trans.x -= mouv;
        if(sf:⌨️:isKeyPressed(sf:⌨️:D))
            trans.x += mouv;

        player.setPosition(player.getPosition().x+trans.x, player.getPosition().y+trans.y);
        playerMovementClock.restart();

        // Collision testing

        for(int c=0; c < 8; c++)
        {
             if(player.getGlobalBounds().intersects(trees[c].getGlobalBounds()))
                player.setPosition(player.getPosition().x-trans.x, player.getPosition().y-trans.y);
        }
        for(int c=0; c < 3; c++)
        {
            if(player.getGlobalBounds().intersects(stones[c].getGlobalBounds()))
                player.setPosition(player.getPosition().x-trans.x, player.getPosition().y-trans.y);
        }
        if(player.getGlobalBounds().intersects(castle.getGlobalBounds()))
            player.setPosition(player.getPosition().x-trans.x, player.getPosition().y-trans.y);
        if(player.getGlobalBounds().intersects(merchant.getGlobalBounds()))
            player.setPosition(player.getPosition().x-trans.x, player.getPosition().y-trans.y);

        // Animation of the monsters

        int index = monstersAnimationClock.getElapsedTime().asMilliseconds() / 333;

        if(index > 2)
        {
            monstersAnimationClock.restart();
            index = 0;
        }

        for(int c=0; c < 4; c++)
        {
            monsters[c].setTexture(monsterTexs[index]);
        }

        // Player attacking

        if((sf:⌨️:isKeyPressed(sf:⌨️:Space) || sf:🐭:isButtonPressed(sf:🐭:Left)) && playerAttackClock.getElapsedTime().asMilliseconds() > 1000)
        {
            playerAttackClock.restart();
            player.setTexture(playerAttackingTex);

            // Testing if the attack reaches a monster

            sf::FloatRect attackRect(player.getPosition()+sf::Vector2f((player.getGlobalBounds().width/4), -player.getGlobalBounds().height/3), sf::Vector2f(player.getGlobalBounds().width/4, player.getGlobalBounds().height/3));

            for(int c=0; c < 4; c++)
            {
                if(monstersDead[c] == false && attackRect.intersects(monsters[c].getGlobalBounds()))
                {
                      monstersDead[c] = true;
                    monsterRespawnClocks[c].restart();
                }
            }
        }

        if(playerAttackClock.getElapsedTime().asMilliseconds() > 1000)
            player.setTexture(playerTex);

        // Monster attacking

        bool isPlayerCurrentlyNearMonster = false;

        for(int c=0; c < 4; c++)
        {
            if(monstersDead[c] == false)
            {
                sf::FloatRect nearMonsterRect(monsters[c].getGlobalBounds());
                nearMonsterRect.left -= nearMonsterRect.width;
                nearMonsterRect.top -= nearMonsterRect.height;
                nearMonsterRect.width *= 3;
                nearMonsterRect.height *= 3;

                if(player.getGlobalBounds().intersects(nearMonsterRect))
                {
                    isPlayerCurrentlyNearMonster = true;

                    if(isPlayerNearMonster)
                    {
                        if(monsterAttackClock.getElapsedTime().asSeconds() >= 1 && playerHealthAmount > 0)
                        {
                            playerHealthAmount--;
                            monsterAttackClock.restart();

                            if(playerHealthAmount == 0)
                                  hearts[0].setTexture(emptyHeartTex);
                                  else if(playerHealthAmount == 1)
                                hearts[1].setTexture(emptyHeartTex);
                            else
                                hearts[2].setTexture(emptyHeartTex);
                        }
                    }
                    else
                    {
                        isPlayerNearMonster = true;
                             monsterAttackClock.restart();
                    }
                }
            }
        }     
        if(isPlayerCurrentlyNearMonster == false)
            isPlayerNearMonster = false;

        // Respawn of the monsters

        for(int c=0; c < 4; c++)
        {
            if(monsterRespawnClocks[c].getElapsedTime().asSeconds() >= 8)
                monstersDead[c] = false;
        }

        // Checks if the player is near the merchant

        sf::FloatRect nearMerchantRect(merchant.getGlobalBounds());
        nearMerchantRect.left -= nearMerchantRect.width;
        nearMerchantRect.top -= nearMerchantRect.height;
        nearMerchantRect.width *= 3;
        nearMerchantRect.height *= 3;

        if(player.getGlobalBounds().intersects(nearMerchantRect))
            isPlayerNearMerchant = true;
        else
            isPlayerNearMerchant = false;

        // Rendering

        win.clear();

        win.draw(grass);

        for(int c = 0; c < 10; c++)
            win.draw(dirtTiles[c]);

        for(int c = 0; c < 8; c++)
            win.draw(trees[c]);

        for(int c = 0; c < 3; c++)
            win.draw(stones[c]);

        win.draw(player);

        for(int c = 0; c < 4; c++)
        {
            if(monstersDead[c] == false)
                win.draw(monsters[c]);
        }

        win.draw(castle);
        win.draw(merchant);


        win.draw(gold);
        win.draw(goldAmountText);

        win.draw(potion);
        win.draw(potionAmountText);

        for(int c = 0; c < 3; c++)
            win.draw(hearts[c]);

        if(isPlayerNearMerchant)
            win.draw(buyPotionText);

        win.display();
    }

    return 0;
}