Adding a merchant and building

Location
  1. Tutorials

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  2. Introduction to coding

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  3. 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:

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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);
A castle is added to the game

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:

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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);
A merchant is added to the game

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:

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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.

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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;
A text telling the player how to buy potions is displayed

The code of the game so far

main.cpp

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#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::Keyboard::isKeyPressed(sf::Keyboard::W)) trans.y -= mouv; if(sf::Keyboard::isKeyPressed(sf::Keyboard::S)) trans.y += mouv; if(sf::Keyboard::isKeyPressed(sf::Keyboard::A)) trans.x -= mouv; if(sf::Keyboard::isKeyPressed(sf::Keyboard::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::Keyboard::isKeyPressed(sf::Keyboard::Space) || sf::Mouse::isButtonPressed(sf::Mouse::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; }