So I am making a 2D platformer using SDL. I have experience in C/C++, but I haven't really written anything with it in the past 8 months. I'm using SDL to render my graphics, and I get an entirely blank screen, and I can't really seem to figure out why. Can anybody help me figure out why this isn't rendering?
EDIT: I added the extra code that was missing.
Map.cpp
#include "Map.h"
int map[10][10] = { {0,0,0,0,0,0,0,0,0,0},
{0,0,0,0,0,0,0,0,0,0},
{0,0,0,0,0,0,0,0,0,0},
{0,0,0,0,0,0,0,0,0,0},
{0,0,0,0,0,0,0,0,0,0},
{0,0,0,0,0,0,0,0,0,0},
{0,0,0,0,0,0,0,0,0,0},
{0,0,0,0,0,0,0,0,0,0},
{0,0,0,0,0,0,0,0,0,0},
{0,0,0,0,0,0,0,0,0,0}
};
Map::Map()
: g( Graphics() )
{
grassTile = SDL_LoadBMP("grass.bmp");
}
Map::~Map()
{
}
void Map::renderMap()
{
for (int y = 0; y < 10; y++)
{
for (int x = 0; x < 10; x++)
{
int newPos = map[y][x];
if (newPos == 0)
{
g.drawImage(x * 32, y * 32, grassTile);
}
}
}
}
Graphics.cpp
#include "Graphics.h"
#include <iostream>
#include <SDL.h>
#include <Windows.h>
using namespace std;
Graphics::Graphics()
: count( 0 )
{
}
Graphics::~Graphics()
{
}
int Graphics::getWidth(int i)
{
return this->width = i;
}
int Graphics::getHeight(int i)
{
return this->height = i;
}
void Graphics::initScreen(int width,int height, char* title)
{
if (!SDL_Init(SDL_INIT_EVERYTHING) == 1)
{
cout << "SDL is running" << endl;
}
SDL_WM_SetCaption(title,NULL);
screen = SDL_SetVideoMode(width,height,8,NULL);
getWidth(width);
getHeight(height);
}
void Graphics::beginFrame()
{
SDL_FillRect(screen,NULL,0x000000);
}
void Graphics::repaint()
{
SDL_Flip(screen);
}
void Graphics::loadImage(char* location, SDL_Surface* sur)
{
sur = SDL_LoadBMP(location);
}
void Graphics::renderTileMap(SDL_Surface* sur, int width, int height, int amountX, int amountY)
{
for (int y = 0; y < amountY; y++)
{
for (int x = 0; x < amountX; x++)
{
drawImage(x * width, y * height, sur);
}
}
}
void Graphics::pixel(int x,int y, int r,int g, int b)
{
if (screen != NULL)
{
if (screen->pixels != NULL)
{
Uint8* pixels = (Uint8*)screen->pixels;
Uint8* indevidualPixel = pixels + (y * screen->pitch) + x;
*indevidualPixel = SDL_MapRGB(screen->format,r,g,b);
}
}
}
void Graphics::drawImage(int x,int y, SDL_Surface* sur)
{
SDL_Rect rect;
rect.x = x;
rect.y = y;
SDL_BlitSurface(sur,NULL,screen,&rect);
}
Main.cpp>
#include <SDL.h>
#include <cstdio>
#include "Graphics.h"
#include "Keyboard.h"
#include "Game.h"
SDL_Event event;
bool running = true;
Game game = Game();
int main(int argc, char* argv[])
{
game.k = Keyboard();
game.g.initScreen(900,500, "theDevCorner's SDL Tutorials!!!");
while (running)
{
SDL_PollEvent(&event);
if (event.type == SDL_QUIT)
{
running = false;
}
if (event.type == SDL_KEYUP)
{
SDLKey keyReleased = event.key.keysym.sym;
if (keyReleased == SDLK_RIGHT)
{
game.k.right = false;
}
if (keyReleased == SDLK_LEFT)
{
game.k.left = false;
}
if (keyReleased == SDLK_DOWN)
{
game.k.down = false;
}
if (keyReleased == SDLK_UP)
{
game.k.up = false;
}
}
if (event.type == SDL_KEYDOWN)
{
SDLKey keyPressed = event.key.keysym.sym;
if (keyPressed == SDLK_RIGHT)
{
game.k.right = true;
}
if (keyPressed == SDLK_LEFT)
{
game.k.left = true;
}
if (keyPressed == SDLK_DOWN)
{
game.k.down = true;
}
if (keyPressed == SDLK_UP)
{
game.k.up = true;
}
}
game.g.beginFrame();
game.render();
game.g.repaint();
}
return 0;
};
Game.cpp
#include "Game.h"
Game::Game()
: g(Graphics()),
x( 0 ),
y( 0 ),
m( Map() )
{
image = SDL_LoadBMP("grass.bmp");
}
Game::~Game()
{
}
void Game::keyLogic()
{
if (k.right)
{
x += 5;
}
if (k.left)
{
x -= 5;
}
if (k.down)
{
y += 5;
}
if (k.up)
{
y -= 5;
}
}
void Game::update()
{
if (count < 10)
{
count++;
}
if (count == 10)
{
keyLogic();
count = 0;
}
}
void Game::render()
{
update();
m.renderMap();
}
You have two instances of Graphics, one in Game and one in Map. You call Graphics::initScreen on the one in the Game instance game, but later you try to render in the Graphics instance of the Map instance game.m, where the SDL surface screen is uninitialized. Specifically game.render(); calls game.m.renderMap();, which calls game.m.g.drawImage(...).
Decide for one location of the Graphics instance or use references.
Related
As a school project, I've made the classic snake game using SDL2 and C++.
I've already implemented the growing, moving features for the Snake but it was required to make the movement based on a grid, but when I implemented the grid feature, the self-collision was always triggering whenever grow one part, so every time I start the game, and eat the first fruit, the snake dies.
I've been trying for a while now, from placing a delay to the adding of the tail and delaying the collision check, but to no avail, it's always colliding with itself even though it is not.
I can't see what is wrong with the self collision, I would gladly appreciate it if someone can point out what's wrong.
Snake.h
#include "GameObject.h"
#include "common.h"
#include "draw.h"
#include "Food.h"
#include "util.h"
#include <vector>
struct Segment {
int x;
int y;
Segment(int posx, int posy) {
x = posx;
y = posy;
}
};
class Snake :
public GameObject
{
public:
~Snake();
void start();
void update();
void draw();
void outOfBoundsCheck();
void move();
void addSegment(int x, int y);
void selfCollisionCheck(bool hasEaten);
void setHasMoved(bool a);
void setIsAlive(bool a);
int getX();
int getY();
int getWidth();
int getHeight();
bool getIsAlive();
bool getHasMoved();
std::vector<Segment*> const& getV() const;
private:
std::vector<Segment*> body;
SDL_Texture* headTexture;
SDL_Texture* bodyTexture;
int x;
int y;
int width;
int height;
int dx;
int dy;
int tempX;
int tempY;
bool isAlive;
bool hasMoved;
};
Snake.cpp
Snake::~Snake()
{
}
void Snake::start()
{
// Load Texture
headTexture = loadTexture("gfx/player.png");
bodyTexture = loadTexture("gfx/body.png");
tempX = 0;
tempY = 0;
x = 0;
y = 0;
dx = 0;
dy = 0;
isAlive = true;
hasMoved = false;
width = 0;
height = 0;
SDL_QueryTexture(headTexture, NULL, NULL, &width, &height);
addSegment(x, y);
}
void Snake::update()
{
std::cout << "Head" << body[0]->x << std::endl;
if (body.size() > 1) {
std::cout << "2nd Segment" << body[1]->x << std::endl;
if (body.size() > 2) {
std::cout << "3nd Segment" << body[2]->x << std::endl;
}
}
move();
outOfBoundsCheck();
}
void Snake::draw()
{
if (!isAlive) return; // Cancel the render if player dies
for (int i = 0; i < body.size(); i++) {
blit(headTexture, body[i]->x, body[i]->y);
}
}
void Snake::outOfBoundsCheck()
{
for (int i = 0; i < body.size(); i++) {
if (body[i]->x > SCREEN_WIDTH) {
body[i]->x = 0;
}
if (body[i]->x < 0) {
body[i]->x = SCREEN_WIDTH;
}
if (body[i]->y > SCREEN_HEIGHT) {
body[i]->y = 0;
}
if (body[i]->y < 0) {
body[i]->y = SCREEN_HEIGHT;
}
}
}
void Snake::move()
{
if (app.keyboard[SDL_SCANCODE_W] && dy != 5) {
dx = 0;
dy = -5;
}
if (app.keyboard[SDL_SCANCODE_A] && dx != 5) {
dx = -5;
dy = 0;
}
if (app.keyboard[SDL_SCANCODE_S] && dy != -5) {
dx = 0;
dy = 5;
}
if (app.keyboard[SDL_SCANCODE_D] && dx != -5) {
dx = 5;
dy = 0;
}
Segment* snakeHead = *(body.begin()); //Grid
tempX += dx;
tempY += dy;
if (tempX % 25 == 0) {
snakeHead->x += tempX;
tempX = 0;
}
if (tempY % 25 == 0) {
snakeHead->y += tempY;
tempY = 0;
}
for (int i = body.size() - 1; i > 0; i--) { //For the other parts to follow
body[i]->x = body[i - 1]->x;
body[i]->y = body[i - 1]->y;
}
}
void Snake::addSegment(int x, int y)
{
Segment* seg = new Segment(x, y );
body.push_back(seg);
}
void Snake::selfCollisionCheck(bool hasEaten) // Fail
{
Segment* head = body[0];
if (hasEaten == false) {
for (int i = 1; i < body.size(); i++) {
if (head->x == body[i]->x && head->y == body[i]->y) {
isAlive = false;
break;
}
}
}
else {
return;
}
}
void Snake::setHasMoved(bool a)
{
hasMoved = a;
}
void Snake::setIsAlive(bool a)
{
isAlive = a;
}
int Snake::getX()
{
return x;
}
int Snake::getY()
{
return y;
}
int Snake::getWidth()
{
return width;
}
int Snake::getHeight()
{
return height;
}
bool Snake::getIsAlive()
{
return isAlive;
}
bool Snake::getHasMoved()
{
return hasMoved;
}
std::vector<Segment*> const& Snake::getV() const
{
// TODO: insert return statement here
return body;
}
GameScene.h
#include "Scene.h"
#include "GameObject.h"
#include "Snake.h"
#include "Food.h"
#include "util.h"
#include "text.h"
#include "SoundManager.h"
class GameScene : public Scene
{
public:
GameScene();
~GameScene();
void start();
void draw();
void update();
void spawnFood();
void collisionLogic();
void selfCollision();
void despawnFood(Food* food);
private:
Snake* snake;
Food* food;
int points;
std::vector<Food*> spawnedFood;
};
GameScene.cpp
#include "GameScene.h"
GameScene::GameScene()
{
// Register and add game objects on constructor
snake = new Snake();
this->addGameObject(snake);
points = 0;
}
GameScene::~GameScene()
{
delete snake;
delete food;
}
void GameScene::start()
{
Scene::start();
// Initialize any scene logic here
initFonts();
spawnFood();
}
void GameScene::draw()
{
Scene::draw();
drawText(110, 20, 255, 255, 255, TEXT_CENTER, "POINTS: %03d", points);
if (snake->getIsAlive() == false) {
drawText(SCREEN_WIDTH / 2, SCREEN_HEIGHT / 2, 255, 255, 255, TEXT_CENTER, "GAME OVER!");
}
}
void GameScene::update()
{
Scene::update();
if (spawnedFood.size() == 0 && spawnedFood.size() != 1) {
spawnFood();
}
collisionLogic();
selfCollision();
}
void GameScene::spawnFood()
{
int random = rand() % 720;
if (random % 25 != 0) {
random = rand() % 720;
}
else {
Food* food = new Food();
this->addGameObject(food);
food->setPosition(rand() % SCREEN_WIDTH, rand() % SCREEN_HEIGHT);
spawnedFood.push_back(food);
}
}
void GameScene::collisionLogic()
{
Segment* head = snake->getV()[0];
std::vector<Segment*> snakeBody = snake->getV();
for (int i = 0; i < objects.size(); i++) {
Food* food = dynamic_cast<Food*>(objects[i]);
if (food != NULL) {
int collision = checkCollision(
head->x, head->y, snake->getWidth(), snake->getHeight(),
food->getX(), food->getY(), food->getWidth(), food->getHeight()
);
if (collision == 1) {
despawnFood(food);
snake->addSegment(snakeBody[snakeBody.size() - 1]->x, snakeBody[snakeBody.size() - 1]->y); //Adds a part to the snake
points++;
break;
}
}
}
}
void GameScene::selfCollision()
{
std::vector<Segment*> body = snake->getV();
Segment* head = snake->getV()[0];
for (int i = 1; i < snake->getV().size(); i++) {
if (head->x == body[i]->x && head->y == body[i]->y) {
snake->setIsAlive(false);
break;
}
}
}
void GameScene::despawnFood(Food* food)
{
int index = -1;
for (int i = 0; i < spawnedFood.size(); i++) {
if (food == spawnedFood[i]) {
index = i;
break;
}
}
if (index != -1) {
spawnedFood.erase(spawnedFood.begin() + index);
delete food;
}
}
It seems that I had some logical errors when it comes to the grid movement because when I re-coded everything and changed the grid movement into cell based instead of using modulo condition by dividing the screen width and height to the pixel size of my snake and using that as the coordinates for my movement, everything went back to normal and the collision bug disappeared.
Instead of doing this for the grid movement
Old Grid Movement Code
tempX += dx;
tempY += dy;
if (tempX % 25 == 0) {
snakeHead->x += tempX;
tempX = 0;
}
if (tempY % 25 == 0) {
snakeHead->y += tempY;
tempY = 0;
}
I defined this as a permanent value in my defs.h
defs.h
#define CELL_SIZE 25 // Size of the segment
#define CELL_WIDTH SCREEN_WIDTH / CELL_SIZE
#define CELL_HEIGHT SCREEN_HEIGHT / CELL_SIZE
After that, since I'm still going to render the picture with the default resolution, I multiplied CELL_SIZE to the dest variable of my blit function
draw.cpp
void blit(SDL_Texture* texture, int x, int y)
{
SDL_Rect dest;
dest.x = x * CELL_SIZE;
dest.y = y * CELL_SIZE;
SDL_QueryTexture(texture, NULL, NULL, &dest.w, &dest.h);
SDL_RenderCopy(app.renderer, texture, NULL, &dest);
}
This results to the snake and any other thing that I'm going to render to follow a grid and by assigning the x and y values with the CELL_WIDTH and CELL_HEIGHT as substitution to the resolution, I accomplished the grid movement with no conflict with my collision check.
The problem I'm having is that when I change an attribute of an Object the change isn't 'saving'. Easier to show you what's happening.
I'm learning c++ and decided to build a small chess app. Each Piece is a seperate Object.
They're stored in a std::vector as such
std::vector<Piece> pieces;
They're initialised like so
for (int i = 0; i < 2; i++)
{
Piece p;
p.Init(i*2+1, 1, renderer, SQUARE_SIZE, "king");
pieces.push_back(p);
}
When I click the mouse I want to select all pieces (temporarily)
for (int i = 0; i < pieces.size(); i++)
{
Piece p = pieces[i];
p.Select();
}
The issue is that while the Select() function is being called, by the time I get to rendering their selected attribute is false. Strangely this does not happen to the piece not contained within in the vector, referred to as k.
Before you ask there is nowhere in my code that I set selected to false :) (Except the constructor :P )
Also if you feel like downvoting, send me a comment first and I'll try fix whatever it is!
Here are the entire files. (not sure if this is the proper way to insert them)
Piece.h
#include <iostream>
#include <SDL2/SDL.h>
#include <SDL2/SDl_image.h>
#include <array>
#include <vector>
class Piece
{
public:
Piece();
void Init(int _x, int _y, SDL_Renderer* renderer, int SQUARE_SIZE, std::string type);
void SetPos(int _x, int _y, int _w);
void LoadTexture(SDL_Renderer* renderer, std::string type);
void LoadMovementVector(std::string type);
void Render(SDL_Renderer* renderer);
void Select(){ selected = true; std::cout << "called\n";}
bool isSelected(){ return selected; }
int GetX(){ return x; } // SDL_Point
int GetY(){ return y; }
private:
int x, y;
std::vector<int> move_vector;
bool selected;
SDL_Rect rect;
SDL_Texture* texture;
};
Piece.cpp
#include <iostream>
#include <SDL2/SDL.h>
#include <SDL2/SDl_image.h>
#include <vector>
#include "Piece.h"
Piece::Piece()
: x(0)
, y(0)
, selected(false)
{
}
void Piece::Init(int _x, int _y, SDL_Renderer* renderer, int SQUARE_SIZE, std::string type)
{
SetPos(_x, _y, SQUARE_SIZE);
LoadTexture(renderer, type);
LoadMovementVector(type);
}
void Piece::Render(SDL_Renderer* renderer)
{
//selected = true;
//std::cout << selected << std::endl;
if (selected)
{
SDL_SetRenderDrawColor(renderer, 255, 0, 0, 255);
SDL_RenderFillRect(renderer, &rect);
}
if (texture != nullptr)
{
SDL_RenderCopy(renderer, texture, nullptr, &rect);
}
else
{
SDL_SetRenderDrawColor(renderer, 255, 0, 0, 255);
SDL_RenderFillRect(renderer, &rect);
}
}
void Piece::LoadMovementVector(std::string type)
{
if (type == "king"){ // There literally has to be a better way to init std::vector
int arr[4] = {1,1,1,0};
for (int i = 0; i < 4; i++){ move_vector.push_back(arr[i]); }
}
for (int i = 0; i < move_vector.size(); i++)
{
std::cout << move_vector[i];
}
std::cout << std::endl;
}
void Piece::LoadTexture(SDL_Renderer* renderer, std::string type)
{
std::string source;
if (type == "king"){
source = "wk.png";
}
texture = IMG_LoadTexture(renderer, "res/wk.png");
}
void Piece::SetPos(int _x, int _y, int _w)
{
x = _x;
y = _y;
rect.x = _w*(_x-1);
rect.y = _w*(8-_y);
rect.w = _w;
rect.h = _w;
std::cout << x << y << std::endl;
}
Main.cpp
#include <iostream>
#include <math.h>
#include <SDL2/SDL.h>
#include <SDL2/SDl_image.h>
#include "Piece.h"
using namespace std::chrono;
// Would be 'const int' but I want to make the board resizeable
int SCREEN_WIDTH = 800;
int SCREEN_HEIGHT = 800;
int BOARD_WIDTH, BOARD_HEIGHT, SQUARE_SIZE;
SDL_Window* window;
SDL_Renderer* renderer;
std::vector<Piece> pieces;
Piece k;
bool InitEverything();
bool InitSDL();
bool CreateWindow();
bool CreateRenderer();
void SetupRenderer();
void Quit();
void RunGame();
void Render();
void HandleInput();
void UpdateDimensions();
double GetDelta();
void RenderGameBoard();
bool loop = true;
auto timePrev = high_resolution_clock::now();
int main(int argc, char* args[])
{
if (!InitEverything())
return -1;
std::cout << "Running Game..." << std::endl;
for (int i = 0; i < 2; i++)
{
Piece p;
p.Init(i*2+1, 1, renderer, SQUARE_SIZE, "king");
pieces.push_back(p);
}
k.Init(5, 1, renderer, SQUARE_SIZE, "king");
RunGame();
Quit();
return 0;
}
void RunGame()
{
while (loop)
{
HandleInput();
Render();
double delta = GetDelta();
}
}
void Render()
{
SDL_SetRenderDrawColor(renderer, 255, 255, 255, 255);
SDL_RenderClear(renderer);
RenderGameBoard();
for (int i = 0; i < pieces.size(); i++)
{
pieces[i].Render(renderer);
}
k.Render(renderer);
SDL_RenderPresent(renderer);
}
void RenderGameBoard()
{
for (int i = 0; i < 8; i++)
{
for (int j = 0; j < 8; j++)
{
if ((j%2==0&&i%2==0)||(j%2!=0&&i%2!=0))
SDL_SetRenderDrawColor(renderer, 255, 255, 255, 255);
else
SDL_SetRenderDrawColor(renderer, 180, 180, 180, 255);
SDL_Rect r = {i*SQUARE_SIZE, j*SQUARE_SIZE, SQUARE_SIZE, SQUARE_SIZE};
SDL_RenderFillRect(renderer, &r);
}
}
}
void HandleInput()
{
SDL_Event event;
while (SDL_PollEvent(&event))
{
if (event.type == SDL_QUIT)
loop = false;
else if (event.type == SDL_KEYDOWN)
{
}
else if (event.type == SDL_MOUSEBUTTONDOWN)
{
if (event.button.button == SDL_BUTTON_LEFT)
{
k.Select();
for (int i = 0; i < pieces.size(); i++)
{
Piece p = pieces[i];
p.Select();
}
int x = floor(event.button.x/SQUARE_SIZE)+1;
int y = 8-floor(event.button.y/SQUARE_SIZE);
for (int i = 0; i < pieces.size(); i++)
{
Piece p = pieces[i];
if (p.GetX() == x && p.GetY() == y)
{
p.Select();
}
}
}
}
}
}
void UpdateDimensions()
{
BOARD_WIDTH = SCREEN_WIDTH;
BOARD_HEIGHT = SCREEN_HEIGHT;
SQUARE_SIZE = BOARD_WIDTH/8;
}
double GetDelta()
{
auto timeCurrent = high_resolution_clock::now();
auto timeDiff = duration_cast< nanoseconds >( timeCurrent - timePrev );
double delta = timeDiff.count();
delta /= 1000000000;
timePrev = timeCurrent;
return delta;
}
bool InitEverything()
{
if (!InitSDL())
return false;
if (!CreateWindow())
return false;
if (!CreateRenderer())
return false;
SetupRenderer();
UpdateDimensions();
return true;
}
bool InitSDL()
{
if (SDL_Init(SDL_INIT_EVERYTHING) < 0)
{
std::cout << "SDL failed to initialize : " << SDL_GetError() << std::endl;
return false;
}
return true;
}
bool CreateWindow()
{
window = SDL_CreateWindow("Chess", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, SCREEN_WIDTH, SCREEN_HEIGHT, SDL_WINDOW_SHOWN);
if (!window)
{
std::cout << "Failed to create window : " << SDL_GetError() << std::endl;
return false;
}
return true;
}
bool CreateRenderer()
{
renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
if (!renderer)
{
std::cout << "Failed to create renderer : " << SDL_GetError() << std::endl;
return false;
}
return true;
}
void SetupRenderer()
{
SDL_RenderSetLogicalSize(renderer, SCREEN_WIDTH, SCREEN_HEIGHT);
}
void Quit()
{
SDL_DestroyWindow(window);
SDL_Quit();
}
This:
Piece p = pieces[i];
is creating a copy of the piece at index i in the vector.
Any methods you call after that are operating on the copy, not on the piece in the array.
Instead, take a reference to it:
Piece& p = pieces[i];
After that, p is a reference to element i in the vector and any operations you perform on it are performed on the vector element.
I am attempting to make a simple scrolling shooter game with SDL2. I have a moving player on a screen, and I am trying to make the player shoot a bullet using an array (so they can shoot multiple bullets) however, when I press the space bar, nothing happens, and instead the bullet image sort of flashes in the top left corner.
Heres the same code in codepad: http://codepad.org/rOhE1AqY
#include <SDL.h>
#include <stdio.h> //use for things like printf, same as cout
#include <iostream>
#include <string>
#include <time.h>
using namespace std;
//screend dimensions& sprtie dimensions
const int SCREEN_HEIGHT = 600;
const int SCREEN_WIDTH = 400;
const int SPRITE_WIDTH = 60;
const int SPRITE_HEIGHT = 80;
const int MAX_BULLETS = 50;
SDL_Window* Window = NULL;//the window rendering to
SDL_Surface* ScreenSurface = NULL;//surface contained by window
SDL_Surface* Background = NULL;
SDL_Surface* Player = NULL;
SDL_Surface* Enemy = NULL;
SDL_Surface* Bullet = NULL;
SDL_Surface* newBullet = NULL;
SDL_Rect posPlayer, posEnemy, posBullet, posnewBullet;
const Uint8* keystate = SDL_GetKeyboardState(NULL);
SDL_Event event;
class thePlayer
{
public:
thePlayer();
void player_movement();
void show_player();
private:
};
class theBullet
{
public:
theBullet();
bool isActive;
int x_position;
int y_position;
void bullet_movement();
void add_new_bullet();
void show_bullet();
private:
};
theBullet arrayofBullets[MAX_BULLETS];
class theEnemy
{
public:
theEnemy();
void enemy_movement();
void show_enemy();
private:
};
thePlayer::thePlayer()
{
posPlayer.x = 170;
posPlayer.y = SCREEN_HEIGHT;
posPlayer.w = 20;
posPlayer.h = 30;
}
void thePlayer::player_movement()
{
if(keystate[SDL_SCANCODE_LEFT])
{
posPlayer.x -= 2;
}
if(keystate[SDL_SCANCODE_RIGHT])
{
posPlayer.x += 2;
}
if(keystate[SDL_SCANCODE_UP])
{
posPlayer.y -= 2;
}
if(keystate[SDL_SCANCODE_DOWN])
{
posPlayer.y += 2;
}
if ((posPlayer.x + SPRITE_WIDTH) > SCREEN_WIDTH)
{
posPlayer.x = (SCREEN_WIDTH - SPRITE_WIDTH);
}
if ((posPlayer.y + SPRITE_HEIGHT) > SCREEN_HEIGHT)
{
posPlayer.y = (SCREEN_HEIGHT - SPRITE_HEIGHT);
}
}
void thePlayer::show_player()
{
SDL_BlitSurface(Player, NULL, ScreenSurface, &posPlayer);
SDL_SetColorKey(Player, SDL_TRUE, SDL_MapRGB(Player->format, 255, 255, 255));
}
theBullet::theBullet()
{
/*posBullet.x;
posBullet.y;
posBullet.w = 10;
posBullet.h = 15;*/
}
void theBullet::bullet_movement()
{
/*if(keystate[SDL_SCANCODE_SPACE])
{
posBullet.x = posPlayer.x + 25;
posBullet.y = posPlayer.y + 10;
}
posBullet.y -= 2;
if(posBullet.y < 0)
{
posBullet.y = -50;
}*/
}
void theBullet::show_bullet()
{
//SDL_BlitSurface(Bullet, NULL, ScreenSurface, &posBullet);
//SDL_SetColorKey(Bullet, SDL_TRUE, SDL_MapRGB(Player->format, 255, 255, 255));//removes white background
}
theEnemy::theEnemy()
{
srand (time(NULL));
posEnemy.x = rand() % 300 + 50;
posEnemy.y =0;
posEnemy.w = 35;
posEnemy.h = 60;
}
void theEnemy::enemy_movement()
{
posEnemy.y += 1;
if(posEnemy.y > SCREEN_HEIGHT)
{
posEnemy.y = SCREEN_HEIGHT +50;
}
}
void theEnemy::show_enemy()
{
SDL_BlitSurface(Enemy, NULL, ScreenSurface, &posEnemy);
SDL_SetColorKey(Enemy, SDL_TRUE, SDL_MapRGB(Player->format, 255, 255, 255));
}
bool initialise()
{
bool success = true;
if (SDL_Init(SDL_INIT_EVERYTHING) !=0)
{
cout<<"SDL_Init Error."<<SDL_GetError()<<endl;
success = false;
}
else
{
//create the window for game
Window = SDL_CreateWindow("Scrolling Shooter Game", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, SCREEN_WIDTH, SCREEN_HEIGHT, SDL_WINDOW_SHOWN);
if (Window == NULL)
{
cout<<"Window Error"<<SDL_GetError()<<endl;
success = false;
}
else
{
//get window surface
ScreenSurface = SDL_GetWindowSurface(Window);
}
}
return success;
}
bool LoadingMedia()
{
bool success = true;
Background = SDL_LoadBMP("background.bmp");
if (Background == NULL)
{
cout<<"Error in loading background."<<SDL_GetError()<<endl;
success = false;
}
Player = SDL_LoadBMP("spaceship.bmp");
if (Player == NULL)
{
cout<<"Error in loading player."<<SDL_GetError()<<endl;
success = false;
}
Enemy = SDL_LoadBMP("enemy.bmp");
if (Enemy == NULL)
{
cout<<"Error in loading enemy."<<SDL_GetError()<<endl;
success = false;
}
Bullet = SDL_LoadBMP("bullet.bmp");
if (Bullet == NULL)
{
cout<<"Error in loading bullet."<<SDL_GetError()<<endl;
success = false;
}
return success;
}
void closedown()
{
SDL_FreeSurface(Background);
Background = NULL;
SDL_FreeSurface(Player);
Player = NULL;
SDL_FreeSurface(Enemy);
Enemy = NULL;
SDL_DestroyWindow(Window);
Window = NULL;
SDL_Quit();
}
int main(int argc, char** argv)
{
bool quit = false;
thePlayer myPlayer;
theEnemy myEnemy;
theBullet myBullet;
if (!initialise())
{
cout<<"Failed to initialise"<<SDL_GetError()<<endl;
}
else
{
if (!LoadingMedia())
{
cout<<"Error loading media"<<SDL_GetError()<<endl;
}
}
//makes all bullets false
for (int i=0; i<MAX_BULLETS; i++)
{
arrayofBullets[i].isActive = false;
}
//GAME LOOP
while (quit == false)
{
SDL_BlitSurface(Background, NULL, ScreenSurface, NULL);
myPlayer.show_player();
myPlayer.player_movement();
while (SDL_PollEvent(&event))
{
if( event.type == SDL_QUIT )
{
quit = true;
break;
}
if(keystate[SDL_SCANCODE_SPACE])
{
for (int i=0; i<MAX_BULLETS; i++)
{
if (arrayofBullets[i].isActive == false)
{
arrayofBullets[i].x_position = posPlayer.x + 25;
arrayofBullets[i].y_position = posPlayer.y + 10;
arrayofBullets[i].isActive = true;
break;
}
}
}
//update game objects
for (int i=0; i<MAX_BULLETS; i++)
{
if (arrayofBullets[i].isActive == true)
{
arrayofBullets[i].y_position -= 2;
if (arrayofBullets[i].y_position < 0)
{
arrayofBullets[i].isActive = false;
}
}
}
for (int i=0; i<MAX_BULLETS; i++)
{
if (arrayofBullets[i].isActive == true)
{
SDL_BlitSurface(Bullet, NULL, ScreenSurface, NULL);
}
}
}
//myPlayer.show_player();
//myBullet.show_bullet();
//myEnemy.show_enemy();
//myPlayer.player_movement();
//myBullet.bullet_movement();
//myEnemy.enemy_movement();
SDL_UpdateWindowSurface(Window); //updates screen
}
closedown();
return 0;
}
SDL_BlitSurface(Bullet, NULL, ScreenSurface, NULL);
You haven't specified destination rect, so it will blit on left-top corner.
It should be
SDL_Rect dstrect;
dstrect.x = arrayofBullets[i].x_position;
dstrect.y = arrayofBullets[i].y_position;
dstrect.w = Bullet->w;
dstrect.h = Bullet->h;
SDL_BlitSurface(Bullet, NULL, ScreenSurface, &dstrect);
I'm trying to write a small game where boxes drop down from the top of the window. But for some reason, I can't change a internal variable in the class, the y-coordinate. I don' knowif I'm missing something basic, but I can't find the bug.
Box.h
#pragma once
#include "SDL.h"
class Box
{
public:
Box();
~Box();
void setX (int a);
void setY (int a);
void setSpeed (int a);
void setSurface ();
void render(SDL_Surface *source, SDL_Window *win);
void update();
private:
int x;
int y;
int speed;
SDL_Surface *sur;
SDL_Rect rect;
};
Box.cpp
#include "Box.h"
#include "SDL_image.h"
#include <iostream>
void Box::setX(int a)
{
x = a;
}
void Box::setY (int a)
{
y = a;
}
void Box::setSpeed (int a)
{
speed = a;
}
void Box::setSurface()
{
sur = IMG_Load("C:/hello.bmp");
if (sur == NULL)
{
std::cout << IMG_GetError();
}
}
Box::Box()
{
speed = 5;
y = 0;
x = 3;
rect.x = 0;
rect.y = 0;
}
Box::~Box()
{
}
void Box::render(SDL_Surface *source, SDL_Window *win)
{
SDL_BlitSurface(sur, NULL, source, &rect);
SDL_UpdateWindowSurface(win);
}
void Box::update()
{
setY(y + speed); //I've also tried y = y + speed
rect.y = y;
}
main.cpp
#include "SDL.h"
#include "Box.h"
#include "SDL_image.h"
#include <iostream>
bool init();
void update(Box test);
void render(Box test);
SDL_Window *win;
SDL_Surface *source;
int main(int argc, char *argv[])
{
init();
bool quit = false;
SDL_Event e;
Box test;
test.setSurface();
test.render(source, win);
while (quit ==false)
{
while( SDL_PollEvent( &e ) != 0 )
{
if( e.type == SDL_QUIT )
{
quit = true;
}
}
update(test);
render(test);
}
return 0;
}
void update(Box test)
{
test.update();
}
void render(Box test)
{
test.render(source, win);
}
bool init()
{
if (SDL_Init(SDL_INIT_EVERYTHING) != 0)
{
std::cout << "SDL_Init Error: " << SDL_GetError() << std::endl;
return 1;
}
win = SDL_CreateWindow("Hello World!", 100, 100, 640, 480, SDL_WINDOW_SHOWN);
if (win == NULL)
{
std::cout << "SDL_CreateWindow Error: " << SDL_GetError() << std::endl;
return 1;
}
source = SDL_GetWindowSurface(win);
return true;
}
update takes its Box argument by value, so a copy of the original Box is always made when update(test) is called. This copy is then modified, and the original is left unchanged. To fix this, make update take its argument by reference.
void update(Box& test);
void update(Box& test)
{
test.update();
}
I am making a TBS game, at least im trying to.
So i've started off by following a tutorial on lazyfoo.net (lesson 29) on how to make a tiled environment and making my own changes along the way.
Every time i try to compile it it gives me two main errors:
No. 1: 255 error: expected primary-expression before ',' token
No. 2: 267 error: expected ';' before 'myUnit'
Here is the source code, i am fairly certain the that the problem is not with the images or the map.
CODE:
#include "SDL/SDL_image.h"
#include "SDL/SDL.h"
#include <string>
#include <fstream>
const int SCREEN_WIDTH = 600;
const int SCREEN_HEIGHT = 600;
const int SCREEN_BPP = 32;
const int FPS = 30;
const int UNIT_WIDTH = 50;
const int UNIT_HEIGHT = 50;
const int LEVEL_WIDTH = 600;
const int LEVEL_HEIGHT = 600;
const int TILE_WIDTH = 60;
const int TILE_HEIGHT = 60;
const int TOTAL_TILES = 100;
const int TILE_SPRITES = 3;
const int TILE_GRASS = 0;
const int TILE_WATER = 1;
const int TILE_MOUNTAIN = 2;
SDL_Surface *screen = NULL;
SDL_Surface *Unit = NULL;
SDL_Surface *tileMap = NULL;
SDL_Rect clips[ TILE_SPRITES ];
SDL_Event occur;
class Tile
{
private:
SDL_Rect box;
int type;
public:
Tile(int x, int y, int tileType);
void show();
int get_type();
SDL_Rect get_box();
};
class Unit
{
private:
SDL_Rect Box;
bool movement;
public:
Unit();
void handle_input();
void move( Tile *tiles[]);
void show();
};
SDL_Surface *load_image(std::string filename)
{
SDL_Surface* loadedImage = NULL;
SDL_Surface* optimizedImage = NULL;
loadedImage = IMG_Load(filename.c_str());
if(loadedImage != NULL)
{
optimizedImage = SDL_DisplayFormat( loadedImage );
SDL_FreeSurface( loadedImage );
if(optimizedImage != NULL)
{
SDL_SetColorKey(optimizedImage, SDL_SRCCOLORKEY, SDL_MapRGB(optimizedImage->format, 0,0xff,0xff));
}
}
return optimizedImage;
}
void apply_surface(int x, int y, SDL_Surface* source, SDL_Surface* destination, SDL_Rect* clip = NULL)
{
SDL_Rect offset;
offset.x = x;
offset.y = y;
SDL_BlitSurface(source, clip, destination, &offset);
}
bool init()
{
if(SDL_Init(SDL_INIT_EVERYTHING) == -1)
{
return false;
}
screen = SDL_SetVideoMode(SCREEN_WIDTH,SCREEN_HEIGHT,SCREEN_BPP,SDL_SWSURFACE);
if(screen == NULL)
{
return false;
}
SDL_WM_SetCaption("Strategy Game", NULL);
return true;
}
bool load_files()
{
Unit = load_image("infantry_red.png");
if(Unit == NULL)
{
return false;
}
tileMap = load_image("tilemap.png");
if( tileMap == NULL)
{
return false;
}
return 0;
}
void clean_up(Tile *tiles[])
{
SDL_FreeSurface(Unit);
SDL_FreeSurface(tileMap);
for(int t = 0;t < TOTAL_TILES; t++)
{
delete tiles[ t ];
}
SDL_Quit();
}
void clip_tiles()
{
clips[TILE_GRASS].x = 0;
clips[TILE_GRASS].y = 0;
clips[TILE_GRASS].w = TILE_WIDTH;
clips[TILE_GRASS].h = TILE_HEIGHT;
clips[TILE_WATER].x = 60;
clips[TILE_WATER].y = 0;
clips[TILE_WATER].w = TILE_WIDTH;
clips[TILE_WATER].h = TILE_HEIGHT;
clips[TILE_MOUNTAIN].x = 120;
clips[TILE_MOUNTAIN].y = 0;
clips[TILE_MOUNTAIN].w = TILE_WIDTH;
clips[TILE_MOUNTAIN].h = TILE_HEIGHT;
}
bool set_tiles( Tile *tiles[])
{
int x = 0, y = 0;
std::ifstream map("strategy_game.map");
if(map == NULL)
{
return false;
}
for(int t = 0; y < TOTAL_TILES; t++)
{
int tileType = -1;
map >> tileType;
if(map.fail() == true)
{
map.close();
return false;
}
if( (tileType >= 0) && (tileType < TILE_SPRITES))
{
tiles[t] = new Tile(x,y,tileType);
}
else
{
map.close();
return false;
}
x += TILE_WIDTH;
if(x >= LEVEL_WIDTH)
{
x = 0;
y += TILE_HEIGHT;
}
}
map.close();
return true;
}
Tile::Tile(int x, int y, int tileType)
{
box.x = x;
box.y = y;
box.w = TILE_WIDTH;
box.h = TILE_HEIGHT;
type = tileType;
}
void Tile::show()
{
apply_surface(box.x, box.y, tileMap, screen, &clips[type]);
}
int Tile::get_type()
{
return type;
}
SDL_Rect Tile::get_box()
{
return box;
}
Unit::Unit()
{
Box.x = 0;
Box.y = 0;
Box.w = UNIT_WIDTH;
Box.h = UNIT_HEIGHT;
}
SDL_Rect rect;
int mouseX,mouseY;
void Unit::handle_input()
{
if(occur.type == SDL_MOUSEBUTTONDOWN)
{
mouseX = occur.button.x;
mouseY = occur.button.y;
}
}
void Unit::move(Tile *tiles[])
{
Box.x += mouseX;
if( Box.x < 0 || Box.x + UNIT_WIDTH > LEVEL_WIDTH )
{
Box.x -= mouseX;
}
Box.y -= mouseY;
if( Box.y < 0 || Box.y + UNIT_HEIGHT > LEVEL_HEIGHT)
{
Box.y -= mouseY;
}
}
void Unit::show()
{
int BoxX;
int BoxY;
Box.x = BoxX;
Box.y = BoxY;
SDL_Rect unitOffset;
unitOffset.x = BoxX;
unitOffset.y = BoxY;
SDL_BlitSurface(Unit,NULL,screen,unitOffset);
}
Uint32 start;
int main(int argc, char* args[])
{
bool quit = false;
Unit myUnit;
Tile *tiles[TOTAL_TILES];
if(init() == false)
{
return 1;
}
if(load_files() == false)
{
return 1;
}
clip_tiles();
if( set_tiles(tiles) == false)
{
return 1;
}
while(quit == false)
{
start = SDL_GetTicks();
while(SDL_PollEvent(&occur));
{
myUnit.handle_input();
switch(occur.type)
{
case SDL_QUIT:
quit = false;
break;
}
}
myUnit.move(tiles);
for(int t = 0;t<TOTAL_TILES;t++)
{
tiles[t]->show();
}
myUnit.show();
//render
SDL_FillRect(screen,&screen->clip_rect,0);
SDL_Flip(screen);
if(1000/FPS > SDL_GetTicks() - start ){
SDL_Delay(1000/FPS - (SDL_GetTicks()-start));
}
}
clean_up( tiles );
return 0;
}
Remove semi-colon from while(SDL_PollEvent(&occur))
Change: SDL_Surface *Unit = NULL; to `SDL_Surface *unitSurf = NULL;'
Change:
Unit = load_image("infantry_red.png");
if(Unit == NULL)
{
return false;
}
to
unitSurf = load_image("infantry_red.png");
if(unitSurf == NULL)
{
return false;
}
Change: SDL_BlitSurface(Unit,NULL,screen,unitOffset); to SDL_BlitSurface(unitSurf,NULL,screen,unitOffset);
Remove the semicolon after while(SDL_PollEvent(&occur))