breakout collision detection using vectors - c++

Question

I am working on a breakout game using C++ and OpenGL. I have stubbed out some code using straight C++. I am using a vector to store objects.
I want to streamline my collision detection code.I am working on breakout game using vectors to store brick values in text based c++ to start with. Well I am attempting to use a vector as a dynamic array. Basically I want to store the values of the bricks in a vector. I then want to iterate through the vector in order to determine if a brick is hit by the ball. I am able to detect if a single brick is hit by the ball but I want to determine if a vector of brick values are hit by a ball. In other words instead of using a collision detection loop for each and every single brick one at a time but I want the vector to store the values for the bricks so that I can iterate through them dynamically.
My code:
class Brick
{
public:
float x;
float y;
float brick_x;
float brick_y;
float brickWidth;
float brickHeight;
};
int main()
{
vector<Brick> brick;
Brick playerBrick;
Brick playerBrick_two;
playerBrick.x = 30.0f;
playerBrick.y = 20.0f;
playerBrick.brick_x = 20.0f;
playerBrick.brick_y = 10.0f;
playerBrick.brickWidth = 60.0f;
playerBrick.brickHeight = 20.0f;
playerBrick_two.x = 40.0f;
playerBrick_two.y = 30.0f;
playerBrick_two.brick_x = 30.0f;
playerBrick_two.brick_y = 20.0f;
playerBrick_two.brickWidth = 60.0f;
playerBrick_two.brickHeight = 20.0f;
brick.push_back(playerBrick);
brick.push_back(playerBrick_two);
for (int i = 0; i < 2; i++)
{
cout << brick[i].x << " " << brick[i].y << " " << brick[i].brick_x << " " << brick[i].brick_y << " " << brick[i].brickWidth << " " << brick[i].brickHeight << endl;
}
for (int i = 0; i < 2; i++)
{
if (brick[i].x > brick[i].brick_x && brick[i].x < brick[i].brick_x + brick[i].brickWidth && brick[i].y > brick[i].brick_y && brick[i].y < brick[i].brick_y + brick[i].brickHeight)
{
cout << "Collision" << endl;
}
}
void bricks_eight()
{
glColor3f(0.8f, 0.0f, 0.0f);
glRectf(50.0f, 60.0f, 70.0f, 50.0f);
glRectf(70.0f, 60.0f, 90.0f, 50.0f);
glRectf(90.0f, 60.0f, 110.0f, 50.0f);
glRectf(110.0f, 60.0f, 130.0f, 50.0f);
glRectf(130.0f, 60.0f, 150.0f, 50.0f);
glRectf(150.0f, 60.0f, 170.0f, 50.0f);
}
Well I am posting a row of bricks I want to eliminate when the ball strikes with them. Since I have several rows of bricks I want to use a collision detection function that checks for a ball and brick collision using a vector. The x and y variables are the ball coordinates and the brick_x and brick_y variables and the brick coordinates.
I adjusted Makogan's code but it still does not check for a lot collisions all at once.
``
class Brick
{
public:
float x;
float y;
float brick_x=0.0f;
float brick_y=0.0f;
float brickWidth=20.0f;
float brickHeight=10.0f;
bool TestCollision(float x, float y)
{
if (x > brick_x && x<brick_x + brickWidth && y > brick_y && y < brick_y + brickHeight)
{
return true;
}
return false;
}
};
class BrickLayer
{
public:
vector<Brick> bricks{(5.0f,5.0f)};
bool TestCollisions(float x, float y) {
for (auto& brick : bricks) if (brick.TestCollision(x, y)) return true;
return false;
}
};
int main()
{
BrickLayer brick;
cout << brick.TestCollisions(5.0f,5.0f)<< endl;
system("pause");
return 0;
}

Answer 1

Based on the comments, it sounds like you just need a wrapper to abstract detecting collisions for a group / row of your bricks.
So my suggestion is
class Brick
{
public:
float x;
float y;
float brick_x;
float brick_y;
float brickWidth;
float brickHeight;
TestCollision(float x,float y) {/* check goes here */}
};
class BrickLayer
{
public:
vector<Brick> bricks;
float min_x;
float min_y;
float total_width;
float total_height;
BrickLayer(vector<Brick> bricks) {/* initialize the instance fields here */}
// Option 1, iterating over every brick:
bool TestCollisions(float x, float y) {
for(auto& brick : bricks) if(brick.testCollision(x,y)) return true;
return false;
}
// Option 2, use cached information:
bool TestCollisions(float x, float y) {
if (x > min_x && x < min_x + total_width && y > min_y && y < min_y + total_height)
return true;
}
};