coffee_crisis_opendingux_dev/source/utils.cpp

#include "utils.h"

// Calcula el cuadrado de la distancia entre dos puntos
double distanceSquared(int x1, int y1, int x2, int y2)
{
    int deltaX = x2 - x1;
    int deltaY = y2 - y1;
    return deltaX * deltaX + deltaY * deltaY;
}

// Detector de colisiones entre dos circulos
bool checkCollision(Circle &a, Circle &b)
{
    // Calcula el radio total al cuadrado
    int totalRadiusSquared = a.r + b.r;
    totalRadiusSquared = totalRadiusSquared * totalRadiusSquared;

    // Si la distancia entre el centro de los circulos es inferior a la suma de sus radios
    if (distanceSquared(a.x, a.y, b.x, b.y) < (totalRadiusSquared))
    {
        // Los circulos han colisionado
        return true;
    }

    // En caso contrario
    return false;
}

// Detector de colisiones entre un circulo y un rectangulo
bool checkCollision(Circle &a, SDL_Rect &b)
{
    //Closest point on collision box
    int cX, cY;

    //Find closest x offset
    if (a.x < b.x)
    {
        cX = b.x;
    }
    else if (a.x > b.x + b.w)
    {
        cX = b.x + b.w;
    }
    else
    {
        cX = a.x;
    }

    //Find closest y offset
    if (a.y < b.y)
    {
        cY = b.y;
    }
    else if (a.y > b.y + b.h)
    {
        cY = b.y + b.h;
    }
    else
    {
        cY = a.y;
    }

    //If the closest point is inside the circle
    if (distanceSquared(a.x, a.y, cX, cY) < a.r * a.r)
    {
        //This box and the circle have collided
        return true;
    }

    //If the shapes have not collided
    return false;
}

// Detector de colisiones entre un dos rectangulos
bool checkCollision(SDL_Rect &a, SDL_Rect &b)
{
    //Calculate the sides of rect A
    int leftA = a.x;
    int rightA = a.x + a.w;
    int topA = a.y;
    int bottomA = a.y + a.h;

    //Calculate the sides of rect B
    int leftB = b.x;
    int rightB = b.x + b.w;
    int topB = b.y;
    int bottomB = b.y + b.h;

    //If any of the sides from A are outside of B
    if (bottomA <= topB)
    {
        return false;
    }

    if (topA >= bottomB)
    {
        return false;
    }

    if (rightA <= leftB)
    {
        return false;
    }

    if (leftA >= rightB)
    {
        return false;
    }

    //If none of the sides from A are outside B
    return true;
}