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  1. #include <iostream>
  2. #include <vector>
  3.  
  4.  
  5. class point
  6. {
  7.     public:
  8. 		point (int a, int b): x(a), y(b) {};
  9. 		~point () {};
  10.  
  11. 		int getX() {return x;}
  12. 		int getY() {return y;}
  13.  
  14. 	private:
  15. 		int x;
  16. 		int y;
  17. };
  18.  
  19.  
  20. class side
  21. {
  22. 	public:
  23. 		side(point f, point s): first(f), second(s) {};
  24. 		~side() {};
  25. 		point getFirst() {return first;}
  26. 		point getSecond() {return second;}
  27.  
  28. 	private:
  29. 		point first;
  30. 		point second;
  31. };
  32.  
  33.  
  34. class boundingBox
  35. {
  36. 	public:
  37. 		boundingBox(std::vector <point> p);
  38. 		~boundingBox() {};
  39.  
  40. 		std::vector <side> getSides() {return boundingSides;}
  41.  
  42. 	private:
  43. 		std::vector <point> boundingPoints;
  44. 		std::vector <side> boundingSides;
  45. };
  46.  
  47.  
  48. boundingBox::boundingBox(std::vector <point> p)
  49. {
  50. 	boundingPoints = p;
  51.  
  52. 	// in the constructor, create a vector of sides from the points
  53. 	for (std::vector <point>::iterator i = boundingPoints.begin(); i != boundingPoints.end()-1; i++)
  54. 	{
  55. 		boundingSides.push_back( side(*i, *(i+1)) );
  56. 	}
  57.  
  58. 	boundingSides.push_back( side (*(boundingPoints.end()-1), *(boundingPoints.begin()) ) );
  59. }
  60.  
  61.  
  62.  
  63.  
  64.  
  65.  
  66. bool collisionCheck(std::vector <side> s, point p)
  67. {
  68. 	std::vector <side> nodeSides;
  69.  
  70. 	int toleft = 0;
  71. 	int toright = 0;
  72.  
  73. 	for (std::vector <side>::iterator i = s.begin(); i != s.end(); i++)
  74. 	{
  75. 		//if the Y value of the point being tested is between the Y values of a side, add a node
  76. 		if (p.getY() > (*i).getFirst().getY() && p.getY() < (*i).getSecond().getY() ||
  77. 		    p.getY() < (*i).getFirst().getY() && p.getY() > (*i).getSecond().getY() )
  78. 		{
  79. 			nodeSides.push_back( side ( (*i).getFirst(), (*i).getSecond() ) );
  80. 		}
  81.  
  82.  
  83. 		// if the Y value of the point being tested is also the Y of the second point of the side...
  84. 		if (p.getY() == (*i).getSecond().getY())
  85. 		{
  86. 			//if it isn't the last side, and this side and the next strattle that y value, add a node
  87. 			if (i != s.end()-1)
  88. 			{
  89. 				if ((*i).getFirst().getY() < p.getY() && (*(i+1)).getSecond().getY() > p.getY() ||
  90. 			   	    (*i).getFirst().getY() > p.getY() && (*(i+1)).getSecond().getY() < p.getY() )
  91. 				{
  92. 					nodeSides.push_back( side ( (*i).getFirst(), (*i).getSecond() ) );
  93. 				}	
  94. 			}	
  95.  
  96. 			//if it is the last side, and this side and the first side strattle that y value, add a node
  97. 			else if ((*i).getFirst().getY() < p.getY() && s.front().getSecond().getY() > p.getY() ||
  98. 			   	 (*i).getFirst().getY() > p.getY() && s.front().getSecond().getY() < p.getY() )
  99. 			{
  100. 				nodeSides.push_back( side ( (*i).getFirst(), (*i).getSecond() ) );
  101. 			}
  102. 		}
  103. 	}
  104.  
  105. 	for (std::vector <side>::iterator i = nodeSides.begin(); i != nodeSides.end(); i++)
  106. 	{
  107. 		double deltaY = (*i).getSecond().getY() - (*i).getFirst().getY();
  108. 		double deltaX = (*i).getSecond().getX() - (*i).getFirst().getX();
  109.  
  110. 		double slope = deltaX - deltaY;
  111.  
  112. 		double x = ( p.getY() - (*i).getSecond().getY() + (slope * (*i).getSecond().getX()) ) / slope;
  113.  
  114. 		if (x < p.getX()) 
  115. 		{
  116. 			toleft++;
  117. 		}
  118.  
  119. 		else
  120. 		{
  121. 			toright++;
  122. 		}
  123. 	}
  124.  
  125.  
  126. 	std::cout << "Analysis: " << toleft << " nodes to the left, " << toright << " nodes to the right." << std::endl;
  127.  
  128. 	if (toleft % 2 == 0)
  129. 	{
  130. 		std::cout << "return false, does not hit" << std::endl;
  131. 		return false;
  132. 	}
  133.  
  134. 	else
  135. 	{
  136. 		std::cout << "return true, hits" << std::endl;
  137. 		return true;
  138. 	}
  139. }
  140.  
  141.  
  142.  
  143.  
  144.  
  145.  
  146. int main ()
  147. {
  148. 	std::vector <point> points;
  149.  
  150. 	points.push_back(point(3, 5));
  151. 	points.push_back(point(1, 13));
  152. 	points.push_back(point(7, 16));
  153. 	points.push_back(point(14, 14));
  154. 	points.push_back(point(8, 13));
  155. 	points.push_back(point(9, 11));
  156. 	points.push_back(point(17, 13));
  157. 	points.push_back(point(16, 18));
  158. 	points.push_back(point(21, 15));
  159. 	points.push_back(point(17, 9));
  160. 	points.push_back(point(9, 7));
  161. 	points.push_back(point(12, 5));
  162. 	points.push_back(point(14, 7));
  163. 	points.push_back(point(15, 2));
  164. 	points.push_back(point(6, 3));
  165.  
  166. 	boundingBox enemy(points);
  167.  
  168. 	point hitSimp(13, 4);
  169. 	point hitComp(19, 15);
  170. 	point missNear(10, 12);
  171. 	point missFar(100,100);
  172.  
  173. 	collisionCheck(enemy.getSides(), hitSimp);
  174.  
  175. 	collisionCheck(enemy.getSides(), hitComp);
  176.  
  177. 	collisionCheck(enemy.getSides(), missNear);
  178.  
  179. 	collisionCheck(enemy.getSides(), missFar);
  180.  
  181. 	return 0;
  182. }
  183.  
  184.  
  185.  
  186.  
  187.  
Success #stdin #stdout 0s 2992KB
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Standard input is empty
stdout
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Analysis: 1 nodes to the left, 1 nodes to the right.
return true, hits
Analysis: 3 nodes to the left, 1 nodes to the right.
return true, hits
Analysis: 2 nodes to the left, 2 nodes to the right.
return false, does not hit
Analysis: 0 nodes to the left, 0 nodes to the right.
return false, does not hit
https://ideone.com/n9cXjZ
language:
C++ (gcc 8.3)
created:
11 years ago
visibility:
public

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