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POLYGON Class Reference

#include <polygon.h>

List of all members.

Public Methods
	POLYGON ()
	~POLYGON ()
VECTOR	GetNormal ()
void	SetNormal ()
VECTOR	GetMidPoint ()
bool	CheckForCollision (CAMERA *pLastCam, CAMERA *pCam)
Public Attributes
TEXTURE	Texture
VERTEX	Vertex [3]

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Constructor & Destructor Documentation

POLYGON::POLYGON (    )

Definition at line 7 of file polygon.cpp. { }

POLYGON::~POLYGON (    )

Definition at line 11 of file polygon.cpp. { }

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Member Function Documentation

bool POLYGON::CheckForCollision (  CAMERA *    pLastCam, CAMERA *    pCam )

Definition at line 70 of file polygon.cpp. References CrossVector(), DotProduct(), GetEdgeVector(), GetNormal(), GetUnitVector(), MagnitudeVector(), OBJECT::Position, Vertex, VERTEX::x, VECTOR::x, VERTEX::y, VECTOR::y, VERTEX::z, and VECTOR::z. { float Radius = 0.5; //Collision sphere radius VECTOR Vect1; //Change vertex representation of data to vectors Vect1.x = Vertex[0].x; Vect1.y = Vertex[0].y; Vect1.z = Vertex[0].z; VECTOR Vect2; Vect2.x = Vertex[1].x; Vect2.y = Vertex[1].y; Vect2.z = Vertex[1].z; VECTOR Vect3; Vect3.x = Vertex[2].x; Vect3.y = Vertex[2].y; Vect3.z = Vertex[2].z; float Flag = 0; //Collision flag, 1 = collision occured float CamDistance; //Camera distance from plane float LastCamDistance; //LastCamera distance from plane VECTOR CameraPos; //Vector for the cameras position VECTOR LastCameraPos; //Vector for the cameras position VECTOR TempVect; //Work variables float TempFloat; VECTOR Normal = GetNormal(); //Get this polygons face normal Normal.x = Normal.x * -1; //Invert normal. Not sure if this is a problem with my code or an ogl thing. Normal.y = Normal.y * -1; Normal.z = Normal.z * -1; Normal = GetUnitVector(Normal); //Convert to a unit vector TempFloat = -1 * DotProduct(Normal, Vect1); // Take the dot product of the face normal and any point on the face, and negate that. This will be your d (distance offset) component of the plane equation. CameraPos.x = -1 * pCam->Position.x; //Get inverted current camera position CameraPos.y = -1 * pCam->Position.y; CameraPos.z = -1 * pCam->Position.z; CamDistance = DotProduct(Normal, CameraPos) - TempFloat; //Distance from polygons plane LastCameraPos.x = -1 * pLastCam->Position.x; //Get inverted last camera position LastCameraPos.y = -1 * pLastCam->Position.y; LastCameraPos.z = -1 * pLastCam->Position.z; LastCamDistance = DotProduct(Normal, LastCameraPos) - TempFloat; //Distance from polygons plane if(!(CamDistance < Radius && LastCamDistance >= Radius)) //If CamDistance < Radius and LastCamDistance >= Radius then it passed through the polygon goto Skip; //If not, end the collision test TempVect = GetEdgeVector(Vect1, Vect2); //Create edge vector TempVect = CrossVector(Normal, TempVect); //Cross product of edge vector and polygons normal gives us the anti-planes normal TempVect = GetUnitVector(TempVect); //Reduce anti-plane normal to a unit vector TempFloat = -1 * DotProduct(TempVect, Vect1); //Distance offset to plane equation TempFloat = DotProduct(TempVect, CameraPos) - TempFloat; //Find distance to the plane if(TempFloat >= Radius)// - 0.2) //Reducing the radius here makes sure the sphere is well on the polygon before colliding goto Skip; TempVect = GetEdgeVector(Vect2, Vect3); TempVect = CrossVector(Normal, TempVect); TempVect = GetUnitVector(TempVect); TempFloat = -1 * DotProduct(TempVect, Vect2); TempFloat = DotProduct(TempVect, CameraPos) - TempFloat; if(TempFloat >= Radius)// - 0.2) goto Skip; TempVect = GetEdgeVector(Vect3, Vect1); TempVect = CrossVector(Normal, TempVect); TempVect = GetUnitVector(TempVect); TempFloat = -1 * DotProduct(TempVect, Vect3); TempFloat = DotProduct(TempVect, CameraPos) - TempFloat; if(TempFloat >= Radius)// - 0.2) goto Skip; TempFloat = (Radius - CamDistance)/MagnitudeVector(Normal); //Calculate new position and distance of slide pCam->Position.x -= (TempFloat * Normal.x); //Update the camera position pCam->Position.y -= (TempFloat * Normal.y); pCam->Position.z -= (TempFloat * Normal.z); Flag = 1; //Set collision flag to true return Flag; Skip: return Flag; }

VECTOR POLYGON::GetMidPoint (    )

Definition at line 61 of file polygon.cpp. References Vertex, VERTEX::x, VECTOR::x, VERTEX::y, VECTOR::y, VERTEX::z, and VECTOR::z. { VECTOR temp; temp.x = (Vertex[0].x + Vertex[1].x + Vertex[2].x)/3; temp.y = (Vertex[0].y + Vertex[1].y + Vertex[2].y)/3; temp.z = (Vertex[0].z + Vertex[1].z + Vertex[2].z)/3; return temp; }

VECTOR POLYGON::GetNormal (    )

Definition at line 15 of file polygon.cpp. References Vertex, VECTOR::x, VERTEX::x, VECTOR::y, VERTEX::y, VECTOR::z, and VERTEX::z. Referenced by CheckForCollision(). { VECTOR temp; float ux; float uy; float uz; float vx; float vy; float vz; ux = Vertex[1].x - Vertex[0].x; uy = Vertex[1].y - Vertex[0].y; uz = Vertex[1].z - Vertex[0].z; vx = Vertex[2].x - Vertex[0].x; vy = Vertex[2].y - Vertex[0].y; vz = Vertex[2].z - Vertex[0].z; temp.x = (uy*vz)-(vy*uz); temp.y = (uz*vx)-(vz*ux); temp.z = (ux*vy)-(vx*uy); return temp; }

void POLYGON::SetNormal (    )

Definition at line 36 of file polygon.cpp. References VERTEX::nx, VERTEX::ny, VERTEX::nz, Vertex, VERTEX::x, VERTEX::y, and VERTEX::z. Referenced by SetPolygons(). { float ux; float uy; float uz; float vx; float vy; float vz; ux = Vertex[1].x - Vertex[0].x; uy = Vertex[1].y - Vertex[0].y; uz = Vertex[1].z - Vertex[0].z; vx = Vertex[2].x - Vertex[0].x; vy = Vertex[2].y - Vertex[0].y; vz = Vertex[2].z - Vertex[0].z; Vertex[0].nx = (uy*vz)-(vy*uz); Vertex[0].ny = (uz*vx)-(vz*ux); Vertex[0].nz = (ux*vy)-(vx*uy); Vertex[1].nx = Vertex[0].nx; Vertex[1].ny = Vertex[0].ny; Vertex[1].nz = Vertex[0].nz; Vertex[2].nx = Vertex[0].nx; Vertex[2].ny = Vertex[0].ny; Vertex[2].nz = Vertex[0].nz; }

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Member Data Documentation

TEXTURE POLYGON::Texture

Definition at line 24 of file polygon.h.

VERTEX POLYGON::Vertex[3]

Definition at line 25 of file polygon.h. Referenced by CheckForCollision(), GetMidPoint(), GetNormal(), SetNormal(), and SetPolygons().

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The documentation for this class was generated from the following files:

• polygon.h
• polygon.cpp

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