transmatrix.cpp

计算机图形学实验设计 计算机图形学实验设计

// TransMatrix.cpp: implementation of the CTransMatrix class.
//
//////////////////////////////////////////////////////////////////////

#include "stdafx.h"
#include "cgDemo.h"
#include "TransMatrix.h"

#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////

CTransMatrix::CTransMatrix()
{

}

CTransMatrix::~CTransMatrix()
{

}

void CTransMatrix::Identity2Dmatrix(float m[3][2])
{
	  for (int i = 0; i < 3; i++)
		for (int j = 0; j < 2; j++)
			m[i][j] = (i == j) ? 1.0 : 0.0;

}


void CTransMatrix::Scale2Dmatrix(float Sx, float Sy,float m[3][2])
{
	for (int i = 0; i < 3; i++) {
		m[i][0] *= Sx;
		m[i][1] *= Sy;
	}
}

void CTransMatrix::Rotate2Dmatrix(float S, float C,float m[3][2])
{
	float temp;

	for (int i = 0; i < 3; i++) {
		temp    = C*m[i][0]-S*m[i][1];
		m[i][1] = S*m[i][0]+C*m[i][1];
		m[i][0] = temp;
	}

}

void CTransMatrix::Translate2Dmatrix(float Tx, float Ty,float m[3][2])
{
		m[2][0] += Tx;
		m[2][1] += Ty;
}

void CTransMatrix::Trans2Dpoint(float *x, float *y,float m[3][2])
{
	float temp;

	  temp = *x * m[0][0]+ *y * m[1][0] + m[2][0];
        *y = *x * m[0][1]+ *y * m[1][1] + m[2][1];
		*x = temp;
}

void CTransMatrix::Trans2Dpoints(int n,float *x, float *y,float m[3][2])
{
	float temp;

	for (int i = 0; i < n; i++) {
	  temp = x[i] * m[0][0]+ y[i] * m[1][0] + m[2][0];
      y[i] = x[i] * m[0][1]+ y[i] * m[1][1] + m[2][1];
	  x[i] = temp;
	}
}