期末用2019.6（计算机图形学3，4次上机题的所有代码）

第4次上机

主要内容：二维投影，三维投影，图形放大缩小

void CTestView::ReadPoint()//点表
{
	//顶点的三维坐标(x,y,z),立方体边长为2a
	double a=150;	
	P[0].x = -a / 2; P[0].y = -a / 2; P[0].z = -a / 2;
	P[1].x = +a / 2; P[1].y = -a / 2; P[1].z = -a / 2;
	P[2].x = +a / 2; P[2].y = +a / 2; P[2].z = -a / 2;
	P[3].x = -a / 2; P[3].y = +a / 2; P[3].z = -a / 2;
	P[4].x = -a / 2; P[4].y = -a / 2; P[4].z = +a / 2;
	P[5].x = +a / 2; P[5].y = -a / 2; P[5].z = +a / 2;
	P[6].x = +a / 2; P[6].y =+a / 2; P[6].z = +a / 2;
	P[7].x = -a / 2; P[7].y = +a / 2; P[7].z = +a / 2;
}



void CTestView::ReadFace()//面表
{
	//面的顶点数和面的顶点索引
	F[0].SetNum(4); F[0].vI[0] = 4;  F[0].vI[1] = 5; F[0].vI[2] = 6; F[0].vI[3] = 7;
	F[1].SetNum(4); F[1].vI[0] = 0; F[1].vI[1] = 3; F[1].vI[2] = 2; F[1].vI[3] = 1;
	F[2].SetNum(4); F[2].vI[0] = 0; F[2].vI[1] = 4; F[2].vI[2] = 7; F[2].vI[3] = 3;
	F[3].SetNum(4); F[3].vI[0] = 1; F[3].vI[1] = 2; F[3].vI[2] = 6; F[3].vI[3] = 5;
	F[4].SetNum(4); F[4].vI[0] = 2; F[4].vI[1] = 3; F[4].vI[2] = 7; F[4].vI[3] = 6;
	F[5].SetNum(4); F[5].vI[0] = 0; F[5].vI[1] = 1; F[5].vI[2] = 5; F[5].vI[3] = 4;
}



void CTestView::InitParameter()//透视变换参数初始化
{	
	k[1] = sin(PI*Theta / 180);
	k[2] = sin(PI*Phi / 180);
	k[3] = cos(PI*Theta / 180);
	k[4] = cos(PI*Phi / 180);
	k[5] = k[2] * k[3];
	k[6] = k[2] * k[1];
	k[7] = k[4] * k[3];
	k[8] = k[4] * k[1];
}


void CTestView::PerProject(CP3 P)//透视变换
{
	CP3 ViewP;
	ViewP.x = P.x*k[3] - P.z*k[1];
	ViewP.y = -P.x*k[8] + P.y*k[2] - P.z*k[7];
	ViewP.z = -P.x*k[6] - P.y*k[4] - P.z*k[5] + R;
	ScreenP.x = d * ViewP.x / ViewP.z;
	ScreenP.y = d * ViewP.y / ViewP.z;
}



void CTestView::DrawObject(CDC* pDC)//绘制立方体线框
{
	CP2 t;
	CLine *line = new CLine;
	for (int nFace = 0; nFace < 6; nFace++)
	{
		for (int nEdge = 0; nEdge < F[nFace].vN; nEdge++)
		{
			PerProject(P[F[nFace].vI[nEdge]]);
			if (nEdge == 0)
			{
				line->MoveTo(pDC, ScreenP);
				t = ScreenP;
			}
			else
			{
				line->LineTo(pDC, ScreenP);
			}
		}
		line->LineTo(pDC, t);
	}
	delete line;
}

void CTestView::OnRButtonDown(UINT nFlags, CPoint point)
{
	// TODO: 在此添加消息处理程序代码和/或调用默认值
	R = R - 100;
	InitParameter();//更新参数
	Invalidate(FALSE);//重新绘制窗口
	CView::OnRButtonDown(nFlags, point);//此行为最后一行
}

void CTestView::OnTwopoint()//工具条中二点透视按钮的响应函数
{
	// TODO: 在此添加命令处理程序代码
	KillTimer(1);
	bPlay = FALSE;
	Phi = 45; Theta = 0;
	InitParameter();
	Invalidate(FALSE);
}


void CTestView::OnThreepoint()//工具条中三点透视按钮的响应函数
{
	// TODO: 在此添加命令处理程序代码
	KillTimer(1);
	bPlay = FALSE;
	Phi = 45; Theta = 45;
	InitParameter();
	Invalidate(FALSE);
}

第三次上机

主要内容：Cohen-Sutherland直线段裁剪算法

void CTestView::Cohen()//Cohen-Sutherland算法，实现函数体
{
	CP2 p;
	EnCode(P[0]);
	EnCode(P[1]);
	while (P[0].rc != 0 || P[1].rc != 0)
	{
		if (0 != (P[0].rc&P[1].rc))
		{
			PtCount = 0;
			return;
		}
		UINT RC = P[0].rc;
		if (P[0].rc == 0) RC = P[1].rc;
		if (RC & LEFT)
		{
			p.x = Wxl;
			p.y = P[0].y + (P[1].y - P[0].y)*(p.x - P[0].x) / (P[1].x - P[0].x);
		}
		else if (RC & RIGHT)
		{
			p.x = Wxr;
			p.y = P[0].y + (P[1].y - P[0].y)*(p.x - P[0].x) / (P[1].x - P[0].x);
		}
		else if (RC & BOTTOM)
		{
			p.y = Wyb;
			p.x = P[0].x + (P[1].x - P[0].x)*(p.y - P[0].x) / (P[1].x - P[0].x);
		}
		else if (RC & TOP)
		{
			p.y = Wyt;
			p.x = P[0].x + (P[1].x - P[0].x)*(p.y - P[0].y) / (P[1].y - P[0].y);
		}
		if (RC == P[0].rc)
		{
			EnCode(p);
			P[0] = p;
		}
		else
		{
			EnCode(p);
			P[1] = p;
		}
	}
}




void CTestView::EnCode(CP2 &pt)//端点编码函数, 实现函数体
{
	pt.rc = 0;
	if (pt.x < Wxl)
	{
		pt.rc = pt.rc | LEFT;
	}
	else if (pt.x > Wxr)
	{
		pt.rc = pt.rc | RIGHT;
	}
	if (pt.y < Wyb)
	{
		pt.rc = pt.rc | BOTTOM;
	}
	else if (pt.y > Wyt)
	{
		pt.rc = pt.rc | TOP;
	}
}