VC6.0_OpenGL_NURBS绘制四分之一圆_半圆_圆.rar

/* nurbs.cpp */ #include "nurbs.h" #pragma comment(lib,"glu32.lib") #pragma comment(lib,"glaux.lib") #pragma comment(lib,"opengl32.lib") /* 只要将前p个控制点和最后p个控制点重合，就能实现闭合。其中，p为次数，不是阶数。 一：初始化 1、先定义控制点 2、定义NURBS对象 GLUnurbsObj *theNurb; theNurb = gluNewNurbsRenderer(); 3、设置NURBS属性 void gluNurbsProperty(GLUnurbsObj* nobj, GLenum property, GLfloat value) nobj： 指向NURBS对象的指针。 　　 property： 需设置的属性。 　　 value： 设置指定属性的值。 gluNurbsProperty( theNurb, GLU_SAMPLING_TOLERANCE, 25.0 ) ; 二：绘制Draw 绘制NURBS曲线的函数：gluNurbsCurve： void gluNurbsCurve( GLUnurbsObj *nobj， 指向NURBS对象的指针 GLint nknots， 节点数，节点数=控制点数+阶数 GLfloat *knot， nknots数组非递减节点值 Glint stride， 跨度，相邻控制点的偏移量，即：单个控制点的坐标元素个数 GLfloat *ctlarray， 指向NURBS的控制点数组的指针 GLint order， NURBS曲线的阶数，阶数=次数+1 GLenum type 曲线、面类型 ); 在glBeginCurve、glEndCurve之间。 */ CNurbs::CNurbs():m_theNurbs(NULL) { initNURBS(); } CNurbs::~CNurbs() { if (m_theNurbs!=NULL) { gluDeleteNurbsRenderer(m_theNurbs); m_theNurbs = NULL; } } void CNurbs::initNURBS() { //创建NURBS对象m_theNurbs m_theNurbs = gluNewNurbsRenderer(); //设置采样容差 gluNurbsProperty( m_theNurbs, GLU_SAMPLING_TOLERANCE, 25.0 ) ; } // 2阶bizer绘制1/4圆 void CNurbs::DrawQuarterCircleDegree2() { int ptCount = 3; // 1/4圆控制点 // w=sqrt(2)/2,中间的控制点w*[1,1,0,1]=[sin(45),sin(45),0,sin(45)] float w = sqrt(2)/2.0; GLfloat ctrlPoints[3][4] = { { 4, 0, 0 , 1}, { 4.0*w, 4.0*w, 0 , 1*w }, { 0, 4, 0 , 1} }; GLfloat circleColors[3][4]= { {1.0,0.0,0.0,1.0}, {1.0,1.0,0.0,1.0}, {1.0,0.5,0.0,1.0} }; GLfloat knots[6] = { 0, 0, 0, 1, 1, 1 }; glPushMatrix(); glTranslatef(-26,0,0); // 绘制1/4圆曲线 int degree = 2; //阶数(度数) int order_number = degree+1; //u(v)方向控制点的个数,=曲线度数+1 gluBeginCurve( m_theNurbs ) ; gluNurbsCurve( m_theNurbs, 6, knots, 4, &ctrlPoints[0][0], order_number, GL_MAP1_VERTEX_4 ) ; gluNurbsCurve( m_theNurbs, 6, knots, 4, &circleColors[0][0], order_number, GL_MAP1_COLOR_4 ); gluEndCurve(m_theNurbs); // 画控制点 glPointSize( 8.0f ); glColor3f( 0.0f, 0.0f, 1.0f ); glBegin( GL_POINTS ); for( int i = 0; i < ptCount; i++ ) { glVertex3fv( &ctrlPoints[i][0] ); } glEnd(); glPopMatrix(); glFlush(); } // 4阶bizer绘制1/4圆 void CNurbs::DrawQuarterCircleDegree4() { int ptCount = 5; float const x1 = 4.0f; float const y1 = 2.0f / sqrt(2); float const x2 = 4.0f - sqrt(2)/2.0f; // 1/4圆控制点 float w = 2.0*sqrt(2)/3.0; GLfloat ctrlPoints[5][4] = { { 4, 0, 0 , 1}, { x1, y1, 0 , 1 }, { x2*w, x2*w, 0 , 1*w}, { y1, x1, 0 , 1 }, { 0, 4, 0 , 1} }; GLfloat circleColors[5][4]= { {1.0,0.0,0.0,1.0}, {1.0,1.0,0.0,1.0}, {1.0,0.5,0.0,1.0}, {0.8,0.0,0.6,1.0}, {0.7,0.3,0.6,1.0} }; // 10=控制点数5+(阶数+1) GLfloat knots[10] = { 0, 0, 0, 0, 0, 1, 1, 1, 1, 1 }; glPushMatrix(); glTranslatef(-20,0,0); // 绘制1/4圆曲线 int degree = 4; //阶数(度数) int order_number = degree+1; //u(v)方向控制点的个数,=曲线度数+1 gluBeginCurve( m_theNurbs ) ; gluNurbsCurve( m_theNurbs, 10, knots, 4, &ctrlPoints[0][0], order_number, GL_MAP1_VERTEX_4 ) ; gluNurbsCurve( m_theNurbs, 10, knots, 4, &circleColors[0][0], order_number, GL_MAP1_COLOR_4 ); gluEndCurve(m_theNurbs); // 画控制点 glPointSize( 8.0f ); glColor3f( 0.0f, 0.0f, 1.0f ); glBegin( GL_POINTS ); for( int i = 0; i < ptCount; i++ ) { glVertex3fv( &ctrlPoints[i][0] ); } glEnd(); glPopMatrix(); glFlush(); } // 3阶bizer绘制1/2圆 void CNurbs::DrawHalfCircleDegree3() { int ptCount = 4; // 1/2圆控制点 float w = 1/3.0f; GLfloat ctrlPoints[4][4] = { { 4, 0, 0 , 1}, { 4*w, 8*w, 0 , 1*w }, { -4*w, 8*w, 0 , 1*w}, { -4, 0, 0 , 1 } }; GLfloat circleColors[4][4]= { {1.0,0.0,0.0,1.0}, {1.0,1.0,0.0,1.0}, {1.0,0.5,0.0,1.0}, {0.8,0.0,0.6,1.0} }; GLfloat knots[8] = { 0, 0, 0, 0, 1, 1, 1, 1 }; glPushMatrix(); glTranslatef(-10,0,0); // 绘制半圆曲线 int degree = 3; //阶数(度数) int order_number = degree+1; //u(v)方向控制点的个数,=曲线度数+1 gluBeginCurve( m_theNurbs ) ; gluNurbsCurve( m_theNurbs, 8, knots, 4, &ctrlPoints[0][0], order_number, GL_MAP1_VERTEX_4 ) ; gluNurbsCurve( m_theNurbs, 8, knots, 4, &circleColors[0][0], order_number, GL_MAP1_COLOR_4 ); gluEndCurve(m_theNurbs); // 绘制四周的由控制点连接生成的直线 glLineWidth( 8.0f ); glBegin(GL_LINE_STRIP); for (int i = 0; i < ptCount; i++ ) { glColor3f( 1.0f, 0.0f, 0.0f ); glVertex3fv( ctrlPoints[i] ) ; } glEnd(); // 画控制点 glPointSize( 8.0f ); glColor3f( 0.0f, 0.0f, 1.0f ); glBegin( GL_POINTS ); for( i = 0; i < ptCount; i++ ) { glVertex3fv( &ctrlPoints[i][0] ); } glEnd(); glPopMatrix(); glFlush(); } // 2阶Bizer由3个控制点控制一段曲线 // 通过9个控制点,绘制4段Bizer曲线,组成一个Nurbs圆 void CNurbs::DrawCircleDegree2_9Point() { if (m_theNurbs==NULL) return; // 圆控制点 int ptCount = 9; float w = sqrt(2)/2.0f; GLfloat ctrlPoints[9][4] = { { 0, -4, 0 , 1}, { -4*w, -4*w, 0 , 1*w }, { -4, 0, 0 , 1}, { -4*w, 4*w, 0 , 1*w}, { 0, 4, 0 , 1}, { 4*w, 4*w, 0 , 1*w}, { 4, 0, 0 , 1}, { 4*w, -4*w, 0 , 1*w}, { 0, -4, 0 , 1} }; GLfloat circleColors[9][4]= { {1.0,0.0,0.0,1.0}, {1.0,1.0,0.0,1.0}, {1.0,0.5,0.0,1.0}, {0.8,0.0,0.6,1.0}, {0.7,0.3,0.6,1.0}, {0.5,0.7,0.6,1.0}, {0.3,1.0,0.6,1.0}, {0.3,1.0,0.6,1.0}, {0.0,1.0,1.0,1.0} }; // 画圆节点序列 // 节点数 = 控制点数9+分段曲线的控制点个数3 GLfloat knots[12] = { 0, 0, 0, 0.25, 0.25, 0.5, 0.5, 0.75, 0.75, 1, 1, 1 }; glPushMatrix(); // 绘制圆曲线 int degree = 2; //阶数(度数) int order_number = degree+1; //u(v)方向控制点的个数,=曲线度数+1 gluBeginCurve( m_theNurbs ) ; gluNurbsCurve( m_theNurbs, 12, knots, 4, &ctrlPoints[0][0], order_number, GL_MAP1_VERTEX_4 ) ; gluNurbsCurve( m_theNurbs, 12, knots, 4, &circleColors[0][0], order_number, GL_MAP1_COLOR_4 ); gluEndCurve(m_theNurbs); // 绘制四周的由控制点连接生成的直线 glLineWidth( 3.0f ); glBegin(GL_LINE_STRIP); for (int i = 0; i < ptCount; i++ ) { glColor3f( 1.0f, 0.0f, 0.0f ); glVertex3fv( ctrlPoints[i] ) ; } glEnd(); // 画控制点 glPointSize( 8.0f ); glColor3f( 0.0f, 0.0f, 1.0f ); glBegin( GL_POINTS ); for( i = 0; i < ptCount; i++ ) { glVertex3fv( &ctrlPoints[i][0] ); } glEnd(); glPopMatrix(); glFlush(); } // 2阶Bizer由3个控制点控制一段曲线 // 通过7个控制点,绘制4段Bizer曲线,组成一个Nurbs圆 void CNurbs::DrawCircleDegree2_7Point() { if (m_theNurbs==NULL) return; // 圆控制点 int ptCount = 7; float w = 0.5f; GLfloat ctrlPoints[7][4] = { { 0, -4, 0 , 1}, { -4*sqrt(3)*w, -4*w, 0 , w }, { -2*sqrt(3), 2, 0 , 1}, { 0, 8*w, 0 , w}, { 2*sqrt(3), 2, 0 , 1}, { 4*sqrt(3)*w, -4*w, 0 , w}, { 0, -4, 0 , 1} }; GLfloat circleColors[7][4]= { {1.0,0.0,0.0,1.0}, {1.0,1.0,0.0,1.0}, {1.0,0.5,0.0,1.0}, {0.8,0.0,0.6,1.0}, {0.7,0.3,0.6,1.0}, {0.5,0.7,0.6,1.0}, {0.3,1.0,0.6,1.0} }; // 画圆节点序列 // 节点数 = 控制点数7+分段曲线的控制点个数3 GLfloat knots[10] = { 0, 0, 0, 1/3.0, 1/3.0, 2/3.0, 2/3.0, 1, 1, 1 }; glPushMatrix(); glTranslatef(10,0,0); // 绘制圆曲线 int degree = 2; //阶数(度数) int order_number = degree+1; //u(v)方向控制点的个数,=曲线度数+1 gluBeginCurve( m_theNurbs ) ; gluNurbsCurve( m_theNurbs, 10, knots, 4, &ctrlPoints[0][0], order_number, GL_MAP1_VERTEX_4 ) ; gluNurbsCurve( m_theNurbs, 10, knots, 4, &circleColors[0][0], order_number, GL_MAP1_COLOR_4 ); gluEndCurve(m_theNurbs); // 绘制四周的由控制点连接生成的直线 glLineWidth( 3.0f ); glBegi