OpenGL由已知控制点绘制模拟曲面地形

1、OpenGL由已知控制点绘制模拟曲面地形 转载请注明出处/zhouchanwen主要要点：1.将离散的数据点网格化曲面2.对3d模型的鼠标控制，如虚拟球的实现由已知控制点通过曲面拟合方法，将不规则的数据分布转换成规则的网格分布，然后绘制三维地形曲面图。即如图所示：数据规则网格化（简称网格化）。网格化实际是一种曲面拟合方法。关于曲面拟合算法有很多，下面我们采用曲面样条方法实现网格化。我们定义曲面样条函数：下面为c+/c代码：3D_MAP.cpp 1 #include 2 #include tools.h 3 #include Grids.h 4 #inc

2、lude 3dmap.h 5 6 using namespace std; 7 8 / 3D_MAP.cpp : 定义控制台应用程序的入口点。 9 10 int xFar=0.0f,yFar=0.0f,zFar=0.0f; 11 int wWidth=1300,wHeight=700; 12 int oldX,oldY; 13 bool gIsStartTrackBall = false; 14 bool gIsMoveMap=false; 15 TrackBall trackball; 16 _3dMap map; 17 18 void displayEvent() 19 20 glClea

3、rColor(0, 0, 0.1f, 1); 21 glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT); 22 23 glMatrixMode(GL_MODELVIEW); 24 glLoadIdentity(); 25 glTranslatef(xFar, yFar,zFar); 26 27 trackball.makeRolate(); 28 map.drawMap(); 29 30 glFlush(); 31 glutSwapBuffers(); / 交换缓存 32 33 34 void mouseMoveEvent(int x, int y

4、) 35 36 if(gIsStartTrackBall) 37 38 trackball.MouseMove(x,y); 39 glutPostRedisplay(); 40 41 if(gIsMoveMap) 42 43 xFar-=oldX-x; 44 yFar+=oldY-y; 45 oldX=x; 46 oldY=y; 47 glutPostRedisplay(); 48 49 50 / 鼠标事件函数 51 void mouseEvent(int button, int state, int x, int y) 52 53 if(button = GLUT_LEFT_BUTTON)

5、54 55 if(state = GLUT_DOWN) 56 57 oldX=x; 58 oldY=y; 59 trackball.setXY(x,y); 60 gIsStartTrackBall = true; 61 62 else if(state = GLUT_UP) 63 64 oldX=x; 65 oldY=y; 66 gIsStartTrackBall = false; 67 68 glutPostRedisplay(); 69 else if(button = GLUT_RIGHT_BUTTON) 70 71 if(state = GLUT_DOWN) 72 73 oldX=x;

6、 74 oldY=y; 75 gIsMoveMap=true; 76 else if(state = GLUT_UP) 77 78 oldX=x; 79 oldY=y; 80 gIsMoveMap = false; 81 82 83 84 / 窗体尺寸变化事件 85 void resizeEvent(int w, int h) 86 87 wWidth=w; 88 wHeight=h; 89 zFar=0.0f; 90 xFar=0.0f; 91 yFar=0.0f; 92 glViewport(0,0, w, h); 93 glMatrixMode(GL_PROJECTION); 94 gl

7、LoadIdentity(); 95 h = h 0 ? h : 1; 96 float aspect = (float)w / (float)h; 97 gluPerspective(45,aspect,1.0,1500.0); 98 glTranslatef(0,0,-300.0f); 99 100 trackball.resize();101 102 103 glutPostRedisplay();104 105 void processSpecialKeys(int key, int x, int y) 106 if(key=101)107 108 zFar+=4;109 glutPo

8、stRedisplay();110 111 if(key=103)112 /113 zFar-=4;114 glutPostRedisplay();115 116 printf(key:%dn,key);117 118 119 void MenuFunc(int data)120 121 switch(data)122 123 case 1:124 map.setLineOrFill();break;125 default:break;126 127 glutPostRedisplay();128 129 void glInit()130 131 glShadeModel(GL_FLAT);/

9、SMOOTH/GL_FLAT132 glClearColor(1.0f, 1.0f, 1.0f, 1.0f);133 glClearDepth(1.0f);134 135 glEnable(GL_NORMALIZE);136 137 glEnable ( GL_DEPTH_TEST );138 glAlphaFunc(GL_GREATER,0);139 glDepthFunc(GL_LEQUAL);140 glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);141 142 glEnable( GL_BLEND); 143 glBlendFunc(

10、 GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);144 145 glEnable(GL_POINT_SMOOTH);146 glEnable(GL_LINE_SMOOTH);147 glEnable (GL_POLYGON_SMOOTH);148 149 glHint(GL_POINT_SMOOTH_HINT, GL_NICEST); / Make round points, not square points150 glHint(GL_LINE_SMOOTH_HINT, GL_NICEST); / Antialias the lines151 glHint (G

11、L_POLYGON_SMOOTH_HINT, GL_NICEST);152 153 154 /glClearColor(1.0,1.0,1.0,1.0); /窗口背景设置为白色155 glMatrixMode(GL_MODELVIEW); /设置投影参数156 157 glEnable( GL_COLOR_MATERIAL) ;158 glColorMaterial(GL_FRONT_AND_BACK,GL_AMBIENT_AND_DIFFUSE);159 160 161 162 int main(int argc,char* argv)163 164 map.initMap();165 16

12、6 glutInit(&argc,argv); /初始化GLUT167 glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB|GLUT_DEPTH | GLUT_MULTISAMPLE); /设置显示模式168 glutInitWindowPosition(0,0); /设置显示窗口的左上角位置169 glutInitWindowSize(wWidth,wHeight); /设置窗口的长和高170 glutCreateWindow(3DMap ); /创造显示窗口171 172 glInit(); /开始初始化过程173 glutReshapeFunc(resi

13、zeEvent);174 glutDisplayFunc(displayEvent);175 glutMouseFunc(mouseEvent);176 glutSpecialFunc(processSpecialKeys);177 glutMotionFunc(mouseMoveEvent);178 glutCreateMenu(MenuFunc);179 glutAddMenuEntry(填充/网格,1);180 glutAttachMenu(GLUT_MIDDLE_BUTTON);181 182 glutMainLoop(); /显示所有并等候183 184 getchar();185

14、return 0;186 tools.htools.h中定义了TrackBall类，用于对3D模型进行鼠标的旋转，世界中心点的移动等控制 1 #include 2 #include 3 4 using namespace std; 5 6 struct GPoint3d 7 double mX, mY, mZ; 8 double x() return mX; 9 double y() return mY; 10 double z() return mZ; 11 void setX(double x) mX = x; 12 void setY(double y) mY = y; 13 void

15、setZ(double z) mZ = z; 14 void set(double x, double y, double z) mX = x; mY = y; mZ = z; 15 ; 16 17 class TrackBall 18 19 int OldX; 20 int OldY; 21 double mMatrix16; 22 public: 23 TrackBall() 24 / 向量的点积 25 double dotMult(GPoint3d v1, GPoint3d v2); 26 / 向量的叉积 27 GPoint3d crossMult(GPoint3d v1, GPoint

16、3d v2); 28 / 将鼠标二维点映射为球面向量(用于鼠标追踪球) 29 GPoint3d gMousePtToSphereVec(int x, int y, int w, int h); 30 void makeRolate(); 31 32 void MouseMove(int x, int y); 33 void resize() 34 35 glGetDoublev(GL_MODELVIEW_MATRIX, mMatrix); / 返回当前模型矩阵 36 37 void setXY(int x, int y)OldX = x;OldY = y; 38 void setP(doubl

17、e *v)/x1,y1,z1, x2,y2,z2, x3,y3,z3 39 40 GPoint3d v1,v2,v3; 41 v1.setX(v3-v0); 42 v1.setY(v4-v1); 43 v1.setZ(v5-v2); 44 45 v2.setX(v6-v0); 46 v2.setY(v7-v1); 47 v2.setZ(v8-v2); 48 49 v3=crossMult(v1,v2); 50 51 glNormal3f(v3.x(),v3.y(),v3.z(); 52 53 ; 54 55 double TrackBall:dotMult(GPoint3d v1, GPoin

18、t3d v2) 56 57 double angle; 58 angle = v1.x()*v2.x()+v1.y()*v2.y()+v1.z()*v2.z(); 59 return angle; 60 61 GPoint3d TrackBall:crossMult(GPoint3d v1, GPoint3d v2) 62 63 GPoint3d v; 64 v.setX(v1.y()*v2.z()-v1.z()*v2.y(); 65 v.setY(v1.z()*v2.x()-v1.x()*v2.z(); 66 v.setZ(v1.x()*v2.y()-v1.y()*v2.x(); 67 re

19、turn v; 68 69 70 / 将鼠标二维点映射为球面向量(用于鼠标追踪球) 71 GPoint3d TrackBall:gMousePtToSphereVec(int x, int y, int w, int h) 72 73 double x1,y1,z1,r,len; 74 GPoint3d vec; 75 x1 = (2.0*x - w) / w; 76 y1 = (h - 2.0*y) / h; 77 r=x1*x1+y1*y1; 78 if(r 1) r = 1; 79 z1 = sqrt(1 - r); 80 len = sqrt(x1*x1+y1*y1+z1*z1); 8

20、1 vec.setX(x1/len); 82 vec.setY(y1/len); 83 vec.setZ(z1/len); 84 return vec; 85 86 void TrackBall:makeRolate() 87 88 glMultMatrixd(mMatrix); 89 90 void TrackBall:MouseMove(int x, int y) 91 92 if(x != OldX | y != OldY) 93 94 int wWidth,wHeight; 95 wWidth = glutGet(GLUT_WINDOW_WIDTH); 96 wHeight = glu

21、tGet(GLUT_WINDOW_HEIGHT); 97 GPoint3d lastVec = gMousePtToSphereVec(OldX, OldY, wWidth, wHeight); 98 GPoint3d currentVec = gMousePtToSphereVec(x, y, wWidth, wHeight); 99 OldX = x; OldY = y;100 / 求旋转角度101 double rotAngle = acos(dotMult(lastVec,currentVec)*57.;102 / 求旋转向量轴103 GPoint3d axis = crossMult

22、(lastVec,currentVec);104 glMatrixMode(GL_MODELVIEW);105 glPushMatrix();106 glLoadIdentity();107 glRotated(rotAngle, axis.x(), axis.y(), axis.z(); / 旋转108 109 glMultMatrixd(mMatrix);110 glGetDoublev(GL_MODELVIEW_MATRIX, mMatrix); / 返回当前模型矩阵111 112 glPopMatrix();113 114 接下来是3dmap.h，其中定义了_3dMap类，主要用来完成

23、3d模型的主要绘制任务 1 class _3dMap 2 3 double *data; 4 int M,N; 5 int dip; 6 double scale; 7 bool showBaseLine; 8 double max,min; 9 bool LineMode; 10 public : 11 _3dMap() 12 13 M=320; 14 N=220; 15 showBaseLine=true; 16 LineMode=false; 17 scale=20.0; 18 dip=1; 19 max=-1000; 20 min=10000; 21 22 _3dMap() 23 vo

24、id initMap(); 24 void drawBaseLine(); 25 void drawMap(); 26 void _3dMap:setLineOrFill() 27 28 LineMode=!LineMode; 29 30 double getAver(double * arr) 31 32 double num=0; 33 int n=3;/(int)(sizeof(arr)/sizeof(double)/3; 34 for(int i=0;itemp) 46 47 r=(aver-temp)/(temp-min); 48 b=0; 49 else 50 r=0; 51 b=

25、(temp-aver)/(temp-min); 52 53 g=1-(abs(temp-aver)/(temp-min); 54 glColor3f(r,g,b); 55 56 ; 57 58 void _3dMap:initMap() 59 60 61 int temp= 62 229,219,199,216,235,255,266,285,272,241,246,281,284,275,261,273, 63 221,214,195,216,234,258,273,289,281,249,259,278,287,272,275,277, 64 213,203,196,206,221,232

26、,259,293,294,277,258,285,287,283,288,286, 65 204,195,200,201,209,218,231,259,288,306,286,291,301,311,319,298, 66 196,207,201,211,239,234,241,259,294,315,317,321,325,322,325,341, 67 208,218,204,214,235,260,239,268,298,291,331,313,281,280,280,280, 68 216,231,218,196,220,255,271,253,264,303,322,312,276

27、,243,238,239, 69 236,242,218,198,200,215,224,238,261,294,324,312,280,255,220,200, 70 255,241,219,211,206,225,252,275,284,285,305,316,271,237,208,191, 71 245,218,207,198,214,241,261,256,273,276,291,298,281,238,197,175, 72 225,215,205,195,208,221,235,252,262,271,301,275,245,212,181,171 73 ; 74 int len

28、=11*16; 75 int i,j; 76 double* src=new double*3; 77 for(i=0;i3;i+) 78 srci=new doublelen; 79 for(i=0;i11;i+) 80 /y 81 for(j=0;j16;j+) 82 /x 83 src0i*16+j=j*10; 84 src1i*16+j=i*10; 85 src2i*16+j=tempi*16+j; 86 87 88 Grids g1(3,len,src); 89 double* des=new double*2; 90 for(i=0;i2;i+) 91 desi=new doubl

29、eN*M; 92 for(i=0;iN;i+) 93 /y 94 for(j=0;jM;j+) 95 /x 96 des0i*M+j=j/2; 97 des1i*M+j=i/2; 98 99 100 Grids g2(2,N*M,des);101 data=g1.Surface_Fitting(&g1,&g2);102 103 for(i=0;iN;i+)104 /height105 for(int j=0;jM;j+)106 /width107 data0i*M+j*=2;108 data1i*M+j*=2;109 data2i*M+j/=5;110 111 if(maxdata2i*M+j

30、)114 min=data2i*M+j;115 116 117 printf(max=%lf,min=%lfn,max,min);118 119 void _3dMap:drawBaseLine()120 121 glBegin(GL_LINES); 122 glColor3f(1, 0, 0);123 glVertex2i(0,0);/x line124 glVertex2i(100,0);125 126 glColor3f(0, 1, 0);127 glVertex2i(0,0);/y line128 glVertex2i(0,100);129 130 glColor3f(0, 0, 1)

31、;131 glVertex3f(0,0,0);/132 glVertex3f(0,0,500);133 glEnd(); 134 135 void _3dMap:drawMap()136 137 138 if(showBaseLine)139 drawBaseLine();140 141 if(LineMode)142 glPolygonMode(GL_FRONT_AND_BACK,GL_LINE);143 else 144 glPolygonMode(GL_FRONT_AND_BACK,GL_FILL);145 146 glLineWidth(0.4f);147 for(int i=0;iN

32、-1;i+)148 /height22149 150 for(int j=0;jM-1;j+)151 /width32152 glBegin(GL_TRIANGLE_FAN);153 int t=i*M+j;154 setColor(data2t,data2t+1,data2t+1+M);155 156 glVertex3f(data0t,data1t,data2t);157 glVertex3f(data0t+1,data1t+1,data2t+1);158 glVertex3f(data0t+1+M,data1t+1+M,data2t+1+M);159 setColor(data2t+M,

33、data2t+1,data2t+1+M);160 glVertex3f(data0t+M,data1t+M,data2t+M);161 glEnd();162 163 164 下面是Grids.h文件，定义了Grids类，用于对控制点的数据进行网格化 1 #include 2 3 #include 4 5 using namespace std; 6 7 class Grids 8 9 int row; 10 int col; 11 double *mat; 12 public: 13 Grids(); 14 Grids(int r, int c); 15 Grids(int r, int c

34、, double *m); 16 Grids(); 17 void Mul_Mat(Grids* m1, Grids* m2, Grids* m3); 18 void Inv_Mat(Grids* m1, Grids* m2); 19 double* Surface_Fitting(Grids* m1, Grids* m2); 20 ; 21 22 Grids:Grids() 23 24 row = 0; 25 col = 0; 26 mat = 0; 27 28 29 Grids:Grids(int r, int c) 30 31 row = r; 32 col = c; 33 mat =

35、0; 34 35 36 Grids:Grids(int r, int c, double *m) 37 38 row = r; 39 col = c; 40 mat = m; 41 42 43 Grids:Grids() 44 45 mat=0; 46 row=0; 47 col=0; 48 49 50 void Grids:Mul_Mat(Grids* m1, Grids* m2, Grids* m3) 51 52 int i=0,j=0,p=0; 53 double sum=0; 54 if (m1-col != m2-row) 55 coutrow=m1-row; 59 m3-col=m

36、2-col; 60 m3-mat=new double*m1-row; 61 if (NULL=m3-mat) 62 coutERROR!n; 63 exit(0); 64 65 for (i=0;irow;i+) 66 m3-mati=new doublem3-col; 67 for (j=0;jcol;j+) 68 for (m3-matij=0,p=0;pcol;p+) 69 m3-matij+=m1-matip*m2-matpj; 70 71 72 73 74 75 void Grids:Inv_Mat(Grids* m1, Grids* m2) 76 77 int i,j,n,*is

37、,*js,k; 78 double d,p; 79 if(m1-row!=m1-col) 80 coutmat=new double*m1-row;/申请行指针数组 84 if(NULL=m2-mat) 85 coutERROR! 申请内存出错!n; 86 exit(1); 87 88 for (i=0;irow;i+) 89 m2-mati=new doublem1-col;/申请行 90 for (j=0;jcol;j+) 91 m2-matij=m1-matij; 92 93 n=m1-row; 94 m2-row=m1-row; 95 m2-col=m1-col; 96 is=new

38、intn; 97 js=new intn; 98 if (NULL=is | NULL=js) 99 coutERROR! 申请内存出错!n;100 exit(1);101 102 for (k=0;k=n-1;k+) /全选主元103 d=0.000;104 for (i=k;i=n-1;i+)105 for (j=k;jmatij);107 if (pd)108 d=p;109 isk=i;110 jsk=j;111 112 113 114 if(1.0=d+1.0)115 delete is;116 delete js;117 coutERROR ! 矩阵求逆出错!n;118 exit(1);119 120 if(isk!=k) /*行交换*/121 for (j=0;jmatkj;123 m2-matkj=m2-matiskj;124 m2-matiskj=p;125 126 127 if(jsk != k) /*列交换*/128 for