第二章图形学编程.pptx

第二章图形学编程;PHIGS与X;SGI和GL;OpenGL;OpenGL的发展;OpenGL库;GLUT;软件组织;OpenGL的函数;OpenGL的状态;面向对象方面的缺陷;OpenGL函数名称的格式;OpenGL中的#define;如何获取OpenGL?;如何编译－VC 6;一个简单的示例程序;;;程序结构;;;;;Main.c;GLUT函数;init.c;坐标系;OpenGL中的照相机;变换与视图;二维与三维视图;mydisplay.c;OpenGL的基本几何形状;属性;RGB颜色;索引颜色;颜色与状态;颜色的光滑化过渡;视窗;三维图形;;Sierpinski Gasket (2D);分形;程序开头;三角形细分;显示与初始化函数;main()函数;注解：效率;改变到三维的情形;三维Gasket;生成三角形的代码;细分代码;生成四面体的代码;结果;问题？;隐藏面的消除;Z缓冲区算法;面细分vs体细分;GLfloat v[4][3]={{0.0, 0.0, 1.0}, {0.0, 0.942809, -0.33333}, {-0.816497, -0.471405, -0.333333}, {0.816497, -0.471405, -0.333333}}; GLfloat colors[4][3] = {{1.0, 0.0, 0.0}, {0.0, 1.0, 0.0}, {0.0, 0.0, 1.0}, {0.0, 0.0, 0.0}}; int n;;void triangle(GLfloat *va, GLfloat *vb, GLfloat *vc) { glVertex3fv(va); glVertex3fv(vb); glVertex3fv(vc); } void tetra(GLfloat *a, GLfloat *b, GLfloat *c, GLfloat *d) { glColor3fv(colors[0]); triangle(a, b, c); glColor3fv(colors[1]); triangle(a, c, d); glColor3fv(colors[2]); triangle(a, d, b); glColor3fv(colors[3]); triangle(b, d, c); };void divide_tetra(GLfloat *a, GLfloat *b, GLfloat *c, GLfloat *d, int m) { GLfloat mid[6][3]; int j; if(m0) { /* compute six midpoints */ for(j=0; j3; j++) mid[0][j]=(a[j]+b[j])/2; for(j=0; j3; j++) mid[1][j]=(a[j]+c[j])/2; for(j=0; j3; j++) mid[2][j]=(a[j]+d[j])/2; for(j=0; j3; j++) mid[3][j]=(b[j]+c[j])/2; for(j=0; j3; j++) mid[4][j]=(c[j]+d[j])/2; for(j=0; j3; j++) mid[5][j]=(b[j]+d[j])/2; /* create 4 tetrahedrons by subdivision */ divide_tetra(a, mid[0], mid[1], mid[2], m-1); divide_tetra(mid[0], b, mid[3], mid[5], m-1); divide_tetra(mid[1], mid[3], c, mid[4], m-1); divide_tetra(mid[2], mid[4], d, mid[5], m-1); } else(tetra(a,b,c,d)); /* draw tetrahedron at end of recursion */ };void display() { glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT); glBegin(GL_TRIANGLES); divide_tetra(v[0], v[1], v[2], v[3], n); glEnd(); glFlush(); };void myReshape(int w, int h) { glViewport(0, 0, w, h); glMatrixMode(GL_PROJECTION); glLoadIdentity(); if (w = h) glOrtho(-2.0, 2.0, -2.0 * (GLfloat) h / (GLfloat) w, 2.0 * (GLf