opengl简单实现鼠标交互

#include "mouse.h" #include "math.h" #include <QtOpenGL/glut.h> //单位矩阵 GLfloat ab_quat[16] = {1,0,0,0, 0,1,0,0, 0,0,1,0, 0,0,0,1}; GLfloat ab_last[16] = {1,0,0,0, 0,1,0,0, 0,0,1,0, 0,0,0,1}; GLfloat ab_next[16] = {1,0,0,0, 0,1,0,0, 0,0,1,0, 0,0,0,1}; //到远点的距离 GLfloat ab_zoom = 1.0; GLfloat ab_zoom2 = 1.0; //球的半径 GLfloat ab_sphere = 1.0; GLfloat ab_sphere2 = 1.0; //距离原点的平面交叉 //边缘的可见范围 GLfloat ab_edge = 1.0; //我们是否在使用球体 bool ab_planar = false; GLfloat ab_planedist = 0.5; Mouse ab_start = Mouse(0,0,1);//开始 Mouse ab_curr = Mouse(0,0,1); Mouse ab_eye = Mouse(0,0,1); Mouse ab_eyedir = Mouse(0,0,1); Mouse ab_up = Mouse(0,1,0); Mouse ab_out = Mouse(1,0,0); GLdouble ab_glp[16] = {1,0,0,0, 0,1,0,0, 0,0,1,0, 0,0,0,1}; GLdouble ab_glm[16] = {1,0,0,0, 0,1,0,0, 0,0,1,0, 0,0,0,1}; int ab_glv[4] = {0,0,640,480}; Mouse::Mouse() { } Mouse::Mouse(GLfloat xx, GLfloat yy, GLfloat zz) { x = xx; y = yy; z = zz; } Mouse::~Mouse() { } //设置缩放 void arcball_setzoom(GLfloat radius, Mouse eye, Mouse up) { ab_eye = eye; ab_zoom2 = ab_eye * ab_eye; ab_zoom = sqrt(ab_zoom2); ab_sphere = radius; // sphere radius ab_sphere2 = ab_sphere * ab_sphere; ab_eyedir = ab_eye * (1.0 / ab_zoom); // distance to eye ab_edge = ab_sphere2 / ab_zoom; // plane of visible edge if(ab_sphere <= 0.0) // 轨迹球模式 { ab_planar = true; ab_up = up; ab_out = ( ab_eyedir ^ ab_up ); ab_planedist = (0.0 - ab_sphere) * ab_zoom; } else ab_planar = false; glGetDoublev(GL_PROJECTION_MATRIX,ab_glp); //在这里获得的矩阵的各元素值 glGetIntegerv(GL_VIEWPORT,ab_glv);//查询特定画面可用的缓冲区的存储信息 } //影响arcball对openGL的取向 void arcball_rotate() { glMultMatrixf(ab_quat); } //四元数 static void quaternion(GLfloat* q, GLfloat x, GLfloat y, GLfloat z, GLfloat w) { GLfloat x2 = x*x; GLfloat y2 = y*y; GLfloat z2 = z*z; GLfloat xy = x*y; GLfloat xz = x*z; GLfloat yz = y*z; GLfloat wx = w*x; GLfloat wy = w*y; GLfloat wz = w*z; q[0] = 1 - 2*y2 - 2*z2; q[1] = 2*xy + 2*wz; q[2] = 2*xz - 2*wy; q[4] = 2*xy - 2*wz; q[5] = 1 - 2*x2 - 2*z2; q[6] = 2*yz + 2*wx; q[8] = 2*xz + 2*wy; q[9] = 2*yz - 2*wx; q[10]= 1 - 2*x2 - 2*y2; } //重置旋转矩阵 static void quatidentity(GLfloat* q) { q[0]=1; q[1]=0; q[2]=0; q[3]=0; q[4]=0; q[5]=1; q[6]=0; q[7]=0; q[8]=0; q[9]=0; q[10]=1; q[11]=0; q[12]=0; q[13]=0; q[14]=0; q[15]=1; } //复制旋转矩阵 static void quatcopy(GLfloat* dst, GLfloat* src) { dst[0]=src[0]; dst[1]=src[1]; dst[2]=src[2]; dst[4]=src[4]; dst[5]=src[5]; dst[6]=src[6]; dst[8]=src[8]; dst[9]=src[9]; dst[10]=src[10]; } //增加两个旋转矩阵 static void quatnext(GLfloat* dest, GLfloat* left, GLfloat* right) { dest[0] = left[0]*right[0] + left[1]*right[4] + left[2] *right[8]; dest[1] = left[0]*right[1] + left[1]*right[5] + left[2] *right[9]; dest[2] = left[0]*right[2] + left[1]*right[6] + left[2] *right[10]; dest[4] = left[4]*right[0] + left[5]*right[4] + left[6] *right[8]; dest[5] = left[4]*right[1] + left[5]*right[5] + left[6] *right[9]; dest[6] = left[4]*right[2] + left[5]*right[6] + left[6] *right[10]; dest[8] = left[8]*right[0] + left[9]*right[4] + left[10]*right[8]; dest[9] = left[8]*right[1] + left[9]*right[5] + left[10]*right[9]; dest[10]= left[8]*right[2] + left[9]*right[6] + left[10]*right[10]; } // 通过可见的边缘找到飞机的十字路口 static Mouse edge_coords(Mouse m) { // 找到边缘平面的交集 float t = (ab_edge - ab_zoom) / (ab_eyedir * m); Mouse a = ab_eye + (m*t); // 从这一点上找到eye-axis的方向 // 沿着边刨 Mouse c = (ab_eyedir * ab_edge) - a; // 找到的十字路口与射线从球体 // 物体向eye-axis以外的领域。 float ac = (a*c); float c2 = (c*c); float q = ( 0.0 - ac - sqrt( ac*ac - c2*((a*a)-ab_sphere2) ) ) / c2; return (a+(c*q)).unit(); } // 找到与球面相交的十字路口 static Mouse sphere_coords(GLdouble mx, GLdouble my) { GLdouble ax,ay,az; gluUnProject(mx,my,0,ab_glm,ab_glp,ab_glv,&ax,&ay,&az); Mouse m = Mouse((float)ax,(float)ay,(float)az) - ab_eye; // 鼠标位置显示: eye + t*m // 交叉领域集中在原点 GLfloat a = m*m; GLfloat b = (ab_eye*m); GLfloat root = (b*b) - a*(ab_zoom2 - ab_sphere2); if(root <= 0) return edge_coords(m); GLfloat t = (0.0 - b - sqrt(root)) / a; return (ab_eye+(m*t)).unit(); } // 得到与平面交叉旋转“轨迹球” static Mouse planar_coords(GLdouble mx, GLdouble my) { GLdouble ax,ay,az; gluUnProject(mx,my,0,ab_glm,ab_glp,ab_glv,&ax,&ay,&az); Mouse m = Mouse((GLfloat)ax,(GLfloat)ay,(GLfloat)az) - ab_eye; // 相交点的轨迹球 GLfloat t = (ab_planedist - ab_zoom) / (ab_eyedir * m); Mouse d = ab_eye + m*t; return Mouse(d*ab_up,d*ab_out,0.0); } // 重置arcball void arcball_reset() { quatidentity(ab_quat); quatidentity(ab_last); } // 开始旋转 void arcball_start(int mx, int my) { // 保存一份当前旋转进行比较 quatcopy(ab_last,ab_quat); if(ab_planar) ab_start = planar_coords((GLdouble)mx,(GLdouble)my); else ab_start = sphere_coords((GLdouble)mx,(GLdouble)my); } // 更新当前arcball旋转 void arcball_move(int mx, int my,float times) { if(ab_planar) { ab_curr = planar_coords((GLdouble)mx,(GLdouble)my); if(ab_curr.equals(ab_start)) return; // d is motion since the last position Mouse d = ab_curr - ab_start; GLfloat angle = d.length() * 0.5; GLfloat cosa = cos( angle ); GLfloat sina = sin( angle ); // p is perpendicular to d Mouse p = ((ab_out*d.x)-(ab_up*d.y)).unit() * sina; quaternion(ab_next,p.x,p.y,p.z,cosa); quatnext(ab_quat,ab_last,ab_next); // planar style only ever relates to the last point quatcopy(ab_last,ab_quat); ab_start = ab_curr; } else { ab_curr = sphere_coords((GLdouble)mx,(GLdouble)my); if(ab_curr.equals(ab_start)) { // avoid potential rare divide by tiny quatcopy(ab_quat,ab_last); return; } // use a dot product to get the angle between them // use a cross product to get the vector to rotate around GLfloat cos2a = ab_start*ab_curr; GLfloat sina = sqrt((1.0 - cos2a)*0.5); GLfloat cosa = sqrt((1.0 + cos2a)*0.5); Mouse cross = (ab_start^ab_curr).unit() * sina ; quaternion(ab_next,cross.x,cross.y,cross.z,cosa); // update the rotation matrix quatnext(ab_quat,ab_last,ab_next); } } Mouse inline Mouse::rotate_x( Mouse v, float sin_ang, float cos_ang ) { return Mouse( v.x, (v.y * cos_ang) + (v.z * sin_ang), (v.z * cos_ang) - (v.y * sin_ang) ); } Mouse inline Mouse::rotate_y( Mouse v, float sin_ang, float cos_ang ) { return Mouse( (v.x * cos_ang) + (v.z * sin_ang), v.y, (v.z * cos_ang) - (v.x * sin_ang) ); } float Mouse::randf() { return ((1.0f / 127.f) * (((float)(rand() & 255)) - 128.0f)) ; }