Opengl鼠标点击物体上的交点坐标

// 渲染void CmfcView::RenderScene(){glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);// Clear Screen And Depth BufferglLoadIdentity();// Reset The Current Modelview MatrixglTranslatef(0,0.0f,-10.0f);// Move Right 1.5 Units And Into The Screen 7.0//glRotatef(45,0.0f,1.0f,0.0f);// Rotate The Quad On The X axis ( NEW )//glRotatef(180,0.0f,0.0f,1.0f);// Rotate The Quad On The X axis ( NEW )glBegin(GL_QUADS);// Draw A QuadglColor3f(0.0f,1.0f,0.0f);// Set The Color To GreenglVertex3f(0, 0, 2);// Top Right Of The Quad (Top)glVertex3f(1, 0, 2);// Top Left Of The Quad (Top)glVertex3f(1, 1, 2);// Bottom Left Of The Quad (Top)glVertex3f(0, 1, 2);// Bottom Right Of The Quad (Top)glEnd();}

/****************************************//*功能：计算直线和平面交点/*param[in]: planePoint--平面上的一个点/*param[in]: planeVector--平面的法向量/*param[in]: linePoint1--直线的点1/*param[in]: linePoint2--直线的点2/*  return: 交点坐标/***************************************/float* CmfcView::CalPlaneLineIntersectPoint(float* planePoint, float* planeVector, float* linePoint1, float* linePoint2){float *res = new float[3];// 交点坐标//float planeVector[3] = {0, 0, 1};float lineVector[3];// 直线向量lineVector[0] = linePoint2[0] - linePoint1[0];lineVector[1] = linePoint2[1] - linePoint1[1];lineVector[2] = linePoint2[2] - linePoint1[2];float vp1, vp2, vp3, n1, n2, n3, v1, v2, v3, m1, m2, m3, t,vpt;vp1 = planeVector[0];vp2 = planeVector[1];vp3 = planeVector[2];n1 = planePoint[0];n2 = planePoint[1];n3 = planePoint[2];v1 = lineVector[0];v2 = lineVector[1];v3 = lineVector[2];m1 = linePoint1[0];m2 = linePoint1[1];m3 = linePoint1[2];vpt = v1 * vp1 + v2 * vp2 + v3 * vp3;//首先判断直线是否与平面平行if (vpt == 0){res = NULL;}else{t = ((n1 - m1) * vp1 + (n2 - m2) * vp2 + (n3 - m3) * vp3) / vpt;res[0] = m1 + v1 * t;res[1] = (m2 + v2 * t);res[2] = m3 + v3 * t;}return res;}

float* CmfcView::CrossPoint(CPoint pt){float *crsPt;GLdouble x1, y1, z1;GLdouble x2, y2, z2;GLdouble    modelview[16];GLdouble    projection[16];GLint       viewport[4];glGetDoublev (GL_MODELVIEW_MATRIX, modelview);glGetDoublev (GL_PROJECTION_MATRIX, projection);glGetIntegerv (GL_VIEWPORT, viewport);GLdouble world_x1, world_y1, world_z1;  GLdouble world_x2, world_y2, world_z2; // 获取近裁剪面上的交点gluUnProject( (GLdouble) pt.x, (GLdouble)(viewport[3] - pt.y - 1), 0.0, modelview, projection, viewport, &world_x1, &world_y1, &world_z1); // 获取远裁剪面上的交点gluUnProject( (GLdouble) pt.x, (GLdouble)(viewport[3] - pt.y - 1), 1.0, modelview, projection, viewport, &world_x2, &world_y2, &world_z2); float planePoint[3] = {10, 13, 2}; // 平面上一点float linePoint1[3];float linePoint2[3];linePoint1[0] = world_x1;linePoint1[1] = world_y1;linePoint1[2] = world_z1;linePoint2[0] = world_x2;linePoint2[1] = world_y2;linePoint2[2] = world_z2;float planeVector[3] = {0, 0, 1};// 平面向量（根据实际情况计算)crsPt = CalPlaneLineIntersectPoint(planePoint, planeVector, linePoint1, linePoint2);return crsPt;}

void CmfcView::OnLButtonDown(UINT nFlags, CPoint point){// TODO: 在此添加消息处理程序代码和/或调用默认值float *crossPoint;crossPoint = CrossPoint(point);CView::OnLButtonDown(nFlags, point);}