小编tib*_*bur的帖子

我想boost::posix_time::ptime通过网络传输一个boost::int64_t.根据将boost :: posix_time :: ptime转换为__int64的方法,我可以轻松定义自己的纪元,并且仅time_duration将该参考纪元作为64位整数传输.但是如何转换回来ptime呢？

#include <iostream>
#include <cassert>
#include <boost/date_time/posix_time/posix_time.hpp>
#include <boost/date_time/gregorian/greg_month.hpp>

using namespace std;

using boost::posix_time::ptime;
using boost::posix_time::time_duration;
using boost::gregorian::date;

int main(int argc, char ** argv){
    ptime t = boost::posix_time::microsec_clock::local_time();

    // convert to int64_t
    ptime myEpoch(date(1970,boost::gregorian::Jan,1));
    time_duration myTimeFromEpoch = t - myEpoch;
    boost::int64_t myTimeAsInt = myTimeFromEpoch.ticks();

    // convert back to ptime
    ptime test = myEpoch + time_duration(myTimeAsInt);

    assert(test == t);
    return 0;
}

这不起作用,因为将time_durationtick计数作为参数的构造函数是私有的.我也对 …

我试图在Mac OSX上使用cmake我既安装了二进制版本,又安装了源代码.但是,在尝试创建Makefile时,我仍然会收到以下错误.

cpc1-dumb4-2-0-cust166:build bcrowhurst $ cmake.CMake错误:错误要求内部CMake变量未设置,cmake可能无法正确构建.

缺少的变量是:

CMAKE_On_COMPILER_ENV_VAR

CMake错误:错误要求内部CMake变量未设置,cmake可能无法正确构建.

缺少的变量是:

CMAKE_On_COMPILER

CMake Error: Could not find cmake module file:/Users/bcrowhurst/NetBeansProjects/appon/build/CMakeFiles/CMakeOnCompiler.cmake

CMake Error: Could not find cmake module file:CMakeOnInformation.cmake

CMake Error: CMAKE_On_COMPILER not set, after EnableLanguage

-- Boost version: 1.43.0

-- Found the following Boost libraries:

--   system

-- Configuring incomplete, errors occurred!

我的CMakeLists.txt如下:

cmake_minimum_required( VERSION 2.6 )

project( Application On )

find_package( Boost COMPONENTS system REQUIRED )

link_directories( ${Boost_LIBRARY_DIRS} )

if(Boost_FOUND)
    include_directories( ${Boost_INCLUDE_DIRS} )

    add_library( object ../source/object.cpp ../source/object.h )   
    target_link_libraries( object …

我有一个简单的程序来使用深度测试.它没有按预期工作.程序绘制X,Y轴和原点附近的球体.如果我没有打开GL_DEPTH_TEST,则会在轴上绘制球体.如果我打开GL_DEPTH_TEST,轴将被绘制在我不期望的球体上.谁能告诉我我做错了什么？

void  
glwid::initializeGL()  
{    
    glClearColor (0.0f, 0.0f, 0.0f, 1.0f);      
}  



void  
glwid::resizeGL(int width, int height)  
{  
    glViewport( 0, 0, (GLint)width, (GLint)height );  
    glMatrixMode( GL_PROJECTION );  
    glLoadIdentity();  

    gluPerspective ( 90, (GLint)width/ (GLint)height, 0.0, 200.0 );  
    glMatrixMode( GL_MODELVIEW );  
    glLoadIdentity();  
    glEnable (GL_DEPTH_TEST);  
}  


void  
glwid::paintGL()  
{
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);  

    glMatrixMode (GL_MODELVIEW);  
    glLoadIdentity();  

    gluLookAt (0, 0, 100, 0, 0, 0, 0, 1, 0);  


    //  
    // X axis  
    //  
    glBegin( GL_LINES );  
    qglColor( green );  
    glVertex3f (-100.0,  0, 0. );  
    glVertex3f (100.0, 0, 0. …

我试图显示"透明"表面(不是封闭的体积),正面和背面都是可见的(没有剔除).

例如,显示在两侧都应用透明度的圆锥或圆柱体.有一些可见的工件,表面的某些部分似乎没有正确处理alpha值.

似乎问题是当我(opengl)试图将alpha从表面的正面应用到表面的背面时.(当表面的内部/外部都可见时).

void init()
{
    glMatrixMode(GL_PROJECTION);
    gluPerspective( /* field of view in degree */ 40.0,
        /* aspect ratio */ 1.0,
        /* Z near */ 1.0, /* Z far */ 10.0);
    glMatrixMode(GL_MODELVIEW);
    gluLookAt(0.0, 0.0, 5.0,  /* eye is at (0,0,5) */
        0.0, 0.0, 0.0,      /* center is at (0,0,0) */
        0.0, 1.0, 0.);      /* up is in positive Y direction */
    glTranslatef(0.0, 0.6, -1.0);

    glEnable(GL_LIGHTING);
    glEnable(GL_LIGHT0);
    glLightfv(GL_LIGHT0, GL_AMBIENT, light0_ambient);
    glLightfv(GL_LIGHT0, GL_DIFFUSE, light0_diffuse);
    glLightfv(GL_LIGHT1, GL_DIFFUSE, light1_diffuse);
    glLightfv(GL_LIGHT1, GL_POSITION, light1_position);
    glLightfv(GL_LIGHT2, GL_DIFFUSE, …

有谁知道检测内存泄漏的一般算法？