使用GLFW3在OpenGL上下文之间共享纹理不起作用

以下程序应该：

• 创建一个不可见的 GLFWwindow* masterWindow

• 从文件加载纹理，而活动的OpenGL上下文是与 masterWindow 关联的上下文

• 创建 GLFWwindow* childWindow ，在此窗口的OpenGL上下文和 masterWindow 的上下文之间激活共享

• 在 childWindow 中显示带有纹理的全窗四边形

但是，这不起作用，即取代纹理，我得到 childWindow 中显示的图形内存的随机片段 . 如果我在加载之前创建 childWindow 的上下文，显示纹理确实有效，这就是为什么我认为问题既不是我的着色器也不是我的纹理加载例程（我从这里开始，https://github.com/DavidEGrayson/ahrs-visualizer/blob/master/png_texture.cpp） . 我明白我应该能够分享纹理（请参阅这个问题的回答：OpenGL - Share existing textures with future contexts?），那么我做错了什么？如果重要的话，我会使用2008年末的Macbook，安装了NVIDIA 9400m和Mavericks / OpenGL 3.3 .

#include <iostream>
#define GLEW_STATIC
#include <glew.h>
#include <glfw3.h>

const char* vShader =
  "#version 150 core\n"
  "in vec2 vertex;"
  "in vec2 vertexUV;"
  "out vec2 UV;"
  "void main() {gl_Position = vec4(vertex,0,1);UV=vertexUV;}";
const char* fShader =
 "#version 150 core\n"
 "uniform sampler2D sampler;"
 "in vec2 UV;"
 "out vec4 color;"
 "void main() {color = texture(sampler, UV);}";

GLuint png_texture_load(const char * file_name, unsigned int * width=NULL, unsigned int * height=NULL);
GLuint make_program(const char* vShader, const char* fShader);

GLFWwindow* masterWindow(NULL);

void create_window_with_texture(GLuint texture)
{
  GLFWwindow* childWindow(glfwCreateWindow(256,256, "", NULL, masterWindow));
  glfwMakeContextCurrent(childWindow);

  // texture appears if loaded from here
  // texture=png_texture_load("rose.png");                                                                                                               

  GLfloat vertices[]={-1,-1,1,-1,-1,1,1,1, // window corners in clip space                                                                               
                  0,0,1,0,0,1,1,1};    // corners in uv-space                                                                                        
  GLubyte indices[]={0,2,1,3};             // points for a two triangle strip                                                                            

  GLuint vArray,vBuffer,iBuffer;
  glGenVertexArrays(1,&vArray);glBindVertexArray(vArray);
  glGenBuffers(1,&vBuffer);glBindBuffer(GL_ARRAY_BUFFER,vBuffer);
  glGenBuffers(1,&iBuffer);glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,iBuffer);
  glBufferData(GL_ARRAY_BUFFER,sizeof(vertices),vertices,GL_DYNAMIC_DRAW);
  glBufferData(GL_ELEMENT_ARRAY_BUFFER,sizeof(indices),indices,GL_DYNAMIC_DRAW);

  GLuint program(make_program(vShader,fShader));
  glUseProgram(program);
  glUniform1i(glGetUniformLocation(program,"sampler"),0);
  GLuint vertexPtr(GLuint(glGetAttribLocation(program,"vertex")));
  glEnableVertexAttribArray(vertexPtr);
  GLuint vertexUVPtr(GLuint(glGetAttribLocation(program, "vertexUV")));
  glEnableVertexAttribArray(vertexUVPtr);
  glVertexAttribPointer(vertexPtr, 2, GL_FLOAT, GL_FALSE, 0, (const GLvoid*)0 );
  glVertexAttribPointer(vertexUVPtr, 2, GL_FLOAT, GL_FALSE, 0, (const GLvoid*)32);

  glActiveTexture(GL_TEXTURE0);
  glDisable(GL_DEPTH_TEST);
  glDisable(GL_BLEND);

  glBindTexture(GL_TEXTURE_2D,texture);
  glDrawElements(GL_TRIANGLE_STRIP,4, GL_UNSIGNED_BYTE, (GLvoid*)0);

  glfwSwapBuffers(childWindow);
}

int main()
{
  if (!glfwInit())
    return -1;
  glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR,3);
  glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR,2);
  glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT,GL_TRUE);
  glfwWindowHint(GLFW_OPENGL_PROFILE,GLFW_OPENGL_CORE_PROFILE);
  glfwWindowHint(GLFW_VISIBLE,GL_FALSE);
  masterWindow=glfwCreateWindow(10,10, "", NULL,NULL);
  glfwWindowHint(GLFW_VISIBLE,GL_TRUE);
  glfwWindowHint(GLFW_SAMPLES, 4);
  glfwMakeContextCurrent(masterWindow);
  glewExperimental = GL_TRUE;
  GLenum err = glewInit();
  if(GLEW_OK!=err)
    return -1;
  glGetError(); // catch benign glewInit() invalid enum error                                                                                            

  GLuint texture(0);
  texture=png_texture_load("rose.png");

  create_window_with_texture(texture);

  std::cin.get();

  return 0;
}