调用 glDrawElements 会导致访问冲突

calling glDrawElements causes access violation

本文关键字：访问冲突 glDrawElements 调用      更新时间：2023-10-16

我目前正在试图弄清楚 VBO 的东西是如何工作的，可悲的是这导致了可怕的问题：/

IM 从 .obj 文件加载数据（请参阅：http://pastebin.com/B8uibDvV .obj 文件）并（试图）将其放入 VBO 中

我绑定数据的代码如下所示：

//Generate Buffers
glGenBuffers(1, &this->glVerticesBufferID);
glGenBuffers(1, &this->glIndexBufferID);
//bind the buffers to set the data
glBindBuffer(GL_ARRAY_BUFFER, this->glVerticesBufferID);
glBufferData(GL_ARRAY_BUFFER, this->verticesList.size() * sizeof(GLfloat), 0, GL_STATIC_DRAW);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, this->glIndexBufferID);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, this->indexList.size() * sizeof(GLshort), 0, GL_STATIC_DRAW);
glBufferSubData(GL_ARRAY_BUFFER, 0, this->verticesList.size(), this->verticesList.data()); 
glBufferSubData(GL_ELEMENT_ARRAY_BUFFER, 0, this->indexList.size(), this->indexList.data()); 
//Clear binds 
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);

最后，我用这个渲染一切：

glBindBuffer(GL_ARRAY_BUFFER, this->glVerticesBufferID);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, this->glIndexBufferID);
glEnableClientState(GL_VERTEX_ARRAY);
    glDrawElements(GL_TRIANGLES, this->indexList.size(), GL_UNSIGNED_SHORT, this->indexList.data());
glDisableClientState(GL_VERTEX_ARRAY);
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);

最后，我在VisualStudio 2010的输出中收到访问冲突消息

0xC0000005：访问违规读取位置0x0147fbd8。

所以我的问题是如何解决这个问题？（或者如果我错了，如何做对）

---------------编辑1---------------

http://pastebin.com/DEbZH9iy

绑定数据

 glGenBuffers(1, &this->glVerticesBufferID);
 glBindBuffer(GL_ARRAY_BUFFER, this->glVerticesBufferID);
 glBufferData(GL_ARRAY_BUFFER, (this->verticesList.size() + this->textureCoordList.size() + this->normalsList.size()) * sizeof(GLfloat), 0, GL_STATIC_DRAW);
 glBufferSubData(GL_ARRAY_BUFFER,
                0,
                this->verticesList.size() * sizeof(GLfloat),
                this->verticesList.data()
               );
 glBufferSubData(
                GL_ARRAY_BUFFER, 
                this->verticesList.size() * sizeof(GLfloat), 
                this->normalsList.size() * sizeof(GLfloat), 
                this->normalsList.data()
               );
 glBufferSubData(
                GL_ARRAY_BUFFER, 
                (this->verticesList.size() + this->normalsList.size()) * sizeof(GLfloat), 
                this->textureCoordList.size() * sizeof(GLfloat),
                this->textureCoordList.data()
               );
 glBindBuffer(GL_ARRAY_BUFFER, 0);
 glGenBuffers(1, &this->glIndexBufferID);
 glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, this->glIndexBufferID);
 glBufferData(GL_ELEMENT_ARRAY_BUFFER, this->indexList.size() * sizeof(GLushort), this->indexList.data(), GL_STATIC_DRAW);
 glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);

 pub_glVerticesBufferID = glVerticesBufferID;
 pub_glIndexBufferID = glIndexBufferID;

渲染部分：

 glBindBuffer(GL_ARRAY_BUFFER, this->glVerticesBufferID);
 glVertexPointer(3, GL_FLOAT, 3 * sizeof(GLfloat), (GLvoid*)0);
 glNormalPointer(GL_FLOAT, 3 * sizeof(GLfloat), (GLvoid*)(this->verticesList.size() * sizeof(GLfloat)));
 glTexCoordPointer(2, GL_FLOAT, 2 * sizeof(GLfloat), (GLvoid*)((this->normalsList.size() + this->verticesList.size()) * sizeof(GLfloat)));
 glBindBuffer(GL_ARRAY_BUFFER, 0);
 glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, this->glIndexBufferID);
 glDrawElements(GL_TRIANGLES, 3, GL_UNSIGNED_SHORT, 0);
 glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);

您可能没有初始化OpenGL-1.1之后引入的功能的入口点。在Windows中，仅指定OpenGL-1.1入口点，超出的所有内容都必须在运行时初始化。否则，将出现访问冲突。看看 GLEW 以获得一种方便的方法，只需 3 行代码即可完成这项繁琐的任务。

话虽如此，您的代码仍然有错误：

你需要告诉OpenGL它应该从缓冲区的确切位置获取它的元素。这是通过调用gl…Pointer函数来完成的，数据元素是缓冲区中的字节偏移量。您的代码错过了这一点。此外，glDrawElements不再期望指针也放置偏移量。

但是，绑定缓冲区对象时，这不应导致段错误/访问冲突。

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