OpenGL的 - 增加顶点 [英] OpenGL - add vertices

问题描述

我有一个子功能读取的数据流，并根据在该顶点数据的数组。主函数反复调用这一子功能，并更新顶点数据阵列，其然后结合至缓冲器和绘制。到现在为止还挺好。但是，我想不出如何添加顶点。 C ++不会让您重新分配或调整整个阵列。因为OpenGL函数采取的阵列，而不是媒介我不能用向量。

I have a subfunction that reads a data stream and creates an array of vertex data based on that. The main function calls this subfunction repeatedly and updates the vertex data array, which is then bound to a buffer and drawn. So far, so good. However, I cannot figure out how to add vertices. C++ does not let you reassign or resize entire arrays. I can't use vectors because the OpenGL functions take in arrays, not vectors.

推荐答案

您可以使用向量来填充OpenGL的顶点缓冲。在矢量值保证是连续的。例如，见对相关语言标准的详细信息这些讨论：

You can use vectors to populate an OpenGL vertex buffer. The values in a vector are guaranteed to be contiguous. See for example these discussions for details on the related language standards:

• Are的std ::矢量元素保证是连续的？


• Is它是安全的假设，STL向量存储始终是连续的？

• Are std::vector elements guaranteed to be contiguous?
• Is it safe to assume that STL vector storage is always contiguous?

这意味着code像下面是安全的：

This means that code like the following is safe:

std::vector<GLfloat> vertexPositions;
// Populate vector with vertex positions.
GLuint bufId = 0;
glGenBuffers(1, &bufId);
glBindBuffer(GL_ARRAY_BUFFER, bufId);
glBufferData(GL_ARRAY_BUFFER, vertexPositions.size() * sizeof(GLfloat),
             &vertexPositions[0], GL_STATIC_DRAW);

微妙而关键的部分是你在第一个元素的地址传递的载体，而不是矢量对象的地址。

The subtle but critical part is that you pass in the address of the first element of the vector, not the address of the vector object.

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