Qt5 C++ GUI Programming Cookbook - Second Edition

How to do it...

Let's get started by following this example:

1. Open up renderwindow.h and add two more VBOs, one called vbo_vertices2 and another called vbo_colors, as highlighted in the following code:

private:    QOpenGLContext* openGLContext;    QOpenGLFunctions* openGLFunctions;    QOpenGLShaderProgram* shaderProgram;    QOpenGLVertexArrayObject* vao;    QOpenGLBuffer* vbo_vertices;    QOpenGLBuffer* vbo_vertices2;    QOpenGLBuffer* vbo_colors;

2. Open up renderwindow.cpp and add the following code to the shader code, as highlighted in the following snippet:

static const char *vertexShaderSource =    "#version 330 core\n"    "layout(location = 0) in vec2 posAttr;\n"    "layout(location = 1) in vec3 colAttr;\n"    "out vec3 fragCol;\n"    "void main() {\n" "fragCol = colAttr;\n" ...