Drawing lines in QPainter takes a lot of time

[xcxl]

As you said, I currently use the classical :

// Setup our vertex buffer object.
m_myVbo.create();
m_myVbo.bind();
m_myVbo.allocate(m_vertexData.constData(), m_floatCount * static_cast<int>(sizeof(GLfloat)));
m_myVbo.release();

// Setup our vertex buffer object.
m_myVbo.create();
m_myVbo.bind();
m_myVbo.allocate(m_vertexData.constData(), m_floatCount * static_cast<int>(sizeof(GLfloat)));
m_myVbo.release();

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Sorry I don't actually have the skills to understand the second option with the CPU/GPU mapping

The full project, configured for the GPU test (test 6) is available here : sources.zip
The VBO setup is in myGLwidget_vertAndFrag.cpp at line 269.

Could you send me the modif to do to test this option ? I'm interested too.