OpenGL Shutting Down Sequence

Usually we might not need to explicitly do this to fully clean up full-chain of OpenGL context which ranges from VBO, VAO, texture objects, disabling all enabled vertex attribute arrays, or even pragamatic setting variable to NULL or 0.

Most likely after the program quits, it will be automatically destroyed and returned back claimed memory to OS. But some says we cannot be relied on such behavior as it might not happen cleanly.

So here is the sequence in shutting down or destroying sequence sequence of OpenGL.

1. Disable all vertex attribute arrays via glDisableVertexAttribArray()
2. Delete all related buffers included (but not limited to) VBOs via glDeleteBuffers()

3. Reset binded texture object via glBindTexture(GL_TEXTURE_2D, 0) and other binding targets i.e.  GL_TEXTURE_1D, GL_TEXTURE_3D, and so on.

   Note: Reset currently using program via glUseProgram(0) will result in undefined behavior as noted in its man page “If program is zero, then the current rendering state refers to an invalid program object and the results of shader execution are undefined. However, this is not an error.”.

4. Delete all texture objects via glDeleteTextures()
5. Delete all shader programs via glDeleteProgram()

6. Delete all VAOs via glDeleteVertexArrays()

First published on Aug, 16, 2019

Written by Wasin Thonkaew
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