Final answer:
The OpenGL function used to generate an ID for a texture is glGenTextures. The function provides a unique identifier for the texture, which does not create the texture itself but is essential for referencing it in subsequent texture operations. The correct option is A.
Step-by-step explanation:
The OpenGL function used to generate an ID for a texture is glGenTextures. When OpenGL works with textures, it requires a unique identifier or a 'name' to reference the texture. This function when called with a number, say 'n', generates 'n' number of textures and stores them in the array provided as the second argument. This generated texture ID is then used for future texture operations.
To use glGenTextures, you first define an unsigned integer to hold the texture ID and then call the function, passing the number of textures you want to generate and the address of the memory where the ID should be stored. Essential steps in texturing include binding the texture using glBindTexture, setting up texture parameters with glTexParameteri, and specifying the texture image through commands like glTexImage2D or glTexSubImage2D.
It's important to note that glGenTextures doesn't actually create a texture; it simply provides a unique identifier for one. The actual texture is created when it's bound for the first time using glBindTexture with the generated ID.