FREE OpenGL Functions Questions and Answers
Similar to glDrawElements, but before completing the array lookup, each element index is offset by a constant value. This helps reduce the amount of buffer object binds that must be made in a program.
Explanation:
glDrawElementsBaseVertex is a function in the OpenGL API used to perform indexed rendering, similar to glDrawElements, with the additional feature of allowing each element index to be offset by a constant value before performing the array lookup. This can be useful for minimizing the number of buffer object binds performed in a program.
Binds an object with a vertex array to the GL VERTEX ARRAY target.
Explanation:
glBindVertexArray is a function in the OpenGL API that binds a Vertex Array Object (VAO) to the GL_VERTEX_ARRAY target. A VAO is an OpenGL object that contains all of the state needed to specify vertex data for rendering. It stores the format of the vertex data, as well as the vertex buffer objects (VBOs) that hold the actual vertex data.
Create and modify buffer objects using these functions. One or more buffers are created by glGenBuffers, attached to a context location by glBindBuffer, and then filled with user data by glBufferData, which allocates memory.
Explanation:
glGenBuffers, glBindBuffer, and glBufferData are functions in the OpenGL API used to create and manipulate buffer objects.
Performs indexed rendering using the current attribute arrays and the bound GL ELEMENT ARRAY BUFFER (supplied by the VAO).
Explanation:
glDrawElements is a function in the OpenGL API that performs indexed rendering with the currently bound GL_ELEMENT_ARRAY_BUFFER and the current attribute arrays specified in the Vertex Array Object (VAO).
Enables depth testing by setting the depth comparison function. If GL DEPTH TEST is not allowed, it has no impact.
Explanation:
glDepthFunc is a function in the OpenGL API used to set the depth comparison function for depth testing. Depth testing is a mechanism used by OpenGL to determine which fragments should be rendered based on their depth values, which represent their distance from the viewer.
Retrieves several context state integer values as well as implementation-dependent integer values. Other typed glGet* functions include glGetFloatv, glGetBooleanv, and several others. The enumerator that is supplied to this determines how many values it returns.
Explanation:
glGetIntegerv is a function in the OpenGL API that retrieves implementation-dependent integer values and a number of context state integer values. The function takes two parameters: the pname parameter specifies the name of the parameter to be retrieved, and the params parameter is a pointer to an array that will receive the retrieved value(s).
Sets the specified uniform in the active program (as determined by glUseProgram) to the fixed value. This is a collection of functions accepting several kinds rather than just one.
Explanation:
glUniform is a suite of functions in the OpenGL API that are used to set the value of a uniform variable in the currently active shader program (set by glUseProgram). A uniform variable is a global variable in the shader program that can be set from outside the shader, such as from the application code.