What is glFinish?

If you render directly to the front buffer, glFinish is the call to make before using the operating system calls to take screenshots. It is far less useful for double buffering, because you don’t see the changes you forced to complete.

How do you perform a glFlush?

The glFlush function empties all these buffers, causing all issued commands to be executed as quickly as they are accepted by the actual rendering engine. Though this execution may not be completed in any particular time period, it does complete in a finite amount of time.

When should I call glFlush?

Because any GL program might be executed over a network, or on an accelerator that buffers commands, all programs should call glFlush whenever they count on having all of their previously issued commands completed.

Is OpenGL asynchronous?

These are usually used for rendering calls; in which case, once the rendering call has returned, the memory to be read from client data has been read. All of this means that OpenGL is a very asynchronous renderer, even if it is defined synchronously.

What is the function of glutSwapBuffers ()?

glutSwapBuffers swaps the buffers of the current window if double buffered. Performs a buffer swap on the layer in use for the current window. Specifically, glutSwapBuffers promotes the contents of the back buffer of the layer in use of the current window to become the contents of the front buffer.

What is glClear opengl?

Description. glClear sets the bitplane area of the window to values previously selected by glClearColor , glClearIndex , glClearDepth , glClearStencil , and glClearAccum . Multiple color buffers can be cleared simultaneously by selecting more than one buffer at a time using glDrawBuffer. Indicates the depth buffer.

What is the use of glLoadIdentity?

The glLoadIdentity function replaces the current matrix with the identity matrix. It is semantically equivalent to calling glLoadMatrix with the following identity matrix. However, in some cases, it is more efficient.

What is Gl_color_buffer_bit?

GL_COLOR_BUFFER_BIT. Indicates the buffers currently enabled for color writing. GL_DEPTH_BUFFER_BIT. Indicates the depth buffer.

Are OpenGL calls blocking?

OpenGL calls will only block, if the result of the call modifies client side memory and depends of data generated by previous OpenGL calls. In other words, when doing OpenGL calls, the OpenGL implementation internally generates a dependency tree to keep track of what depends on what.

What is glTexSubImage2D?

glTexSubImage2D and glTextureSubImage2D redefine a contiguous subregion of an existing two-dimensional or one-dimensional array texture image.

What is difference between glColor3d and glColor3f?

What is the difference between glColor3d and glColor3f? A. glColor3d only sets RGB, while glColor3f sets R,G,B and A B.

What is glMaterialf?

The glMaterialf function assigns values to material parameters. There are two matched sets of material parameters. One, the front-facing set, is used to shade points, lines, bitmaps, and all polygons (when two-sided lighting is disabled), or just front-facing polygons (when two-sided lighting is enabled).