glutInitDisplayModeGLUTDOUBLE

glutInitDisplayMode is a function in the OpenGL Utility Toolkit (GLUT) that specifies the initial display mode for windows created by GLUT. It does not create a window itself; instead, it configures the properties of subsequent windows and remains in effect until changed by another call.

The function accepts a single argument: mode, an unsigned integer formed by bitwise OR-ing one or more display mode flags. Common flags include GLUT_RGBA or GLUT_RGB (color model), GLUT_SINGLE or GLUT_DOUBLE (buffering), GLUT_DEPTH (depth buffer), GLUT_STENCIL (stencil buffer), GLUT_ACCUM (accumulation buffer), GLUT_ALPHA (alpha channel), GLUT_MULTISAMPLE (multisampling), and GLUT_STEREO (stereo rendering). GLUT_INDEX is an alternative color mode in some implementations. Flags are combined to request a specific set of features for the windows that GLUT creates.

Usage and behavior: Call glutInitDisplayMode before the first window is created with glutCreateWindow, typically after initializing GLUT with glutInit. The chosen mode applies to all windows created after the call unless it is changed by a subsequent glutInitDisplayMode invocation. While GLUT will attempt to create windows with the requested capabilities, support for specific modes depends on the underlying window system and graphics drivers; unsupported requests may be ignored or result in a window with a closest-supported configuration.

In practice, developers choose a mode that matches their rendering needs, such as double buffering with a color RGB space and a depth buffer for 3D applications. glutInitDisplayMode is a fundamental part of GLUT initialization, shaping how rendering surfaces are prepared for subsequent OpenGL drawing.