# NSOpenGLContext.Parameter Constants that specify context parameters. ``` enum Parameter ``` ## Overview These attribute names are used by [`setValues(_:for:)`](/documentation/AppKit/NSOpenGLContext/setValues(_:for:)) and [`getValues(_:for:)`](/documentation/AppKit/NSOpenGLContext/getValues(_:for:)). ## Topics ### Parameters [`NSOpenGLContext.Parameter.swapInterval`](/documentation/AppKit/NSOpenGLContext/Parameter/swapInterval) Set or get the swap interval. [`NSOpenGLContext.Parameter.surfaceOrder`](/documentation/AppKit/NSOpenGLContext/Parameter/surfaceOrder) Set or get the surface order. [`NSOpenGLContext.Parameter.surfaceOpacity`](/documentation/AppKit/NSOpenGLContext/Parameter/surfaceOpacity) Set or get the surface opacity. [`NSOpenGLContext.Parameter.surfaceBackingSize`](/documentation/AppKit/NSOpenGLContext/Parameter/surfaceBackingSize) Set or get the height and width of the back buffer. [`NSOpenGLContext.Parameter.reclaimResources`](/documentation/AppKit/NSOpenGLContext/Parameter/reclaimResources) Enable or disable reclaiming resources. [`NSOpenGLContext.Parameter.currentRendererID`](/documentation/AppKit/NSOpenGLContext/Parameter/currentRendererID) Get the current renderer ID. [`NSOpenGLContext.Parameter.gpuVertexProcessing`](/documentation/AppKit/NSOpenGLContext/Parameter/gpuVertexProcessing) Get whether the CPU is currently processing vertices with the GPU. [`NSOpenGLContext.Parameter.gpuFragmentProcessing`](/documentation/AppKit/NSOpenGLContext/Parameter/gpuFragmentProcessing) Get whether the CPU is currently processing fragments with the GPU. [`NSOpenGLContext.Parameter.hasDrawable`](/documentation/AppKit/NSOpenGLContext/Parameter/hasDrawable) Returns a Boolean that indicates whether a drawable is attached to the context. [`NSOpenGLContext.Parameter.mpSwapsInFlight`](/documentation/AppKit/NSOpenGLContext/Parameter/mpSwapsInFlight) The number of frames that the multithreaded OpenGL engine can process before stalling. [`NSOpenGLContext.Parameter.swapRectangle`](/documentation/AppKit/NSOpenGLContext/Parameter/swapRectangle) Sets or gets the swap rectangle. [`NSOpenGLContext.Parameter.swapRectangleEnable`](/documentation/AppKit/NSOpenGLContext/Parameter/swapRectangleEnable) Enables or disables the swap rectangle in the context’s drawable object. [`NSOpenGLContext.Parameter.rasterizationEnable`](/documentation/AppKit/NSOpenGLContext/Parameter/rasterizationEnable) If disabled, all rasterization of 2D and 3D primitives is disabled. [`NSOpenGLContext.Parameter.stateValidation`](/documentation/AppKit/NSOpenGLContext/Parameter/stateValidation) If enabled, OpenGL inspects the context state each time the update method is called to ensure that it is in an appropriate state for switching between renderers. [`NSOpenGLContext.Parameter.surfaceSurfaceVolatile`](/documentation/AppKit/NSOpenGLContext/Parameter/surfaceSurfaceVolatile) ### Deprecated [`NSOpenGLCPSwapInterval`](/documentation/AppKit/NSOpenGLCPSwapInterval) Sets or gets the swap interval. [`NSOpenGLCPSurfaceOrder`](/documentation/AppKit/NSOpenGLCPSurfaceOrder) Get or set the surface order. [`NSOpenGLCPSurfaceOpacity`](/documentation/AppKit/NSOpenGLCPSurfaceOpacity) Set or get the surface opacity. [`NSOpenGLCPSurfaceBackingSize`](/documentation/AppKit/NSOpenGLCPSurfaceBackingSize) Set or get the height and width of the back buffer. You can use this to let the system scale an image automatically on swapping to a variable-size buffer. The back buffer size remains fixed at the size that you set up regardless of whether the image is resized to display larger onscreen. [`NSOpenGLCPReclaimResources`](/documentation/AppKit/NSOpenGLCPReclaimResources) Enable or disable reclaiming resources. [`NSOpenGLCPCurrentRendererID`](/documentation/AppKit/NSOpenGLCPCurrentRendererID) The current renderer ID. You can get this setting. [`NSOpenGLCPGPUVertexProcessing`](/documentation/AppKit/NSOpenGLCPGPUVertexProcessing) The CPU is currently processing vertices with the GPU. You can get this state. [`NSOpenGLCPGPUFragmentProcessing`](/documentation/AppKit/NSOpenGLCPGPUFragmentProcessing) The CPU is currently processing fragments with the GPU. You can get this state. [`NSOpenGLCPHasDrawable`](/documentation/AppKit/NSOpenGLCPHasDrawable) Returns a Boolean that indicates whether a drawable is attached to the context. [`NSOpenGLCPMPSwapsInFlight`](/documentation/AppKit/NSOpenGLCPMPSwapsInFlight) The number of frames that the multithreaded OpenGL engine can process before stalling. The default value is 1. New frames are queued when the application calls the [`flushBuffer()`](/documentation/AppKit/NSOpenGLContext/flushBuffer()) method. A larger number may improve overall performance, but adds latency between when a frame is rendered and when a frame is displayed. Interactive applications should leave this value at the default. [`NSOpenGLCPSwapRectangle`](/documentation/AppKit/NSOpenGLCPSwapRectangle) Sets or gets the swap rectangle. [`NSOpenGLCPSwapRectangleEnable`](/documentation/AppKit/NSOpenGLCPSwapRectangleEnable) Enables or disables the swap rectangle in the context’s drawable object. [`NSOpenGLCPRasterizationEnable`](/documentation/AppKit/NSOpenGLCPRasterizationEnable) If disabled, all rasterization of 2D and 3D primitives is disabled. [`NSOpenGLCPStateValidation`](/documentation/AppKit/NSOpenGLCPStateValidation) If enabled, OpenGL inspects the context state each time the [`update()`](/documentation/AppKit/NSOpenGLContext/update()) method is called to ensure that it is in an appropriate state for switching between renderers. [`NSOpenGLCPSurfaceSurfaceVolatile`](/documentation/AppKit/NSOpenGLCPSurfaceSurfaceVolatile) --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)