GRContext = ref object
  native*: ptr gr_context_t

GRGlInterface = ref object
  native*: ptr gr_glinterface_t

GRBackendRenderTarget = ref object
  native*: ptr gr_backendrendertarget_t

GRGlFramebufferInfo = ref object
  native*: ptr gr_gl_framebufferinfo_t

GRBackend = enum
  Metal = METAL_GR_BACKEND, OpenGL = OPENGL_GR_BACKEND, Vulkan = VULKAN_GR_BACKEND

GRBackendState {...}{.pure.} = enum
  None = 0.uint32, All = 0x0000000000000000'i64

GRGlBackendState = enum
  None = 0.uint32, RenderTarget = 1 shl 0, TextureBinding = 1 shl 1, View = 1 shl 2,
  Blend = 1 shl 3, MSAAEnable = 1 shl 4, Vertex = 1 shl 5, Stencil = 1 shl 6, PixelStore = 1 shl 7,
  Program = 1 shl 8, FixedFunction = 1 shl 9, Misc = 1 shl 10, PathRendering = 1 shl 11,
  All = 0x0000FFFF

GRSurfaceOrigin = enum
  TopLeft = 0.uint32, BottomLeft

proc newSkFrameBufferInfo(fFBOID: uint32; format: uint32): GRGlFramebufferInfo {...}{.
    raises: [], tags: [].}

proc dispose(this: GRGlFramebufferInfo) {...}{.raises: [], tags: [].}

proc flush(this: GRContext) {...}{.raises: [], tags: [].}

proc createGL(iface: GRGlInterface): GRContext {...}{.raises: [], tags: [].}

proc createGL(): GRContext {...}{.raises: [], tags: [].}

proc abandonContext(this: GRContext; releaseResources: bool) {...}{.raises: [], tags: [].}

proc createGRContext(backend: GRBackend): GRContext {...}{.raises: [ValueError], tags: [].}

proc resetContext(this: GRContext; state: GRGlBackendState) {...}{.raises: [], tags: [].}

proc resetContext(this: GRContext; state: GRBackendState) {...}{.raises: [], tags: [].}

proc createBackendRenderTarget(width: int32; height: int32; sampleCount: int32;
                              stencilBits: int32; glInfo: GRGlFramebufferInfo): GRBackendRenderTarget {...}{.
    raises: [], tags: [].}

proc dispose(this: GRBackendRenderTarget) {...}{.raises: [], tags: [].}

proc createNativeGlInterface(): GRGlInterface {...}{.raises: [], tags: [].}

proc validate(this: GRGlInterface): bool {...}{.raises: [], tags: [].}

template samples(this: GRBackendRenderTarget): int

template stencils(this: GRBackendRenderTarget): int