Contents

init(texture:size:flipped:colorSpace:)

Initializes an image object with data supplied by an OpenGL texture.

Declaration

init(texture name: UInt32, size: CGSize, flipped: Bool, colorSpace: CGColorSpace?)

Parameters

  • name:

    An OpenGL texture. Because Ciimage objects are immutable, the texture must remain unchanged for the life of the image object. See the discussion for more information.

  • size:

    The dimensions of the texture.

  • flipped:

    true to have Core Image flip the coordinates of the texture vertically to convert between OpenGL and Core Image coordinate systems.

  • colorSpace:

    The color space that the image is defined in. This must be a Quartz color space (Cgcolorspace). If the colorSpace value is nil, the image is not color matched. Pass nil for images that don’t contain color data (such as elevation maps, normal vector maps, and sampled function tables).

Return Value

The initialized image object.

Discussion

When you use a texture to create a CIImage object, the texture must be valid in the Core Image context (CIContext) that you draw the CIImage object into. This means that one of the following must be true:

  • The texture must be created using the CGLContext object that the CIContext is based on.

  • The context that the texture was created in must be shared with the CGLContext that the CIContextis based on.

Note that textures do not have a retain and release mechanism. This means that your application must make sure that the texture exists for the life cycle of the image. When you no longer need the image, you can delete the texture.

Core Image ignores the texture filtering and wrap modes (GL_TEXTURE_FILTER and GL_TEXTURE_WRAP) that you set through OpenGL. The filter and wrap modes are overridden by what the CISampler object specifies when you apply a filter to the CIImage object.

See Also

Deprecated