EXT_multiview_window

EGL_EXT_multiview_window

Acorn Pooley
Greg Roth

Greg Roth (groth 'at' nvidia.com)

Complete

Version 3, Sept 03, 2011

EGL Extension #42

Requires EGL 1.4

Written against the EGL 1.4 specification.

Adds support for creating an onscreen EGLSurface containing
multiple color buffers.

EXT_multi_draw_buffers can be used with this extension to
render and display multiple color buffers to a supported
device.

None

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Accepted as an attribute in the <attrib_list> parameter of
CreateWindowSurface:

    EGL_MULTIVIEW_VIEW_COUNT_EXT        0x3134

Additions to section 3.5.1 (Creating On-Screen Rendering Surfaces)

Alter the end of the second paragraph:

    Attributes that can be specified in <attrib_list> include
    EGL_RENDER_BUFFER, EGL_VG_COLORSPACE, EGL_VG_ALPHA_FORMAT, and
    EGL_MULTIVIEW_VIEW_COUNT_EXT.

Add before the last paragraph of section 3.5.1:

    EGL_MULTIVIEW_VIEW_COUNT_EXT specifies how many multiview color
    buffers should be created for the surface. Each color buffer has
    the same properties as the primary color buffer as specified by
    window and surface attributes. The default value of
    EGL_MULTIVIEW_VIEW_COUNT_EXT is one.

    EGL may not be able to create as many multiview color buffers as
    EGL_MULTIVIEW_VIEW_COUNT_EXT specifies. To determine the number
    of multiview color buffers created by a context, call
    eglQueryContext (see section 3.7.4).

Add to the last paragraph of section 3.5.1:

    If the value specified for EGL_MULTIVIEW_VIEW_COUNT_EXT is less
    than one, an EGL_BAD_PARAMETER error is generated. If the value
    specified for EGL_MULTIVIEW_VIEW_COUNT_EXT is greater than one
    and the <config> does not support multiple multiview color
    buffers, an EGL_BAD_MATCH error is generated.

Additions to section 3.5.6 (Surface Attributes)

Add to table 3.5, "Queryable surface attributes and types"

    Attribute                    Type       Description
    ---------                    ----       -----------
    EGL_MULTIVIEW_VIEW_COUNT_EXT  integer    Requested multiview
                                            color buffers

Add before the last paragraph describing eglQuerySurface:

    Querying EGL_MULTIVIEW_VIEW_COUNT_EXT for a window surface
    returns the number of multiview color buffers requested. For a
    pbuffer or pixmap surface, the contents of <value> are not
    modified. To determine the actual number of multiview color
    buffers created by a context, call eglQueryContext (see
    section 3.7.4).


Additions to section 3.7.4 (Context Queries)

Add before the last paragraph describing eglQueryContext:

    Querying EGL_MULTIVIEW_VIEW_COUNT_EXT returns the number of
    multiview color buffers created. The value returned depends on
    properties of both the context, and the surface to which the
    context is bound.

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