sdk/docs/man/eglCreatePbufferSurface.xml

<refentry xmlns="http://docbook.org/ns/docbook" version="5.0" xml:base="" xml:id="eglCreatePbufferSurface">
    <info>
         <copyright>
             <year>2003-2014</year>
             <holder>The Khronos Group Inc.</holder>
         </copyright>
    </info>
    <refmeta>
        <refentrytitle>eglCreatePbufferSurface</refentrytitle>
        <manvolnum>3G</manvolnum>
    </refmeta>
    <refnamediv>
        <refname>eglCreatePbufferSurface</refname>
        <refpurpose>
            create a new <acronym>EGL</acronym> pixel buffer surface
        </refpurpose>
    </refnamediv>
    <refsynopsisdiv>
        <title>C Specification</title>
        <funcsynopsis>
            <funcprototype>
                <funcdef>EGLSurface <function>eglCreatePbufferSurface</function></funcdef>
                <paramdef>EGLDisplay <parameter>display</parameter></paramdef>
                <paramdef>EGLConfig <parameter>config</parameter></paramdef>
                <paramdef>EGLint const * <parameter>attrib_list</parameter></paramdef>
            </funcprototype>
        </funcsynopsis>
    </refsynopsisdiv>
    <refsect1 xml:id="parameters"><title>Parameters</title>
        <variablelist>
            <varlistentry>
                <term><parameter>display</parameter></term>
                <listitem><para>Specifies the EGL display connection.</para></listitem>
            </varlistentry>
            <varlistentry>
                <term><parameter>config</parameter></term>
                <listitem><para>
                    Specifies the EGL frame buffer configuration that defines the
                    frame buffer resource available to the surface.
                </para></listitem>
            </varlistentry>
            <varlistentry>
                <term><parameter>attrib_list</parameter></term>
                <listitem><para>
                    Specifies pixel buffer surface attributes.
                    May be <constant>NULL</constant> or empty
                    (first attribute is <constant>EGL_NONE</constant>).
                </para></listitem>
            </varlistentry>
        </variablelist>
    </refsect1>
    <refsect1 xml:id="description"><title>Description</title>
        <para>
            <function>eglCreatePbufferSurface</function> creates an
            off-screen pixel buffer surface and returns its handle. If
            <function>eglCreatePbufferSurface</function> fails to create
            a pixel buffer surface, <constant>EGL_NO_SURFACE</constant>
            is returned.
        </para>
        <para>
            Surface attributes are specified as a list of
            attribute-value pairs, terminated with
            <constant>EGL_NONE</constant>. Accepted attributes
            are:
        </para>
        <variablelist>
            <varlistentry>
                <term><constant>EGL_GL_COLORSPACE</constant></term>
                <listitem>
                <para>
                    Specifies the color space used by OpenGL and OpenGL ES
                    when rendering to the surface. If its value is
                    <constant>EGL_GL_COLORSPACE_SRGB</constant>, then a
                    non-linear, perceptually uniform color space is assumed,
                    with a corresponding
                    <constant>GL_FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING</constant>
                    value of <constant>GL_SRGB</constant>. If its value is
                    <constant>EGL_GL_COLORSPACE_LINEAR</constant>, then a
                    linear color space is assumed, with a corresponding
                    <constant>GL_FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING</constant>
                    value of <constant>GL_LINEAR</constant>. The default
                    value of <constant>EGL_GL_COLORSPACE</constant> is
                    <constant>EGL_GL_COLORSPACE_SRGB</constant>.
                </para>
                <para>
                    Note that the <constant>EGL_GL_COLORSPACE</constant>
                    attribute is used only by OpenGL and OpenGL ES contexts
                    supporting sRGB framebuffers. EGL itself does not
                    distinguish multiple colorspace models. Refer to the
                    ``sRGB Conversion'' sections of the OpenGL 4.6 and
                    OpenGL ES 3.2 Specifications for more information.
                </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>EGL_HEIGHT</constant></term>
                <listitem>
                <para>
                    Specifies the required height of the pixel buffer
                    surface. The default value is
                    <constant>0</constant>.
                </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>EGL_LARGEST_PBUFFER</constant></term>
                <listitem>
                <para>
                    Requests the largest available pixel buffer surface
                    when the allocation would otherwise fail. Use
                    <citerefentry><refentrytitle>eglQuerySurface</refentrytitle></citerefentry>
                    to retrieve the dimensions of the allocated pixel
                    buffer. The default value is
                    <constant>EGL_FALSE</constant>.
                </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>EGL_MIPMAP_TEXTURE</constant></term>
                <listitem>
                <para>
                    Specifies whether storage for mipmaps should be
                    allocated. Space for mipmaps will be set aside if
                    the attribute value is <constant>EGL_TRUE</constant>
                    and <constant>EGL_TEXTURE_FORMAT</constant> is not
                    <constant>EGL_NO_TEXTURE</constant>. The default
                    value is <constant>EGL_FALSE</constant>.
                </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>EGL_TEXTURE_FORMAT</constant></term>
                <listitem>
                <para>
                    Specifies the format of the texture that will be
                    created when a pbuffer is bound to a texture map.
                    Possible values are
                    <constant>EGL_NO_TEXTURE</constant>,
                    <constant>EGL_TEXTURE_RGB</constant>, and
                    <constant>EGL_TEXTURE_RGBA</constant>. The default
                    value is <constant>EGL_NO_TEXTURE</constant>.
                </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>EGL_TEXTURE_TARGET</constant></term>
                <listitem>
                <para>
                    Specifies the target for the texture that will be
                    created when the pbuffer is created with a texture
                    format of <constant>EGL_TEXTURE_RGB</constant> or
                    <constant>EGL_TEXTURE_RGBA</constant>. Possible
                    values are <constant>EGL_NO_TEXTURE</constant>, or
                    <constant>EGL_TEXTURE_2D</constant>. The default
                    value is <constant>EGL_NO_TEXTURE</constant>.
                </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>EGL_VG_ALPHA_FORMAT</constant></term>
                <listitem>
                <para>
                    Specifies how alpha values are interpreted by OpenVG
                    when rendering to the surface. If its value is
                    <constant>EGL_VG_ALPHA_FORMAT_NONPRE</constant>,
                    then alpha values are not premultipled. If its value
                    is <constant>EGL_VG_ALPHA_FORMAT_PRE</constant>,
                    then alpha values are premultiplied. The default
                    value of <constant>EGL_VG_ALPHA_FORMAT</constant> is
                    <constant>EGL_VG_ALPHA_FORMAT_NONPRE</constant>.
                </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>EGL_VG_COLORSPACE</constant></term>
                <listitem>
                <para>
                    Specifies the color space used by OpenVG when
                    rendering to the surface. If its value is
                    <constant>EGL_VG_COLORSPACE_sRGB</constant>, then a
                    non-linear, perceptually uniform color space is
                    assumed, with a corresponding
                    <type>VGImageFormat</type> of form
                    <constant>VG_s*</constant>. If its value is
                    <constant>EGL_VG_COLORSPACE_LINEAR</constant>, then
                    a linear color space is assumed, with a
                    corresponding <type>VGImageFormat</type> of form
                    <constant>VG_l*</constant>. The default value of
                    <constant>EGL_VG_COLORSPACE</constant> is
                    <constant>EGL_VG_COLORSPACE_sRGB</constant>.
                </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>EGL_WIDTH</constant></term>
                <listitem>
                <para>
                    Specifies the required width of the pixel buffer
                    surface. The default value is
                    <constant>0</constant>.
                </para>
                </listitem>
            </varlistentry>
        </variablelist>
        <para>
            Any EGL rendering context that was created with respect to
            <parameter>config</parameter> can be used to render into the
            surface. Use
            <citerefentry><refentrytitle>eglMakeCurrent</refentrytitle></citerefentry>
            to attach an EGL rendering context to the surface.
        </para>
        <para>
            Use
            <citerefentry><refentrytitle>eglQuerySurface</refentrytitle></citerefentry>
            to retrieve the dimensions of the allocated pixel buffer
            surface or the ID of <parameter>config</parameter>.
        </para>
        <para>
            Use <citerefentry><refentrytitle>eglDestroySurface</refentrytitle></citerefentry>
            to destroy the surface.
        </para>
    </refsect1>
    <refsect1 xml:id="notes"><title>Notes</title>
        <para>
            Attribute <constant>EGL_GL_COLORSPACE</constant>, and the
            <constant>EGL_OPENGL_ES3_BIT</constant> bit value for attribute
            <constant>EGL_RENDERABLE_TYPE</constant>, are supported only if
            the EGL version is 1.5 or greater.
        </para>
        <para>
            Attributes
            <constant>EGL_RENDERABLE_TYPE</constant>,
            <constant>EGL_VG_ALPHA_FORMAT</constant>, and
            <constant>EGL_VG_COLORSPACE</constant>, and the
            corresponding attribute values, are supported only if the
            EGL version is 1.2 or greater.
        </para>
        <para>
            If the value of <parameter>config</parameter> attribute
            <constant>EGL_TEXTURE_FORMAT</constant> is not
            <constant>EGL_NO_TEXTURE</constant>, then the pbuffer width
            and height specify the size of the level zero texture image
        </para>
        <para>
            If <constant>EGL_LARGEST_PBUFFER</constant> is specified and
            if the pbuffer will be used as a texture (i.e. the value of
            <constant>EGL_TEXTURE_TARGET</constant> is
            <constant>EGL_TEXTURE_2D</constant>, and the value of
            <constant>EGL_TEXTURE FORMAT</constant> is
            <constant>EGL_TEXTURE_RGB</constant> or
            <constant>EGL_TEXTURE_RGBA</constant>), then the aspect
            ratio will be preserved and the new width and height will be
            valid sizes for the texture target (e.g. if the underlying
            OpenGL ES implementation does not support non-power-of-two
            textures, both the width and height will be a power of 2).
        </para>
        <para>
            The contents of the depth and stencil buffers may not be
            preserved when rendering a texture to the pbuffer and
            switching which image of the texture is rendered to (e.g.,
            switching from rendering one mipmap level to rendering
            another).
        </para>
    </refsect1>
    <refsect1 xml:id="errors"><title>Errors</title>
        <para>
            <constant>EGL_NO_SURFACE</constant> is returned if creation of
            the context fails.
        </para>
        <para>
            <constant>EGL_BAD_DISPLAY</constant> is generated if
            <parameter>display</parameter> is not an EGL display connection.
        </para>
        <para>
            <constant>EGL_NOT_INITIALIZED</constant> is generated if
            <parameter>display</parameter> has not been initialized.
        </para>
        <para>
            <constant>EGL_BAD_CONFIG</constant> is generated if
            <parameter>config</parameter> is not an EGL frame buffer configuration.
        </para>
        <para>
            <constant>EGL_BAD_ATTRIBUTE</constant> is generated if
            <parameter>attrib_list</parameter> contains an invalid pixel
            buffer attribute or if an attribute value is not recognized
            or out of range.
        </para>
        <para>
            <constant>EGL_BAD_ATTRIBUTE</constant> is generated if
            <parameter>attrib_list</parameter> contains any of the
            attributes <constant>EGL_MIPMAP_TEXTURE</constant>,
            <constant>EGL_TEXTURE_FORMAT</constant>, or
            <constant>EGL_TEXTURE_TARGET</constant>, and
            <parameter>config</parameter> does not support OpenGL ES
            rendering (e.g. the EGL version is 1.2 or later, and the
            <constant>EGL_RENDERABLE_TYPE</constant> attribute of
            <parameter>config</parameter> does not include at least one
            of <constant>EGL_OPENGL_ES_BIT</constant>,
            <constant>EGL_OPENGL_ES2_BIT</constant>, or
            <constant>EGL_OPENGL_ES3_BIT</constant>),
        </para>
        <para>
            <constant>EGL_BAD_ALLOC</constant> is generated if there are not
            enough resources to allocate the new surface.
        </para>
        <para>
            <constant>EGL_BAD_MATCH</constant> is generated if
            <parameter>config</parameter> does not support rendering to pixel buffers
            (the <constant>EGL_SURFACE_TYPE</constant> attribute does not contain
            <constant>EGL_PBUFFER_BIT</constant>).
        </para>
        <para>
            <constant>EGL_BAD_MATCH</constant> is generated if the
            <constant>EGL_TEXTURE_FORMAT</constant> attribute is not
            <constant>EGL_NO_TEXTURE</constant>, and
            <constant>EGL_WIDTH</constant> and/or
            <constant>EGL_HEIGHT</constant> specify an invalid size
            (e.g., the texture size is not a power of 2, and the
            underlying OpenGL ES implementation does not support
            non-power-of-two textures).
        </para>
        <para>
            <constant>EGL_BAD_MATCH</constant> is generated if
            the <constant>EGL_TEXTURE_FORMAT</constant> attribute is
            <constant>EGL_NO_TEXTURE</constant>, and
            <constant>EGL_TEXTURE_TARGET</constant> is something other
            than <constant>EGL_NO_TEXTURE</constant>; or,
            <constant>EGL_TEXTURE_FORMAT</constant> is something other
            than <constant>EGL_NO_TEXTURE</constant>, and
            <constant>EGL_TEXTURE_TARGET</constant> is
            <constant>EGL_NO_TEXTURE</constant>.
        </para>
        <para>
            <constant>EGL_BAD_MATCH</constant> is generated if
            <parameter>config</parameter> does not support the specified
            OpenVG alpha format attribute (the value of
            <constant>EGL_VG_ALPHA_FORMAT</constant> is
            <constant>EGL_VG_ALPHA_FORMAT_PRE</constant> and the
            <constant>EGL_VG_ALPHA_FORMAT_PRE_BIT</constant> is not set
            in the <constant>EGL_SURFACE_TYPE</constant> attribute of
            <parameter>config</parameter>) or colorspace attribute (the
            value of <constant>EGL_VG_COLORSPACE</constant> is
            <constant>EGL_VG_COLORSPACE_LINEAR</constant> and the
            <constant>EGL_VG_COLORSPACE_LINEAR_IT</constant> is not set
            in the <constant>EGL_SURFACE_TYPE</constant> attribute of
            <parameter>config</parameter>).
        </para>
    </refsect1>
    <refsect1 xml:id="seealso"><title>See Also</title>
        <para>
            <citerefentry><refentrytitle>eglDestroySurface</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>eglChooseConfig</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>eglGetConfigs</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>eglMakeCurrent</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>eglQuerySurface</refentrytitle></citerefentry>
        </para>
    </refsect1>
    <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="copyright.xml"/>
</refentry>