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1<refentry xmlns="http://docbook.org/ns/docbook" version="5.0" xml:base="" xml:id="eglCreatePlatformPixmapSurface">
2    <info>
3         <copyright>
4             <year>2003-2018</year>
5             <holder>The Khronos Group Inc.</holder>
6         </copyright>
7    </info>
8    <refmeta>
9        <refentrytitle>eglCreatePlatformPixmapSurface</refentrytitle>
10        <manvolnum>3G</manvolnum>
11    </refmeta>
12    <refnamediv>
13        <refname>eglCreatePlatformPixmapSurface</refname>
14        <refpurpose>
15            create a new <acronym>EGL</acronym> offscreen surface
16        </refpurpose>
17    </refnamediv>
18    <refsynopsisdiv>
19        <title>C Specification</title>
20        <funcsynopsis>
21            <funcprototype>
22                <funcdef>EGLSurface <function>eglCreatePlatformPixmapSurface</function></funcdef>
23                <paramdef>EGLDisplay <parameter>display</parameter></paramdef>
24                <paramdef>EGLConfig <parameter>config</parameter></paramdef>
25                <paramdef>void * <parameter>native_pixmap</parameter></paramdef>
26                <paramdef>EGLint const * <parameter>attrib_list</parameter></paramdef>
27            </funcprototype>
28        </funcsynopsis>
29    </refsynopsisdiv>
30    <refsect1 xml:id="parameters"><title>Parameters</title>
31        <variablelist>
32            <varlistentry>
33                <term><parameter>display</parameter></term>
34                <listitem><para>Specifies the EGL display connection.</para></listitem>
35            </varlistentry>
36            <varlistentry>
37                <term><parameter>config</parameter></term>
38                <listitem><para>
39                    Specifies the EGL frame buffer configuration that defines the
40                    frame buffer resource available to the surface.</para>
41                </listitem>
42            </varlistentry>
43            <varlistentry>
44                <term><parameter>native_pixmap</parameter></term>
45                <listitem><para>Specifies the native pixmap.</para></listitem>
46            </varlistentry>
47            <varlistentry>
48                <term><parameter>attrib_list</parameter></term>
49                <listitem><para>
50                    Specifies pixmap surface attributes.
51                    May be <constant>NULL</constant> or empty
52                    (first attribute is <constant>EGL_NONE</constant>).
53                </para></listitem>
54            </varlistentry>
55        </variablelist>
56    </refsect1>
57    <refsect1 xml:id="description"><title>Description</title>
58        <para>
59            <function>eglCreatePlatformPixmapSurface</function> creates an
60            off-screen <acronym>EGL</acronym> pixmap surface and returns
61            a handle to it.
62        </para>
63        <para>
64            If <function>eglCreatePlatformPixmapSurface</function> fails to
65            create a pixmap surface, <constant>EGL_NO_SURFACE</constant> is
66            returned.
67        </para>
68        <para>
69            <parameter>native_pixmap</parameter> must belong to the same
70            platform as <parameter>display</parameter>, and EGL considers
71            the returned <type>EGLSurface</type> as belonging to that same
72            platform. The EGL extension that defines the platform to which
73            <parameter>display</parameter> belongs also defines the
74            requirements for the <parameter>native_pixmap</parameter>
75            parameter.
76        </para>
77        <para>
78            Surface attributes are specified as a list of
79            attribute-value pairs, terminated with
80            <constant>EGL_NONE</constant>. Accepted attributes
81            are:
82        </para>
83        <variablelist>
84            <varlistentry>
85                <term><constant>EGL_GL_COLORSPACE</constant></term>
86                <listitem>
87                <para>
88                    Specifies the color space used by OpenGL and OpenGL ES
89                    when rendering to the surface. If its value is
90                    <constant>EGL_GL_COLORSPACE_SRGB</constant>, then a
91                    non-linear, perceptually uniform color space is assumed,
92                    with a corresponding
93                    <constant>GL_FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING</constant>
94                    value of <constant>GL_SRGB</constant>. If its value is
95                    <constant>EGL_GL_COLORSPACE_LINEAR</constant>, then a
96                    linear color space is assumed, with a corresponding
97                    <constant>GL_FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING</constant>
98                    value of <constant>GL_LINEAR</constant>. The default
99                    value of <constant>EGL_GL_COLORSPACE</constant> is
100                    <constant>EGL_GL_COLORSPACE_SRGB</constant>.
101                </para>
102                <para>
103                    Note that the <constant>EGL_GL_COLORSPACE</constant>
104                    attribute is used only by OpenGL and OpenGL ES contexts
105                    supporting sRGB framebuffers. EGL itself does not
106                    distinguish multiple colorspace models. Refer to the
107                    ``sRGB Conversion'' sections of the OpenGL 4.6 and
108                    OpenGL ES 3.2 Specifications for more information.
109                </para>
110                </listitem>
111            </varlistentry>
112            <varlistentry>
113                <term><constant>EGL_VG_ALPHA_FORMAT</constant></term>
114                <listitem>
115                <para>
116                    Specifies how alpha values are interpreted by OpenVG
117                    when rendering to the surface. If its value is
118                    <constant>EGL_VG_ALPHA_FORMAT_NONPRE</constant>,
119                    then alpha values are not premultipled. If its value
120                    is <constant>EGL_VG_ALPHA_FORMAT_PRE</constant>,
121                    then alpha values are premultiplied. The default
122                    value of <constant>EGL_VG_ALPHA_FORMAT</constant> is
123                    <constant>EGL_VG_ALPHA_FORMAT_NONPRE</constant>.
124                </para>
125                </listitem>
126            </varlistentry>
127            <varlistentry>
128                <term><constant>EGL_VG_COLORSPACE</constant></term>
129                <listitem>
130                <para>
131                    Specifies the color space used by OpenVG when
132                    rendering to the surface. If its value is
133                    <constant>EGL_VG_COLORSPACE_sRGB</constant>, then a
134                    non-linear, perceptually uniform color space is
135                    assumed, with a corresponding
136                    <type>VGImageFormat</type> of form
137                    <constant>VG_s*</constant>. If its value is
138                    <constant>EGL_VG_COLORSPACE_LINEAR</constant>, then
139                    a linear color space is assumed, with a
140                    corresponding <type>VGImageFormat</type> of form
141                    <constant>VG_l*</constant>. The default value of
142                    <constant>EGL_VG_COLORSPACE</constant> is
143                    <constant>EGL_VG_COLORSPACE_sRGB</constant>.
144                </para>
145                </listitem>
146            </varlistentry>
147        </variablelist>
148        <para>
149            Any EGL rendering context that was created with respect to
150            <parameter>config</parameter> can be used to render into the
151            surface. Use
152            <citerefentry><refentrytitle>eglMakeCurrent</refentrytitle></citerefentry>
153            to attach an EGL rendering context to the surface.
154        </para>
155        <para>
156            Use
157            <citerefentry><refentrytitle>eglQuerySurface</refentrytitle></citerefentry>
158            to retrieve the ID of <parameter>config</parameter>.
159        </para>
160        <para>
161            Use <citerefentry><refentrytitle>eglDestroySurface</refentrytitle></citerefentry>
162            to destroy the surface.
163        </para>
164    </refsect1>
165    <refsect1 xml:id="notes"><title>Notes</title>
166        <para>
167            The <constant>EGL_MATCH_NATIVE_PIXMAP</constant> attribute
168            of
169            <citerefentry><refentrytitle>eglChooseConfig</refentrytitle></citerefentry>
170            can be used to select a frame buffer configuration matching
171            a specified native pixmap.
172        </para>
173        <para>
174            Attribute <constant>EGL_GL_COLORSPACE</constant> is supported
175            only if the EGL version is 1.5 or greater.
176        </para>
177        <para>
178            Attributes
179            <constant>EGL_VG_ALPHA_FORMAT</constant> and
180            <constant>EGL_VG_COLORSPACE</constant>, and the
181            corresponding attribute values, are supported only if the
182            EGL version is 1.2 or greater.
183        </para>
184        <!-- Might want to mention aliasing of EGL_VG_* -> EGL_* that occurred in EGL 1.3 -->
185        <para>
186            The <constant>EGL_VG_ALPHA_FORMAT</constant> and
187            <constant>EGL_VG_COLORSPACE</constant> attributes are used only
188            by OpenVG and EGL itself. Refer to section 11.2 of the OpenVG
189            1.0 specification for more information. The platform's use and
190            interpretation of alpha values is outside the scope of EGL.
191            However, the preferred behavior is for the window system to
192            ignore the value of <constant>EGL_VG_ALPHA_FORMAT</constant>.
193        </para>
194    </refsect1>
195    <refsect1 xml:id="errors"><title>Errors</title>
196        <para>
197            If <parameter>display</parameter> and
198            <parameter>native_pixmap</parameter> do not belong to the same
199            platform, then undefined behavior occurs.
200        </para>
201        <para>
202            <constant>EGL_NO_SURFACE</constant> is returned if creation of
203            the surface fails.
204        </para>
205        <para>
206            <constant>EGL_BAD_DISPLAY</constant> is generated if
207            <parameter>display</parameter> is not an EGL display connection.
208        </para>
209        <para>
210            <constant>EGL_NOT_INITIALIZED</constant> is generated if
211            <parameter>display</parameter> has not been initialized.
212        </para>
213        <para>
214            <constant>EGL_BAD_CONFIG</constant> is generated if
215            <parameter>config</parameter> is not an EGL config.
216        </para>
217        <para>
218            <constant>EGL_BAD_NATIVE_PIXMAP</constant> may be generated if
219            <parameter>native_pixmap</parameter> is not a valid native pixmap.
220        </para>
221        <para>
222            <constant>EGL_BAD_ATTRIBUTE</constant> is generated if
223            <parameter>attrib_list</parameter> contains an invalid pixmap attribute
224            or if an attribute value is not recognized or out of range.
225        </para>
226        <para>
227            <constant>EGL_BAD_ALLOC</constant> is generated if there is
228            already an <type>EGLSurface</type> associated with
229            <parameter>native_pixmap</parameter> (as a result of a previous
230            <function>eglCreatePlatformPixmapSurface</function> call).
231        </para>
232        <para>
233            <constant>EGL_BAD_ALLOC</constant> is generated if the
234            implementation cannot allocate resources for the new EGL window.
235        </para>
236        <para>
237            <constant>EGL_BAD_MATCH</constant> is generated if the attributes of
238            <parameter>native_pixmap</parameter> do not correspond to
239            <parameter>config</parameter> or if
240            <parameter>config</parameter> does not support rendering to pixmaps
241            (the <constant>EGL_SURFACE_TYPE</constant> attribute does not contain
242            <constant>EGL_PIXMAP_BIT</constant>).
243        </para>
244        <para>
245            <constant>EGL_BAD_MATCH</constant> is generated if
246            <parameter>config</parameter> does not support the specified
247            OpenVG alpha format attribute (the value of
248            <constant>EGL_VG_ALPHA_FORMAT</constant> is
249            <constant>EGL_VG_ALPHA_FORMAT_PRE</constant> and the
250            <constant>EGL_VG_ALPHA_FORMAT_PRE_BIT</constant> is not set
251            in the <constant>EGL_SURFACE_TYPE</constant> attribute of
252            <parameter>config</parameter>) or colorspace attribute (the
253            value of <constant>EGL_VG_COLORSPACE</constant> is
254            <constant>EGL_VG_COLORSPACE_LINEAR</constant> and the
255            <constant>EGL_VG_COLORSPACE_LINEAR_IT</constant> is not set
256            in the <constant>EGL_SURFACE_TYPE</constant> attribute of
257            <parameter>config</parameter>).
258        </para>
259    </refsect1>
260    <refsect1 xml:id="seealso"><title>See Also</title>
261        <para>
262            <citerefentry><refentrytitle>eglDestroySurface</refentrytitle></citerefentry>,
263            <citerefentry><refentrytitle>eglChooseConfig</refentrytitle></citerefentry>,
264            <citerefentry><refentrytitle>eglGetConfigs</refentrytitle></citerefentry>,
265            <citerefentry><refentrytitle>eglMakeCurrent</refentrytitle></citerefentry>,
266            <citerefentry><refentrytitle>eglQuerySurface</refentrytitle></citerefentry>
267        </para>
268    </refsect1>
269    <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="copyright.xml"/>
270</refentry>
271