sdk/docs/man/eglBindTexImage.xml

<refentry xmlns="http://docbook.org/ns/docbook" version="5.0" xml:base="" xml:id="eglBindTexImage">
    <info>
         <copyright>
             <year>2003-2014</year>
             <holder>The Khronos Group Inc.</holder>
         </copyright>
    </info>
    <refmeta>
        <refentrytitle>eglBindTexImage</refentrytitle>
        <manvolnum>3G</manvolnum>
    </refmeta>
    <refnamediv>
        <refname>eglBindTexImage</refname>
        <refpurpose>
            Defines a two-dimensional texture image
        </refpurpose>
    </refnamediv>
    <refsynopsisdiv>
        <title>C Specification</title>
        <funcsynopsis>
            <funcprototype>
                <funcdef>EGLBoolean <function>eglBindTexImage</function></funcdef>
                <paramdef>EGLDisplay <parameter>display</parameter></paramdef>
                <paramdef>EGLSurface <parameter>surface</parameter></paramdef>
                <paramdef>EGLint <parameter>buffer</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>surface</parameter></term>
                <listitem>
                    <para>
                        Specifies the EGL surface.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><parameter>buffer</parameter></term>
                <listitem><para>Specifies the texture image data.</para></listitem>
            </varlistentry>
        </variablelist>
    </refsect1>
    <refsect1 xml:id="description"><title>Description</title>
        <para>
            The texture image consists of the image data in <parameter>buffer</parameter> for the specified surface, and need not be copied.
        </para>
        <para>
            The texture target, the texture format and the size of the texture components are derived from
            attributes of the specified surface, which must be a pbuffer supporting one of the
            <constant>EGL_BIND_TO_TEXTURE_RGB</constant> or <constant>EGL_BIND_TO_TEXTURE_RGBA</constant> attributes.
        </para>
        <para>
            The pbuffer attribute <constant>EGL_TEXTURE_FORMAT</constant> determines the base internal format
            of the texture.
        </para>
        <para>
            The texture target is derived from the <constant>EGL_TEXTURE_TARGET</constant> attribute of surface.
            If the attribute value is <constant>EGL_TEXTURE_2D</constant>, then <parameter>buffer</parameter> defines a texture for
            the two-dimensional texture object which is bound to the current context (hereafter
            referred to as the current texture object).
        </para>
        <para>
            If <parameter>display</parameter> and <parameter>surface</parameter> are the display and surface for the calling thread's current
            context, <function>eglBindTexImage</function> performs an implicit <citerefentry><refentrytitle>glFlush</refentrytitle></citerefentry>.
            For other surfaces, <function>eglBindTexImage</function> waits for all effects from previously issued OpenGL ES commands
            drawing to the surface to complete before defining the texture image, as
            though <citerefentry><refentrytitle>glFinish</refentrytitle></citerefentry>  were called on the last context to which that surface were bound.
        </para>
        <para>
            After <function>eglBindTexImage</function> is called, the specified surface is no longer available
            for reading or writing. Any read operation, such as <citerefentry><refentrytitle>glReadPixels</refentrytitle></citerefentry> or
            <citerefentry><refentrytitle>eglCopyBuffers</refentrytitle></citerefentry>, which reads values from any of the surface's color buffers or ancillary
            buffers will produce indeterminate results. In addition, draw operations that are
            done to the surface before its color buffer is released from the texture produce indeterminate
            results. Specifically, if the surface is current to a context and thread
            then rendering commands will be processed and the context state will be updated,
            but the surface may or may not be written.
        </para>
        <para>
            Texture mipmap levels are automatically generated when all of the following
            conditions are met while calling <function>eglBindTexImage</function>:
        </para>
        <itemizedlist>
        <listitem>
        <para>
            The <constant>EGL_MIPMAP_TEXTURE</constant> attribute of the pbuffer being bound is
            <constant>EGL_TRUE</constant>.
        </para>
        </listitem>
        <listitem>
        <para>
            The OpenGL ES texture parameter <constant>GL_GENERATE_MIPMAP</constant> is <constant>GL_TRUE</constant> for
            the currently bound texture.
        </para>
        </listitem>
        <listitem>
        <para>
            The value of the <constant>EGL_MIPMAP_LEVEL</constant> attribute of the pbuffer being bound is
            equal to the value of the texture parameter <constant>GL_TEXTURE_BASE_LEVEL</constant>.
            In this case, additional mipmap levels are generated as described in section 3.8
            of the OpenGL ES 1.1 Specification.
        </para>
        </listitem>
        </itemizedlist>
        <para>
            In this case, additional mipmap levels are generated as described in section 3.8
            of the OpenGL ES 1.1 Specification.
        </para>
    </refsect1>
    <refsect1 xml:id="notes"><title>Notes</title>
        <para>
            <citerefentry><refentrytitle>eglSwapBuffers</refentrytitle></citerefentry> has no effect if it is
            called on a bound surface.
        </para>
        <para>
            Any existing images associated with the different mipmap levels of the texture object
            are freed (it is as if <citerefentry><refentrytitle>glTexImage</refentrytitle></citerefentry>
            was called with an image of zero width).
        </para>
        <para>
            The color buffer is bound to a texture object. If the texture object is
            shared between contexts, then the color buffer is also shared. If a texture object is
            deleted before <citerefentry><refentrytitle>eglReleaseTexImage</refentrytitle></citerefentry> is called, then the color buffer is released and
            the surface is made available for reading and writing.
        </para>
        <para>
            It is not an error to call <citerefentry><refentrytitle>glTexImage2D</refentrytitle></citerefentry> or
            <citerefentry><refentrytitle>glCopyTexImage2D</refentrytitle></citerefentry> to replace an
            image of a texture object that has a color buffer bound to it. However, these calls
            will cause the color buffer to be released back to the surface and new memory will
            be allocated for the texture. Note that the color buffer is released even if the image
            that is being defined is a mipmap level that was not defined by the color buffer.
        </para>
        <para>
            <function>eglBindTexImage</function> is ignored if there is no current rendering context.
        </para>
    </refsect1>
    <refsect1 xml:id="errors"><title>Errors</title>
        <para>
            <constant>EGL_BAD_ACCESS</constant> is generated if
            <parameter>buffer</parameter> is already bound to a texture.
        </para>
        <para>
            <constant>EGL_BAD_MATCH</constant> is generated if the
            surface attribute <constant>EGL_TEXTURE_FORMAT</constant> is
            set to <constant>EGL_NO_TEXTURE</constant>.
        </para>
        <para>
            <constant>EGL_BAD_MATCH</constant> is generated if
            <parameter>buffer</parameter> is not a valid buffer
            (currently only <constant>EGL_BACK_BUFFER</constant> may be
            specified).
        </para>
        <para>
            <constant>EGL_BAD_SURFACE</constant> is generated if
            <parameter>surface</parameter> is not an EGL surface, or is
            not a pbuffer surface supporting texture binding.
        </para>
    </refsect1>
    <refsect1 xml:id="seealso"><title>See Also</title>
        <para>
            <citerefentry><refentrytitle>eglReleaseTexImage</refentrytitle></citerefentry>
        </para>
    </refsect1>
    <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="copyright.xml"/>
</refentry>