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<refentry xmlns="http://docbook.org/ns/docbook" version="5.0" xml:id="glCopyTexImage2D">
    <info>
        <copyright>
            <year>2013</year>
            <holder>Khronos Group</holder>
        </copyright>
    </info>
    <refmeta>
        <refentrytitle>glCopyTexImage2D</refentrytitle>
        <manvolnum>3G</manvolnum>
    </refmeta>
    <refnamediv>
        <refname>glCopyTexImage2D</refname>
        <refpurpose>copy pixels into a 2D texture image</refpurpose>
    </refnamediv>
    <refsynopsisdiv><title>C Specification</title>
        <funcsynopsis>
            <funcprototype>
                <funcdef>void <function>glCopyTexImage2D</function></funcdef>
                <paramdef>GLenum <parameter>target</parameter></paramdef>
                <paramdef>GLint <parameter>level</parameter></paramdef>
                <paramdef>GLenum <parameter>internalformat</parameter></paramdef>
                <paramdef>GLint <parameter>x</parameter></paramdef>
                <paramdef>GLint <parameter>y</parameter></paramdef>
                <paramdef>GLsizei <parameter>width</parameter></paramdef>
                <paramdef>GLsizei <parameter>height</parameter></paramdef>
                <paramdef>GLint <parameter>border</parameter></paramdef>
            </funcprototype>
        </funcsynopsis>
    </refsynopsisdiv>
    <refsect1 xml:id="parameters"><title>Parameters</title>
        <variablelist>
        <varlistentry>
            <term><parameter>target</parameter></term>
            <listitem>
                <para>
                    Specifies the target texture.
                    Must be <constant>GL_TEXTURE_2D</constant>,
                    <constant>GL_TEXTURE_CUBE_MAP_POSITIVE_X</constant>,
                    <constant>GL_TEXTURE_CUBE_MAP_NEGATIVE_X</constant>,
                    <constant>GL_TEXTURE_CUBE_MAP_POSITIVE_Y</constant>,
                    <constant>GL_TEXTURE_CUBE_MAP_NEGATIVE_Y</constant>,
                    <constant>GL_TEXTURE_CUBE_MAP_POSITIVE_Z</constant>, or
                    <constant>GL_TEXTURE_CUBE_MAP_NEGATIVE_Z</constant>.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>level</parameter></term>
            <listitem>
                <para>
                    Specifies the level-of-detail number.
                    Level 0 is the base image level.
                    Level <emphasis>n</emphasis> is the <emphasis>n</emphasis>th mipmap reduction image.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>internalformat</parameter></term>
            <listitem>
                <para>
                    Specifies the internal format of the texture.
                    Must be one of the following symbolic constants:
                    <constant>GL_COMPRESSED_RED</constant>,
                    <constant>GL_COMPRESSED_RG</constant>,
                    <constant>GL_COMPRESSED_RGB</constant>,
                    <constant>GL_COMPRESSED_RGBA</constant>.
                    <constant>GL_COMPRESSED_SRGB</constant>,
                    <constant>GL_COMPRESSED_SRGB_ALPHA</constant>.
                    <constant>GL_DEPTH_COMPONENT</constant>,
                    <constant>GL_DEPTH_COMPONENT16</constant>,
                    <constant>GL_DEPTH_COMPONENT24</constant>,
                    <constant>GL_DEPTH_COMPONENT32</constant>,
                    <constant>GL_STENCIL_INDEX8</constant>,
                    <constant>GL_RED</constant>,
                    <constant>GL_RG</constant>,
                    <constant>GL_RGB</constant>,
                    <constant>GL_R3_G3_B2</constant>,
                    <constant>GL_RGB4</constant>,
                    <constant>GL_RGB5</constant>,
                    <constant>GL_RGB8</constant>,
                    <constant>GL_RGB10</constant>,
                    <constant>GL_RGB12</constant>,
                    <constant>GL_RGB16</constant>,
                    <constant>GL_RGBA</constant>,
                    <constant>GL_RGBA2</constant>,
                    <constant>GL_RGBA4</constant>,
                    <constant>GL_RGB5_A1</constant>,
                    <constant>GL_RGBA8</constant>,
                    <constant>GL_RGB10_A2</constant>,
                    <constant>GL_RGBA12</constant>,
                    <constant>GL_RGBA16</constant>,
                    <constant>GL_SRGB</constant>,
                    <constant>GL_SRGB8</constant>,
                    <constant>GL_SRGB_ALPHA</constant>, or
                    <constant>GL_SRGB8_ALPHA8</constant>.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>x</parameter></term>
            <term><parameter>y</parameter></term>
            <listitem>
                <para>
                    Specify the window coordinates of the lower left corner
                    of the rectangular region of pixels to be copied.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>width</parameter></term>
            <listitem>
                <para>
                    Specifies the width of the texture image.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>height</parameter></term>
            <listitem>
                <para>
                    Specifies the height of the texture image.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>border</parameter></term>
            <listitem>
                <para>
                    Must be 0.
                </para>
            </listitem>
        </varlistentry>
        </variablelist>
    </refsect1>
    <refsect1 xml:id="description"><title>Description</title>
        <para>
            <function>glCopyTexImage2D</function> defines a two-dimensional texture image, or cube-map texture image
            with pixels from the current
            <constant>GL_READ_BUFFER</constant>.
        </para>
        <para>
            The screen-aligned pixel rectangle with lower left corner at (<parameter>x</parameter>,
            <parameter>y</parameter>) and with a width of
            <inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
                <mml:mi mathvariant="italic">width</mml:mi>
            </mml:math></inlineequation>
            and a height of
            <inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
                <mml:mi mathvariant="italic">height</mml:mi>
            </mml:math></inlineequation>
            defines the texture array
            at the mipmap level specified by <parameter>level</parameter>.
            <parameter>internalformat</parameter> specifies the internal format of the texture array.
        </para>
        <para>
            The pixels in the rectangle are processed exactly as if
            <citerefentry><refentrytitle>glReadPixels</refentrytitle></citerefentry> had been called, but the process stops just before
            final conversion.
            At this point all pixel component values are clamped to the range
            <inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
                <!-- eqn: [0,1]: -->
                <mml:mfenced open="[" close="]">
                    <mml:mn>0</mml:mn>
                    <mml:mn>1</mml:mn>
                </mml:mfenced>
            </mml:math></inlineequation>
            and then converted to the texture's internal format for storage in the texel
            array.
        </para>
        <para>
            Pixel ordering is such that lower
            <inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">x</mml:mi></mml:math></inlineequation>
            and
            <inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">y</mml:mi></mml:math></inlineequation>
            screen coordinates correspond to
            lower
            <inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math></inlineequation>
            and
            <inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">t</mml:mi></mml:math></inlineequation>
            texture coordinates.
        </para>
        <para>
            If any of the pixels within the specified rectangle of the current
            <constant>GL_READ_BUFFER</constant> are outside the window associated with the current
            rendering context, then the values obtained for those pixels are undefined.
        </para>
         <para>
            When <parameter>internalformat</parameter> is one of the sRGB  types, the GL does not automatically convert the source pixels to the sRGB color space.  In this case, the <function>glPixelMap</function> function can be used to accomplish the conversion.
        </para>
    </refsect1>
    <refsect1 xml:id="notes"><title>Notes</title>
        <para>
            1, 2, 3, and 4 are not accepted values for <parameter>internalformat</parameter>.
        </para>
        <para>
            An image with height or width of 0 indicates a NULL texture.
        </para>
        <para>
            <constant>GL_STENCIL_INDEX8</constant> is accepted for <parameter>internalformat</parameter> only
            if the GL version is 4.4 or higher.
        </para>
    </refsect1>
    <refsect1 xml:id="errors"><title>Errors</title>
        <para>
            <constant>GL_INVALID_ENUM</constant> is generated if <parameter>target</parameter> is not <constant>GL_TEXTURE_2D</constant>,
            <constant>GL_TEXTURE_CUBE_MAP_POSITIVE_X</constant>,
            <constant>GL_TEXTURE_CUBE_MAP_NEGATIVE_X</constant>,
            <constant>GL_TEXTURE_CUBE_MAP_POSITIVE_Y</constant>,
            <constant>GL_TEXTURE_CUBE_MAP_NEGATIVE_Y</constant>,
            <constant>GL_TEXTURE_CUBE_MAP_POSITIVE_Z</constant>, or
            <constant>GL_TEXTURE_CUBE_MAP_NEGATIVE_Z</constant>.
        </para>
        <para>
            <constant>GL_INVALID_VALUE</constant> is generated if <parameter>level</parameter> is less than 0.
        </para>
        <para>
            <constant>GL_INVALID_VALUE</constant> may be generated if <parameter>level</parameter> is greater
            than
            <inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
                <!-- eqn: log sub 2 max: -->
                <mml:mrow>
                    <mml:msub><mml:mi mathvariant="italic">log</mml:mi>
                    <mml:mn>2</mml:mn>
                    </mml:msub>
                    <mml:mo>&it;</mml:mo>
                    <mml:mi mathvariant="italic">max</mml:mi>
                </mml:mrow>
            </mml:math></inlineequation>,
            where
            <inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">max</mml:mi></mml:math></inlineequation>
            is the returned value of <constant>GL_MAX_TEXTURE_SIZE</constant>.
        </para>
        <para>
            <constant>GL_INVALID_VALUE</constant> is generated if <parameter>width</parameter> is less than 0
            or greater than
            <constant>GL_MAX_TEXTURE_SIZE</constant>.
        </para>
        <para>
            <constant>GL_INVALID_VALUE</constant> is generated if <parameter>border</parameter> is not 0.
        </para>
        <para>
            <constant>GL_INVALID_VALUE</constant> is generated if <parameter>internalformat</parameter> is not an
            accepted format.
        </para>
        <para>
            <constant>GL_INVALID_OPERATION</constant> is generated if <parameter>internalformat</parameter> is
            <constant>GL_DEPTH_COMPONENT</constant>, <constant>GL_DEPTH_COMPONENT16</constant>,
            <constant>GL_DEPTH_COMPONENT24</constant>, or <constant>GL_DEPTH_COMPONENT32</constant> and there is no depth
            buffer.
        </para>
    </refsect1>
    <refsect1 xml:id="associatedgets"><title>Associated Gets</title>
        <para>
            <citerefentry><refentrytitle>glGetTexImage</refentrytitle></citerefentry>
        </para>
    </refsect1>
    <refsect1 xml:id="seealso"><title>See Also</title>
        <para>
            <citerefentry><refentrytitle>glCopyTexImage1D</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glCopyTexSubImage1D</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glCopyTexSubImage2D</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glPixelStore</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glTexImage1D</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glTexImage2D</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glTexSubImage1D</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glTexSubImage2D</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glTexParameter</refentrytitle></citerefentry>
        </para>
    </refsect1>
    <refsect1 xml:id="Copyright"><title>Copyright</title>
        <para>
            Copyright <trademark class="copyright"/> 1991-2006
            Silicon Graphics, Inc.
            Copyright <trademark class="copyright"/> 2012-2013 Khronos Group.
            This document is licensed under the SGI
            Free Software B License. For details, see
            <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</link>.
        </para>
    </refsect1>
</refentry>
