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<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN"
"http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd">
<refentry id="glCopyTexImage2D">
<refentryinfo>
<copyright>
<year>2013</year>
<holder>Khronos Group</holder>
</copyright>
</refentryinfo>
<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 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 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>
<mml:mi mathvariant="italic">width</mml:mi>
</mml:math></inlineequation>
and a height of
<inlineequation><mml:math>
<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>
<!-- 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><mml:mi mathvariant="italic">x</mml:mi></mml:math></inlineequation>
and
<inlineequation><mml:math><mml:mi mathvariant="italic">y</mml:mi></mml:math></inlineequation>
screen coordinates correspond to
lower
<inlineequation><mml:math><mml:mi mathvariant="italic">s</mml:mi></mml:math></inlineequation>
and
<inlineequation><mml:math><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 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 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>
<!-- 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>⁢</mml:mo>
<mml:mi mathvariant="italic">max</mml:mi>
</mml:mrow>
</mml:math></inlineequation>,
where
<inlineequation><mml:math><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 id="associatedgets"><title>Associated Gets</title>
<para>
<citerefentry><refentrytitle>glGetTexImage</refentrytitle></citerefentry>
</para>
</refsect1>
<refsect1 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 id="Copyright"><title>Copyright</title>
<para>
Copyright <trademark class="copyright"></trademark> 1991-2006
Silicon Graphics, Inc.
Copyright <trademark class="copyright"></trademark> 2012-2013 Khronos Group.
This document is licensed under the SGI
Free Software B License. For details, see
<ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>.
</para>
</refsect1>
</refentry>
|
