| 1 | <?xml version="1.0" encoding="UTF-8"?> |
| 2 | <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN" |
| 3 | "http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd"> |
| 4 | <refentry id="glTexStorage2D"> |
| 5 | <refmeta> |
| 6 | <refmetainfo> |
| 7 | <copyright> |
| 8 | <year>2011</year> |
| 9 | <holder>Khronos Group</holder> |
| 10 | </copyright> |
| 11 | </refmetainfo> |
| 12 | <refentrytitle>glTexStorage2D</refentrytitle> |
| 13 | <manvolnum>3G</manvolnum> |
| 14 | </refmeta> |
| 15 | <refnamediv> |
| 16 | <refname>glTexStorage2D</refname> |
| 17 | <refpurpose>simultaneously specify storage for all levels of a two-dimensional or one-dimensional array texture</refpurpose> |
| 18 | </refnamediv> |
| 19 | <refsynopsisdiv><title>C Specification</title> |
| 20 | <funcsynopsis> |
| 21 | <funcprototype> |
| 22 | <funcdef>void <function>glTexStorage2D</function></funcdef> |
| 23 | <paramdef>GLenum <parameter>target</parameter></paramdef> |
| 24 | <paramdef>GLsizei <parameter>levels</parameter></paramdef> |
| 25 | <paramdef>GLenum <parameter>internalformat</parameter></paramdef> |
| 26 | <paramdef>GLsizei <parameter>width</parameter></paramdef> |
| 27 | <paramdef>GLsizei <parameter>height</parameter></paramdef> |
| 28 | </funcprototype> |
| 29 | </funcsynopsis> |
| 30 | </refsynopsisdiv> |
| 31 | <refsect1 id="parameters"><title>Parameters</title> |
| 32 | <variablelist> |
| 33 | <varlistentry> |
| 34 | <term><parameter>target</parameter></term> |
| 35 | <listitem> |
| 36 | <para> |
| 37 | Specify the target of the operation. <parameter>target</parameter> must be |
| 38 | one of <constant>GL_TEXTURE_2D</constant>, <constant>GL_PROXY_TEXTURE_2D</constant>, |
| 39 | <constant>GL_TEXTURE_1D_ARRAY</constant>, <constant>GL_PROXY_TEXTURE_1D_ARRAY</constant>, |
| 40 | <constant>GL_TEXTURE_RECTANGLE</constant>, <constant>GL_PROXY_TEXTURE_RECTANGLE</constant>, |
| 41 | or <constant>GL_PROXY_TEXTURE_CUBE_MAP</constant>. |
| 42 | </para> |
| 43 | </listitem> |
| 44 | </varlistentry> |
| 45 | <varlistentry> |
| 46 | <term><parameter>levels</parameter></term> |
| 47 | <listitem> |
| 48 | <para> |
| 49 | Specify the number of texture levels. |
| 50 | </para> |
| 51 | </listitem> |
| 52 | </varlistentry> |
| 53 | <varlistentry> |
| 54 | <term><parameter>internalformat</parameter></term> |
| 55 | <listitem> |
| 56 | <para> |
| 57 | Specifies the sized internal format to be used to store texture image data. |
| 58 | </para> |
| 59 | </listitem> |
| 60 | </varlistentry> |
| 61 | <varlistentry> |
| 62 | <term><parameter>width</parameter></term> |
| 63 | <listitem> |
| 64 | <para> |
| 65 | Specifies the width of the texture, in texels. |
| 66 | </para> |
| 67 | </listitem> |
| 68 | </varlistentry> |
| 69 | <varlistentry> |
| 70 | <term><parameter>height</parameter></term> |
| 71 | <listitem> |
| 72 | <para> |
| 73 | Specifies the height of the texture, in texels. |
| 74 | </para> |
| 75 | </listitem> |
| 76 | </varlistentry> |
| 77 | </variablelist> |
| 78 | </refsect1> |
| 79 | <refsect1 id="description"><title>Description</title> |
| 80 | <para> |
| 81 | <function>glTexStorage2D</function> specifies the storage requirements for all levels |
| 82 | of a two-dimensional texture or one-dimensional texture array simultaneously. Once a texture is specified with this |
| 83 | command, the format and dimensions of all levels become immutable unless it is a proxy |
| 84 | texture. The contents of the image may still be modified, however, its storage requirements |
| 85 | may not change. Such a texture is referred to as an <emphasis>immutable-format</emphasis> |
| 86 | texture. |
| 87 | </para> |
| 88 | <para> |
| 89 | The behavior of <function>glTexStorage2D</function> depends on the <parameter>target</parameter> parameter. |
| 90 | When <parameter>target</parameter> is <constant>GL_TEXTURE_2D</constant>, <constant>GL_PROXY_TEXTURE_2D</constant>, |
| 91 | <constant>GL_TEXTURE_RECTANGLE</constant>, <constant>GL_PROXY_TEXTURE_RECTANGLE</constant> or <constant>GL_PROXY_TEXTURE_CUBE_MAP</constant>, |
| 92 | calling <function>glTexStorage2D</function> is equivalent, assuming no errors are generated, |
| 93 | to executing the following pseudo-code: |
| 94 | </para> |
| 95 | <programlisting><![CDATA[ for (i = 0; i < levels; i++) |
| 96 | { |
| 97 | glTexImage2D(target, i, internalformat, width, height, 0, format, type, NULL); |
| 98 | width = max(1, (width / 2)); |
| 99 | height = max(1, (height / 2)); |
| 100 | }]]></programlisting> |
| 101 | <para> |
| 102 | When <parameter>target</parameter> is <constant>GL_TEXTURE_CUBE_MAP</constant>, <function>glTexStorage2D</function> |
| 103 | is equivalent to: |
| 104 | </para> |
| 105 | <programlisting><![CDATA[ for (i = 0; i < levels; i++) |
| 106 | { |
| 107 | for (face in (+X, -X, +Y, -Y, +Z, -Z)) |
| 108 | { |
| 109 | glTexImage2D(face, i, internalformat, width, height, 0, format, type, NULL); |
| 110 | } |
| 111 | width = max(1, (width / 2)); |
| 112 | height = max(1, (height / 2)); |
| 113 | }]]></programlisting> |
| 114 | <para> |
| 115 | When <parameter>target</parameter> is <constant>GL_TEXTURE_1D</constant> or <constant>GL_TEXTURE_1D_ARRAY</constant>, |
| 116 | <function>glTexStorage2D</function> is equivalent to: |
| 117 | </para> |
| 118 | <programlisting><![CDATA[ for (i = 0; i < levels; i++) |
| 119 | { |
| 120 | glTexImage2D(target, i, internalformat, width, height, 0, format, type, NULL); |
| 121 | width = max(1, (width / 2)); |
| 122 | }]]></programlisting> |
| 123 | <para> |
| 124 | Since no texture data is actually provided, the values used in the pseudo-code |
| 125 | for <parameter>format</parameter> and <parameter>type</parameter> are |
| 126 | irrelevant and may be considered to be any values that are legal for the |
| 127 | chosen <parameter>internalformat</parameter> enumerant. <parameter>internalformat</parameter> |
| 128 | must be one of the sized internal formats given in Table 1 below, one of the sized depth-component |
| 129 | formats <constant>GL_DEPTH_COMPONENT32F</constant>, <constant>GL_DEPTH_COMPONENT24</constant>, or |
| 130 | <constant>GL_DEPTH_COMPONENT16</constant>, or one of the combined depth-stencil formats, |
| 131 | <constant>GL_DEPTH32F_STENCIL8</constant>, or <constant>GL_DEPTH24_STENCIL8</constant>. Upon success, |
| 132 | the value of <constant>GL_TEXTURE_IMMUTABLE_FORMAT</constant> becomes |
| 133 | <constant>GL_TRUE</constant>. The value of <constant>GL_TEXTURE_IMMUTABLE_FORMAT</constant> |
| 134 | may be discovered by calling <citerefentry><refentrytitle>glGetTexParameter</refentrytitle></citerefentry> |
| 135 | with <parameter>pname</parameter> set to <constant>GL_TEXTURE_IMMUTABLE_FORMAT</constant>. |
| 136 | No further changes to the dimensions or format of the texture object may be |
| 137 | made. Using any command that might alter the dimensions or format of the |
| 138 | texture object (such as <citerefentry><refentrytitle>glTexImage2D</refentrytitle></citerefentry> or |
| 139 | another call to <function>glTexStorage2D</function>) will result in the |
| 140 | generation of a <constant>GL_INVALID_OPERATION</constant> error, even if it |
| 141 | would not, in fact, alter the dimensions or format of the object. |
| 142 | </para> |
| 143 | <para> |
| 144 | <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="internalformattable.xml" /> |
| 145 | </para> |
| 146 | </refsect1> |
| 147 | <refsect1 id="errors"><title>Errors</title> |
| 148 | <para> |
| 149 | <constant>GL_INVALID_ENUM</constant> is generated if <parameter>internalformat</parameter> is not a |
| 150 | valid sized internal format. |
| 151 | </para> |
| 152 | <para> |
| 153 | <constant>GL_INVALID_ENUM</constant> is generated if <parameter>target</parameter> is not |
| 154 | one of the accepted target enumerants. |
| 155 | </para> |
| 156 | <para> |
| 157 | <constant>GL_INVALID_VALUE</constant> is generated if <parameter>width</parameter> or <parameter>levels</parameter> |
| 158 | are less than 1. |
| 159 | </para> |
| 160 | <para> |
| 161 | <constant>GL_INVALID_OPERATION</constant> is generated if <parameter>target</parameter> is <constant>GL_TEXTURE_1D_ARRAY</constant> |
| 162 | or <constant>GL_PROXY_TEXTURE_1D_ARRAY</constant> and <parameter>levels</parameter> is greater than <mml:math> |
| 163 | <mml:mrow> |
| 164 | <mml:mfenced open = '⌊' close = '⌋'> |
| 165 | <mml:mrow> |
| 166 | <mml:msub> |
| 167 | <mml:mi>log</mml:mi> |
| 168 | <mml:mn>2</mml:mn> |
| 169 | </mml:msub> |
| 170 | <mml:mfenced open = '(' close = ')'> |
| 171 | <mml:mi>width</mml:mi> |
| 172 | </mml:mfenced> |
| 173 | </mml:mrow> |
| 174 | </mml:mfenced> |
| 175 | <mml:mo>+</mml:mo> |
| 176 | <mml:mn>1</mml:mn> |
| 177 | </mml:mrow> |
| 178 | </mml:math>. |
| 179 | </para> |
| 180 | <para> |
| 181 | <constant>GL_INVALID_OPERATION</constant> is generated if <parameter>target</parameter> is not <constant>GL_TEXTURE_1D_ARRAY</constant> |
| 182 | or <constant>GL_PROXY_TEXTURE_1D_ARRAY</constant> and <parameter>levels</parameter> is greater than <mml:math> |
| 183 | <mml:mrow> |
| 184 | <mml:mfenced open = '⌊' close = '⌋'> |
| 185 | <mml:mrow> |
| 186 | <mml:msub> |
| 187 | <mml:mi>log</mml:mi> |
| 188 | <mml:mn>2</mml:mn> |
| 189 | </mml:msub> |
| 190 | <mml:mfenced open = '(' close = ')'> |
| 191 | <mml:mrow> |
| 192 | <mml:mi>max</mml:mi> |
| 193 | <mml:mfenced open = '(' close = ')'> |
| 194 | <mml:mrow> |
| 195 | <mml:mi>width</mml:mi> |
| 196 | <mml:mo>,</mml:mo> |
| 197 | <mml:mtext fontfamily='Times New Roman'> </mml:mtext> |
| 198 | <mml:mi>height</mml:mi> |
| 199 | </mml:mrow> |
| 200 | </mml:mfenced> |
| 201 | </mml:mrow> |
| 202 | </mml:mfenced> |
| 203 | </mml:mrow> |
| 204 | </mml:mfenced> |
| 205 | <mml:mo>+</mml:mo> |
| 206 | <mml:mn>1</mml:mn> |
| 207 | </mml:mrow> |
| 208 | </mml:math>. |
| 209 | </para> |
| 210 | </refsect1> |
| 211 | <refsect1 id="seealso"><title>See Also</title> |
| 212 | <para> |
| 213 | <citerefentry><refentrytitle>glTexImage2D</refentrytitle></citerefentry>, |
| 214 | <citerefentry><refentrytitle>glTexStorage1D</refentrytitle></citerefentry>, |
| 215 | <citerefentry><refentrytitle>glTexStorage3D</refentrytitle></citerefentry>. |
| 216 | </para> |
| 217 | </refsect1> |
| 218 | <refsect1 id="Copyright"><title>Copyright</title> |
| 219 | <para> |
| 220 | Copyright <trademark class="copyright"></trademark> 2011 Khronos Group. |
| 221 | This material may be distributed subject to the terms and conditions set forth in |
| 222 | the Open Publication License, v 1.0, 8 June 1999. |
| 223 | <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>. |
| 224 | </para> |
| 225 | </refsect1> |
| 226 | </refentry> |