| 1 | <?xml version="1.0" encoding="UTF-8"?>\r |
| 2 | <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN"\r |
| 3 | "http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd">\r |
| 4 | <refentry id="glGetFramebufferAttachmentParameter">\r |
| 5 | <refmeta>\r |
| 6 | <refmetainfo>\r |
| 7 | <copyright>\r |
| 8 | <year>2010</year>\r |
| 9 | <holder>Khronos Group</holder>\r |
| 10 | </copyright>\r |
| 11 | </refmetainfo>\r |
| 12 | <refentrytitle>glGetFramebufferAttachmentParameteriv</refentrytitle>\r |
| 13 | <manvolnum>3G</manvolnum>\r |
| 14 | </refmeta>\r |
| 15 | <refnamediv>\r |
| 16 | <refname>glGetFramebufferAttachmentParameteriv</refname>\r |
| 17 | <refpurpose>retrieve information about attachments of a bound framebuffer object</refpurpose>\r |
| 18 | </refnamediv>\r |
| 19 | <refsynopsisdiv><title>C Specification</title>\r |
| 20 | <funcsynopsis>\r |
| 21 | <funcprototype>\r |
| 22 | <funcdef>void <function>glGetFramebufferAttachmentParameter</function></funcdef>\r |
| 23 | <paramdef>GLenum <parameter>target</parameter></paramdef>\r |
| 24 | <paramdef>GLenum <parameter>attachment</parameter></paramdef>\r |
| 25 | <paramdef>GLenum <parameter>pname</parameter></paramdef>\r |
| 26 | <paramdef>GLint *<parameter>params</parameter></paramdef>\r |
| 27 | </funcprototype>\r |
| 28 | </funcsynopsis>\r |
| 29 | </refsynopsisdiv>\r |
| 30 | <!-- eqn: ignoring delim $$ -->\r |
| 31 | <refsect1 id="parameters"><title>Parameters</title>\r |
| 32 | <variablelist>\r |
| 33 | <varlistentry>\r |
| 34 | <term><parameter>target</parameter></term>\r |
| 35 | <listitem>\r |
| 36 | <para>\r |
| 37 | Specifies the target of the query operation.\r |
| 38 | </para>\r |
| 39 | </listitem>\r |
| 40 | </varlistentry>\r |
| 41 | <varlistentry>\r |
| 42 | <term><parameter>attachment</parameter></term>\r |
| 43 | <listitem>\r |
| 44 | <para>\r |
| 45 | Specifies the attachment within <parameter>target</parameter>\r |
| 46 | </para>\r |
| 47 | </listitem>\r |
| 48 | </varlistentry>\r |
| 49 | <varlistentry>\r |
| 50 | <term><parameter>pname</parameter></term>\r |
| 51 | <listitem>\r |
| 52 | <para>\r |
| 53 | Specifies the parameter of <parameter>attachment</parameter> to query.\r |
| 54 | </para>\r |
| 55 | </listitem>\r |
| 56 | </varlistentry>\r |
| 57 | <varlistentry>\r |
| 58 | <term><parameter>params</parameter></term>\r |
| 59 | <listitem>\r |
| 60 | <para>\r |
| 61 | Specifies the address of a variable receive the value of <parameter>pname</parameter> for <parameter>attachment</parameter>.\r |
| 62 | </para>\r |
| 63 | </listitem>\r |
| 64 | </varlistentry>\r |
| 65 | </variablelist>\r |
| 66 | </refsect1>\r |
| 67 | <refsect1 id="description"><title>Description</title>\r |
| 68 | <para>\r |
| 69 | <function>glGetFramebufferAttachmentParameter</function> returns information about attachments of a bound framebuffer\r |
| 70 | object. <parameter>target</parameter> specifies the framebuffer binding point and must be <constant>GL_DRAW_FRAMEBUFFER</constant>,\r |
| 71 | <constant>GL_READ_FRAMEBUFFER</constant> or <constant>GL_FRAMEBUFFER</constant>. <constant>GL_FRAMEBUFFER</constant> is equivalent\r |
| 72 | to <constant>GL_DRAW_FRAMEBUFFER</constant>.\r |
| 73 | </para>\r |
| 74 | <para>\r |
| 75 | If the default framebuffer is bound to <parameter>target</parameter> then <parameter>attachment</parameter> must be one of\r |
| 76 | <constant>GL_FRONT_LEFT</constant>, <constant>GL_FRONT_RIGHT</constant>, <constant>GL_BACK_LEFT</constant>, or\r |
| 77 | <constant>GL_BACK_RIGHT</constant>, identifying a color buffer, <constant>GL_DEPTH</constant>, identifying the depth buffer,\r |
| 78 | or <constant>GL_STENCIL</constant>, identifying the stencil buffer.\r |
| 79 | </para>\r |
| 80 | <para>\r |
| 81 | If a framebuffer object is bound, then <parameter>attachment</parameter> must be one of <constant>GL_COLOR_ATTACHMENT<emphasis>i</emphasis></constant>,\r |
| 82 | <constant>GL_DEPTH_ATTACHMENT</constant>, <constant>GL_STENCIL_ATTACHMENT</constant>, or <constant>GL_DEPTH_STENCIL_ATTACHMENT</constant>.\r |
| 83 | <emphasis>i</emphasis> in <constant>GL_COLOR_ATTACHMENT<emphasis>i</emphasis></constant> must be in the range zero to the value of\r |
| 84 | <constant>GL_MAX_COLOR_ATTACHMENTS</constant> - 1.\r |
| 85 | </para>\r |
| 86 | <para>\r |
| 87 | If <parameter>attachment</parameter> is <constant>GL_DEPTH_STENCIL_ATTACHMENT</constant> and different objects are bound\r |
| 88 | to the depth and stencil attachment points of <parameter>target</parameter> the query will fail. If the same object\r |
| 89 | is bound to both attachment points, information about that object will be returned.\r |
| 90 | </para>\r |
| 91 | <para>\r |
| 92 | Upon successful return from <function>glGetFramebufferAttachmentParameteriv</function>, if <parameter>pname</parameter> is\r |
| 93 | <constant>GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE</constant>, then <parameter>params</parameter> will contain one of <constant>GL_NONE</constant>,\r |
| 94 | <constant>GL_FRAMEBUFFER_DEFAULT</constant>, <constant>GL_TEXTURE</constant>, or <constant>GL_RENDERBUFFER</constant>, identifying the type of\r |
| 95 | object which contains the attached image. Other values accepted for <parameter>pname</parameter> depend on the type of object, as described below.\r |
| 96 | </para>\r |
| 97 | <para>\r |
| 98 | If the value of <constant>GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE</constant> is <constant>GL_NONE</constant>, no framebuffer is bound to\r |
| 99 | <parameter>target</parameter>. In this case querying <parameter>pname</parameter> <constant>GL_FRAMEBUFFER_ATTACHMENT_OBJECT_NAME</constant>\r |
| 100 | will return zero, and all other queries will generate an error.\r |
| 101 | </para>\r |
| 102 | <para>\r |
| 103 | If the value of <constant>GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE</constant> is not <constant>GL_NONE</constant>, these queries apply to all other\r |
| 104 | framebuffer types:\r |
| 105 | </para>\r |
| 106 | <itemizedlist>\r |
| 107 | <listitem>\r |
| 108 | <para>\r |
| 109 | If <parameter>pname</parameter> is <constant>GL_FRAMEBUFFER_ATTACHMENT_RED_SIZE</constant>,\r |
| 110 | <constant>GL_FRAMEBUFFER_ATTACHMENT_GREEN_SIZE</constant>, <constant>GL_FRAMEBUFFER_ATTACHMENT_BLUE_SIZE</constant>,\r |
| 111 | <constant>GL_FRAMEBUFFER_ATTACHMENT_ALPHA_SIZE</constant>, <constant>GL_FRAMEBUFFER_ATTACHMENT_DEPTH_SIZE</constant>,\r |
| 112 | or <constant>GL_FRAMEBUFFER_ATTACHMENT_STENCIL_SIZE</constant>, then <parameter>params</parameter> will contain the number\r |
| 113 | of bits in the corresponding red, green, blue, alpha, depth, or stencil component of the specified attachment. Zero is returned\r |
| 114 | if the requested component is not present in <parameter>attachment</parameter>.\r |
| 115 | </para>\r |
| 116 | </listitem>\r |
| 117 | <listitem>\r |
| 118 | <para>\r |
| 119 | If <parameter>pname</parameter> is <constant>GL_FRAMEBUFFER_ATTACHMENT_COMPONENT_TYPE</constant>, <parameter>params</parameter> will\r |
| 120 | contain the format of components of the specified attachment, one of <constant>GL_FLOAT</constant>, <parameter>GL_INT</parameter>,\r |
| 121 | <parameter>GL_UNSIGNED_INT</parameter>, <parameter>GL_SIGNED_NORMALIZED</parameter>, or <parameter>GL_UNSIGNED_NORMALIZED</parameter>\r |
| 122 | for floating-point, signed integer, unsigned integer, signed normalized fixed-point, or unsigned normalized fixed-point components\r |
| 123 | respectively. Only color buffers may have integer components.\r |
| 124 | </para>\r |
| 125 | </listitem>\r |
| 126 | <listitem>\r |
| 127 | <para>\r |
| 128 | If <parameter>pname</parameter> is <constant>GL_FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING</constant>, <parameter>param</parameter> will\r |
| 129 | contain the encoding of components of the specified attachment, one of <constant>GL_LINEAR</constant> or <constant>GL_SRGB</constant>\r |
| 130 | for linear or sRGB-encoded components, respectively. Only color buffer components may be sRGB-encoded; such components\r |
| 131 | are treated as described in sections 4.1.7 and 4.1.8. For the default framebuffer, color encoding is determined by the implementation.\r |
| 132 | For framebuffer objects, components are sRGB-encoded if the internal format of a color attachment is one of the color-renderable SRGB\r |
| 133 | formats.\r |
| 134 | </para>\r |
| 135 | </listitem>\r |
| 136 | </itemizedlist>\r |
| 137 | <para>\r |
| 138 | If the value of <constant>GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE</constant> is <constant>GL_RENDERBUFFER</constant>, then:\r |
| 139 | </para>\r |
| 140 | <itemizedlist>\r |
| 141 | <listitem>\r |
| 142 | <para>\r |
| 143 | If <parameter>pname</parameter> is <constant>GL_FRAMEBUFFER_ATTACHMENT_OBJECT_NAME</constant>, <parameter>params</parameter> will contain\r |
| 144 | the name of the renderbuffer object which contains the attached image.\r |
| 145 | </para>\r |
| 146 | </listitem>\r |
| 147 | </itemizedlist>\r |
| 148 | <para>\r |
| 149 | If the value of <constant>GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE</constant> is <constant>GL_TEXTURE</constant>, then:\r |
| 150 | </para>\r |
| 151 | <itemizedlist>\r |
| 152 | <listitem>\r |
| 153 | <para>\r |
| 154 | If <parameter>pname</parameter> is <constant>GL_FRAMEBUFFER_ATTACHMENT_OBJECT_NAME</constant>, then <parameter>params</parameter> will\r |
| 155 | contain the name of the texture object which contains the attached image.\r |
| 156 | </para>\r |
| 157 | </listitem>\r |
| 158 | <listitem>\r |
| 159 | <para>\r |
| 160 | If <parameter>pname</parameter> is <constant>GL_FRAMEBUFFER_ATTACHMENT_TEXTURE_LEVEL</constant>, then <parameter>params</parameter>\r |
| 161 | will contain the mipmap level of the texture object which contains the attached image.\r |
| 162 | </para>\r |
| 163 | </listitem>\r |
| 164 | <listitem>\r |
| 165 | <para>\r |
| 166 | If <parameter>pname</parameter> is <constant>GL_FRAMEBUFFER_ATTACHMENT_TEXTURE_CUBE_MAP_FACE</constant> and the texture object named\r |
| 167 | <constant>GL_FRAMEBUFFER_ATTACHMENT_OBJECT_NAME</constant> is a cube map texture, then <parameter>params</parameter> will contain the cube map\r |
| 168 | face of the cubemap texture object which contains the attached image. Otherwise <parameter>params</parameter> will contain the value\r |
| 169 | zero.\r |
| 170 | </para>\r |
| 171 | </listitem>\r |
| 172 | <listitem>\r |
| 173 | <para>\r |
| 174 | If <parameter>pname</parameter> is <constant>GL_FRAMEBUFFER_ATTACHMENT_TEXTURE_LAYER</constant> and the texture object named\r |
| 175 | <constant>GL_FRAMEBUFFER_ATTACHMENT_OBJECT_NAME</constant> is a layer of a three-dimensional texture or a one-or two-dimensional\r |
| 176 | array texture, then <parameter>params</parameter> will contain the number of the texture layer which contains the attached image.\r |
| 177 | Otherwise <parameter>params</parameter> will contain the value zero.\r |
| 178 | </para>\r |
| 179 | </listitem>\r |
| 180 | <listitem>\r |
| 181 | <para>\r |
| 182 | If <parameter>pname</parameter> is <constant>GL_FRAMEBUFFER_ATTACHMENT_LAYERED</constant>, then <parameter>params</parameter> will\r |
| 183 | contain <constant>GL_TRUE</constant> if an entire level of a three-dimesional texture, cube map texture, or one-or two-dimensional\r |
| 184 | array texture is attached. Otherwise, <parameter>params</parameter> will contain <constant>GL_FALSE</constant>.\r |
| 185 | </para>\r |
| 186 | </listitem>\r |
| 187 | </itemizedlist>\r |
| 188 | <para>\r |
| 189 | Any combinations of framebuffer type and <parameter>pname</parameter> not described above will generate an error.\r |
| 190 | </para>\r |
| 191 | </refsect1>\r |
| 192 | <refsect1 id="errors"><title>Errors</title>\r |
| 193 | <para>\r |
| 194 | <constant>GL_INVALID_ENUM</constant> is generated if <parameter>target</parameter> is not one of the accepted tokens.\r |
| 195 | </para>\r |
| 196 | <para>\r |
| 197 | <constant>GL_INVALID_ENUM</constant> is generated if <parameter>pname</parameter> is not valid for the value of\r |
| 198 | <constant>GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE</constant>.\r |
| 199 | </para>\r |
| 200 | <para>\r |
| 201 | <constant>GL_INVALID_OPERATION</constant> is generated if <parameter>attachment</parameter> is not the accepted values\r |
| 202 | for <parameter>target</parameter>.\r |
| 203 | </para>\r |
| 204 | <para>\r |
| 205 | <constant>GL_INVALID_OPERATION</constant> is generated if <parameter>attachment</parameter> is <constant>GL_DEPTH_STENCIL_ATTACHMENT</constant>\r |
| 206 | and different objects are bound to the depth and stencil attachment points of <parameter>target</parameter>.\r |
| 207 | </para>\r |
| 208 | <para>\r |
| 209 | <constant>GL_INVALID_OPERATION</constant> is generated if the value of <constant>GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE</constant> is\r |
| 210 | <constant>GL_NONE</constant> and <parameter>pname</parameter> is not <constant>GL_FRAMEBUFFER_ATTACHMENT_OBJECT_NAME</constant>.\r |
| 211 | </para>\r |
| 212 | </refsect1>\r |
| 213 | <refsect1 id="seealso"><title>See Also</title>\r |
| 214 | <para>\r |
| 215 | <citerefentry><refentrytitle>glGenFramebuffers</refentrytitle></citerefentry>,\r |
| 216 | <citerefentry><refentrytitle>glBindFramebuffer</refentrytitle></citerefentry>\r |
| 217 | </para>\r |
| 218 | </refsect1>\r |
| 219 | <refsect1 id="Copyright"><title>Copyright</title>\r |
| 220 | <para>\r |
| 221 | Copyright <trademark class="copyright"></trademark> 2010 Khronos Group. \r |
| 222 | This material may be distributed subject to the terms and conditions set forth in \r |
| 223 | the Open Publication License, v 1.0, 8 June 1999.\r |
| 224 | <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.\r |
| 225 | </para>\r |
| 226 | </refsect1>\r |
| 227 | </refentry>\r |