| 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="glGetInternalFormativ"> |
| 5 | <refmeta> |
| 6 | <refmetainfo> |
| 7 | <copyright> |
| 8 | <year>2011</year> |
| 9 | <holder>Khronos Group.</holder> |
| 10 | </copyright> |
| 11 | </refmetainfo> |
| 12 | <refentrytitle>glGetInternalFormativ</refentrytitle> |
| 13 | <manvolnum>3G</manvolnum> |
| 14 | </refmeta> |
| 15 | <refnamediv> |
| 16 | <refname>glGetInternalFormativ</refname> |
| 17 | <refpurpose>retrieve information about implementation-dependent support for internal formats</refpurpose> |
| 18 | </refnamediv> |
| 19 | <refsynopsisdiv><title>C Specification</title> |
| 20 | <funcsynopsis> |
| 21 | <funcprototype> |
| 22 | <funcdef>void <function>glGetInternalFormativ</function></funcdef> |
| 23 | <paramdef>GLenum <parameter>target</parameter></paramdef> |
| 24 | <paramdef>GLenum <parameter>internalformat</parameter></paramdef> |
| 25 | <paramdef>GLenum <parameter>pname</parameter></paramdef> |
| 26 | <paramdef>GLsizei <parameter>bufSize</parameter></paramdef> |
| 27 | <paramdef>GLint *<parameter>params</parameter></paramdef> |
| 28 | </funcprototype> |
| 29 | <funcprototype> |
| 30 | <funcdef>void <function>glGetInternalFormati64v</function></funcdef> |
| 31 | <paramdef>GLenum <parameter>target</parameter></paramdef> |
| 32 | <paramdef>GLenum <parameter>internalformat</parameter></paramdef> |
| 33 | <paramdef>GLenum <parameter>pname</parameter></paramdef> |
| 34 | <paramdef>GLsizei <parameter>bufSize</parameter></paramdef> |
| 35 | <paramdef>GLint64 *<parameter>params</parameter></paramdef> |
| 36 | </funcprototype> |
| 37 | </funcsynopsis> |
| 38 | </refsynopsisdiv> |
| 39 | <!-- eqn: ignoring delim $$ --> |
| 40 | <refsect1 id="parameters"><title>Parameters</title> |
| 41 | <variablelist> |
| 42 | <varlistentry> |
| 43 | <term><parameter>target</parameter></term> |
| 44 | <listitem> |
| 45 | <para> |
| 46 | Indicates the usage of the internal format. <parameter>target</parameter> must be <constant>GL_TEXTURE_1D</constant>, <constant>GL_TEXTURE_1D_ARRAY</constant>, |
| 47 | <constant>GL_TEXTURE_2D</constant>, <constant>GL_TEXTURE_2D_ARRAY</constant>, <constant>GL_TEXTURE_3D</constant>, |
| 48 | <constant>GL_TEXTURE_CUBE_MAP</constant>, <constant>GL_TEXTURE_CUBE_MAP_ARRAY</constant>, <constant>GL_TEXTURE_RECTANGLE</constant>, |
| 49 | <constant>GL_TEXTURE_BUFFER</constant>, |
| 50 | <constant>GL_RENDERBUFFER</constant>, <constant>GL_TEXTURE_2D_MULTISAMPLE</constant> or <constant>GL_TEXTURE_2D_MULTISAMPLE_ARRAY</constant>. |
| 51 | </para> |
| 52 | </listitem> |
| 53 | </varlistentry> |
| 54 | <varlistentry> |
| 55 | <term><parameter>internalformat</parameter></term> |
| 56 | <listitem> |
| 57 | <para> |
| 58 | Specifies the internal format about which to retrieve information. |
| 59 | </para> |
| 60 | </listitem> |
| 61 | </varlistentry> |
| 62 | <varlistentry> |
| 63 | <term><parameter>pname</parameter></term> |
| 64 | <listitem> |
| 65 | <para> |
| 66 | Specifies the type of information to query. |
| 67 | </para> |
| 68 | </listitem> |
| 69 | </varlistentry> |
| 70 | <varlistentry> |
| 71 | <term><parameter>bufSize</parameter></term> |
| 72 | <listitem> |
| 73 | <para> |
| 74 | Specifies the maximum number of basic machine units that may be written to <parameter>params</parameter> by the function. |
| 75 | </para> |
| 76 | </listitem> |
| 77 | </varlistentry> |
| 78 | <varlistentry> |
| 79 | <term><parameter>params</parameter></term> |
| 80 | <listitem> |
| 81 | <para> |
| 82 | Specifies the address of a variable into which to write the retrieved information. |
| 83 | </para> |
| 84 | </listitem> |
| 85 | </varlistentry> |
| 86 | </variablelist> |
| 87 | </refsect1> |
| 88 | <refsect1 id="description"><title>Description</title> |
| 89 | <para> |
| 90 | <function>glGetInternalFormativ</function> and <function>glGetInternalFormati64v</function> retrieve information about implementation-dependent support for |
| 91 | internal formats. <parameter>target</parameter> indicates the target with which the internal format will |
| 92 | be used and must be one of <constant>GL_RENDERBUFFER</constant>, <constant>GL_TEXTURE_2D_MULTISAMPLE</constant>, |
| 93 | or <constant>GL_TEXTURE_2D_MULTISAMPLE_ARRAY</constant>, corresponding to usage as a renderbuffer, two-dimensional |
| 94 | multisample texture or two-dimensional multisample array texture, respectively. |
| 95 | </para> |
| 96 | <para> |
| 97 | <parameter>internalformat</parameter> specifies the internal format about which to retrieve information and |
| 98 | must be a color-renderable, depth-renderable or stencil-renderable format. |
| 99 | </para> |
| 100 | <para> |
| 101 | The information retrieved will be written to memory addressed by the pointer specified in <parameter>params</parameter>. No |
| 102 | more than <parameter>bufSize</parameter> basic machine units will be written to this memory. |
| 103 | </para> |
| 104 | <para> |
| 105 | If <parameter>pname</parameter> is <constant>GL_NUM_SAMPLE_COUNTS</constant>, the number of sample counts that would be |
| 106 | returned by querying <constant>GL_SAMPLES</constant> will be returned in <parameter>params</parameter>. |
| 107 | </para> |
| 108 | <para> |
| 109 | If <parameter>pname</parameter> is <constant>GL_SAMPLES</constant>, the sample counts supported for <parameter>internalformat</parameter> |
| 110 | and <parameter>target</parameter> are written into <parameter>params</parameter> in descending numeric order. Only positive values are returned. |
| 111 | Querying <constant>GL_SAMPLES</constant> with <parameter>bufSize</parameter> of one will return just the maximum supported number of |
| 112 | samples for this format. The maximum value in <constant>GL_SAMPLES</constant> is guaranteed to be at least the lowest of the following: |
| 113 | <itemizedlist> |
| 114 | <listitem>The value of <constant>GL_MAX_INTEGER_SAMPLES</constant> if <parameter>internalformat</parameter> is a signed or unsigned integer format.</listitem> |
| 115 | <listitem>The value of <constant>GL_MAX_DEPTH_TEXTURE_SAMPLES</constant> if <parameter>internalformat</parameter> is a depth- or stencil-renderable format and |
| 116 | <parameter>target</parameter> is <constant>GL_TEXTURE_2D_MULTISAMPLE</constant>, <constant>GL_TEXTURE_2D_MULTISAMPLE_ARRAY</constant>.</listitem> |
| 117 | <listitem>The value of <constant>GL_MAX_COLOR_TEXTURE_SAMPLES</constant> if <parameter>internalformat</parameter> is a color-renderable format and |
| 118 | <parameter>target</parameter> is <constant>GL_TEXTURE_2D_MULTISAMPLE</constant> or <constant>GL_TEXTURE_2D_MULTISAMPLE_ARRAY</constant>.</listitem> |
| 119 | <listitem>The value of <constant>GL_MAX_SAMPLES</constant>.</listitem> |
| 120 | </itemizedlist> |
| 121 | </para> |
| 122 | <para> |
| 123 | If <parameter>pname</parameter> is <constant>GL_INTERNALFORMAT_SUPPORTED</constant>, <parameter>params</parameter> is set to <constant>GL_TRUE</constant> if <parameter>internalFormat</parameter> |
| 124 | is a supported internal format for <parameter>target</parameter> and to <constant>GL_FALSE</constant> otherwise. |
| 125 | </para> |
| 126 | <para> |
| 127 | If <parameter>pname</parameter> is <constant>GL_INTERNALFORMAT_PREFERRED</constant>, <parameter>params</parameter> is set to <constant>GL_TRUE</constant> if <parameter>internalFormat</parameter> |
| 128 | is an format for <parameter>target</parameter> that is preferred by the implementation and to <constant>GL_FALSE</constant> otherwise. |
| 129 | </para> |
| 130 | <para> |
| 131 | If <parameter>pname</parameter> is <constant>GL_INTERNALFORMAT_RED_SIZE</constant>, <constant>GL_INTERNALFORMAT_GREEN_SIZE</constant>, |
| 132 | <constant>GL_INTERNALFORMAT_BLUE_SIZE</constant>, <constant>GL_INTERNALFORMAT_ALPHA_SIZE</constant>, <constant>GL_INTERNALFORMAT_DEPTH_SIZE</constant>, |
| 133 | <constant>GL_INTERNALFORMAT_STENCIL_SIZE</constant>, or <constant>GL_INTERNALFORMAT_SHARED_SIZE</constant> then |
| 134 | <parameter>params</parameter> is set to the actual resolutions that would be used for storing image array components |
| 135 | for the resource for the red, green, blue, alpha, depth, stencil and shared channels respectively. If <parameter>internalFormat</parameter> |
| 136 | is a compressed internal format, then <parameter>params</parameter> is set to the component resolution of an uncompressed internal format that produces |
| 137 | an image of roughly the same quality as the compressed algorithm. If the internal format is unsupported, or if a particular component is |
| 138 | not present in the format, 0 is written to <parameter>params</parameter>. |
| 139 | </para> |
| 140 | <para> |
| 141 | If <parameter>pname</parameter> is <constant>GL_INTERNALFORMAT_RED_TYPE</constant>, <constant>GL_INTERNALFORMAT_GREEN_TYPE</constant>, |
| 142 | <constant>GL_INTERNALFORMAT_BLUE_TYPE</constant>, <constant>GL_INTERNALFORMAT_ALPHA_TYPE</constant>, <constant>GL_INTERNALFORMAT_DEPTH_TYPE</constant>, |
| 143 | or <constant>GL_INTERNALFORMAT_STENCIL_TYPE</constant> then <parameter>params</parameter> is set to a token identifying the data type used |
| 144 | to store the respective component. If the <parameter>internalFormat</parameter> represents a compressed internal format then |
| 145 | the types returned specify how components are interpreted after decompression. |
| 146 | </para> |
| 147 | <para> |
| 148 | If <parameter>pname</parameter> is <constant>GL_MAX_WIDTH</constant>, <constant>GL_MAX_HEIGHT</constant>, <constant>GL_MAX_DEPTH</constant>, |
| 149 | or <constant>GL_MAX_LAYERS</constant> then <parameter>pname</parameter> is filled with the maximum width, height, depth or layer count |
| 150 | for textures with internal format <parameter>internalFormat</parameter>, respectively. If <parameter>pname</parameter> is <constant>GL_MAX_COMBINED_DIMENSIONS</constant> |
| 151 | then <parameter>pname</parameter> is filled with the maximum combined dimensions of a texture of the specified internal format. |
| 152 | </para> |
| 153 | <para> |
| 154 | If <parameter>pname</parameter> is <constant>GL_COLOR_COMPONENTS</constant> then <parameter>params</parameter> is set to the value <constant>GL_TRUE</constant> |
| 155 | if the internal format contains any color component (i.e., red, green, blue or alpha) and to <constant>GL_FALSE</constant> otherwise. If |
| 156 | <parameter>pname</parameter> is <constant>GL_DEPTH_COMPONENTS</constant> or <constant>GL_STENCIL_COMPONENTS</constant> then <parameter>params</parameter> |
| 157 | is set to <constant>GL_TRUE</constant> if the internal format contains a depth or stencil component, respectively, and to <constant>GL_FALSE</constant> |
| 158 | otherwise. |
| 159 | </para> |
| 160 | <para> |
| 161 | If <parameter>pname</parameter> is <constant>GL_COLOR_RENDERABLE</constant>, <constant>GL_DEPTH_RENDERABLE</constant> or <constant>GL_STENCIL_RENDERABLE</constant> |
| 162 | then <parameter>params</parameter> is set to <constant>GL_TRUE</constant> if the specified internal format is color, depth or stencil renderable, respectively, |
| 163 | and to <constant>GL_FALSE</constant> otherwise. |
| 164 | </para> |
| 165 | <para> |
| 166 | If <parameter>pname</parameter> is <constant>GL_FRAMEBUFFER_RENDERABLE</constant> or <constant>GL_FRAMEBUFFER_RENDERABLE_LAYERED</constant> |
| 167 | then <parameter>params</parameter> is set to one of <constant>GL_FULL_SUPPORT</constant>, |
| 168 | <constant>GL_CAVEAT_SUPPORT</constant> or <constant>GL_NONE</constant> to indicate that framebuffer attachments (layered attachments in the |
| 169 | case of <constant>GL_FRAMEBUFFER_RENDERABLE_LAYERED</constant>) with that internal format are either |
| 170 | renderable with no restrictions, renderable with some restrictions or not renderable at all. |
| 171 | </para> |
| 172 | <para> |
| 173 | If <parameter>pname</parameter> is <constant>GL_FRAMEBUFFER_BLEND</constant>, <parameter>params</parameter> is set to <constant>GL_TRUE</constant> |
| 174 | to indicate that the internal format is supported for blending operations when attached to a framebuffer, and to <constant>GL_FALSE</constant> otherwise. |
| 175 | </para> |
| 176 | <para> |
| 177 | If <parameter>pname</parameter> is <constant>GL_READ_PIXELS</constant> then <parameter>params</parameter> is set to <constant>GL_FULL_SUPPORT</constant>, |
| 178 | <constant>GL_CAVEAT_SUPPORT</constant> or <constant>GL_NONE</constant> to that either full support, limited support or no support at all is supplied |
| 179 | for reading pixels from framebuffer attachments in the specified internal format. |
| 180 | </para> |
| 181 | <para> |
| 182 | If <parameter>pname</parameter> is <constant>GL_READ_PIXELS_FORMAT</constant> or <constant>GL_READ_PIXELS_TYPE</constant> then <parameter>params</parameter> |
| 183 | is filled with the format or type, respectively, most recommended to obtain the highest image quality and performance. For |
| 184 | <constant>GL_READ_PIXELS_FORMAT</constant>, the value returned in <parameter>params</parameter> is a token that is accepted for |
| 185 | the <parameter>format</parameter> argument to <citerefentry><refentrytitle>glReadPixels</refentrytitle></citerefentry>. For |
| 186 | <constant>GL_READ_PIXELS_TYPE</constant>, the value returned in <parameter>params</parameter> is a token that is accepted for |
| 187 | the <parameter>type</parameter> argument to <citerefentry><refentrytitle>glReadPixels</refentrytitle></citerefentry>. |
| 188 | </para> |
| 189 | <para> |
| 190 | If <parameter>pname</parameter> is <constant>GL_TEXTURE_IMAGE_FORMAT</constant> or <constant>GL_TEXTURE_IMAGE_TYPE</constant> then |
| 191 | <parameter>params</parameter> is filled with the implementation-recommended format or type to be used in calls to |
| 192 | <citerefentry><refentrytitle>glTexImage2D</refentrytitle></citerefentry> and other similar functions. For <constant>GL_TEXTURE_IMAGE_FORMAT</constant>, |
| 193 | <parameter>params</parameter> is filled with a token suitable for use as the <parameter>format</parameter> argument to |
| 194 | <citerefentry><refentrytitle>glTexImage2D</refentrytitle></citerefentry>. For <constant>GL_TEXTURE_IMAGE_TYPE</constant>, |
| 195 | <parameter>params</parameter> is filled with a token suitable for use as the <parameter>type</parameter> argument to |
| 196 | <citerefentry><refentrytitle>glTexImage2D</refentrytitle></citerefentry>. |
| 197 | </para> |
| 198 | <para> |
| 199 | If <parameter>pname</parameter> is <constant>GL_GET_TEXTURE_IMAGE_FORMAT</constant> or <constant>GL_GET_TEXTURE_IMAGE_TYPE</constant> then |
| 200 | <parameter>params</parameter> is filled with the implementation-recommended format or type to be used in calls to |
| 201 | <citerefentry><refentrytitle>glGetTexImage2D</refentrytitle></citerefentry> and other similar functions. For <constant>GL_GET_TEXTURE_IMAGE_FORMAT</constant>, |
| 202 | <parameter>params</parameter> is filled with a token suitable for use as the <parameter>format</parameter> argument to |
| 203 | <citerefentry><refentrytitle>glGetTexImage2D</refentrytitle></citerefentry>. For <constant>GL_GET_TEXTURE_IMAGE_TYPE</constant>, |
| 204 | <parameter>params</parameter> is filled with a token suitable for use as the <parameter>type</parameter> argument to |
| 205 | <citerefentry><refentrytitle>glGetTexImage2D</refentrytitle></citerefentry>. |
| 206 | </para> |
| 207 | <para> |
| 208 | If <parameter>pname</parameter> is <constant>GL_MIPMAP</constant> then <parameter>pname</parameter> is set to <constant>GL_TRUE</constant> |
| 209 | to indicate that the specified internal format supports mipmaps and to <constant>GL_FALSE</constant> otherwise. |
| 210 | </para> |
| 211 | <para> |
| 212 | If <parameter>pname</parameter> is <constant>GL_GENERATE_MIPMAP</constant> or <constant>GL_AUTO_GENERATE_MIPMAP</constant> then <parameter>params</parameter> |
| 213 | is indicates the level of support for manual or automatic mipmap generation for the specified internal format, respectively. Returned values |
| 214 | may be one of <constant>GL_FULL_SUPPORT</constant>, <constant>GL_CAVEAT_SUPPORT</constant> and <constant>GL_NONE</constant> to indicate |
| 215 | either full support, limited support or no support at all. |
| 216 | </para> |
| 217 | <para> |
| 218 | If <parameter>pname</parameter> is <constant>GL_COLOR_ENCODING</constant> then the color encoding for the resource is returned in |
| 219 | <parameter>params</parameter>. Possible values for color buffers are <constant>GL_LINEAR</constant> or <constant>GL_SRGB</constant>, |
| 220 | for linear or sRGB-encoded color components, respectively. For non-color |
| 221 | formats (such as depth or stencil), or for unsupported resources, |
| 222 | the value <constant>GL_NONE</constant> is returned. |
| 223 | </para> |
| 224 | <para> |
| 225 | If <parameter>pname</parameter> is <constant>GL_SRGB_READ</constant>, or <constant>GL_SRGB_WRITE</constant> then <parameter>params</parameter> |
| 226 | indicates the level of support for reading and writing to sRGB encoded images, respectively. For <constant>GL_SRGB_READ</constant>, |
| 227 | support for converting from sRGB colorspace on read operations is returned in <parameter>params</parameter> and for <constant>GL_SRGB_WRITE</constant>, |
| 228 | support for converting to sRGB colorspace on write operations to the resource is returned in <parameter>params</parameter>. <parameter>params</parameter> may be |
| 229 | set to <constant>GL_FULL_SUPPORT</constant>, <constant>GL_CAVEAT_SUPPORT</constant>, or <constant>GL_NONE</constant> to indicate |
| 230 | full support, limited support or no support at all, respecitively. |
| 231 | </para> |
| 232 | <para> |
| 233 | If <parameter>pname</parameter> is <constant>GL_FILTER</constant> the <parameter>params</parameter> is set to either <constant>GL_TRUE</constant> |
| 234 | or <constant>GL_FALSE</constant> to indicate support or lack thereof for filter modes other than <constant>GL_NEAREST</constant> or <constant>GL_NEAREST_MIPMAP</constant> |
| 235 | for the specified internal format. |
| 236 | </para> |
| 237 | <para> |
| 238 | If <parameter>pname</parameter> is <constant>GL_VERTEX_TEXTURE</constant>, <constant>GL_TESS_CONTROL_TEXTURE</constant>, <constant>GL_TESS_EVALUATION_TEXTURE</constant>, |
| 239 | <constant>GL_GEOMETRY_TEXTURE</constant>, <constant>GL_FRAGMENT_TEXTURE</constant>, or <constant>GL_COMPUTE_TEXTURE</constant>, then the value |
| 240 | written to <parameter>params</parameter> indicates support for use of the resource as a source of texturing in the vertex, tessellation control, |
| 241 | tessellation evaluation, geometry, fragment and compute shader stages, respectively. <parameter>params</parameter> may be set to |
| 242 | <constant>GL_FULL_SUPPORT</constant>, <constant>GL_CAVEAT_SUPPORT</constant> or <constant>GL_NONE</constant> to indicate full support, |
| 243 | limited support or no support at all, respectively. |
| 244 | </para> |
| 245 | <para> |
| 246 | If <parameter>pname</parameter> is <constant>GL_TEXTURE_SHADOW</constant>, <constant>GL_TEXTURE_GATHER</constant> or <constant>GL_TEXTURE_GATHER_SHADOW</constant> then the value written to |
| 247 | <parameter>params</parameter> indicates the level of support for using the resource with a shadow sampler, in gather operations or as a shadow sampler in gather operations, respectively. Returned values |
| 248 | may be <constant>GL_FULL_SUPPORT</constant>, <constant>GL_CAVEAT_SUPPORT</constant> or <constant>GL_NONE</constant> to indicate full support, |
| 249 | limited support or no support at all, respectively. |
| 250 | </para> |
| 251 | <para> |
| 252 | If <parameter>pname</parameter> is <constant>GL_SHADER_IMAGE_LOAD</constant>, <constant>GL_SHADER_IMAGE_STORE</constant> or <constant>GL_SHADER_IMAGE_ATOMIC</constant> |
| 253 | then the value returned in <parameter>params</parameter> indicates the level of support for image loads, stores and atomics for resources of the specified internal |
| 254 | format. Returned values |
| 255 | may be <constant>GL_FULL_SUPPORT</constant>, <constant>GL_CAVEAT_SUPPORT</constant> or <constant>GL_NONE</constant> to indicate full support, |
| 256 | limited support or no support at all, respectively. |
| 257 | </para> |
| 258 | <para> |
| 259 | If <parameter>pname</parameter> is <constant>GL_IMAGE_TEXEL_SIZE</constant> then the size of a texel when the resource when used as |
| 260 | an image texture is returned in <parameter>params</parameter>. If the resource is not supported for image |
| 261 | textures zero is returned. |
| 262 | </para> |
| 263 | <para> |
| 264 | If <parameter>pname</parameter> is <constant>GL_IMAGE_COMPATIBILITY_CLASS</constant> then the compatibility class of the resource when |
| 265 | used as an image texture is returned in <parameter>params</parameter>. The possible values |
| 266 | returned are <constant>GL_IMAGE_CLASS_4_X_32</constant>, <constant>GL_IMAGE_CLASS_2_X_32</constant>, <constant>GL_IMAGE_CLASS_1_X_32</constant>, |
| 267 | <constant>GL_IMAGE_CLASS_4_X_16</constant>, <constant>GL_IMAGE_CLASS_2_X_16</constant>, <constant>GL_IMAGE_CLASS_1_X_16</constant>, |
| 268 | <constant>GL_IMAGE_CLASS_4_X_8</constant>, <constant>GL_IMAGE_CLASS_2_X_8</constant>, <constant>GL_IMAGE_CLASS_1_X_8</constant>, |
| 269 | <constant>GL_IMAGE_CLASS_11_11_10</constant>, and <constant>GL_IMAGE_CLASS_10_10_10_2</constant>, which correspond to |
| 270 | the 4x32, 2x32, 1x32, 4x16, 2x16, 1x16, 4x8, 2x8, 1x8, the class |
| 271 | (a) 11/11/10 packed floating-point format, and the class (b) |
| 272 | 10/10/10/2 packed formats, respectively. |
| 273 | If the resource is not supported for image textures, <constant>GL_NONE</constant> is returned. |
| 274 | </para> |
| 275 | <para> |
| 276 | If <parameter>pname</parameter> is <constant>GL_IMAGE_PIXEL_FORMAT</constant> or <constant>GL_IMAGE_PIXEL_TYPE</constant> then |
| 277 | the pixel format or type of the resource when used as an image texture is returned in <parameter>params</parameter>, respectively. |
| 278 | In either case, the resource is not supported for image textures <constant>GL_NONE</constant> is returned. |
| 279 | </para> |
| 280 | <para> |
| 281 | If <parameter>pname</parameter> is <constant>GL_IMAGE_FORMAT_COMPATIBILITY_TYPE</constant>, the matching criteria use for the |
| 282 | resource when used as an image textures is returned in <parameter>params</parameter>. Possible values returned in <parameter>params</parameter> are |
| 283 | <constant>GL_IMAGE_FORMAT_COMPATIBILITY_BY_SIZE</constant> or <constant>GL_IMAGE_FORMAT_COMPATIBILITY_BY_CLASS</constant>. |
| 284 | If the resource is not supported for image textures, <constant>GL_NONE</constant> is returned. |
| 285 | </para> |
| 286 | <para> |
| 287 | If <parameter>pname</parameter> is <constant>GL_SIMULTANEOUS_TEXTURE_AND_DEPTH_TEST</constant> or <constant>GL_SIMULTANEOUS_TEXTURE_AND_STENCIL_TEST</constant>, |
| 288 | support for using the resource both as a source for texture sampling while it is bound as a buffer for depth or stencil test, respectively, is written to <parameter>params</parameter>. |
| 289 | Possible values returned are <constant>GL_FULL_SUPPORT</constant>, <constant>GL_CAVEAT_SUPPORT</constant>, or <constant>GL_NONE</constant> to indicate |
| 290 | full support, limited support or no support at all. If the resource or operation is not supported, <constant>GL_NONE</constant> is returned. |
| 291 | </para> |
| 292 | <para> |
| 293 | If <parameter>pname</parameter> is <constant>GL_SIMULTANEOUS_TEXTURE_AND_DEPTH_WRITE</constant> or <constant>GL_SIMULTANEOUS_TEXTURE_AND_STENCIL_WRITE</constant>, |
| 294 | support for using the resource both as a source for texture sampling while performing depth or stencil writes to the resources, respectively, is written to <parameter>params</parameter>. |
| 295 | Possible values returned are <constant>GL_FULL_SUPPORT</constant>, <constant>GL_CAVEAT_SUPPORT</constant>, or <constant>GL_NONE</constant> to indicate |
| 296 | full support, limited support or no support at all. If the resource or operation is not supported, <constant>GL_NONE</constant> is returned. |
| 297 | </para> |
| 298 | <para> |
| 299 | If <parameter>pname</parameter> is <constant>GL_TEXTURE_COMPRESSED</constant> then <constant>GL_TRUE</constant> is returned in <parameter>params</parameter> |
| 300 | if <parameter>internalformat</parameter> is a compressed internal format. <constant>GL_FALSE</constant> is returned in <parameter>params</parameter> |
| 301 | otherwise. |
| 302 | </para> |
| 303 | <para> |
| 304 | If <parameter>pname</parameter> is <constant>GL_TEXTURE_COMPRESSED_BLOCK_WIDTH</constant>, <constant>GL_TEXTURE_COMPRESSED_BLOCK_HEIGHT</constant> or |
| 305 | <constant>GL_TEXTURE_COMPRESSED_BLOCK_SIZE</constant> then the width, height or total size, respectively of a block (in basic machine units) is returned in |
| 306 | <parameter>params</parameter>. If the internal format is not compressed, or the resource is not supported, 0 is returned. |
| 307 | </para> |
| 308 | <para> |
| 309 | If <parameter>pname</parameter> is <constant>GL_CLEAR_BUFFER</constant>, the level of support for using the resource with <citerefentry><refentrytitle>glClearBufferData</refentrytitle></citerefentry> |
| 310 | and <citerefentry><refentrytitle>glClearBufferSubData</refentrytitle></citerefentry> is returned in <parameter>params</parameter>. Possible values returned are <constant>GL_FULL_SUPPORT</constant>, |
| 311 | <constant>GL_CAVEAT_SUPPORT</constant>, or <constant>GL_NONE</constant> to indicate |
| 312 | full support, limited support or no support at all, respectively. If the resource or operation is not supported, <constant>GL_NONE</constant> is returned. |
| 313 | </para> |
| 314 | <para> |
| 315 | If <parameter>pname</parameter> is <constant>GL_TEXTURE_VIEW</constant>, the level of support for using the resource with the <citerefentry><refentrytitle>glTextureView</refentrytitle></citerefentry> |
| 316 | command is returned in <parameter>params</parameter>. Possible values returned are <constant>GL_FULL_SUPPORT</constant>, |
| 317 | <constant>GL_CAVEAT_SUPPORT</constant>, or <constant>GL_NONE</constant> to indicate |
| 318 | full support, limited support or no support at all, respectively. If the resource or operation is not supported, <constant>GL_NONE</constant> is returned. |
| 319 | </para> |
| 320 | <para> |
| 321 | If <parameter>pname</parameter> is <constant>GL_VIEW_COMPATIBILITY_CLASS</constant> then the compatibility class of the resource when |
| 322 | used as a texture view is returned in <parameter>params</parameter>. The possible values |
| 323 | returned are <constant>GL_VIEW_CLASS_128_BITS</constant>, <constant>GL_VIEW_CLASS_96_BITS</constant>, |
| 324 | <constant>GL_VIEW_CLASS_64_BITS</constant>, <constant>GL_VIEW_CLASS_48_BITS</constant>, <constant>GL_VIEW_CLASS_32_BITS</constant>, |
| 325 | <constant>GL_VIEW_CLASS_24_BITS</constant>, <constant>GL_VIEW_CLASS_16_BITS</constant>, <constant>GL_VIEW_CLASS_8_BITS</constant>, |
| 326 | <constant>GL_VIEW_CLASS_S3TC_DXT1_RGB</constant>, <constant>GL_VIEW_CLASS_S3TC_DXT1_RGBA</constant>, |
| 327 | <constant>GL_VIEW_CLASS_S3TC_DXT3_RGBA</constant>, <constant>GL_VIEW_CLASS_S3TC_DXT5_RGBA</constant>, |
| 328 | <constant>GL_VIEW_CLASS_RGTC1_RED</constant>, <constant>GL_VIEW_CLASS_RGTC2_RG</constant>, <constant>GL_VIEW_CLASS_BPTC_UNORM</constant>, and |
| 329 | <constant>GL_VIEW_CLASS_BPTC_FLOAT</constant>. |
| 330 | </para> |
| 331 | </refsect1> |
| 332 | <refsect1 id="notes"><title>Notes</title> |
| 333 | <para> |
| 334 | <function>glGetInternalFormativ</function> is available only if the |
| 335 | GL version is 4.2 or higher. |
| 336 | </para> |
| 337 | <para> |
| 338 | The tokens |
| 339 | <constant>GL_INTERNALFORMAT_SUPPORTED</constant>, |
| 340 | <constant>GL_INTERNALFORMAT_PREFERRED</constant>, |
| 341 | <constant>GL_INTERNALFORMAT_RED_SIZE</constant>, |
| 342 | <constant>GL_INTERNALFORMAT_GREEN_SIZE</constant>, |
| 343 | <constant>GL_INTERNALFORMAT_BLUE_SIZE</constant>, |
| 344 | <constant>GL_INTERNALFORMAT_ALPHA_SIZE</constant>, |
| 345 | <constant>GL_INTERNALFORMAT_DEPTH_SIZE</constant>, |
| 346 | <constant>GL_INTERNALFORMAT_STENCIL_SIZE</constant>, |
| 347 | <constant>GL_INTERNALFORMAT_SHARED_SIZE</constant>, |
| 348 | <constant>GL_INTERNALFORMAT_RED_TYPE</constant>, |
| 349 | <constant>GL_INTERNALFORMAT_GREEN_TYPE</constant>, |
| 350 | <constant>GL_INTERNALFORMAT_BLUE_TYPE</constant>, |
| 351 | <constant>GL_INTERNALFORMAT_ALPHA_TYPE</constant>, |
| 352 | <constant>GL_INTERNALFORMAT_DEPTH_TYPE</constant>, |
| 353 | <constant>GL_INTERNALFORMAT_STENCIL_TYPE</constant>, |
| 354 | <constant>GL_MAX_WIDTH</constant>, |
| 355 | <constant>GL_MAX_HEIGHT</constant>, |
| 356 | <constant>GL_MAX_DEPTH</constant>, |
| 357 | <constant>GL_MAX_LAYERS</constant>, |
| 358 | <constant>GL_MAX_COMBINED_DIMENSIONS</constant>, |
| 359 | <constant>GL_COLOR_COMPONENTS</constant>, |
| 360 | <constant>GL_DEPTH_COMPONENTS</constant>, |
| 361 | <constant>GL_STENCIL_COMPONENTS</constant>, |
| 362 | <constant>GL_COLOR_RENDERABLE</constant>, |
| 363 | <constant>GL_DEPTH_RENDERABLE</constant>, |
| 364 | <constant>GL_STENCIL_RENDERABLE</constant>, |
| 365 | <constant>GL_FRAMEBUFFER_RENDERABLE</constant>, |
| 366 | <constant>GL_FRAMEBUFFER_RENDERABLE_LAYERED</constant>, |
| 367 | <constant>GL_FRAMEBUFFER_BLEND</constant>, |
| 368 | <constant>GL_READ_PIXELS</constant>, |
| 369 | <constant>GL_READ_PIXELS_FORMAT</constant>, |
| 370 | <constant>GL_READ_PIXELS_TYPE</constant>, |
| 371 | <constant>GL_TEXTURE_IMAGE_FORMAT</constant>, |
| 372 | <constant>GL_TEXTURE_IMAGE_TYPE</constant>, |
| 373 | <constant>GL_GET_TEXTURE_IMAGE_FORMAT</constant>, |
| 374 | <constant>GL_GET_TEXTURE_IMAGE_TYPE</constant>, |
| 375 | <constant>GL_MIPMAP</constant>, |
| 376 | <constant>GL_GENERATE_MIPMAP</constant>, |
| 377 | <constant>GL_AUTO_GENERATE_MIPMAP</constant>, |
| 378 | <constant>GL_COLOR_ENCODING</constant>, |
| 379 | <constant>GL_SRGB_READ</constant>, |
| 380 | <constant>GL_SRGB_WRITE</constant>, |
| 381 | <constant>GL_SRGB_DECODE_ARB</constant>, |
| 382 | <constant>GL_FILTER</constant>, |
| 383 | <constant>GL_VERTEX_TEXTURE</constant>, |
| 384 | <constant>GL_TESS_CONTROL_TEXTURE</constant>, |
| 385 | <constant>GL_TESS_EVALUATION_TEXTURE</constant>, |
| 386 | <constant>GL_GEOMETRY_TEXTURE</constant>, |
| 387 | <constant>GL_FRAGMENT_TEXTURE</constant>, |
| 388 | <constant>GL_COMPUTE_TEXTURE</constant>, |
| 389 | <constant>GL_TEXTURE_SHADOW</constant>, |
| 390 | <constant>GL_TEXTURE_GATHER</constant>, |
| 391 | <constant>GL_TEXTURE_GATHER_SHADOW</constant>, |
| 392 | <constant>GL_SHADER_IMAGE_LOAD</constant>, |
| 393 | <constant>GL_SHADER_IMAGE_STORE</constant>, |
| 394 | <constant>GL_SHADER_IMAGE_ATOMIC</constant>, |
| 395 | <constant>GL_IMAGE_TEXEL_SIZE</constant>, |
| 396 | <constant>GL_IMAGE_COMPATIBILITY_CLASS</constant>, |
| 397 | <constant>GL_IMAGE_PIXEL_FORMAT</constant>, |
| 398 | <constant>GL_IMAGE_PIXEL_TYPE</constant>, |
| 399 | <constant>GL_IMAGE_FORMAT_COMPATIBILITY_TYPE</constant>, |
| 400 | <constant>GL_SIMULTANEOUS_TEXTURE_AND_DEPTH_TEST</constant>, |
| 401 | <constant>GL_SIMULTANEOUS_TEXTURE_AND_STENCIL_TEST</constant>, |
| 402 | <constant>GL_SIMULTANEOUS_TEXTURE_AND_DEPTH_WRITE</constant>, |
| 403 | <constant>GL_SIMULTANEOUS_TEXTURE_AND_STENCIL_WRITE</constant>, |
| 404 | <constant>GL_TEXTURE_COMPRESSED</constant>, |
| 405 | <constant>GL_TEXTURE_COMPRESSED_BLOCK_WIDTH</constant>, |
| 406 | <constant>GL_TEXTURE_COMPRESSED_BLOCK_HEIGHT</constant>, |
| 407 | <constant>GL_TEXTURE_COMPRESSED_BLOCK_SIZE</constant>, |
| 408 | <constant>GL_CLEAR_BUFFER</constant>, |
| 409 | <constant>GL_TEXTURE_VIEW</constant>, and |
| 410 | <constant>GL_VIEW_COMPATIBILITY_CLASS</constant> are supported only if the GL |
| 411 | version is 4.3 or higher. |
| 412 | </para> |
| 413 | </refsect1> |
| 414 | <refsect1 id="errors"><title>Errors</title> |
| 415 | <para> |
| 416 | <constant>GL_INVALID_VALUE</constant> is generated if <parameter>bufSize</parameter> is negative. |
| 417 | </para> |
| 418 | <para> |
| 419 | <constant>GL_INVALID_ENUM</constant> is generated if <parameter>pname</parameter> is not <constant>GL_SAMPLES</constant> or <constant>GL_NUM_SAMPLE_COUNTS</constant>. |
| 420 | </para> |
| 421 | <para> |
| 422 | <constant>GL_INVALID_ENUM</constant> is generated if <parameter>internalformat</parameter> is not color-, depth-, or stencil-renderable. |
| 423 | </para> |
| 424 | <para> |
| 425 | <constant>GL_INVALID_ENUM</constant> is generated if <parameter>target</parameter> is not one of <constant>GL_TEXTURE_2D_MULTISAMPLE</constant>, |
| 426 | <constant>GL_TEXTURE_2D_MULTISAMPLE_ARRAY</constant> or <constant>GL_RENDERBUFFER</constant>. |
| 427 | </para> |
| 428 | </refsect1> |
| 429 | <refsect1 id="seealso"><title>See Also</title> |
| 430 | <para> |
| 431 | <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> |
| 432 | </para> |
| 433 | </refsect1> |
| 434 | <refsect1 id="Copyright"><title>Copyright</title> |
| 435 | <para> |
| 436 | Copyright <trademark class="copyright"></trademark> 2011-2012 Khronos Group. |
| 437 | This material may be distributed subject to the terms and conditions set forth in |
| 438 | the Open Publication License, v 1.0, 8 June 1999. |
| 439 | <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>. |
| 440 | </para> |
| 441 | </refsect1> |
| 442 | </refentry> |