| 1 | <?xml version="1.0" encoding="UTF-8"?> |
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| 4 | <?xml-stylesheet type="text/xsl" href="mathml.xsl"?><html xmlns="http://www.w3.org/1999/xhtml" xmlns:pref="http://www.w3.org/2002/Math/preference" pref:renderer="mathplayer-dl"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><link rel="stylesheet" type="text/css" href="opengl-man.css" /><title>glBufferData</title><meta name="generator" content="DocBook XSL Stylesheets V1.69.1" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glBufferData"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glBufferData — creates and initializes a buffer object's data store</p></div><div class="refsynopsisdiv"><h2>C Specification</h2><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">void <b class="fsfunc">glBufferData</b>(</code></td><td>GLenum </td><td><var class="pdparam">target</var>, </td></tr><tr><td> </td><td>GLsizeiptr </td><td><var class="pdparam">size</var>, </td></tr><tr><td> </td><td>const GLvoid * </td><td><var class="pdparam">data</var>, </td></tr><tr><td> </td><td>GLenum </td><td><var class="pdparam">usage</var><code>)</code>;</td></tr></table></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="parameters"></a><h2>Parameters</h2><div class="variablelist"><dl><dt><span class="term"><em class="parameter"><code>target</code></em></span></dt><dd><p> |
| 5 | Specifies the target buffer object. |
| 6 | The symbolic constant must be <code class="constant">GL_ARRAY_BUFFER</code>, |
| 7 | <code class="constant">GL_COPY_READ_BUFFER</code>, |
| 8 | <code class="constant">GL_COPY_WRITE_BUFFER</code>, |
| 9 | <code class="constant">GL_ELEMENT_ARRAY_BUFFER</code>, |
| 10 | <code class="constant">GL_PIXEL_PACK_BUFFER</code>, |
| 11 | <code class="constant">GL_PIXEL_UNPACK_BUFFER</code>, |
| 12 | <code class="constant">GL_TEXTURE_BUFFER</code>, |
| 13 | <code class="constant">GL_TRANSFORM_FEEDBACK_BUFFER</code>, or |
| 14 | <code class="constant">GL_UNIFORM_BUFFER</code>. |
| 15 | </p></dd><dt><span class="term"><em class="parameter"><code>size</code></em></span></dt><dd><p> |
| 16 | Specifies the size in bytes of the buffer object's new data store. |
| 17 | </p></dd><dt><span class="term"><em class="parameter"><code>data</code></em></span></dt><dd><p> |
| 18 | Specifies a pointer to data that will be copied into the data store for initialization, |
| 19 | or <code class="constant">NULL</code> if no data is to be copied. |
| 20 | </p></dd><dt><span class="term"><em class="parameter"><code>usage</code></em></span></dt><dd><p> |
| 21 | Specifies the expected usage pattern of the data store. The symbolic constant must be |
| 22 | <code class="constant">GL_STREAM_DRAW</code>, <code class="constant">GL_STREAM_READ</code>, <code class="constant">GL_STREAM_COPY</code>, |
| 23 | <code class="constant">GL_STATIC_DRAW</code>, <code class="constant">GL_STATIC_READ</code>, <code class="constant">GL_STATIC_COPY</code>, |
| 24 | <code class="constant">GL_DYNAMIC_DRAW</code>, <code class="constant">GL_DYNAMIC_READ</code>, or <code class="constant">GL_DYNAMIC_COPY</code>. |
| 25 | </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p> |
| 26 | <code class="function">glBufferData</code> creates a new data store for the buffer object currently bound to |
| 27 | <em class="parameter"><code>target</code></em>. Any pre-existing data store is deleted. The new data store is created with the |
| 28 | specified <em class="parameter"><code>size</code></em> in bytes and <em class="parameter"><code>usage</code></em>. If <em class="parameter"><code>data</code></em> |
| 29 | is not <code class="constant">NULL</code>, the data store is initialized with data from this pointer. In its initial |
| 30 | state, the new data store is not mapped, it has a <code class="constant">NULL</code> mapped pointer, and its mapped access |
| 31 | is <code class="constant">GL_READ_WRITE</code>. |
| 32 | </p><p> |
| 33 | <em class="parameter"><code>usage</code></em> is a hint to the GL implementation as to how a buffer object's data store will be |
| 34 | accessed. This enables the GL implementation to make more intelligent decisions that may significantly |
| 35 | impact buffer object performance. It does not, however, constrain the actual usage of the data store. |
| 36 | <em class="parameter"><code>usage</code></em> can be broken down into two parts: first, the frequency of access (modification |
| 37 | and usage), and second, the nature of that access. The frequency of access may be one of these: |
| 38 | </p><div class="variablelist"><dl><dt><span class="term">STREAM</span></dt><dd><p> |
| 39 | The data store contents will be modified once and used at most a few times. |
| 40 | </p></dd><dt><span class="term">STATIC</span></dt><dd><p> |
| 41 | The data store contents will be modified once and used many times. |
| 42 | </p></dd><dt><span class="term">DYNAMIC</span></dt><dd><p> |
| 43 | The data store contents will be modified repeatedly and used many times. |
| 44 | </p></dd></dl></div><p> |
| 45 | The nature of access may be one of these: |
| 46 | </p><div class="variablelist"><dl><dt><span class="term">DRAW</span></dt><dd><p> |
| 47 | The data store contents are modified by the application, and used as the source for GL drawing and |
| 48 | image specification commands. |
| 49 | </p></dd><dt><span class="term">READ</span></dt><dd><p> |
| 50 | The data store contents are modified by reading data from the GL, and used to return that data |
| 51 | when queried by the application. |
| 52 | </p></dd><dt><span class="term">COPY</span></dt><dd><p> |
| 53 | The data store contents are modified by reading data from the GL, and used as the source for GL |
| 54 | drawing and image specification commands. |
| 55 | </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p> |
| 56 | If <em class="parameter"><code>data</code></em> is <code class="constant">NULL</code>, a data store of the specified size is still created, |
| 57 | but its contents remain uninitialized and thus undefined. |
| 58 | </p><p> |
| 59 | Clients must align data elements consistent with the requirements of the client |
| 60 | platform, with an additional base-level requirement that an offset within a buffer to |
| 61 | a datum comprising <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">N</mml:mi> bytes be a |
| 62 | multiple of <mml:mi mathvariant="italic">N</mml:mi></mml:math>. |
| 63 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p> |
| 64 | <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>target</code></em> is not |
| 65 | one of the accepted buffer targets. |
| 66 | </p><p> |
| 67 | <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>usage</code></em> is not |
| 68 | <code class="constant">GL_STREAM_DRAW</code>, <code class="constant">GL_STREAM_READ</code>, <code class="constant">GL_STREAM_COPY</code>, |
| 69 | <code class="constant">GL_STATIC_DRAW</code>, <code class="constant">GL_STATIC_READ</code>, <code class="constant">GL_STATIC_COPY</code>, |
| 70 | <code class="constant">GL_DYNAMIC_DRAW</code>, <code class="constant">GL_DYNAMIC_READ</code>, or <code class="constant">GL_DYNAMIC_COPY</code>. |
| 71 | </p><p> |
| 72 | <code class="constant">GL_INVALID_VALUE</code> is generated if <em class="parameter"><code>size</code></em> is negative. |
| 73 | </p><p> |
| 74 | <code class="constant">GL_INVALID_OPERATION</code> is generated if the reserved buffer object name 0 is bound to <em class="parameter"><code>target</code></em>. |
| 75 | </p><p> |
| 76 | <code class="constant">GL_OUT_OF_MEMORY</code> is generated if the GL is unable to create a data store with the specified <em class="parameter"><code>size</code></em>. |
| 77 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="associatedgets"></a><h2>Associated Gets</h2><p> |
| 78 | <a href="glGetBufferSubData.xml"><span class="citerefentry"><span class="refentrytitle">glGetBufferSubData</span></span></a> |
| 79 | </p><p> |
| 80 | <a href="glGetBufferParameter.xml"><span class="citerefentry"><span class="refentrytitle">glGetBufferParameter</span></span></a> with argument <code class="constant">GL_BUFFER_SIZE</code> or <code class="constant">GL_BUFFER_USAGE</code> |
| 81 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p> |
| 82 | <a href="glBindBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glBindBuffer</span></span></a>, |
| 83 | <a href="glBufferSubData.xml"><span class="citerefentry"><span class="refentrytitle">glBufferSubData</span></span></a>, |
| 84 | <a href="glMapBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glMapBuffer</span></span></a>, |
| 85 | <a href="glUnmapBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glUnmapBuffer</span></span></a> |
| 86 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p> |
| 87 | Copyright <span class="trademark"></span>© 2005 Addison-Wesley. |
| 88 | This material may be distributed subject to the terms and conditions set forth in |
| 89 | the Open Publication License, v 1.0, 8 June 1999. |
| 90 | <a href="http://opencontent.org/openpub/" target="_top">http://opencontent.org/openpub/</a>. |
| 91 | </p></div></div></body></html> |