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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="glValidateProgram"> | |
5 | <refmeta> | |
6 | <refentrytitle>glValidateProgram</refentrytitle> | |
7 | <manvolnum>3G</manvolnum> | |
8 | </refmeta> | |
9 | <refnamediv> | |
10 | <refname>glValidateProgram</refname> | |
11 | <refpurpose>Validates a program object</refpurpose> | |
12 | </refnamediv> | |
13 | <refsynopsisdiv><title>C Specification</title> | |
14 | <funcsynopsis> | |
15 | <funcprototype> | |
16 | <funcdef>void <function>glValidateProgram</function></funcdef> | |
17 | <paramdef>GLuint <parameter>program</parameter></paramdef> | |
18 | </funcprototype> | |
19 | </funcsynopsis> | |
20 | </refsynopsisdiv> | |
21 | <refsect1 id="parameters"><title>Parameters</title> | |
22 | <variablelist> | |
23 | <varlistentry> | |
24 | <term><parameter>program</parameter></term> | |
25 | <listitem> | |
26 | <para>Specifies the handle of the program object to | |
27 | be validated.</para> | |
28 | </listitem> | |
29 | </varlistentry> | |
30 | </variablelist> | |
31 | </refsect1> | |
32 | <refsect1 id="description"><title>Description</title> | |
33 | <para><function>glValidateProgram</function> checks to see | |
34 | whether the executables contained in | |
35 | <parameter>program</parameter> can execute given the current | |
36 | OpenGL state. The information generated by the validation | |
37 | process will be stored in <parameter>program</parameter>'s | |
38 | information log. The validation information may consist of an | |
39 | empty string, or it may be a string containing information about | |
40 | how the current program object interacts with the rest of | |
41 | current OpenGL state. This provides a way for OpenGL | |
42 | implementers to convey more information about why the current | |
43 | program is inefficient, suboptimal, failing to execute, and so | |
44 | on.</para> | |
45 | ||
46 | <para>The status of the validation operation will be stored as | |
47 | part of the program object's state. This value will be set to | |
48 | <constant>GL_TRUE</constant> if the validation succeeded, and | |
49 | <constant>GL_FALSE</constant> otherwise. It can be queried by | |
50 | calling | |
51 | <citerefentry><refentrytitle>glGetProgram</refentrytitle></citerefentry> | |
52 | with arguments <parameter>program</parameter> and | |
53 | <constant>GL_VALIDATE_STATUS</constant>. If validation is | |
54 | successful, <parameter>program</parameter> is guaranteed to | |
55 | execute given the current state. Otherwise, | |
56 | <parameter>program</parameter> is guaranteed to not execute.</para> | |
57 | ||
58 | <para>This function is typically useful only during application | |
59 | development. The informational string stored in the information | |
60 | log is completely implementation dependent; therefore, an | |
61 | application should not expect different OpenGL implementations | |
62 | to produce identical information strings.</para> | |
63 | </refsect1> | |
64 | <refsect1 id="notes"><title>Notes</title> | |
65 | <para><function>glValidateProgram</function> is available only | |
66 | if the GL version is 2.0 or greater.</para> | |
67 | ||
68 | <para>This function mimics the validation operation that OpenGL | |
69 | implementations must perform when rendering commands are issued | |
70 | while programmable shaders are part of current state. The error | |
71 | <constant>GL_INVALID_OPERATION</constant> will be generated by | |
72 | <citerefentry><refentrytitle>glBegin</refentrytitle></citerefentry>, | |
73 | <citerefentry><refentrytitle>glRasterPos</refentrytitle></citerefentry>, | |
74 | or any command that performs an implicit call to | |
75 | <citerefentry><refentrytitle>glBegin</refentrytitle></citerefentry> | |
76 | if:</para> | |
77 | ||
78 | <itemizedlist> | |
79 | <listitem> | |
80 | <para>any two active samplers in the current program | |
81 | object are of different types, but refer to the same | |
82 | texture image unit,</para> | |
83 | </listitem> | |
84 | <listitem> | |
85 | <para>any active sampler in the current program object | |
86 | refers to a texture image unit where fixed-function | |
87 | fragment processing accesses a texture target that does | |
88 | not match the sampler type, or</para> | |
89 | </listitem> | |
90 | <listitem> | |
91 | <para>the sum of the number of active samplers in the | |
92 | program and the number of texture image units enabled | |
93 | for fixed-function fragment processing exceeds the | |
94 | combined limit on the total number of texture image | |
95 | units allowed.</para> | |
96 | </listitem> | |
97 | </itemizedlist> | |
98 | ||
99 | <para>It may be difficult or cause a performance degradation for | |
100 | applications to catch these errors when rendering commands are | |
101 | issued. Therefore, applications are advised to make calls to | |
102 | <function>glValidateProgram</function> to detect these issues | |
103 | during application development.</para> | |
104 | </refsect1> | |
105 | <refsect1 id="errors"><title>Errors</title> | |
106 | <para><constant>GL_INVALID_VALUE</constant> is generated if | |
107 | <parameter>program</parameter> is not a value generated by | |
108 | OpenGL.</para> | |
109 | ||
110 | <para><constant>GL_INVALID_OPERATION</constant> is generated if | |
111 | <parameter>program</parameter> is not a program object.</para> | |
112 | ||
113 | <para><constant>GL_INVALID_OPERATION</constant> is generated if | |
114 | <function>glValidateProgram</function> is executed between the | |
115 | execution of | |
116 | <citerefentry><refentrytitle>glBegin</refentrytitle></citerefentry> | |
117 | and the corresponding execution of | |
118 | <citerefentry><refentrytitle>glEnd</refentrytitle></citerefentry>.</para> | |
119 | </refsect1> | |
120 | <refsect1 id="associatedgets"><title>Associated Gets</title> | |
121 | <para><citerefentry><refentrytitle>glGetProgram</refentrytitle></citerefentry> | |
122 | with arguments <parameter>program</parameter> and | |
123 | <constant>GL_VALIDATE_STATUS</constant></para> | |
124 | ||
125 | <para><citerefentry><refentrytitle>glGetProgramInfoLog</refentrytitle></citerefentry> | |
126 | with argument <parameter>program</parameter></para> | |
127 | ||
128 | <para><citerefentry><refentrytitle>glIsProgram</refentrytitle></citerefentry></para> | |
129 | </refsect1> | |
130 | <refsect1 id="seealso"><title>See Also</title> | |
131 | <para><citerefentry><refentrytitle>glLinkProgram</refentrytitle></citerefentry>, | |
132 | <citerefentry><refentrytitle>glUseProgram</refentrytitle></citerefentry></para> | |
133 | </refsect1> | |
134 | <refsect1 id="Copyright"><title>Copyright</title> | |
135 | <para> | |
136 | Copyright <trademark class="copyright"></trademark> 2003-2005 3Dlabs Inc. Ltd. | |
137 | This material may be distributed subject to the terms and conditions set forth in | |
138 | the Open Publication License, v 1.0, 8 June 1999. | |
139 | <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>. | |
140 | </para> | |
141 | </refsect1> | |
142 | </refentry> |