HCoop / clinton / guile-figl.git / blame
| Commit | Line | Data |
|---|---|---|
| 7faf1d71 AW |
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="glProvokingVertex">\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>glProvokingVertex</refentrytitle>\r | |
| 13 | <manvolnum>3G</manvolnum>\r | |
| 14 | </refmeta>\r | |
| 15 | <refnamediv>\r | |
| 16 | <refname>glProvokingVertex</refname>\r | |
| 17 | <refpurpose>specifiy the vertex to be used as the source of data for flat shaded varyings</refpurpose>\r | |
| 18 | </refnamediv>\r | |
| 19 | <refsynopsisdiv><title>C Specification</title>\r | |
| 20 | <funcsynopsis>\r | |
| 21 | <funcprototype>\r | |
| 22 | <funcdef>void <function>glProvokingVertex</function></funcdef>\r | |
| 23 | <paramdef>GLenum <parameter>provokeMode</parameter></paramdef>\r | |
| 24 | </funcprototype>\r | |
| 25 | </funcsynopsis>\r | |
| 26 | </refsynopsisdiv>\r | |
| 27 | <!-- eqn: ignoring delim $$ -->\r | |
| 28 | <refsect1 id="parameters"><title>Parameters</title>\r | |
| 29 | <variablelist>\r | |
| 30 | <varlistentry>\r | |
| 31 | <term><parameter>provokeMode</parameter></term>\r | |
| 32 | <listitem>\r | |
| 33 | <para>\r | |
| 34 | Specifies the vertex to be used as the source of data for flat shaded varyings.\r | |
| 35 | </para>\r | |
| 36 | </listitem>\r | |
| 37 | </varlistentry>\r | |
| 38 | </variablelist>\r | |
| 39 | </refsect1>\r | |
| 40 | <refsect1 id="description"><title>Description</title>\r | |
| 41 | <para>\r | |
| 42 | <emphasis>Flatshading</emphasis> a vertex shader varying output means to assign all vetices of the primitive the same value\r | |
| 43 | for that output. The vertex from which these values is derived is known as the <emphasis>provoking vertex</emphasis> and\r | |
| 44 | <function>glProvokingVertex</function> specifies which vertex is to be used as the source of data for flat shaded varyings.\r | |
| 45 | </para>\r | |
| 46 | <para>\r | |
| 47 | <parameter>provokeMode</parameter> must be either <constant>GL_FIRST_VERTEX_CONVENTION</constant> or\r | |
| 48 | <constant>GL_LAST_VERTEX_CONVENTION</constant>, and controls the selection of the vertex whose values are assigned to flatshaded\r | |
| 49 | varying outputs. The interpretation of these values for the supported primitive types is:\r | |
| 50 | <informaltable frame="topbot">\r | |
| 51 | <tgroup cols="3" align="left">\r | |
| 52 | <colspec colwidth="1.1*" />\r | |
| 53 | <colspec colwidth="1*" />\r | |
| 54 | <colspec colwidth="1*" />\r | |
| 55 | <thead>\r | |
| 56 | <row>\r | |
| 57 | <entry rowsep="1" align="left"><emphasis role="bold">\r | |
| 58 | Primitive Type of Polygon <emphasis>i</emphasis>\r | |
| 59 | </emphasis></entry>\r | |
| 60 | <entry rowsep="1" align="left"><emphasis role="bold">\r | |
| 61 | First Vertex Convention\r | |
| 62 | </emphasis></entry>\r | |
| 63 | <entry rowsep="1" align="left"><emphasis role="bold">\r | |
| 64 | Last Vertex Convention\r | |
| 65 | </emphasis></entry>\r | |
| 66 | </row>\r | |
| 67 | <row>\r | |
| 68 | <entry>\r | |
| 69 | point\r | |
| 70 | </entry>\r | |
| 71 | <entry>\r | |
| 72 | <emphasis>i</emphasis>\r | |
| 73 | </entry>\r | |
| 74 | <entry>\r | |
| 75 | <emphasis>i</emphasis>\r | |
| 76 | </entry>\r | |
| 77 | </row>\r | |
| 78 | <row>\r | |
| 79 | <entry>\r | |
| 80 | independent line\r | |
| 81 | </entry>\r | |
| 82 | <entry>\r | |
| 83 | 2<emphasis>i</emphasis> - 1\r | |
| 84 | </entry>\r | |
| 85 | <entry>\r | |
| 86 | 2<emphasis>i</emphasis>\r | |
| 87 | </entry>\r | |
| 88 | </row>\r | |
| 89 | <row>\r | |
| 90 | <entry>\r | |
| 91 | line loop\r | |
| 92 | </entry>\r | |
| 93 | <entry>\r | |
| 94 | <emphasis>i</emphasis>\r | |
| 95 | </entry>\r | |
| 96 | <entry>\r | |
| 97 | <para>\r | |
| 98 | <emphasis>i</emphasis> + 1, if <emphasis>i</emphasis> < <emphasis>n</emphasis>\r | |
| 99 | </para>\r | |
| 100 | <para>\r | |
| 101 | 1, if <emphasis>i</emphasis> = <emphasis>n</emphasis>\r | |
| 102 | </para>\r | |
| 103 | </entry>\r | |
| 104 | </row>\r | |
| 105 | <row>\r | |
| 106 | <entry>\r | |
| 107 | line strip\r | |
| 108 | </entry>\r | |
| 109 | <entry>\r | |
| 110 | <emphasis>i</emphasis>\r | |
| 111 | </entry>\r | |
| 112 | <entry>\r | |
| 113 | <emphasis>i</emphasis> + 1\r | |
| 114 | </entry>\r | |
| 115 | </row>\r | |
| 116 | <row>\r | |
| 117 | <entry>\r | |
| 118 | independent triangle\r | |
| 119 | </entry>\r | |
| 120 | <entry>\r | |
| 121 | 3<emphasis>i</emphasis> - 2\r | |
| 122 | </entry>\r | |
| 123 | <entry>\r | |
| 124 | 3<emphasis>i</emphasis>\r | |
| 125 | </entry>\r | |
| 126 | </row>\r | |
| 127 | <row>\r | |
| 128 | <entry>\r | |
| 129 | triangle strip\r | |
| 130 | </entry>\r | |
| 131 | <entry>\r | |
| 132 | <emphasis>i</emphasis>\r | |
| 133 | </entry>\r | |
| 134 | <entry>\r | |
| 135 | <emphasis>i</emphasis> + 2\r | |
| 136 | </entry>\r | |
| 137 | </row>\r | |
| 138 | <row>\r | |
| 139 | <entry>\r | |
| 140 | triangle fan\r | |
| 141 | </entry>\r | |
| 142 | <entry>\r | |
| 143 | <emphasis>i</emphasis> + 1\r | |
| 144 | </entry>\r | |
| 145 | <entry>\r | |
| 146 | <emphasis>i</emphasis> + 2\r | |
| 147 | </entry>\r | |
| 148 | </row>\r | |
| 149 | <row>\r | |
| 150 | <entry>\r | |
| 151 | line adjacency\r | |
| 152 | </entry>\r | |
| 153 | <entry>\r | |
| 154 | 4<emphasis>i</emphasis> - 2\r | |
| 155 | </entry>\r | |
| 156 | <entry>\r | |
| 157 | 4<emphasis>i</emphasis> - 1\r | |
| 158 | </entry>\r | |
| 159 | </row>\r | |
| 160 | <row>\r | |
| 161 | <entry>\r | |
| 162 | line strip adjacency\r | |
| 163 | </entry>\r | |
| 164 | <entry>\r | |
| 165 | <emphasis>i</emphasis> + 1\r | |
| 166 | </entry>\r | |
| 167 | <entry>\r | |
| 168 | <emphasis>i</emphasis> + 2\r | |
| 169 | </entry>\r | |
| 170 | </row>\r | |
| 171 | <row>\r | |
| 172 | <entry>\r | |
| 173 | triangle adjacency\r | |
| 174 | </entry>\r | |
| 175 | <entry>\r | |
| 176 | 6<emphasis>i</emphasis> - 5\r | |
| 177 | </entry>\r | |
| 178 | <entry>\r | |
| 179 | 6<emphasis>i</emphasis> - 1\r | |
| 180 | </entry>\r | |
| 181 | </row>\r | |
| 182 | <row>\r | |
| 183 | <entry>\r | |
| 184 | triangle strip adjacency\r | |
| 185 | </entry>\r | |
| 186 | <entry>\r | |
| 187 | 2<emphasis>i</emphasis> - 1\r | |
| 188 | </entry>\r | |
| 189 | <entry>\r | |
| 190 | 2<emphasis>i</emphasis> + 3\r | |
| 191 | </entry>\r | |
| 192 | </row>\r | |
| 193 | </thead>\r | |
| 194 | </tgroup>\r | |
| 195 | </informaltable>\r | |
| 196 | </para>\r | |
| 197 | <para>\r | |
| 198 | If a vertex or geometry shader is active, user-defined varying outputs may be flatshaded by using the\r | |
| 199 | <code>flat</code> qualifier when declaring the output.\r | |
| 200 | </para>\r | |
| 201 | </refsect1>\r | |
| 202 | <refsect1 id="notes"><title>Notes</title>\r | |
| 203 | <para>\r | |
| 204 | <function>glProvokingVertex</function> is available only if the GL version is 3.2 or greater.\r | |
| 205 | </para>\r | |
| 206 | </refsect1>\r | |
| 207 | <refsect1 id="errors"><title>Errors</title>\r | |
| 208 | <para>\r | |
| 209 | <constant>GL_INVALID_ENUM</constant> is generated if <parameter>provokeMode</parameter> is not an accepted value.\r | |
| 210 | </para>\r | |
| 211 | </refsect1>\r | |
| 212 | <refsect1 id="Copyright"><title>Copyright</title>\r | |
| 213 | <para>\r | |
| 214 | Copyright <trademark class="copyright"></trademark> 2010 Khronos Group. \r | |
| 215 | This material may be distributed subject to the terms and conditions set forth in \r | |
| 216 | the Open Publication License, v 1.0, 8 June 1999.\r | |
| 217 | <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.\r | |
| 218 | </para>\r | |
| 219 | </refsect1>\r | |
| 220 | </refentry>\r |