lines.c revision 13fedf2883c7a1d7ff911b75eb88df00ba22eea7 
1/*
2 * Mesa 3-D graphics library
3 *
4 * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included
14 * in all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
17 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
20 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
21 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
22 * OTHER DEALINGS IN THE SOFTWARE.
23 */
24
25
26#include "glheader.h"
27#include "context.h"
28#include "lines.h"
29#include "macros.h"
30#include "mtypes.h"
31
32
33/**
34 * Set the line width.
35 *
36 * \param width line width in pixels.
37 *
38 * \sa glLineWidth().
39 */
40void GLAPIENTRY
41_mesa_LineWidth( GLfloat width )
42{
43   GET_CURRENT_CONTEXT(ctx);
44
45   if (MESA_VERBOSE & VERBOSE_API)
46      _mesa_debug(ctx, "glLineWidth %f\n", width);
47
48   if (width<=0.0) {
49      _mesa_error( ctx, GL_INVALID_VALUE, "glLineWidth" );
50      return;
51   }
52
53   /* Page 407 (page 423 of the PDF) of the OpenGL 3.0 spec says (in the list
54    * of deprecated functionality):
55    *
56    *     "Wide lines and line stipple - LineWidth is not deprecated, but
57    *     values greater than 1.0 will generate an INVALID_VALUE error;"
58    *
59    * This is one of the very few cases where functionality was deprecated but
60    * *NOT* removed in a later spec.  Therefore, we only disallow this in a
61    * forward compatible context.
62    */
63   if (ctx->API == API_OPENGL_CORE
64       && ((ctx->Const.ContextFlags & GL_CONTEXT_FLAG_FORWARD_COMPATIBLE_BIT)
65           != 0)
66       && width > 1.0) {
67      _mesa_error( ctx, GL_INVALID_VALUE, "glLineWidth" );
68      return;
69   }
70
71   if (ctx->Line.Width == width)
72      return;
73
74   FLUSH_VERTICES(ctx, _NEW_LINE);
75   ctx->Line.Width = width;
76
77   if (ctx->Driver.LineWidth)
78      ctx->Driver.LineWidth(ctx, width);
79}
80
81
82/**
83 * Set the line stipple pattern.
84 *
85 * \param factor pattern scale factor.
86 * \param pattern bit pattern.
87 *
88 * \sa glLineStipple().
89 *
90 * Updates gl_line_attrib::StippleFactor and gl_line_attrib::StipplePattern. On
91 * change flushes the vertices and notifies the driver via
92 * the dd_function_table::LineStipple callback.
93 */
94void GLAPIENTRY
95_mesa_LineStipple( GLint factor, GLushort pattern )
96{
97   GET_CURRENT_CONTEXT(ctx);
98
99   if (MESA_VERBOSE & VERBOSE_API)
100      _mesa_debug(ctx, "glLineStipple %d %u\n", factor, pattern);
101
102   factor = CLAMP( factor, 1, 256 );
103
104   if (ctx->Line.StippleFactor == factor &&
105       ctx->Line.StipplePattern == pattern)
106      return;
107
108   FLUSH_VERTICES(ctx, _NEW_LINE);
109   ctx->Line.StippleFactor = factor;
110   ctx->Line.StipplePattern = pattern;
111
112   if (ctx->Driver.LineStipple)
113      ctx->Driver.LineStipple( ctx, factor, pattern );
114}
115
116
117/**
118 * Initialize the context line state.
119 *
120 * \param ctx GL context.
121 *
122 * Initializes __struct gl_contextRec::Line and line related constants in
123 * __struct gl_contextRec::Const.
124 */
125void GLAPIENTRY
126_mesa_init_line( struct gl_context * ctx )
127{
128   ctx->Line.SmoothFlag = GL_FALSE;
129   ctx->Line.StippleFlag = GL_FALSE;
130   ctx->Line.Width = 1.0;
131   ctx->Line.StipplePattern = 0xffff;
132   ctx->Line.StippleFactor = 1;
133}
134