xref: /third_party/mesa3d/src/mesa/main/lines.c (revision bf215546) 
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#include "api_exec_decl.h"
32
33#include "state_tracker/st_context.h"
34
35/**
36 * Set the line width.
37 *
38 * \param width line width in pixels.
39 *
40 * \sa glLineWidth().
41 */
42static ALWAYS_INLINE void
43line_width(struct gl_context *ctx, GLfloat width, bool no_error)
44{
45   /* If width is unchanged, there can't be an error */
46   if (ctx->Line.Width == width)
47      return;
48
49   if (!no_error && width <= 0.0F) {
50      _mesa_error( ctx, GL_INVALID_VALUE, "glLineWidth" );
51      return;
52   }
53
54   /* Page 407 (page 423 of the PDF) of the OpenGL 3.0 spec says (in the list
55    * of deprecated functionality):
56    *
57    *     "Wide lines and line stipple - LineWidth is not deprecated, but
58    *     values greater than 1.0 will generate an INVALID_VALUE error;"
59    *
60    * This is one of the very few cases where functionality was deprecated but
61    * *NOT* removed in a later spec.  Therefore, we only disallow this in a
62    * forward compatible context.
63    */
64   if (!no_error && ctx->API == API_OPENGL_CORE
65       && ((ctx->Const.ContextFlags & GL_CONTEXT_FLAG_FORWARD_COMPATIBLE_BIT)
66           != 0)
67       && width > 1.0F) {
68      _mesa_error( ctx, GL_INVALID_VALUE, "glLineWidth" );
69      return;
70   }
71
72   FLUSH_VERTICES(ctx, 0, GL_LINE_BIT);
73   ctx->NewDriverState |= ST_NEW_RASTERIZER;
74   ctx->Line.Width = width;
75}
76
77
78void GLAPIENTRY
79_mesa_LineWidth_no_error(GLfloat width)
80{
81   GET_CURRENT_CONTEXT(ctx);
82   line_width(ctx, width, true);
83}
84
85
86void GLAPIENTRY
87_mesa_LineWidth(GLfloat width)
88{
89   GET_CURRENT_CONTEXT(ctx);
90
91   if (MESA_VERBOSE & VERBOSE_API)
92      _mesa_debug(ctx, "glLineWidth %f\n", width);
93
94   line_width(ctx, width, false);
95}
96
97
98/**
99 * Set the line stipple pattern.
100 *
101 * \param factor pattern scale factor.
102 * \param pattern bit pattern.
103 *
104 * \sa glLineStipple().
105 *
106 * Updates gl_line_attrib::StippleFactor and gl_line_attrib::StipplePattern. On
107 * change flushes the vertices and notifies the driver via
108 * the dd_function_table::LineStipple callback.
109 */
110void GLAPIENTRY
111_mesa_LineStipple( GLint factor, GLushort pattern )
112{
113   GET_CURRENT_CONTEXT(ctx);
114
115   if (MESA_VERBOSE & VERBOSE_API)
116      _mesa_debug(ctx, "glLineStipple %d %u\n", factor, pattern);
117
118   factor = CLAMP( factor, 1, 256 );
119
120   if (ctx->Line.StippleFactor == factor &&
121       ctx->Line.StipplePattern == pattern)
122      return;
123
124   FLUSH_VERTICES(ctx, 0, GL_LINE_BIT);
125   ctx->NewDriverState |= ST_NEW_RASTERIZER;
126   ctx->Line.StippleFactor = factor;
127   ctx->Line.StipplePattern = pattern;
128}
129
130
131/**
132 * Initialize the context line state.
133 *
134 * \param ctx GL context.
135 *
136 * Initializes __struct gl_contextRec::Line and line related constants in
137 * __struct gl_contextRec::Const.
138 */
139void
140_mesa_init_line( struct gl_context * ctx )
141{
142   ctx->Line.SmoothFlag = GL_FALSE;
143   ctx->Line.StippleFlag = GL_FALSE;
144   ctx->Line.Width = 1.0;
145   ctx->Line.StipplePattern = 0xffff;
146   ctx->Line.StippleFactor = 1;
147}
148