src/mesa/main/lines.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.5.3
   4  *
   5  * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included
  15  * in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  21  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  22  * CONNECTION WITH THE SOFTWARE OR THE USE OR 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  */
  40 void 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       _mesa_error( ctx, GL_INVALID_VALUE, "glLineWidth" );
  67       return;
  68    }
  69
  70    if (ctx->Line.Width == width)
  71       return;
  72
  73    FLUSH_VERTICES(ctx, _NEW_LINE);
  74    ctx->Line.Width = width;
  75
  76    if (ctx->Driver.LineWidth)
  77       ctx->Driver.LineWidth(ctx, width);
  78 }
  79
  80
  81 /**
  82  * Set the line stipple pattern.
  83  *
  84  * \param factor pattern scale factor.
  85  * \param pattern bit pattern.
  86  *
  87  * \sa glLineStipple().
  88  *
  89  * Updates gl_line_attrib::StippleFactor and gl_line_attrib::StipplePattern. On
  90  * change flushes the vertices and notifies the driver via
  91  * the dd_function_table::LineStipple callback.
  92  */
  93 void GLAPIENTRY
  94 _mesa_LineStipple( GLint factor, GLushort pattern )
  95 {
  96    GET_CURRENT_CONTEXT(ctx);
  97
  98    if (MESA_VERBOSE & VERBOSE_API)
  99       _mesa_debug(ctx, "glLineStipple %d %u\n", factor, pattern);
 100
 101    factor = CLAMP( factor, 1, 256 );
 102
 103    if (ctx->Line.StippleFactor == factor &&
 104        ctx->Line.StipplePattern == pattern)
 105       return;
 106
 107    FLUSH_VERTICES(ctx, _NEW_LINE);
 108    ctx->Line.StippleFactor = factor;
 109    ctx->Line.StipplePattern = pattern;
 110
 111    if (ctx->Driver.LineStipple)
 112       ctx->Driver.LineStipple( ctx, factor, pattern );
 113 }
 114
 115
 116 /**
 117  * Initialize the context line state.
 118  *
 119  * \param ctx GL context.
 120  *
 121  * Initializes __struct gl_contextRec::Line and line related constants in
 122  * __struct gl_contextRec::Const.
 123  */
 124 void GLAPIENTRY
 125 _mesa_init_line( struct gl_context * ctx )
 126 {
 127    ctx->Line.SmoothFlag = GL_FALSE;
 128    ctx->Line.StippleFlag = GL_FALSE;
 129    ctx->Line.Width = 1.0;
 130    ctx->Line.StipplePattern = 0xffff;
 131    ctx->Line.StippleFactor = 1;
 132 }