src/mesa/main/lines.c

   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  */
  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        && 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  */
  94 void 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  */
 125 void 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 }