src/mesa/main/lines.c

   1 /**
   2  * \file lines.c
   3  * Line operations.
   4  */
   5
   6 /*
   7  * Mesa 3-D graphics library
   8  * Version:  5.1
   9  *
  10  * Copyright (C) 1999-2003  Brian Paul   All Rights Reserved.
  11  *
  12  * Permission is hereby granted, free of charge, to any person obtaining a
  13  * copy of this software and associated documentation files (the "Software"),
  14  * to deal in the Software without restriction, including without limitation
  15  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  16  * and/or sell copies of the Software, and to permit persons to whom the
  17  * Software is furnished to do so, subject to the following conditions:
  18  *
  19  * The above copyright notice and this permission notice shall be included
  20  * in all copies or substantial portions of the Software.
  21  *
  22  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  23  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  25  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  26  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  27  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  28  */
  29
  30
  31 #include "glheader.h"
  32 #include "context.h"
  33 #include "depth.h"
  34 #include "lines.h"
  35 #include "macros.h"
  36 #include "texstate.h"
  37 #include "mtypes.h"
  38
  39
  40 /**
  41  * Set the line width.
  42  *
  43  * \param width line width in pixels.
  44  *
  45  * \sa glLineWidth().
  46  *
  47  * Verifies the parameter and updates gl_line_attrib::Width. On a change,
  48  * flushes the vertices, updates the clamped line width and marks the
  49  * DD_LINE_WIDTH flag in __GLcontextRec::_TriangleCaps for the drivers if the
  50  * width is different from one. Notifies the driver via the
  51  * dd_function_table::LineWidth callback.
  52  */
  53 void GLAPIENTRY
  54 _mesa_LineWidth( GLfloat width )
  55 {
  56    GET_CURRENT_CONTEXT(ctx);
  57    ASSERT_OUTSIDE_BEGIN_END(ctx);
  58
  59    if (width<=0.0) {
  60       _mesa_error( ctx, GL_INVALID_VALUE, "glLineWidth" );
  61       return;
  62    }
  63
  64    if (ctx->Line.Width == width)
  65       return;
  66
  67    FLUSH_VERTICES(ctx, _NEW_LINE);
  68    ctx->Line.Width = width;
  69    ctx->Line._Width = CLAMP(width,
  70                             ctx->Const.MinLineWidth,
  71                             ctx->Const.MaxLineWidth);
  72
  73
  74    if (width != 1.0)
  75       ctx->_TriangleCaps |= DD_LINE_WIDTH;
  76    else
  77       ctx->_TriangleCaps &= ~DD_LINE_WIDTH;
  78
  79    if (ctx->Driver.LineWidth)
  80       (*ctx->Driver.LineWidth)(ctx, width);
  81 }
  82
  83
  84 /**
  85  * Set the line stipple pattern.
  86  *
  87  * \param factor pattern scale factor.
  88  * \param pattern bit pattern.
  89  *
  90  * \sa glLineStipple().
  91  *
  92  * Updates gl_line_attrib::StippleFactor and gl_line_attrib::StipplePattern. On
  93  * change flushes the vertices and notifies the driver via
  94  * the dd_function_table::LineStipple callback.
  95  */
  96 void GLAPIENTRY
  97 _mesa_LineStipple( GLint factor, GLushort pattern )
  98 {
  99    GET_CURRENT_CONTEXT(ctx);
 100    ASSERT_OUTSIDE_BEGIN_END(ctx);
 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 __GLcontextRec::Line and line related constants in
 123  * __GLcontextRec::Const.
 124  */
 125 void _mesa_init_line( GLcontext * ctx )
 126 {
 127    /* Line group */
 128    ctx->Line.SmoothFlag = GL_FALSE;
 129    ctx->Line.StippleFlag = GL_FALSE;
 130    ctx->Line.Width = 1.0;
 131    ctx->Line._Width = 1.0;
 132    ctx->Line.StipplePattern = 0xffff;
 133    ctx->Line.StippleFactor = 1;
 134 }