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 is unchanged, there can't be an error */
  49    if (ctx->Line.Width == width)
  50       return;
  51
  52    if (width <= 0.0F) {
  53       _mesa_error( ctx, GL_INVALID_VALUE, "glLineWidth" );
  54       return;
  55    }
  56
  57    /* Page 407 (page 423 of the PDF) of the OpenGL 3.0 spec says (in the list
  58     * of deprecated functionality):
  59     *
  60     *     "Wide lines and line stipple - LineWidth is not deprecated, but
  61     *     values greater than 1.0 will generate an INVALID_VALUE error;"
  62     *
  63     * This is one of the very few cases where functionality was deprecated but
  64     * *NOT* removed in a later spec.  Therefore, we only disallow this in a
  65     * forward compatible context.
  66     */
  67    if (ctx->API == API_OPENGL_CORE
  68        && ((ctx->Const.ContextFlags & GL_CONTEXT_FLAG_FORWARD_COMPATIBLE_BIT)
  69            != 0)
  70        && width > 1.0F) {
  71       _mesa_error( ctx, GL_INVALID_VALUE, "glLineWidth" );
  72       return;
  73    }
  74
  75    FLUSH_VERTICES(ctx, _NEW_LINE);
  76    ctx->Line.Width = width;
  77
  78    if (ctx->Driver.LineWidth)
  79       ctx->Driver.LineWidth(ctx, width);
  80 }
  81
  82
  83 /**
  84  * Set the line stipple pattern.
  85  *
  86  * \param factor pattern scale factor.
  87  * \param pattern bit pattern.
  88  *
  89  * \sa glLineStipple().
  90  *
  91  * Updates gl_line_attrib::StippleFactor and gl_line_attrib::StipplePattern. On
  92  * change flushes the vertices and notifies the driver via
  93  * the dd_function_table::LineStipple callback.
  94  */
  95 void GLAPIENTRY
  96 _mesa_LineStipple( GLint factor, GLushort pattern )
  97 {
  98    GET_CURRENT_CONTEXT(ctx);
  99
 100    if (MESA_VERBOSE & VERBOSE_API)
 101       _mesa_debug(ctx, "glLineStipple %d %u\n", factor, pattern);
 102
 103    factor = CLAMP( factor, 1, 256 );
 104
 105    if (ctx->Line.StippleFactor == factor &&
 106        ctx->Line.StipplePattern == pattern)
 107       return;
 108
 109    FLUSH_VERTICES(ctx, _NEW_LINE);
 110    ctx->Line.StippleFactor = factor;
 111    ctx->Line.StipplePattern = pattern;
 112
 113    if (ctx->Driver.LineStipple)
 114       ctx->Driver.LineStipple( ctx, factor, pattern );
 115 }
 116
 117
 118 /**
 119  * Initialize the context line state.
 120  *
 121  * \param ctx GL context.
 122  *
 123  * Initializes __struct gl_contextRec::Line and line related constants in
 124  * __struct gl_contextRec::Const.
 125  */
 126 void GLAPIENTRY
 127 _mesa_init_line( struct gl_context * ctx )
 128 {
 129    ctx->Line.SmoothFlag = GL_FALSE;
 130    ctx->Line.StippleFlag = GL_FALSE;
 131    ctx->Line.Width = 1.0;
 132    ctx->Line.StipplePattern = 0xffff;
 133    ctx->Line.StippleFactor = 1;
 134 }