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 static ALWAYS_INLINE void
  41 line_width(struct gl_context *ctx, GLfloat width, bool no_error)
  42 {
  43    /* If width is unchanged, there can't be an error */
  44    if (ctx->Line.Width == width)
  45       return;
  46
  47    if (!no_error && width <= 0.0F) {
  48       _mesa_error( ctx, GL_INVALID_VALUE, "glLineWidth" );
  49       return;
  50    }
  51
  52    /* Page 407 (page 423 of the PDF) of the OpenGL 3.0 spec says (in the list
  53     * of deprecated functionality):
  54     *
  55     *     "Wide lines and line stipple - LineWidth is not deprecated, but
  56     *     values greater than 1.0 will generate an INVALID_VALUE error;"
  57     *
  58     * This is one of the very few cases where functionality was deprecated but
  59     * *NOT* removed in a later spec.  Therefore, we only disallow this in a
  60     * forward compatible context.
  61     */
  62    if (!no_error && ctx->API == API_OPENGL_CORE
  63        && ((ctx->Const.ContextFlags & GL_CONTEXT_FLAG_FORWARD_COMPATIBLE_BIT)
  64            != 0)
  65        && width > 1.0F) {
  66       _mesa_error( ctx, GL_INVALID_VALUE, "glLineWidth" );
  67       return;
  68    }
  69
  70    FLUSH_VERTICES(ctx, ctx->DriverFlags.NewLineState ? 0 : _NEW_LINE);
  71    ctx->NewDriverState |= ctx->DriverFlags.NewLineState;
  72    ctx->Line.Width = width;
  73
  74    if (ctx->Driver.LineWidth)
  75       ctx->Driver.LineWidth(ctx, width);
  76 }
  77
  78
  79 void GLAPIENTRY
  80 _mesa_LineWidth_no_error(GLfloat width)
  81 {
  82    GET_CURRENT_CONTEXT(ctx);
  83    line_width(ctx, width, true);
  84 }
  85
  86
  87 void GLAPIENTRY
  88 _mesa_LineWidth(GLfloat width)
  89 {
  90    GET_CURRENT_CONTEXT(ctx);
  91
  92    if (MESA_VERBOSE & VERBOSE_API)
  93       _mesa_debug(ctx, "glLineWidth %f\n", width);
  94
  95    line_width(ctx, width, false);
  96 }
  97
  98
  99 /**
 100  * Set the line stipple pattern.
 101  *
 102  * \param factor pattern scale factor.
 103  * \param pattern bit pattern.
 104  *
 105  * \sa glLineStipple().
 106  *
 107  * Updates gl_line_attrib::StippleFactor and gl_line_attrib::StipplePattern. On
 108  * change flushes the vertices and notifies the driver via
 109  * the dd_function_table::LineStipple callback.
 110  */
 111 void GLAPIENTRY
 112 _mesa_LineStipple( GLint factor, GLushort pattern )
 113 {
 114    GET_CURRENT_CONTEXT(ctx);
 115
 116    if (MESA_VERBOSE & VERBOSE_API)
 117       _mesa_debug(ctx, "glLineStipple %d %u\n", factor, pattern);
 118
 119    factor = CLAMP( factor, 1, 256 );
 120
 121    if (ctx->Line.StippleFactor == factor &&
 122        ctx->Line.StipplePattern == pattern)
 123       return;
 124
 125    FLUSH_VERTICES(ctx, ctx->DriverFlags.NewLineState ? 0 : _NEW_LINE);
 126    ctx->NewDriverState |= ctx->DriverFlags.NewLineState;
 127    ctx->Line.StippleFactor = factor;
 128    ctx->Line.StipplePattern = pattern;
 129
 130    if (ctx->Driver.LineStipple)
 131       ctx->Driver.LineStipple( ctx, factor, pattern );
 132 }
 133
 134
 135 /**
 136  * Initialize the context line state.
 137  *
 138  * \param ctx GL context.
 139  *
 140  * Initializes __struct gl_contextRec::Line and line related constants in
 141  * __struct gl_contextRec::Const.
 142  */
 143 void
 144 _mesa_init_line( struct gl_context * ctx )
 145 {
 146    ctx->Line.SmoothFlag = GL_FALSE;
 147    ctx->Line.StippleFlag = GL_FALSE;
 148    ctx->Line.Width = 1.0;
 149    ctx->Line.StipplePattern = 0xffff;
 150    ctx->Line.StippleFactor = 1;
 151 }