src/mesa/drivers/dri/i965/brw_util.h

   1 /*
   2  Copyright (C) Intel Corp.  2006.  All Rights Reserved.
   3  Intel funded Tungsten Graphics to
   4  develop this 3D driver.
   5
   6  Permission is hereby granted, free of charge, to any person obtaining
   7  a copy of this software and associated documentation files (the
   8  "Software"), to deal in the Software without restriction, including
   9  without limitation the rights to use, copy, modify, merge, publish,
  10  distribute, sublicense, and/or sell copies of the Software, and to
  11  permit persons to whom the Software is furnished to do so, subject to
  12  the following conditions:
  13
  14  The above copyright notice and this permission notice (including the
  15  next paragraph) shall be included in all copies or substantial
  16  portions of the Software.
  17
  18  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  19  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
  21  IN NO EVENT SHALL THE COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS BE
  22  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  23  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  24  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25
  26  **********************************************************************/
  27  /*
  28   * Authors:
  29   *   Keith Whitwell <keithw@vmware.com>
  30   */
  31
  32
  33 #ifndef BRW_UTIL_H
  34 #define BRW_UTIL_H
  35
  36 #include "brw_context.h"
  37 #include "main/framebuffer.h"
  38
  39 extern GLuint brw_translate_blend_factor( GLenum factor );
  40 extern GLuint brw_translate_blend_equation( GLenum mode );
  41
  42 static inline float
  43 brw_get_line_width(struct brw_context *brw)
  44 {
  45    /* From the OpenGL 4.4 spec:
  46     *
  47     * "The actual width of non-antialiased lines is determined by rounding
  48     * the supplied width to the nearest integer, then clamping it to the
  49     * implementation-dependent maximum non-antialiased line width."
  50     */
  51    float line_width =
  52       CLAMP(!_mesa_is_multisample_enabled(&brw->ctx) && !brw->ctx.Line.SmoothFlag
  53             ? roundf(brw->ctx.Line.Width) : brw->ctx.Line.Width,
  54             0.125f, brw->ctx.Const.MaxLineWidth);
  55
  56    if (!_mesa_is_multisample_enabled(&brw->ctx) && brw->ctx.Line.SmoothFlag && line_width < 1.5f) {
  57       /* For 1 pixel line thickness or less, the general
  58        * anti-aliasing algorithm gives up, and a garbage line is
  59        * generated.  Setting a Line Width of 0.0 specifies the
  60        * rasterization of the "thinnest" (one-pixel-wide),
  61        * non-antialiased lines.
  62        *
  63        * Lines rendered with zero Line Width are rasterized using
  64        * Grid Intersection Quantization rules as specified by
  65        * bspec section 6.3.12.1 Zero-Width (Cosmetic) Line
  66        * Rasterization.
  67        */
  68       line_width = 0.0f;
  69    }
  70
  71    return line_width;
  72 }
  73
  74 #endif