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      1 /**************************************************************************
      2  *
      3  * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
      4  * 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
      8  * "Software"), to deal in the Software without restriction, including
      9  * without limitation the rights to use, copy, modify, merge, publish,
     10  * distribute, sub license, 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 portions
     16  * of the Software.
     17  *
     18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
     19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
     20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
     21  * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
     22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
     23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
     24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
     25  *
     26  **************************************************************************/
     27 
     28  /*
     29   * \brief polygon stipple state
     30   *
     31   * Authors:
     32   *   Brian Paul
     33   */
     34 
     35 
     36 #include <assert.h>
     37 
     38 #include "st_context.h"
     39 #include "st_atom.h"
     40 #include "pipe/p_context.h"
     41 #include "pipe/p_defines.h"
     42 
     43 
     44 /**
     45  * OpenGL's polygon stipple is indexed with window coordinates in which
     46  * the origin (0,0) is the lower-left corner of the window.
     47  * With Gallium, the origin is the upper-left corner of the window.
     48  * To convert GL's polygon stipple to what gallium expects we need to
     49  * invert the pattern vertically and rotate the stipple rows according
     50  * to the window height.
     51  */
     52 static void
     53 invert_stipple(GLuint dest[32], const GLuint src[32], GLuint winHeight)
     54 {
     55    GLuint i;
     56 
     57    for (i = 0; i < 32; i++) {
     58       dest[i] = src[(winHeight - 1 - i) & 0x1f];
     59    }
     60 }
     61 
     62 
     63 
     64 static void
     65 update_stipple( struct st_context *st )
     66 {
     67    const struct gl_context *ctx = st->ctx;
     68    const GLuint sz = sizeof(st->state.poly_stipple);
     69    assert(sz == sizeof(ctx->PolygonStipple));
     70 
     71    if (memcmp(st->state.poly_stipple, ctx->PolygonStipple, sz)) {
     72       /* state has changed */
     73       struct pipe_poly_stipple newStipple;
     74 
     75       memcpy(st->state.poly_stipple, ctx->PolygonStipple, sz);
     76 
     77       invert_stipple(newStipple.stipple, ctx->PolygonStipple,
     78                      ctx->DrawBuffer->Height);
     79 
     80       st->pipe->set_polygon_stipple(st->pipe, &newStipple);
     81    }
     82 }
     83 
     84 
     85 /** Update the stipple when the pattern or window height changes */
     86 const struct st_tracked_state st_update_polygon_stipple = {
     87    "st_update_polygon_stipple",				/* name */
     88    {							/* dirty */
     89       (_NEW_POLYGONSTIPPLE |
     90        _NEW_BUFFERS),					/* mesa */
     91       0,						/* st */
     92    },
     93    update_stipple					/* update */
     94 };
     95