src/mesa/drivers/dri/intel/intel_tex_layout.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2006 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   * Authors:
  29   *   Keith Whitwell <keith@tungstengraphics.com>
  30   *   Michel Dänzer <michel@tungstengraphics.com>
  31   */
  32
  33 #include "intel_mipmap_tree.h"
  34 #include "intel_tex_layout.h"
  35 #include "macros.h"
  36
  37
  38 static int align(int value, int alignment)
  39 {
  40    return (value + alignment - 1) & ~(alignment - 1);
  41 }
  42
  43 void i945_miptree_layout_2d( struct intel_mipmap_tree *mt )
  44 {
  45    GLint align_h = 2, align_w = 4;
  46    GLuint level;
  47    GLuint x = 0;
  48    GLuint y = 0;
  49    GLuint width = mt->width0;
  50    GLuint height = mt->height0;
  51
  52    mt->pitch = mt->width0;
  53
  54    /* May need to adjust pitch to accomodate the placement of
  55     * the 2nd mipmap.  This occurs when the alignment
  56     * constraints of mipmap placement push the right edge of the
  57     * 2nd mipmap out past the width of its parent.
  58     */
  59    if (mt->first_level != mt->last_level) {
  60       GLuint mip1_width = align(minify(mt->width0), align_w)
  61                         + minify(minify(mt->width0));
  62
  63       if (mip1_width > mt->width0)
  64          mt->pitch = mip1_width;
  65    }
  66
  67    /* Pitch must be a whole number of dwords, even though we
  68     * express it in texels.
  69     */
  70    mt->pitch = align(mt->pitch * mt->cpp, 4) / mt->cpp;
  71    mt->total_height = 0;
  72
  73    for ( level = mt->first_level ; level <= mt->last_level ; level++ ) {
  74       GLuint img_height;
  75
  76       intel_miptree_set_level_info(mt, level, 1, x, y, width,
  77                                    height, 1);
  78
  79       if (mt->compressed)
  80          img_height = MAX2(1, height/4);
  81       else
  82          img_height = align(height, align_h);
  83
  84
  85       /* Because the images are packed better, the final offset
  86        * might not be the maximal one:
  87        */
  88       mt->total_height = MAX2(mt->total_height, y + img_height);
  89
  90       /* Layout_below: step right after second mipmap.
  91        */
  92       if (level == mt->first_level + 1) {
  93          x += align(width, align_w);
  94       }
  95       else {
  96          y += img_height;
  97       }
  98
  99       width  = minify(width);
 100       height = minify(height);
 101    }
 102 }