OpenTTD
viewport_sprite_sorter_sse4.cpp
1 /* $Id: viewport_sprite_sorter_sse4.cpp 26482 2014-04-23 20:13:33Z rubidium $ */
2 
3 /*
4  * This file is part of OpenTTD.
5  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
6  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
7  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
8  */
9 
12 #ifdef WITH_SSE
13 
14 #include "stdafx.h"
15 #include "cpu.h"
16 #include "smmintrin.h"
17 #include "viewport_sprite_sorter.h"
18 
19 #include "safeguards.h"
20 
21 #ifdef _SQ64
22  assert_compile((sizeof(ParentSpriteToDraw) % 16) == 0);
23  #define LOAD_128 _mm_load_si128
24 #else
25  #define LOAD_128 _mm_loadu_si128
26 #endif
27 
29 void ViewportSortParentSpritesSSE41(ParentSpriteToSortVector *psdv)
30 {
31  const __m128i mask_ptest = _mm_setr_epi8(-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 0, 0, 0, 0);
32  ParentSpriteToDraw ** const psdvend = psdv->End();
33  ParentSpriteToDraw **psd = psdv->Begin();
34  while (psd != psdvend) {
35  ParentSpriteToDraw * const ps = *psd;
36 
37  if (ps->comparison_done) {
38  psd++;
39  continue;
40  }
41 
42  ps->comparison_done = true;
43 
44  for (ParentSpriteToDraw **psd2 = psd + 1; psd2 != psdvend; psd2++) {
45  ParentSpriteToDraw * const ps2 = *psd2;
46 
47  if (ps2->comparison_done) continue;
48 
49  /*
50  * Decide which comparator to use, based on whether the bounding boxes overlap
51  *
52  * Original code:
53  * if (ps->xmax >= ps2->xmin && ps->xmin <= ps2->xmax && // overlap in X?
54  * ps->ymax >= ps2->ymin && ps->ymin <= ps2->ymax && // overlap in Y?
55  * ps->zmax >= ps2->zmin && ps->zmin <= ps2->zmax) { // overlap in Z?
56  *
57  * Above conditions are equivalent to:
58  * 1/ !( (ps->xmax >= ps2->xmin) && (ps->ymax >= ps2->ymin) && (ps->zmax >= ps2->zmin) && (ps->xmin <= ps2->xmax) && (ps->ymin <= ps2->ymax) && (ps->zmin <= ps2->zmax) )
59  * 2/ !( (ps->xmax >= ps2->xmin) && (ps->ymax >= ps2->ymin) && (ps->zmax >= ps2->zmin) && (ps2->xmax >= ps->xmin) && (ps2->ymax >= ps->ymin) && (ps2->zmax >= ps->zmin) )
60  * 3/ !( ( (ps->xmax >= ps2->xmin) && (ps->ymax >= ps2->ymin) && (ps->zmax >= ps2->zmin) ) && ( (ps2->xmax >= ps->xmin) && (ps2->ymax >= ps->ymin) && (ps2->zmax >= ps->zmin) ) )
61  * 4/ !( !( (ps->xmax < ps2->xmin) || (ps->ymax < ps2->ymin) || (ps->zmax < ps2->zmin) ) && !( (ps2->xmax < ps->xmin) || (ps2->ymax < ps->ymin) || (ps2->zmax < ps->zmin) ) )
62  * 5/ PTEST <---------------------------------- rslt1 ----------------------------------> <------------------------------ rslt2 -------------------------------------->
63  */
64  __m128i ps1_max = LOAD_128((__m128i*) &ps->xmax);
65  __m128i ps2_min = LOAD_128((__m128i*) &ps2->xmin);
66  __m128i rslt1 = _mm_cmplt_epi32(ps1_max, ps2_min);
67  if (!_mm_testz_si128(mask_ptest, rslt1))
68  continue;
69 
70  __m128i ps1_min = LOAD_128((__m128i*) &ps->xmin);
71  __m128i ps2_max = LOAD_128((__m128i*) &ps2->xmax);
72  __m128i rslt2 = _mm_cmplt_epi32(ps2_max, ps1_min);
73  if (_mm_testz_si128(mask_ptest, rslt2)) {
74  /* Use X+Y+Z as the sorting order, so sprites closer to the bottom of
75  * the screen and with higher Z elevation, are drawn in front.
76  * Here X,Y,Z are the coordinates of the "center of mass" of the sprite,
77  * i.e. X=(left+right)/2, etc.
78  * However, since we only care about order, don't actually divide / 2
79  */
80  if (ps->xmin + ps->xmax + ps->ymin + ps->ymax + ps->zmin + ps->zmax <=
81  ps2->xmin + ps2->xmax + ps2->ymin + ps2->ymax + ps2->zmin + ps2->zmax) {
82  continue;
83  }
84  }
85 
86  /* Move ps2 in front of ps */
87  ParentSpriteToDraw * const temp = ps2;
88  for (ParentSpriteToDraw **psd3 = psd2; psd3 > psd; psd3--) {
89  *psd3 = *(psd3 - 1);
90  }
91  *psd = temp;
92  }
93  }
94 }
95 
100 bool ViewportSortParentSpritesSSE41Checker()
101 {
102  return HasCPUIDFlag(1, 2, 19);
103 }
104 
105 #endif /* WITH_SSE */