1 /*
2  * Copyright © 2011 Intel Corporation
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice (including the next
12  * paragraph) shall be included in all copies or substantial portions of the
13  * Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21  * IN THE SOFTWARE.
22  */
23 
24 #pragma once
25 
26 #include <stdint.h>
27 
28 #ifdef __cplusplus
29 extern "C" {
30 #endif
31 
32 /**
33  * For an overview of the HiZ operations, see the following sections of the
34  * Sandy Bridge PRM, Volume 1, Part2:
35  *   - 7.5.3.1 Depth Buffer Clear
36  *   - 7.5.3.2 Depth Buffer Resolve
37  *   - 7.5.3.3 Hierarchical Depth Buffer Resolve
38  *
39  * Of these, two get entered in the resolve map as needing to be done to the
40  * buffer: depth resolve and hiz resolve.
41  */
42 enum gen6_hiz_op {
43    GEN6_HIZ_OP_DEPTH_CLEAR,
44    GEN6_HIZ_OP_DEPTH_RESOLVE,
45    GEN6_HIZ_OP_HIZ_RESOLVE,
46    GEN6_HIZ_OP_NONE,
47 };
48 
49 /**
50  * \brief Map of miptree slices to needed resolves.
51  *
52  * The map is implemented as a linear doubly-linked list.
53  *
54  * In the intel_resolve_map*() functions, the \c head argument is not
55  * inspected for its data. It only serves as an anchor for the list.
56  *
57  * \par Design Discussion
58  *
59  *     There are two possible ways to record which miptree slices need
60  *     resolves. 1) Maintain a flag for every miptree slice in the texture,
61  *     likely in intel_mipmap_level::slice, or 2) maintain a list of only
62  *     those slices that need a resolve.
63  *
64  *     Immediately before drawing, a full depth resolve performed on each
65  *     enabled depth texture. If design 1 were chosen, then at each draw call
66  *     it would be necessary to iterate over each miptree slice of each
67  *     enabled depth texture in order to query if each slice needed a resolve.
68  *     In the worst case, this would require 2^16 iterations: 16 texture
69  *     units, 16 miplevels, and 256 depth layers (assuming maximums for OpenGL
70  *     2.1).
71  *
72  *     By choosing design 2, the number of iterations is exactly the minimum
73  *     necessary.
74  */
75 struct intel_resolve_map {
76    uint32_t level;
77    uint32_t layer;
78    enum gen6_hiz_op need;
79 
80    struct intel_resolve_map *next;
81    struct intel_resolve_map *prev;
82 };
83 
84 void
85 intel_resolve_map_set(struct intel_resolve_map *head,
86 		      uint32_t level,
87 		      uint32_t layer,
88 		      enum gen6_hiz_op need);
89 
90 struct intel_resolve_map*
91 intel_resolve_map_get(struct intel_resolve_map *head,
92 		      uint32_t level,
93 		      uint32_t layer);
94 
95 void
96 intel_resolve_map_remove(struct intel_resolve_map *elem);
97 
98 void
99 intel_resolve_map_clear(struct intel_resolve_map *head);
100 
101 #ifdef __cplusplus
102 } /* extern "C" */
103 #endif
104 
105