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
29extern "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 */
42enum 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 */
75struct 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
84void
85intel_resolve_map_set(struct intel_resolve_map *head,
86		      uint32_t level,
87		      uint32_t layer,
88		      enum gen6_hiz_op need);
89
90struct intel_resolve_map*
91intel_resolve_map_get(struct intel_resolve_map *head,
92		      uint32_t level,
93		      uint32_t layer);
94
95void
96intel_resolve_map_remove(struct intel_resolve_map *elem);
97
98void
99intel_resolve_map_clear(struct intel_resolve_map *head);
100
101#ifdef __cplusplus
102} /* extern "C" */
103#endif
104
105