1 /*
2 * Copyright © 2014 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 /**
25 * @file glamor_vbo.c
26 *
27 * Helpers for managing streamed vertex bufffers used in glamor.
28 */
29
30 #include "glamor_priv.h"
31
32 /** Default size of the VBO, in bytes.
33 *
34 * If a single request is larger than this size, we'll resize the VBO
35 * and return an appropriate mapping, but we'll resize back down after
36 * that to avoid hogging that memory forever. We don't anticipate
37 * normal usage actually requiring larger VBO sizes.
38 */
39 #define GLAMOR_VBO_SIZE (512 * 1024)
40
41 /**
42 * Returns a pointer to @size bytes of VBO storage, which should be
43 * accessed by the GL using vbo_offset within the VBO.
44 */
45 void *
glamor_get_vbo_space(ScreenPtr screen,unsigned size,char ** vbo_offset)46 glamor_get_vbo_space(ScreenPtr screen, unsigned size, char **vbo_offset)
47 {
48 glamor_screen_private *glamor_priv = glamor_get_screen_private(screen);
49 void *data;
50
51 glamor_make_current(glamor_priv);
52
53 glBindBuffer(GL_ARRAY_BUFFER, glamor_priv->vbo);
54
55 if (glamor_priv->has_buffer_storage) {
56 if (glamor_priv->vbo_size < glamor_priv->vbo_offset + size) {
57 if (glamor_priv->vbo_size)
58 glUnmapBuffer(GL_ARRAY_BUFFER);
59
60 if (size > glamor_priv->vbo_size) {
61 glamor_priv->vbo_size = MAX(GLAMOR_VBO_SIZE, size);
62
63 /* We aren't allowed to resize glBufferStorage()
64 * buffers, so we need to gen a new one.
65 */
66 glDeleteBuffers(1, &glamor_priv->vbo);
67 glGenBuffers(1, &glamor_priv->vbo);
68 glBindBuffer(GL_ARRAY_BUFFER, glamor_priv->vbo);
69
70 assert(glGetError() == GL_NO_ERROR);
71 glBufferStorage(GL_ARRAY_BUFFER, glamor_priv->vbo_size, NULL,
72 GL_MAP_WRITE_BIT |
73 GL_MAP_PERSISTENT_BIT |
74 GL_MAP_COHERENT_BIT);
75
76 if (glGetError() != GL_NO_ERROR) {
77 /* If the driver failed our coherent mapping, fall
78 * back to the ARB_mbr path.
79 */
80 glamor_priv->has_buffer_storage = false;
81 glamor_priv->vbo_size = 0;
82
83 return glamor_get_vbo_space(screen, size, vbo_offset);
84 }
85 }
86
87 glamor_priv->vbo_offset = 0;
88 glamor_priv->vb = glMapBufferRange(GL_ARRAY_BUFFER,
89 0, glamor_priv->vbo_size,
90 GL_MAP_WRITE_BIT |
91 GL_MAP_INVALIDATE_BUFFER_BIT |
92 GL_MAP_PERSISTENT_BIT |
93 GL_MAP_COHERENT_BIT);
94 }
95 *vbo_offset = (void *)(uintptr_t)glamor_priv->vbo_offset;
96 data = glamor_priv->vb + glamor_priv->vbo_offset;
97 glamor_priv->vbo_offset += size;
98 } else if (glamor_priv->has_map_buffer_range) {
99 /* Avoid GL errors on GL 4.5 / ES 3.0 with mapping size == 0,
100 * which callers may sometimes pass us (for example, if
101 * clipping leads to zero rectangles left). Prior to that
102 * version, Mesa would sometimes throw errors on unmapping a
103 * zero-size mapping.
104 */
105 if (size == 0)
106 return NULL;
107
108 if (glamor_priv->vbo_size < glamor_priv->vbo_offset + size) {
109 glamor_priv->vbo_size = MAX(GLAMOR_VBO_SIZE, size);
110 glamor_priv->vbo_offset = 0;
111 glBufferData(GL_ARRAY_BUFFER,
112 glamor_priv->vbo_size, NULL, GL_STREAM_DRAW);
113 }
114
115 data = glMapBufferRange(GL_ARRAY_BUFFER,
116 glamor_priv->vbo_offset,
117 size,
118 GL_MAP_WRITE_BIT |
119 GL_MAP_UNSYNCHRONIZED_BIT |
120 GL_MAP_INVALIDATE_RANGE_BIT);
121 *vbo_offset = (char *)(uintptr_t)glamor_priv->vbo_offset;
122 glamor_priv->vbo_offset += size;
123 glamor_priv->vbo_mapped = TRUE;
124 } else {
125 /* Return a pointer to the statically allocated non-VBO
126 * memory. We'll upload it through glBufferData() later.
127 */
128 if (glamor_priv->vbo_size < size) {
129 glamor_priv->vbo_size = MAX(GLAMOR_VBO_SIZE, size);
130 free(glamor_priv->vb);
131 glamor_priv->vb = xnfalloc(glamor_priv->vbo_size);
132 }
133 *vbo_offset = NULL;
134 /* We point to the start of glamor_priv->vb every time, and
135 * the vbo_offset determines the size of the glBufferData().
136 */
137 glamor_priv->vbo_offset = size;
138 data = glamor_priv->vb;
139 }
140
141 return data;
142 }
143
144 void
glamor_put_vbo_space(ScreenPtr screen)145 glamor_put_vbo_space(ScreenPtr screen)
146 {
147 glamor_screen_private *glamor_priv = glamor_get_screen_private(screen);
148
149 glamor_make_current(glamor_priv);
150
151 if (glamor_priv->has_buffer_storage) {
152 /* If we're in the ARB_buffer_storage path, we have a
153 * persistent mapping, so we can leave it around until we
154 * reach the end of the buffer.
155 */
156 } else if (glamor_priv->has_map_buffer_range) {
157 if (glamor_priv->vbo_mapped) {
158 glUnmapBuffer(GL_ARRAY_BUFFER);
159 glamor_priv->vbo_mapped = FALSE;
160 }
161 } else {
162 glBufferData(GL_ARRAY_BUFFER, glamor_priv->vbo_offset,
163 glamor_priv->vb, GL_DYNAMIC_DRAW);
164 }
165
166 glBindBuffer(GL_ARRAY_BUFFER, 0);
167 }
168
169 void
glamor_init_vbo(ScreenPtr screen)170 glamor_init_vbo(ScreenPtr screen)
171 {
172 glamor_screen_private *glamor_priv = glamor_get_screen_private(screen);
173
174 glamor_make_current(glamor_priv);
175
176 glGenBuffers(1, &glamor_priv->vbo);
177 glGenVertexArrays(1, &glamor_priv->vao);
178 glBindVertexArray(glamor_priv->vao);
179 }
180
181 void
glamor_fini_vbo(ScreenPtr screen)182 glamor_fini_vbo(ScreenPtr screen)
183 {
184 glamor_screen_private *glamor_priv = glamor_get_screen_private(screen);
185
186 glamor_make_current(glamor_priv);
187
188 glDeleteVertexArrays(1, &glamor_priv->vao);
189 glamor_priv->vao = 0;
190 if (!glamor_priv->has_map_buffer_range)
191 free(glamor_priv->vb);
192 }
193