1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
|
/*
* Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
* All Rights Reserved.
*
* Copyright © 2012 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*
* Authors:
* Jordan Justen <jordan.l.justen@intel.com>
*
*/
#include "main/imports.h"
#include "main/bufferobj.h"
#include "main/macros.h"
#include "main/varray.h"
#include "vbo.h"
#include "vbo_context.h"
#define UPDATE_MIN2(a, b) (a) = MIN2((a), (b))
#define UPDATE_MAX2(a, b) (a) = MAX2((a), (b))
/*
* Notes on primitive restart:
* The code below is used when the driver does not support primitive
* restart itself. (ctx->Const.PrimitiveRestartInSoftware == GL_TRUE)
*
* We map the index buffer, find the restart indexes, unmap
* the index buffer then draw the sub-primitives delineated by the restarts.
*
* A couple possible optimizations:
* 1. Save the list of sub-primitive (start, count) values in a list attached
* to the index buffer for re-use in subsequent draws. The list would be
* invalidated when the contents of the buffer changed.
* 2. If drawing triangle strips or quad strips, create a new index buffer
* that uses duplicated vertices to render the disjoint strips as one
* long strip. We'd have to be careful to avoid using too much memory
* for this.
*
* Finally, some apps might perform better if they don't use primitive restart
* at all rather than this fallback path. Set MESA_EXTENSION_OVERRIDE to
* "-GL_NV_primitive_restart" to test that.
*/
struct sub_primitive
{
GLuint start;
GLuint count;
GLuint min_index;
GLuint max_index;
};
/**
* Scan the elements array to find restart indexes. Return an array
* of struct sub_primitive to indicate how to draw the sub-primitives
* are delineated by the restart index.
*/
static struct sub_primitive *
find_sub_primitives(const void *elements, unsigned element_size,
unsigned start, unsigned end, unsigned restart_index,
unsigned *num_sub_prims)
{
const unsigned max_prims = end - start;
struct sub_primitive *sub_prims;
unsigned i, cur_start, cur_count;
GLuint scan_index;
unsigned scan_num;
sub_prims =
malloc(max_prims * sizeof(struct sub_primitive));
if (!sub_prims) {
*num_sub_prims = 0;
return NULL;
}
cur_start = start;
cur_count = 0;
scan_num = 0;
#define IB_INDEX_READ(TYPE, INDEX) (((const GL##TYPE *) elements)[INDEX])
#define SCAN_ELEMENTS(TYPE) \
sub_prims[scan_num].min_index = (GL##TYPE) 0xffffffff; \
sub_prims[scan_num].max_index = 0; \
for (i = start; i < end; i++) { \
scan_index = IB_INDEX_READ(TYPE, i); \
if (scan_index == restart_index) { \
if (cur_count > 0) { \
assert(scan_num < max_prims); \
sub_prims[scan_num].start = cur_start; \
sub_prims[scan_num].count = cur_count; \
scan_num++; \
sub_prims[scan_num].min_index = (GL##TYPE) 0xffffffff; \
sub_prims[scan_num].max_index = 0; \
} \
cur_start = i + 1; \
cur_count = 0; \
} \
else { \
UPDATE_MIN2(sub_prims[scan_num].min_index, scan_index); \
UPDATE_MAX2(sub_prims[scan_num].max_index, scan_index); \
cur_count++; \
} \
} \
if (cur_count > 0) { \
assert(scan_num < max_prims); \
sub_prims[scan_num].start = cur_start; \
sub_prims[scan_num].count = cur_count; \
scan_num++; \
}
switch (element_size) {
case 1:
SCAN_ELEMENTS(ubyte);
break;
case 2:
SCAN_ELEMENTS(ushort);
break;
case 4:
SCAN_ELEMENTS(uint);
break;
default:
assert(0 && "bad index_size in find_sub_primitives()");
}
#undef SCAN_ELEMENTS
*num_sub_prims = scan_num;
return sub_prims;
}
/**
* Handle primitive restart in software.
*
* This function breaks up calls into the driver so primitive restart
* support is not required in the driver.
*/
void
vbo_sw_primitive_restart(struct gl_context *ctx,
const struct _mesa_prim *prims,
GLuint nr_prims,
const struct _mesa_index_buffer *ib,
struct gl_buffer_object *indirect)
{
GLuint prim_num;
struct sub_primitive *sub_prims;
struct sub_primitive *sub_prim;
GLuint num_sub_prims;
GLuint sub_prim_num;
GLuint end_index;
GLuint sub_end_index;
GLuint restart_index = _mesa_primitive_restart_index(ctx, ib->type);
struct _mesa_prim temp_prim;
struct vbo_context *vbo = vbo_context(ctx);
vbo_draw_func draw_prims_func = vbo->draw_prims;
GLboolean map_ib = ib->obj->Name && !ib->obj->Pointer;
void *ptr;
/* Find the sub-primitives. These are regions in the index buffer which
* are split based on the primitive restart index value.
*/
if (map_ib) {
ctx->Driver.MapBufferRange(ctx, 0, ib->obj->Size, GL_MAP_READ_BIT,
ib->obj);
}
ptr = ADD_POINTERS(ib->obj->Pointer, ib->ptr);
sub_prims = find_sub_primitives(ptr, vbo_sizeof_ib_type(ib->type),
0, ib->count, restart_index,
&num_sub_prims);
if (map_ib) {
ctx->Driver.UnmapBuffer(ctx, ib->obj);
}
/* Loop over the primitives, and use the located sub-primitives to draw
* each primitive with a break to implement each primitive restart.
*/
for (prim_num = 0; prim_num < nr_prims; prim_num++) {
end_index = prims[prim_num].start + prims[prim_num].count;
memcpy(&temp_prim, &prims[prim_num], sizeof (temp_prim));
/* Loop over the sub-primitives drawing sub-ranges of the primitive. */
for (sub_prim_num = 0; sub_prim_num < num_sub_prims; sub_prim_num++) {
sub_prim = &sub_prims[sub_prim_num];
sub_end_index = sub_prim->start + sub_prim->count;
if (prims[prim_num].start <= sub_prim->start) {
temp_prim.start = MAX2(prims[prim_num].start, sub_prim->start);
temp_prim.count = MIN2(sub_end_index, end_index) - temp_prim.start;
if ((temp_prim.start == sub_prim->start) &&
(temp_prim.count == sub_prim->count)) {
draw_prims_func(ctx, &temp_prim, 1, ib,
GL_TRUE, sub_prim->min_index, sub_prim->max_index,
NULL, NULL);
} else {
draw_prims_func(ctx, &temp_prim, 1, ib,
GL_FALSE, -1, -1,
NULL, NULL);
}
}
if (sub_end_index >= end_index) {
break;
}
}
}
free(sub_prims);
}
|
