u_helpers.c revision 848b8605 
1/**************************************************************************
2 *
3 * Copyright 2012 Marek Olšák <maraeo@gmail.com>
4 * All Rights Reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sub license, and/or sell copies of the Software, and to
11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
13 *
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
16 * of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
19 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
21 * IN NO EVENT SHALL THE AUTHORS AND/OR THEIR SUPPLIERS BE LIABLE FOR
22 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
23 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
24 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
25 *
26 **************************************************************************/
27
28#include "util/u_helpers.h"
29#include "util/u_inlines.h"
30
31/**
32 * This function is used to copy an array of pipe_vertex_buffer structures,
33 * while properly referencing the pipe_vertex_buffer::buffer member.
34 *
35 * enabled_buffers is updated such that the bits corresponding to the indices
36 * of disabled buffers are set to 0 and the enabled ones are set to 1.
37 *
38 * \sa util_copy_framebuffer_state
39 */
40void util_set_vertex_buffers_mask(struct pipe_vertex_buffer *dst,
41                                  uint32_t *enabled_buffers,
42                                  const struct pipe_vertex_buffer *src,
43                                  unsigned start_slot, unsigned count)
44{
45   unsigned i;
46   uint32_t bitmask = 0;
47
48   dst += start_slot;
49
50   if (src) {
51      for (i = 0; i < count; i++) {
52         if (src[i].buffer || src[i].user_buffer) {
53            bitmask |= 1 << i;
54         }
55         pipe_resource_reference(&dst[i].buffer, src[i].buffer);
56      }
57
58      /* Copy over the other members of pipe_vertex_buffer. */
59      memcpy(dst, src, count * sizeof(struct pipe_vertex_buffer));
60
61      *enabled_buffers &= ~(((1ull << count) - 1) << start_slot);
62      *enabled_buffers |= bitmask << start_slot;
63   }
64   else {
65      /* Unreference the buffers. */
66      for (i = 0; i < count; i++) {
67         pipe_resource_reference(&dst[i].buffer, NULL);
68         dst[i].user_buffer = NULL;
69      }
70
71      *enabled_buffers &= ~(((1ull << count) - 1) << start_slot);
72   }
73}
74
75/**
76 * Same as util_set_vertex_buffers_mask, but it only returns the number
77 * of bound buffers.
78 */
79void util_set_vertex_buffers_count(struct pipe_vertex_buffer *dst,
80                                   unsigned *dst_count,
81                                   const struct pipe_vertex_buffer *src,
82                                   unsigned start_slot, unsigned count)
83{
84   uint32_t enabled_buffers = (1ull << *dst_count) - 1;
85
86   util_set_vertex_buffers_mask(dst, &enabled_buffers, src, start_slot,
87                                count);
88
89   *dst_count = util_last_bit(enabled_buffers);
90}
91