aboutsummaryrefslogtreecommitdiff
path: root/mesalib/src/gallium/auxiliary/util/u_draw.c
blob: b9f8fcd3c2ac873058d4cc18f6626b8804a1cdbc (plain)
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
/**************************************************************************
 *
 * Copyright 2011 VMware, Inc.
 * All Rights Reserved.
 *
 * 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, sub license, 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 NON-INFRINGEMENT.
 * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS 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.
 *
 **************************************************************************/


#include "util/u_debug.h"
#include "util/u_inlines.h"
#include "util/u_math.h"
#include "util/u_format.h"
#include "util/u_draw.h"


/**
 * Returns the largest legal index value plus one for the current set
 * of bound vertex buffers.  Regardless of any other consideration,
 * all vertex lookups need to be clamped to 0..max_index-1 to prevent
 * an out-of-bound access.
 *
 * Note that if zero is returned it means that one or more buffers is
 * too small to contain any valid vertex data.
 */
unsigned
util_draw_max_index(
      const struct pipe_vertex_buffer *vertex_buffers,
      const struct pipe_vertex_element *vertex_elements,
      unsigned nr_vertex_elements,
      const struct pipe_draw_info *info)
{
   unsigned max_index;
   unsigned i;

   max_index = ~0U - 1;
   for (i = 0; i < nr_vertex_elements; i++) {
      const struct pipe_vertex_element *element =
         &vertex_elements[i];
      const struct pipe_vertex_buffer *buffer =
         &vertex_buffers[element->vertex_buffer_index];
      unsigned buffer_size;
      const struct util_format_description *format_desc;
      unsigned format_size;

      if (!buffer->buffer) {
         continue;
      }

      assert(buffer->buffer->height0 == 1);
      assert(buffer->buffer->depth0 == 1);
      buffer_size = buffer->buffer->width0;

      format_desc = util_format_description(element->src_format);
      assert(format_desc->block.width == 1);
      assert(format_desc->block.height == 1);
      assert(format_desc->block.bits % 8 == 0);
      format_size = format_desc->block.bits/8;

      if (buffer->buffer_offset >= buffer_size) {
         /* buffer is too small */
         return 0;
      }

      buffer_size -= buffer->buffer_offset;

      if (element->src_offset >= buffer_size) {
         /* buffer is too small */
         return 0;
      }

      buffer_size -= element->src_offset;

      if (format_size > buffer_size) {
         /* buffer is too small */
         return 0;
      }

      buffer_size -= format_size;

      if (buffer->stride != 0) {
         unsigned buffer_max_index;

         buffer_max_index = buffer_size / buffer->stride;

         if (element->instance_divisor == 0) {
            /* Per-vertex data */
            max_index = MIN2(max_index, buffer_max_index);
         }
         else {
            /* Per-instance data. Simply make sure the state tracker didn't
             * request more instances than those that fit in the buffer */
            if ((info->start_instance + info->instance_count)/element->instance_divisor
                > (buffer_max_index + 1)) {
               /* FIXME: We really should stop thinking in terms of maximum
                * indices/instances and simply start clamping against buffer
                * size. */
               debug_printf("%s: too many instances for vertex buffer\n",
                            __FUNCTION__);
               return 0;
            }
         }
      }
   }

   return max_index + 1;
}


/* This extracts the draw arguments from the info_in->indirect resource,
 * puts them into a new instance of pipe_draw_info, and calls draw_vbo on it.
 */
void
util_draw_indirect(struct pipe_context *pipe,
                   const struct pipe_draw_info *info_in)
{
   struct pipe_draw_info info;
   struct pipe_transfer *transfer;
   uint32_t *params;
   const unsigned num_params = info_in->indexed ? 5 : 4;

   assert(info_in->indirect);
   assert(!info_in->count_from_stream_output);

   memcpy(&info, info_in, sizeof(info));

   params = (uint32_t *)
      pipe_buffer_map_range(pipe,
                            info_in->indirect,
                            info_in->indirect_offset,
                            num_params * sizeof(uint32_t),
                            PIPE_TRANSFER_READ,
                            &transfer);
   if (!transfer) {
      debug_printf("%s: failed to map indirect buffer\n", __FUNCTION__);
      return;
   }

   info.count = params[0];
   info.instance_count = params[1];
   info.start = params[2];
   info.index_bias = info_in->indexed ? params[3] : 0;
   info.start_instance = info_in->indexed ? params[4] : params[3];
   info.indirect = NULL;

   pipe_buffer_unmap(pipe, transfer);

   pipe->draw_vbo(pipe, &info);
}