src/gallium/auxiliary/util/u_draw.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2011 VMware, Inc.
   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 VMWARE AND/OR ITS 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
  29 #include "util/u_debug.h"
  30 #include "util/u_inlines.h"
  31 #include "util/u_math.h"
  32 #include "util/format/u_format.h"
  33 #include "util/u_draw.h"
  34
  35
  36 /**
  37  * Returns the largest legal index value plus one for the current set
  38  * of bound vertex buffers.  Regardless of any other consideration,
  39  * all vertex lookups need to be clamped to 0..max_index-1 to prevent
  40  * an out-of-bound access.
  41  *
  42  * Note that if zero is returned it means that one or more buffers is
  43  * too small to contain any valid vertex data.
  44  */
  45 unsigned
  46 util_draw_max_index(
  47       const struct pipe_vertex_buffer *vertex_buffers,
  48       const struct pipe_vertex_element *vertex_elements,
  49       unsigned nr_vertex_elements,
  50       const struct pipe_draw_info *info)
  51 {
  52    unsigned max_index;
  53    unsigned i;
  54
  55    max_index = ~0U - 1;
  56    for (i = 0; i < nr_vertex_elements; i++) {
  57       const struct pipe_vertex_element *element =
  58          &vertex_elements[i];
  59       const struct pipe_vertex_buffer *buffer =
  60          &vertex_buffers[element->vertex_buffer_index];
  61       unsigned buffer_size;
  62       const struct util_format_description *format_desc;
  63       unsigned format_size;
  64
  65       if (buffer->is_user_buffer || !buffer->buffer.resource) {
  66          continue;
  67       }
  68
  69       assert(buffer->buffer.resource->height0 == 1);
  70       assert(buffer->buffer.resource->depth0 == 1);
  71       buffer_size = buffer->buffer.resource->width0;
  72
  73       format_desc = util_format_description(element->src_format);
  74       assert(format_desc->block.width == 1);
  75       assert(format_desc->block.height == 1);
  76       assert(format_desc->block.bits % 8 == 0);
  77       format_size = format_desc->block.bits/8;
  78
  79       if (buffer->buffer_offset >= buffer_size) {
  80          /* buffer is too small */
  81          return 0;
  82       }
  83
  84       buffer_size -= buffer->buffer_offset;
  85
  86       if (element->src_offset >= buffer_size) {
  87          /* buffer is too small */
  88          return 0;
  89       }
  90
  91       buffer_size -= element->src_offset;
  92
  93       if (format_size > buffer_size) {
  94          /* buffer is too small */
  95          return 0;
  96       }
  97
  98       buffer_size -= format_size;
  99
 100       if (buffer->stride != 0) {
 101          unsigned buffer_max_index;
 102
 103          buffer_max_index = buffer_size / buffer->stride;
 104
 105          if (element->instance_divisor == 0) {
 106             /* Per-vertex data */
 107             max_index = MIN2(max_index, buffer_max_index);
 108          }
 109          else {
 110             /* Per-instance data. Simply make sure gallium frontends didn't
 111              * request more instances than those that fit in the buffer */
 112             if ((info->start_instance + info->instance_count)/element->instance_divisor
 113                 > (buffer_max_index + 1)) {
 114                /* FIXME: We really should stop thinking in terms of maximum
 115                 * indices/instances and simply start clamping against buffer
 116                 * size. */
 117                debug_printf("%s: too many instances for vertex buffer\n",
 118                             __FUNCTION__);
 119                return 0;
 120             }
 121          }
 122       }
 123    }
 124
 125    return max_index + 1;
 126 }
 127
 128
 129 /* This extracts the draw arguments from the info_in->indirect resource,
 130  * puts them into a new instance of pipe_draw_info, and calls draw_vbo on it.
 131  */
 132 void
 133 util_draw_indirect(struct pipe_context *pipe,
 134                    const struct pipe_draw_info *info_in)
 135 {
 136    struct pipe_draw_info info;
 137    struct pipe_transfer *transfer;
 138    uint32_t *params;
 139    unsigned num_params = info_in->index_size ? 5 : 4;
 140
 141    assert(info_in->indirect);
 142    assert(!info_in->count_from_stream_output);
 143
 144    memcpy(&info, info_in, sizeof(info));
 145
 146    uint32_t draw_count = info_in->indirect->draw_count;
 147
 148    if (info_in->indirect->indirect_draw_count) {
 149       struct pipe_transfer *dc_transfer;
 150       uint32_t *dc_param = pipe_buffer_map_range(pipe,
 151                                                  info_in->indirect->indirect_draw_count,
 152                                                  info_in->indirect->indirect_draw_count_offset,
 153                                                  4, PIPE_TRANSFER_READ, &dc_transfer);
 154       if (!dc_transfer) {
 155          debug_printf("%s: failed to map indirect draw count buffer\n", __FUNCTION__);
 156          return;
 157       }
 158       if (dc_param[0] < draw_count)
 159          draw_count = dc_param[0];
 160       pipe_buffer_unmap(pipe, dc_transfer);
 161    }
 162
 163    if (info_in->indirect->stride)
 164       num_params = MIN2(info_in->indirect->stride / 4, num_params);
 165    params = (uint32_t *)
 166       pipe_buffer_map_range(pipe,
 167                             info_in->indirect->buffer,
 168                             info_in->indirect->offset,
 169                             (num_params * info_in->indirect->draw_count) * sizeof(uint32_t),
 170                             PIPE_TRANSFER_READ,
 171                             &transfer);
 172    if (!transfer) {
 173       debug_printf("%s: failed to map indirect buffer\n", __FUNCTION__);
 174       return;
 175    }
 176
 177    for (unsigned i = 0; i < draw_count; i++) {
 178       info.count = params[0];
 179       info.instance_count = params[1];
 180       info.start = params[2];
 181       info.index_bias = info_in->index_size ? params[3] : 0;
 182       info.start_instance = info_in->index_size ? params[4] : params[3];
 183       info.drawid = i;
 184       info.indirect = NULL;
 185
 186       pipe->draw_vbo(pipe, &info);
 187
 188       params += info_in->indirect->stride / 4;
 189    }
 190    pipe_buffer_unmap(pipe, transfer);
 191 }