src/gallium/auxiliary/util/u_helpers.c

   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  */
  40 void 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  */
  79 void 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 }