src/base/pixel.cc

   1 /*
   2  * Copyright (c) 2015 ARM Limited
   3  * All rights reserved
   4  *
   5  * The license below extends only to copyright in the software and shall
   6  * not be construed as granting a license to any other intellectual
   7  * property including but not limited to intellectual property relating
   8  * to a hardware implementation of the functionality of the software
   9  * licensed hereunder.  You may use the software subject to the license
  10  * terms below provided that you ensure that this notice is replicated
  11  * unmodified and in its entirety in all distributions of the software,
  12  * modified or unmodified, in source code or in binary form.
  13  *
  14  * Redistribution and use in source and binary forms, with or without
  15  * modification, are permitted provided that the following conditions are
  16  * met: redistributions of source code must retain the above copyright
  17  * notice, this list of conditions and the following disclaimer;
  18  * redistributions in binary form must reproduce the above copyright
  19  * notice, this list of conditions and the following disclaimer in the
  20  * documentation and/or other materials provided with the distribution;
  21  * neither the name of the copyright holders nor the names of its
  22  * contributors may be used to endorse or promote products derived from
  23  * this software without specific prior written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  26  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  27  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  28  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  29  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  30  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  31  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  32  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  35  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38 #include "base/pixel.hh"
  39
  40 #include <cassert>
  41
  42 #include "base/bitfield.hh"
  43
  44 const PixelConverter PixelConverter::rgba8888_le(4, 0, 8, 16, 8, 8, 8);
  45 const PixelConverter PixelConverter::rgba8888_be(4, 0, 8, 16, 8, 8, 8,
  46                                                  ByteOrder::big);
  47 const PixelConverter PixelConverter::rgb565_le(2,  0, 5, 11, 5, 6, 5);
  48 const PixelConverter PixelConverter::rgb565_be(2,  0, 5, 11, 5, 6, 5,
  49                                                ByteOrder::big);
  50
  51 PixelConverter::PixelConverter(unsigned _length,
  52                                unsigned ro, unsigned go, unsigned bo,
  53                                unsigned rw, unsigned gw, unsigned bw,
  54                                ByteOrder _byte_order)
  55     : length(_length),
  56       depth(rw + gw + bw),
  57       byte_order(_byte_order),
  58       ch_r(ro, rw),
  59       ch_g(go, gw),
  60       ch_b(bo, bw)
  61 {
  62     assert(length > 1);
  63 }
  64
  65 PixelConverter::Channel::Channel(unsigned _offset, unsigned width)
  66     : offset(_offset),
  67       mask(::mask(width)),
  68       factor(255.0 / mask)
  69 {
  70 }
  71
  72 uint32_t
  73 PixelConverter::readWord(const uint8_t *p) const
  74 {
  75     uint32_t word(0);
  76
  77     if (byte_order == ByteOrder::little) {
  78         for (int i = 0; i < length; ++i)
  79             word |= p[i] << (8 * i);
  80     } else {
  81         for (int i = 0; i < length; ++i)
  82             word |= p[i] << (8 * (length - i - 1));
  83     }
  84
  85     return word;
  86 }
  87
  88 void
  89 PixelConverter::writeWord(uint8_t *p, uint32_t word) const
  90 {
  91     if (byte_order == ByteOrder::little) {
  92         for (int i = 0; i < length; ++i)
  93             p[i] = (word >> (8 * i)) & 0xFF;
  94     } else {
  95         for (int i = 0; i < length; ++i)
  96             p[i] = (word >> (8 * (length - i - 1))) & 0xFF;
  97     }
  98 }