1/*
2 * Copyright (c) 2017 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 * Authors: Giacomo Travaglini
38 */
39
40/**
41 * @file Definition of a class that writes a frame buffer to a png
42 */
43
44#include "base/pngwriter.hh"
45
46extern "C"
47{
48#include <png.h>
49}
50
51#include <cstdio>
52#include <cstdlib>
53
54#include "base/logging.hh"
55
56const char* PngWriter::_imgExtension = "png";
57
58/**
59 * Write callback to use with libpng APIs
60 *
61 * @param pngPtr  pointer to the png_struct structure
62 * @param data    pointer to the data being written
63 * @param length  number of bytes being written
64 */
65static void
66writePng(png_structp pngPtr, png_bytep data, png_size_t length)
67{
68    // Here we get our IO pointer back from the write struct
69    // and we cast it into a ostream* type.
70    std::ostream* strmPtr = reinterpret_cast<std::ostream*>(
71        png_get_io_ptr(pngPtr)
72    );
73
74    // Write length bytes to data
75    strmPtr->write(reinterpret_cast<const char *>(data), length);
76}
77
78struct PngWriter::PngStructHandle {
79  private:
80    // Make PngStructHandle uncopyable
81    PngStructHandle(const PngStructHandle&) = delete;
82    PngStructHandle& operator=(const PngStructHandle&) = delete;
83  public:
84
85    PngStructHandle() :
86        pngWriteP(NULL), pngInfoP(NULL)
87    {
88        // Creating write structure
89        pngWriteP = png_create_write_struct(
90            PNG_LIBPNG_VER_STRING, NULL, NULL, NULL
91        );
92
93        if (pngWriteP) {
94            // Creating info structure
95            pngInfoP = png_create_info_struct(pngWriteP);
96        }
97    }
98
99    ~PngStructHandle()
100    {
101        if (pngWriteP) {
102            png_destroy_write_struct(&pngWriteP, &pngInfoP);
103        }
104    }
105
106    /** Pointer to PNG Write struct */
107    png_structp pngWriteP;
108
109    /** Pointer to PNG Info struct */
110    png_infop pngInfoP;
111};
112
113void
114PngWriter::write(std::ostream &png) const
115{
116
117    // Height of the frame buffer
118    unsigned height = fb.height();
119    unsigned width  = fb.width();
120
121    // Do not write if frame buffer is empty
122    if (!fb.area()) {
123        png.flush();
124        return;
125    }
126
127    // Initialize Png structures
128    PngStructHandle handle;
129
130    // Png info/write pointers.
131    png_structp pngPtr  = handle.pngWriteP;
132    png_infop   infoPtr = handle.pngInfoP;
133
134    if (!pngPtr) {
135        warn("Frame buffer dump aborted: Unable to create"
136             "Png Write Struct\n");
137        return;
138    }
139
140    if (!infoPtr) {
141        warn("Frame buffer dump aborted: Unable to create"
142             "Png Info Struct\n");
143        return;
144    }
145
146    // We cannot use default libpng write function since it requires
147    // a file pointer (FILE*), whereas we want to use the ostream.
148    // The following function replaces the write function with a custom
149    // one provided by us (writePng)
150    png_set_write_fn(pngPtr, (png_voidp)&png, writePng, NULL);
151
152    png_set_IHDR(pngPtr, infoPtr, width, height, 8,
153                 PNG_COLOR_TYPE_RGB,
154                 PNG_INTERLACE_NONE,
155                 PNG_COMPRESSION_TYPE_DEFAULT,
156                 PNG_FILTER_TYPE_DEFAULT);
157
158    png_write_info(pngPtr, infoPtr);
159
160    // libpng requires an array of pointers to the frame buffer's rows.
161    std::vector<PixelType> rowPacked(width);
162    for (unsigned y=0; y < height; ++y) {
163        for (unsigned x=0; x < width; ++x) {
164            rowPacked[x] = fb.pixel(x, y);
165        }
166
167        png_write_row(pngPtr,
168            reinterpret_cast<png_bytep>(rowPacked.data())
169        );
170    }
171
172    // End of write
173    png_write_end(pngPtr, NULL);
174}
175
176