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<h1 class="title">waveform.cpp Example File</h1>
<span class="subtitle">multimedia/spectrum/app/waveform.cpp</span>
<!-- $$$multimedia/spectrum/app/waveform.cpp-description -->
<div class="descr"> <a name="details"></a>
<pre class="cpp">
<span class="comment">/****************************************************************************
**
** Copyright (C) 2017 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** BSD License Usage
** Alternatively, you may use this file under the terms of the BSD license
** as follows:
**
** "Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are
** met:
** * Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** * Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in
** the documentation and/or other materials provided with the
** distribution.
** * Neither the name of The Qt Company Ltd nor the names of its
** contributors may be used to endorse or promote products derived
** from this software without specific prior written permission.
**
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
**
** $QT_END_LICENSE$
**
****************************************************************************/</span>
<span class="preprocessor">#include "waveform.h"</span>
<span class="preprocessor">#include "utils.h"</span>
<span class="preprocessor">#include <QPainter></span>
<span class="preprocessor">#include <QResizeEvent></span>
<span class="preprocessor">#include <QDebug></span>
<span class="comment">//#define PAINT_EVENT_TRACE</span>
<span class="preprocessor">#ifdef PAINT_EVENT_TRACE</span>
<span class="preprocessor"># define WAVEFORM_PAINT_DEBUG qDebug()</span>
<span class="preprocessor">#else</span>
<span class="preprocessor"># define WAVEFORM_PAINT_DEBUG nullDebug()</span>
<span class="preprocessor">#endif</span>
Waveform<span class="operator">::</span>Waveform(<span class="type">QWidget</span> <span class="operator">*</span>parent)
: <span class="type">QWidget</span>(parent)
<span class="operator">,</span> m_bufferPosition(<span class="number">0</span>)
<span class="operator">,</span> m_bufferLength(<span class="number">0</span>)
<span class="operator">,</span> m_audioPosition(<span class="number">0</span>)
<span class="operator">,</span> m_active(<span class="keyword">false</span>)
<span class="operator">,</span> m_tileLength(<span class="number">0</span>)
<span class="operator">,</span> m_tileArrayStart(<span class="number">0</span>)
<span class="operator">,</span> m_windowPosition(<span class="number">0</span>)
<span class="operator">,</span> m_windowLength(<span class="number">0</span>)
{
setSizePolicy(<span class="type">QSizePolicy</span><span class="operator">::</span>Preferred<span class="operator">,</span> <span class="type">QSizePolicy</span><span class="operator">::</span>Fixed);
setMinimumHeight(<span class="number">50</span>);
}
Waveform<span class="operator">::</span><span class="operator">~</span>Waveform()
{
deletePixmaps();
}
<span class="type">void</span> Waveform<span class="operator">::</span>paintEvent(<span class="type">QPaintEvent</span> <span class="operator">*</span> <span class="comment">/*event*/</span>)
{
<span class="type">QPainter</span> painter(<span class="keyword">this</span>);
painter<span class="operator">.</span>fillRect(rect()<span class="operator">,</span> <span class="type">Qt</span><span class="operator">::</span>black);
<span class="keyword">if</span> (m_active) {
WAVEFORM_PAINT_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Waveform::paintEvent"</span>
<span class="operator"><</span><span class="operator"><</span> <span class="string">"windowPosition"</span> <span class="operator"><</span><span class="operator"><</span> m_windowPosition
<span class="operator"><</span><span class="operator"><</span> <span class="string">"windowLength"</span> <span class="operator"><</span><span class="operator"><</span> m_windowLength;
<span class="type">qint64</span> pos <span class="operator">=</span> m_windowPosition;
<span class="keyword">const</span> <span class="type">qint64</span> windowEnd <span class="operator">=</span> m_windowPosition <span class="operator">+</span> m_windowLength;
<span class="type">int</span> destLeft <span class="operator">=</span> <span class="number">0</span>;
<span class="type">int</span> destRight <span class="operator">=</span> <span class="number">0</span>;
<span class="keyword">while</span> (pos <span class="operator"><</span> windowEnd) {
<span class="keyword">const</span> TilePoint point <span class="operator">=</span> tilePoint(pos);
WAVEFORM_PAINT_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Waveform::paintEvent"</span> <span class="operator"><</span><span class="operator"><</span> <span class="string">"pos"</span> <span class="operator"><</span><span class="operator"><</span> pos
<span class="operator"><</span><span class="operator"><</span> <span class="string">"tileIndex"</span> <span class="operator"><</span><span class="operator"><</span> point<span class="operator">.</span>index
<span class="operator"><</span><span class="operator"><</span> <span class="string">"positionOffset"</span> <span class="operator"><</span><span class="operator"><</span> point<span class="operator">.</span>positionOffset
<span class="operator"><</span><span class="operator"><</span> <span class="string">"pixelOffset"</span> <span class="operator"><</span><span class="operator"><</span> point<span class="operator">.</span>pixelOffset;
<span class="keyword">if</span> (point<span class="operator">.</span>index <span class="operator">!</span><span class="operator">=</span> NullIndex) {
<span class="keyword">const</span> Tile <span class="operator">&</span>tile <span class="operator">=</span> m_tiles<span class="operator">[</span>point<span class="operator">.</span>index<span class="operator">]</span>;
<span class="keyword">if</span> (tile<span class="operator">.</span>painted) {
<span class="keyword">const</span> <span class="type">qint64</span> sectionLength <span class="operator">=</span> qMin((m_tileLength <span class="operator">-</span> point<span class="operator">.</span>positionOffset)<span class="operator">,</span>
(windowEnd <span class="operator">-</span> pos));
Q_ASSERT(sectionLength <span class="operator">></span> <span class="number">0</span>);
<span class="keyword">const</span> <span class="type">int</span> sourceRight <span class="operator">=</span> tilePixelOffset(point<span class="operator">.</span>positionOffset <span class="operator">+</span> sectionLength);
destRight <span class="operator">=</span> windowPixelOffset(pos <span class="operator">-</span> m_windowPosition <span class="operator">+</span> sectionLength);
<span class="type">QRect</span> destRect <span class="operator">=</span> rect();
destRect<span class="operator">.</span>setLeft(destLeft);
destRect<span class="operator">.</span>setRight(destRight);
<span class="type">QRect</span> sourceRect(<span class="type">QPoint</span>()<span class="operator">,</span> m_pixmapSize);
sourceRect<span class="operator">.</span>setLeft(point<span class="operator">.</span>pixelOffset);
sourceRect<span class="operator">.</span>setRight(sourceRight);
WAVEFORM_PAINT_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Waveform::paintEvent"</span> <span class="operator"><</span><span class="operator"><</span> <span class="string">"tileIndex"</span> <span class="operator"><</span><span class="operator"><</span> point<span class="operator">.</span>index
<span class="operator"><</span><span class="operator"><</span> <span class="string">"source"</span> <span class="operator"><</span><span class="operator"><</span> point<span class="operator">.</span>pixelOffset <span class="operator"><</span><span class="operator"><</span> sourceRight
<span class="operator"><</span><span class="operator"><</span> <span class="string">"dest"</span> <span class="operator"><</span><span class="operator"><</span> destLeft <span class="operator"><</span><span class="operator"><</span> destRight;
painter<span class="operator">.</span>drawPixmap(destRect<span class="operator">,</span> <span class="operator">*</span>tile<span class="operator">.</span>pixmap<span class="operator">,</span> sourceRect);
destLeft <span class="operator">=</span> destRight;
<span class="keyword">if</span> (point<span class="operator">.</span>index <span class="operator"><</span> m_tiles<span class="operator">.</span>count()) {
pos <span class="operator">=</span> tilePosition(point<span class="operator">.</span>index <span class="operator">+</span> <span class="number">1</span>);
WAVEFORM_PAINT_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Waveform::paintEvent"</span> <span class="operator"><</span><span class="operator"><</span> <span class="string">"pos ->"</span> <span class="operator"><</span><span class="operator"><</span> pos;
} <span class="keyword">else</span> {
<span class="comment">// Reached end of tile array</span>
WAVEFORM_PAINT_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Waveform::paintEvent"</span> <span class="operator"><</span><span class="operator"><</span> <span class="string">"reached end of tile array"</span>;
<span class="keyword">break</span>;
}
} <span class="keyword">else</span> {
<span class="comment">// Passed last tile which is painted</span>
WAVEFORM_PAINT_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Waveform::paintEvent"</span> <span class="operator"><</span><span class="operator"><</span> <span class="string">"tile"</span> <span class="operator"><</span><span class="operator"><</span> point<span class="operator">.</span>index <span class="operator"><</span><span class="operator"><</span> <span class="string">"not painted"</span>;
<span class="keyword">break</span>;
}
} <span class="keyword">else</span> {
<span class="comment">// pos is past end of tile array</span>
WAVEFORM_PAINT_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Waveform::paintEvent"</span> <span class="operator"><</span><span class="operator"><</span> <span class="string">"pos"</span> <span class="operator"><</span><span class="operator"><</span> pos <span class="operator"><</span><span class="operator"><</span> <span class="string">"past end of tile array"</span>;
<span class="keyword">break</span>;
}
}
WAVEFORM_PAINT_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Waveform::paintEvent"</span> <span class="operator"><</span><span class="operator"><</span> <span class="string">"final pos"</span> <span class="operator"><</span><span class="operator"><</span> pos <span class="operator"><</span><span class="operator"><</span> <span class="string">"final x"</span> <span class="operator"><</span><span class="operator"><</span> destRight;
}
}
<span class="type">void</span> Waveform<span class="operator">::</span>resizeEvent(<span class="type">QResizeEvent</span> <span class="operator">*</span>event)
{
<span class="keyword">if</span> (event<span class="operator">-</span><span class="operator">></span>size() <span class="operator">!</span><span class="operator">=</span> event<span class="operator">-</span><span class="operator">></span>oldSize())
createPixmaps(event<span class="operator">-</span><span class="operator">></span>size());
}
<span class="type">void</span> Waveform<span class="operator">::</span>initialize(<span class="keyword">const</span> <span class="type"><a href="qaudioformat.html">QAudioFormat</a></span> <span class="operator">&</span>format<span class="operator">,</span> <span class="type">qint64</span> audioBufferSize<span class="operator">,</span> <span class="type">qint64</span> windowDurationUs)
{
WAVEFORM_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Waveform::initialize"</span>
<span class="operator"><</span><span class="operator"><</span> <span class="string">"audioBufferSize"</span> <span class="operator"><</span><span class="operator"><</span> audioBufferSize
<span class="operator"><</span><span class="operator"><</span> <span class="string">"windowDurationUs"</span> <span class="operator"><</span><span class="operator"><</span> windowDurationUs;
reset();
m_format <span class="operator">=</span> format;
<span class="comment">// Calculate tile size</span>
m_tileLength <span class="operator">=</span> audioBufferSize;
<span class="comment">// Calculate window size</span>
m_windowLength <span class="operator">=</span> audioLength(m_format<span class="operator">,</span> windowDurationUs);
<span class="comment">// Calculate number of tiles required</span>
<span class="type">int</span> nTiles;
<span class="keyword">if</span> (m_tileLength <span class="operator">></span> m_windowLength) {
nTiles <span class="operator">=</span> <span class="number">2</span>;
} <span class="keyword">else</span> {
nTiles <span class="operator">=</span> m_windowLength <span class="operator">/</span> m_tileLength <span class="operator">+</span> <span class="number">1</span>;
<span class="keyword">if</span> (m_windowLength <span class="operator">%</span> m_tileLength)
<span class="operator">+</span><span class="operator">+</span>nTiles;
}
WAVEFORM_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Waveform::initialize"</span>
<span class="operator"><</span><span class="operator"><</span> <span class="string">"tileLength"</span> <span class="operator"><</span><span class="operator"><</span> m_tileLength
<span class="operator"><</span><span class="operator"><</span> <span class="string">"windowLength"</span> <span class="operator"><</span><span class="operator"><</span> m_windowLength
<span class="operator"><</span><span class="operator"><</span> <span class="string">"nTiles"</span> <span class="operator"><</span><span class="operator"><</span> nTiles;
m_pixmaps<span class="operator">.</span>fill(<span class="number">0</span><span class="operator">,</span> nTiles);
m_tiles<span class="operator">.</span>resize(nTiles);
createPixmaps(rect()<span class="operator">.</span>size());
m_active <span class="operator">=</span> <span class="keyword">true</span>;
}
<span class="type">void</span> Waveform<span class="operator">::</span>reset()
{
WAVEFORM_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Waveform::reset"</span>;
m_bufferPosition <span class="operator">=</span> <span class="number">0</span>;
m_buffer <span class="operator">=</span> <span class="type">QByteArray</span>();
m_audioPosition <span class="operator">=</span> <span class="number">0</span>;
m_format <span class="operator">=</span> <span class="type"><a href="qaudioformat.html">QAudioFormat</a></span>();
m_active <span class="operator">=</span> <span class="keyword">false</span>;
deletePixmaps();
m_tiles<span class="operator">.</span>clear();
m_tileLength <span class="operator">=</span> <span class="number">0</span>;
m_tileArrayStart <span class="operator">=</span> <span class="number">0</span>;
m_windowPosition <span class="operator">=</span> <span class="number">0</span>;
m_windowLength <span class="operator">=</span> <span class="number">0</span>;
}
<span class="type">void</span> Waveform<span class="operator">::</span>bufferChanged(<span class="type">qint64</span> position<span class="operator">,</span> <span class="type">qint64</span> length<span class="operator">,</span> <span class="keyword">const</span> <span class="type">QByteArray</span> <span class="operator">&</span>buffer)
{
WAVEFORM_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Waveform::bufferChanged"</span>
<span class="operator"><</span><span class="operator"><</span> <span class="string">"audioPosition"</span> <span class="operator"><</span><span class="operator"><</span> m_audioPosition
<span class="operator"><</span><span class="operator"><</span> <span class="string">"bufferPosition"</span> <span class="operator"><</span><span class="operator"><</span> position
<span class="operator"><</span><span class="operator"><</span> <span class="string">"bufferLength"</span> <span class="operator"><</span><span class="operator"><</span> length;
m_bufferPosition <span class="operator">=</span> position;
m_bufferLength <span class="operator">=</span> length;
m_buffer <span class="operator">=</span> buffer;
paintTiles();
}
<span class="type">void</span> Waveform<span class="operator">::</span>audioPositionChanged(<span class="type">qint64</span> position)
{
WAVEFORM_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Waveform::audioPositionChanged"</span>
<span class="operator"><</span><span class="operator"><</span> <span class="string">"audioPosition"</span> <span class="operator"><</span><span class="operator"><</span> position
<span class="operator"><</span><span class="operator"><</span> <span class="string">"bufferPosition"</span> <span class="operator"><</span><span class="operator"><</span> m_bufferPosition
<span class="operator"><</span><span class="operator"><</span> <span class="string">"bufferLength"</span> <span class="operator"><</span><span class="operator"><</span> m_bufferLength;
<span class="keyword">if</span> (position <span class="operator">></span><span class="operator">=</span> m_bufferPosition) {
<span class="keyword">if</span> (position <span class="operator">+</span> m_windowLength <span class="operator">></span> m_bufferPosition <span class="operator">+</span> m_bufferLength)
position <span class="operator">=</span> qMax(<span class="type">qint64</span>(<span class="number">0</span>)<span class="operator">,</span> m_bufferPosition <span class="operator">+</span> m_bufferLength <span class="operator">-</span> m_windowLength);
m_audioPosition <span class="operator">=</span> position;
setWindowPosition(position);
}
}
<span class="type">void</span> Waveform<span class="operator">::</span>deletePixmaps()
{
<span class="type">QPixmap</span> <span class="operator">*</span>pixmap;
foreach (pixmap<span class="operator">,</span> m_pixmaps)
<span class="keyword">delete</span> pixmap;
m_pixmaps<span class="operator">.</span>clear();
}
<span class="type">void</span> Waveform<span class="operator">::</span>createPixmaps(<span class="keyword">const</span> <span class="type">QSize</span> <span class="operator">&</span>widgetSize)
{
m_pixmapSize <span class="operator">=</span> widgetSize;
m_pixmapSize<span class="operator">.</span>setWidth(<span class="type">qreal</span>(widgetSize<span class="operator">.</span>width()) <span class="operator">*</span> m_tileLength <span class="operator">/</span> m_windowLength);
WAVEFORM_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Waveform::createPixmaps"</span>
<span class="operator"><</span><span class="operator"><</span> <span class="string">"widgetSize"</span> <span class="operator"><</span><span class="operator"><</span> widgetSize
<span class="operator"><</span><span class="operator"><</span> <span class="string">"pixmapSize"</span> <span class="operator"><</span><span class="operator"><</span> m_pixmapSize;
Q_ASSERT(m_tiles<span class="operator">.</span>count() <span class="operator">=</span><span class="operator">=</span> m_pixmaps<span class="operator">.</span>count());
<span class="comment">// (Re)create pixmaps</span>
<span class="keyword">for</span> (<span class="type">int</span> i<span class="operator">=</span><span class="number">0</span>; i<span class="operator"><</span>m_pixmaps<span class="operator">.</span>size(); <span class="operator">+</span><span class="operator">+</span>i) {
<span class="keyword">delete</span> m_pixmaps<span class="operator">[</span>i<span class="operator">]</span>;
m_pixmaps<span class="operator">[</span>i<span class="operator">]</span> <span class="operator">=</span> <span class="number">0</span>;
m_pixmaps<span class="operator">[</span>i<span class="operator">]</span> <span class="operator">=</span> <span class="keyword">new</span> <span class="type">QPixmap</span>(m_pixmapSize);
}
<span class="comment">// Update tile pixmap pointers, and mark for repainting</span>
<span class="keyword">for</span> (<span class="type">int</span> i<span class="operator">=</span><span class="number">0</span>; i<span class="operator"><</span>m_tiles<span class="operator">.</span>count(); <span class="operator">+</span><span class="operator">+</span>i) {
m_tiles<span class="operator">[</span>i<span class="operator">]</span><span class="operator">.</span>pixmap <span class="operator">=</span> m_pixmaps<span class="operator">[</span>i<span class="operator">]</span>;
m_tiles<span class="operator">[</span>i<span class="operator">]</span><span class="operator">.</span>painted <span class="operator">=</span> <span class="keyword">false</span>;
}
}
<span class="type">void</span> Waveform<span class="operator">::</span>setWindowPosition(<span class="type">qint64</span> position)
{
WAVEFORM_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Waveform::setWindowPosition"</span>
<span class="operator"><</span><span class="operator"><</span> <span class="string">"old"</span> <span class="operator"><</span><span class="operator"><</span> m_windowPosition <span class="operator"><</span><span class="operator"><</span> <span class="string">"new"</span> <span class="operator"><</span><span class="operator"><</span> position
<span class="operator"><</span><span class="operator"><</span> <span class="string">"tileArrayStart"</span> <span class="operator"><</span><span class="operator"><</span> m_tileArrayStart;
<span class="keyword">const</span> <span class="type">qint64</span> oldPosition <span class="operator">=</span> m_windowPosition;
m_windowPosition <span class="operator">=</span> position;
<span class="keyword">if</span> ((m_windowPosition <span class="operator">></span><span class="operator">=</span> oldPosition) <span class="operator">&</span><span class="operator">&</span>
(m_windowPosition <span class="operator">-</span> m_tileArrayStart <span class="operator"><</span> (m_tiles<span class="operator">.</span>count() <span class="operator">*</span> m_tileLength))) {
<span class="comment">// Work out how many tiles need to be shuffled</span>
<span class="keyword">const</span> <span class="type">qint64</span> offset <span class="operator">=</span> m_windowPosition <span class="operator">-</span> m_tileArrayStart;
<span class="keyword">const</span> <span class="type">int</span> nTiles <span class="operator">=</span> offset <span class="operator">/</span> m_tileLength;
shuffleTiles(nTiles);
} <span class="keyword">else</span> {
resetTiles(m_windowPosition);
}
<span class="keyword">if</span> (<span class="operator">!</span>paintTiles() <span class="operator">&</span><span class="operator">&</span> m_windowPosition <span class="operator">!</span><span class="operator">=</span> oldPosition)
update();
}
<span class="type">qint64</span> Waveform<span class="operator">::</span>tilePosition(<span class="type">int</span> index) <span class="keyword">const</span>
{
<span class="keyword">return</span> m_tileArrayStart <span class="operator">+</span> index <span class="operator">*</span> m_tileLength;
}
Waveform<span class="operator">::</span>TilePoint Waveform<span class="operator">::</span>tilePoint(<span class="type">qint64</span> position) <span class="keyword">const</span>
{
TilePoint result;
<span class="keyword">if</span> (position <span class="operator">></span><span class="operator">=</span> m_tileArrayStart) {
<span class="keyword">const</span> <span class="type">qint64</span> tileArrayEnd <span class="operator">=</span> m_tileArrayStart <span class="operator">+</span> m_tiles<span class="operator">.</span>count() <span class="operator">*</span> m_tileLength;
<span class="keyword">if</span> (position <span class="operator"><</span> tileArrayEnd) {
<span class="keyword">const</span> <span class="type">qint64</span> offsetIntoTileArray <span class="operator">=</span> position <span class="operator">-</span> m_tileArrayStart;
result<span class="operator">.</span>index <span class="operator">=</span> offsetIntoTileArray <span class="operator">/</span> m_tileLength;
Q_ASSERT(result<span class="operator">.</span>index <span class="operator">></span><span class="operator">=</span> <span class="number">0</span> <span class="operator">&</span><span class="operator">&</span> result<span class="operator">.</span>index <span class="operator"><</span><span class="operator">=</span> m_tiles<span class="operator">.</span>count());
result<span class="operator">.</span>positionOffset <span class="operator">=</span> offsetIntoTileArray <span class="operator">%</span> m_tileLength;
result<span class="operator">.</span>pixelOffset <span class="operator">=</span> tilePixelOffset(result<span class="operator">.</span>positionOffset);
Q_ASSERT(result<span class="operator">.</span>pixelOffset <span class="operator">></span><span class="operator">=</span> <span class="number">0</span> <span class="operator">&</span><span class="operator">&</span> result<span class="operator">.</span>pixelOffset <span class="operator"><</span><span class="operator">=</span> m_pixmapSize<span class="operator">.</span>width());
}
}
<span class="keyword">return</span> result;
}
<span class="type">int</span> Waveform<span class="operator">::</span>tilePixelOffset(<span class="type">qint64</span> positionOffset) <span class="keyword">const</span>
{
Q_ASSERT(positionOffset <span class="operator">></span><span class="operator">=</span> <span class="number">0</span> <span class="operator">&</span><span class="operator">&</span> positionOffset <span class="operator"><</span><span class="operator">=</span> m_tileLength);
<span class="keyword">const</span> <span class="type">int</span> result <span class="operator">=</span> (<span class="type">qreal</span>(positionOffset) <span class="operator">/</span> m_tileLength) <span class="operator">*</span> m_pixmapSize<span class="operator">.</span>width();
<span class="keyword">return</span> result;
}
<span class="type">int</span> Waveform<span class="operator">::</span>windowPixelOffset(<span class="type">qint64</span> positionOffset) <span class="keyword">const</span>
{
Q_ASSERT(positionOffset <span class="operator">></span><span class="operator">=</span> <span class="number">0</span> <span class="operator">&</span><span class="operator">&</span> positionOffset <span class="operator"><</span><span class="operator">=</span> m_windowLength);
<span class="keyword">const</span> <span class="type">int</span> result <span class="operator">=</span> (<span class="type">qreal</span>(positionOffset) <span class="operator">/</span> m_windowLength) <span class="operator">*</span> rect()<span class="operator">.</span>width();
<span class="keyword">return</span> result;
}
bool Waveform<span class="operator">::</span>paintTiles()
{
WAVEFORM_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Waveform::paintTiles"</span>;
bool updateRequired <span class="operator">=</span> <span class="keyword">false</span>;
<span class="keyword">for</span> (<span class="type">int</span> i<span class="operator">=</span><span class="number">0</span>; i<span class="operator"><</span>m_tiles<span class="operator">.</span>count(); <span class="operator">+</span><span class="operator">+</span>i) {
<span class="keyword">const</span> Tile <span class="operator">&</span>tile <span class="operator">=</span> m_tiles<span class="operator">[</span>i<span class="operator">]</span>;
<span class="keyword">if</span> (<span class="operator">!</span>tile<span class="operator">.</span>painted) {
<span class="keyword">const</span> <span class="type">qint64</span> tileStart <span class="operator">=</span> m_tileArrayStart <span class="operator">+</span> i <span class="operator">*</span> m_tileLength;
<span class="keyword">const</span> <span class="type">qint64</span> tileEnd <span class="operator">=</span> tileStart <span class="operator">+</span> m_tileLength;
<span class="keyword">if</span> (m_bufferPosition <span class="operator"><</span><span class="operator">=</span> tileStart <span class="operator">&</span><span class="operator">&</span> m_bufferPosition <span class="operator">+</span> m_bufferLength <span class="operator">></span><span class="operator">=</span> tileEnd) {
paintTile(i);
updateRequired <span class="operator">=</span> <span class="keyword">true</span>;
}
}
}
<span class="keyword">if</span> (updateRequired)
update();
<span class="keyword">return</span> updateRequired;
}
<span class="type">void</span> Waveform<span class="operator">::</span>paintTile(<span class="type">int</span> index)
{
<span class="keyword">const</span> <span class="type">qint64</span> tileStart <span class="operator">=</span> m_tileArrayStart <span class="operator">+</span> index <span class="operator">*</span> m_tileLength;
WAVEFORM_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Waveform::paintTile"</span>
<span class="operator"><</span><span class="operator"><</span> <span class="string">"index"</span> <span class="operator"><</span><span class="operator"><</span> index
<span class="operator"><</span><span class="operator"><</span> <span class="string">"bufferPosition"</span> <span class="operator"><</span><span class="operator"><</span> m_bufferPosition
<span class="operator"><</span><span class="operator"><</span> <span class="string">"bufferLength"</span> <span class="operator"><</span><span class="operator"><</span> m_bufferLength
<span class="operator"><</span><span class="operator"><</span> <span class="string">"start"</span> <span class="operator"><</span><span class="operator"><</span> tileStart
<span class="operator"><</span><span class="operator"><</span> <span class="string">"end"</span> <span class="operator"><</span><span class="operator"><</span> tileStart <span class="operator">+</span> m_tileLength;
Q_ASSERT(m_bufferPosition <span class="operator"><</span><span class="operator">=</span> tileStart);
Q_ASSERT(m_bufferPosition <span class="operator">+</span> m_bufferLength <span class="operator">></span><span class="operator">=</span> tileStart <span class="operator">+</span> m_tileLength);
Tile <span class="operator">&</span>tile <span class="operator">=</span> m_tiles<span class="operator">[</span>index<span class="operator">]</span>;
Q_ASSERT(<span class="operator">!</span>tile<span class="operator">.</span>painted);
<span class="keyword">const</span> <span class="type">qint16</span><span class="operator">*</span> base <span class="operator">=</span> <span class="keyword">reinterpret_cast</span><span class="operator"><</span><span class="keyword">const</span> <span class="type">qint16</span><span class="operator">*</span><span class="operator">></span>(m_buffer<span class="operator">.</span>constData());
<span class="keyword">const</span> <span class="type">qint16</span><span class="operator">*</span> buffer <span class="operator">=</span> base <span class="operator">+</span> ((tileStart <span class="operator">-</span> m_bufferPosition) <span class="operator">/</span> <span class="number">2</span>);
<span class="keyword">const</span> <span class="type">int</span> numSamples <span class="operator">=</span> m_tileLength <span class="operator">/</span> (<span class="number">2</span> <span class="operator">*</span> m_format<span class="operator">.</span>channelCount());
<span class="type">QPainter</span> painter(tile<span class="operator">.</span>pixmap);
painter<span class="operator">.</span>fillRect(tile<span class="operator">.</span>pixmap<span class="operator">-</span><span class="operator">></span>rect()<span class="operator">,</span> <span class="type">Qt</span><span class="operator">::</span>black);
<span class="type">QPen</span> pen(<span class="type">Qt</span><span class="operator">::</span>white);
painter<span class="operator">.</span>setPen(pen);
<span class="comment">// Calculate initial PCM value</span>
<span class="type">qint16</span> previousPcmValue <span class="operator">=</span> <span class="number">0</span>;
<span class="keyword">if</span> (buffer <span class="operator">></span> base)
previousPcmValue <span class="operator">=</span> <span class="operator">*</span>(buffer <span class="operator">-</span> m_format<span class="operator">.</span>channelCount());
<span class="comment">// Calculate initial point</span>
<span class="keyword">const</span> <span class="type">qreal</span> previousRealValue <span class="operator">=</span> pcmToReal(previousPcmValue);
<span class="keyword">const</span> <span class="type">int</span> originY <span class="operator">=</span> ((previousRealValue <span class="operator">+</span> <span class="number">1.0</span>) <span class="operator">/</span> <span class="number">2</span>) <span class="operator">*</span> m_pixmapSize<span class="operator">.</span>height();
<span class="keyword">const</span> <span class="type">QPoint</span> origin(<span class="number">0</span><span class="operator">,</span> originY);
<span class="type">QLine</span> line(origin<span class="operator">,</span> origin);
<span class="keyword">for</span> (<span class="type">int</span> i<span class="operator">=</span><span class="number">0</span>; i<span class="operator"><</span>numSamples; <span class="operator">+</span><span class="operator">+</span>i) {
<span class="keyword">const</span> <span class="type">qint16</span><span class="operator">*</span> ptr <span class="operator">=</span> buffer <span class="operator">+</span> i <span class="operator">*</span> m_format<span class="operator">.</span>channelCount();
<span class="keyword">const</span> <span class="type">int</span> offset <span class="operator">=</span> <span class="keyword">reinterpret_cast</span><span class="operator"><</span><span class="keyword">const</span> <span class="type">char</span><span class="operator">*</span><span class="operator">></span>(ptr) <span class="operator">-</span> m_buffer<span class="operator">.</span>constData();
Q_ASSERT(offset <span class="operator">></span><span class="operator">=</span> <span class="number">0</span>);
Q_ASSERT(offset <span class="operator"><</span> m_bufferLength);
Q_UNUSED(offset);
<span class="keyword">const</span> <span class="type">qint16</span> pcmValue <span class="operator">=</span> <span class="operator">*</span>ptr;
<span class="keyword">const</span> <span class="type">qreal</span> realValue <span class="operator">=</span> pcmToReal(pcmValue);
<span class="keyword">const</span> <span class="type">int</span> x <span class="operator">=</span> tilePixelOffset(i <span class="operator">*</span> <span class="number">2</span> <span class="operator">*</span> m_format<span class="operator">.</span>channelCount());
<span class="keyword">const</span> <span class="type">int</span> y <span class="operator">=</span> ((realValue <span class="operator">+</span> <span class="number">1.0</span>) <span class="operator">/</span> <span class="number">2</span>) <span class="operator">*</span> m_pixmapSize<span class="operator">.</span>height();
line<span class="operator">.</span>setP2(<span class="type">QPoint</span>(x<span class="operator">,</span> y));
painter<span class="operator">.</span>drawLine(line);
line<span class="operator">.</span>setP1(line<span class="operator">.</span>p2());
}
tile<span class="operator">.</span>painted <span class="operator">=</span> <span class="keyword">true</span>;
}
<span class="type">void</span> Waveform<span class="operator">::</span>shuffleTiles(<span class="type">int</span> n)
{
WAVEFORM_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Waveform::shuffleTiles"</span> <span class="operator"><</span><span class="operator"><</span> <span class="string">"n"</span> <span class="operator"><</span><span class="operator"><</span> n;
<span class="keyword">while</span> (n<span class="operator">-</span><span class="operator">-</span>) {
Tile tile <span class="operator">=</span> m_tiles<span class="operator">.</span>first();
tile<span class="operator">.</span>painted <span class="operator">=</span> <span class="keyword">false</span>;
m_tiles<span class="operator">.</span>erase(m_tiles<span class="operator">.</span>begin());
m_tiles <span class="operator">+</span><span class="operator">=</span> tile;
m_tileArrayStart <span class="operator">+</span><span class="operator">=</span> m_tileLength;
}
WAVEFORM_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Waveform::shuffleTiles"</span> <span class="operator"><</span><span class="operator"><</span> <span class="string">"tileArrayStart"</span> <span class="operator"><</span><span class="operator"><</span> m_tileArrayStart;
}
<span class="type">void</span> Waveform<span class="operator">::</span>resetTiles(<span class="type">qint64</span> newStartPos)
{
WAVEFORM_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Waveform::resetTiles"</span> <span class="operator"><</span><span class="operator"><</span> <span class="string">"newStartPos"</span> <span class="operator"><</span><span class="operator"><</span> newStartPos;
<span class="type">QVector</span><span class="operator"><</span>Tile<span class="operator">></span><span class="operator">::</span>iterator i <span class="operator">=</span> m_tiles<span class="operator">.</span>begin();
<span class="keyword">for</span> ( ; i <span class="operator">!</span><span class="operator">=</span> m_tiles<span class="operator">.</span>end(); <span class="operator">+</span><span class="operator">+</span>i)
i<span class="operator">-</span><span class="operator">></span>painted <span class="operator">=</span> <span class="keyword">false</span>;
m_tileArrayStart <span class="operator">=</span> newStartPos;
}
</pre>
</div>
<!-- @@@multimedia/spectrum/app/waveform.cpp -->
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Documentation contributions included herein are the copyrights of
their respective owners.<br/> The documentation provided herein is licensed under the terms of the <a href="http://www.gnu.org/licenses/fdl.html">GNU Free Documentation License version 1.3</a> as published by the Free Software Foundation.<br/> Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property
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