void
BlockAnalyzer::transform( Analyzer::Scope &s ) //pure virtual
{
for( uint x = 0; x < s.size(); ++x )
s[x] *= 2;
float *front = static_cast<float*>( &s.front() );
m_fht->spectrum( front );
m_fht->scale( front, 1.0 / 20 );
//the second half is pretty dull, so only show it if the user has a large analyzer
//by setting to m_scope.size() if large we prevent interpolation of large analyzers, this is good!
s.resize( m_scope.size() <= MAX_COLUMNS/2 ? MAX_COLUMNS/2 : m_scope.size() );
}
void NyanCatAnalyzer::analyze(QPainter& p, const Analyzer::Scope& s,
bool new_frame) {
// Discard the second half of the transform
const int scope_size = s.size() / 2;
if ((new_frame && is_playing_) ||
(buffer_[0].isNull() && buffer_[1].isNull())) {
// Transform the music into rainbows!
for (int band = 0; band < kRainbowBands; ++band) {
float* band_start = history_ + band * kHistorySize;
// Move the history of each band across by 1 frame.
memmove(band_start, band_start + 1, (kHistorySize - 1) * sizeof(float));
}
// Now accumulate the scope data into each band. Should maybe use a series
// of band pass filters for this, so bands can leak into neighbouring bands,
// but for now it's a series of separate square filters.
const int samples_per_band = scope_size / kRainbowBands;
int sample = 0;
for (int band = 0; band < kRainbowBands; ++band) {
float accumulator = 0.0;
for (int i = 0; i < samples_per_band; ++i) {
accumulator += s[sample++];
}
history_[(band + 1) * kHistorySize - 1] = accumulator * band_scale_[band];
}
// Create polylines for the rainbows.
QPointF polyline[kRainbowBands * kHistorySize];
QPointF* dest = polyline;
float* source = history_;
const float top_of_cat = float(height()) / 2 - float(kCatHeight) / 2;
for (int band = 0; band < kRainbowBands; ++band) {
// Calculate the Y position of this band.
const float y =
float(kCatHeight) / (kRainbowBands + 1) * (band + 0.5) + top_of_cat;
// Add each point in the line.
for (int x = 0; x < kHistorySize; ++x) {
*dest = QPointF(px_per_frame_ * x, y + *source * kPixelScale);
++dest;
++source;
}
}
// Do we have to draw the whole rainbow into the buffer?
if (buffer_[0].isNull()) {
for (int i = 0; i < 2; ++i) {
buffer_[i] = QPixmap(QSize(width() + x_offset_, height()));
buffer_[i].fill(background_brush_.color());
}
current_buffer_ = 0;
QPainter buffer_painter(&buffer_[0]);
buffer_painter.setRenderHint(QPainter::Antialiasing);
for (int band = kRainbowBands - 1; band >= 0; --band) {
buffer_painter.setPen(colors_[band]);
buffer_painter.drawPolyline(&polyline[band * kHistorySize],
kHistorySize);
buffer_painter.drawPolyline(&polyline[band * kHistorySize],
kHistorySize);
}
} else {
const int last_buffer = current_buffer_;
current_buffer_ = (current_buffer_ + 1) % 2;
// We can just shuffle the buffer along a bit and draw the new frame's
// data.
QPainter buffer_painter(&buffer_[current_buffer_]);
buffer_painter.setRenderHint(QPainter::Antialiasing);
buffer_painter.drawPixmap(
0, 0, buffer_[last_buffer], px_per_frame_, 0,
x_offset_ + available_rainbow_width_ - px_per_frame_, 0);
buffer_painter.fillRect(
x_offset_ + available_rainbow_width_ - px_per_frame_, 0,
kCatWidth - kRainbowOverlap + px_per_frame_, height(),
background_brush_);
for (int band = kRainbowBands - 1; band >= 0; --band) {
buffer_painter.setPen(colors_[band]);
buffer_painter.drawPolyline(&polyline[(band + 1) * kHistorySize - 3],
3);
}
}
}
// Draw the buffer on to the widget
p.drawPixmap(0, 0, buffer_[current_buffer_], x_offset_, 0, 0, 0);
// Draw nyan cat (he's been waiting for this for 75 lines).
// Nyan nyan nyan nyan.
if (!is_playing_) {
// Ssshhh!
p.drawPixmap(SleepingCatDestRect(), cat_, SleepingCatSourceRect());
} else {
p.drawPixmap(CatDestRect(), cat_, CatSourceRect());
}
}