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- use double precision to store the position / zoom / other stuff

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- some temporary fix to get a +50% improvement from vectorization until
  we have vectorisation for comparisons and redux
This commit is contained in:
Benoit Jacob 2008-06-30 07:33:08 +00:00
parent 37a50fa526
commit cacf986a7f
2 changed files with 12 additions and 10 deletions
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18
demos/mandelbrot/mandelbrot.cpp
View File

@ -21,9 +21,10 @@ template<typename Real> int MandelbrotWidget::render(int max_iter, int img_width
typedef Eigen::Matrix<Real, packetSize, 1> Packet; // wrap a Packet as a vector
int alignedWidth = (img_width/packetSize)*packetSize;
float yradius = xradius * img_height / img_width;
Eigen::Vector2f start(center.x() - xradius, center.y() - yradius);
Eigen::Vector2f step(2*xradius/img_width, 2*yradius/img_height);
double yradius = xradius * img_height / img_width;
typedef Eigen::Matrix<Real, 2, 1> Vector2;
Vector2 start(center.x() - xradius, center.y() - yradius);
Vector2 step(2*xradius/img_width, 2*yradius/img_height);
int pix = 0, total_iter = 0;
for(int y = 0; y < img_height; y++)
@ -53,6 +54,7 @@ template<typename Real> int MandelbrotWidget::render(int max_iter, int img_width
pzi = 2 * pzr_buf.cwiseProduct(pzi) + pci;
}
pix_dont_diverge = (pzr.cwiseAbs2() + pzi.cwiseAbs2())
.eval() // temporary fix for lack of vectorizability of what follows
.cwiseLessThan(Packet::constant(4))
.template cast<int>();
pix_iter += 4 * pix_dont_diverge;
@ -65,7 +67,7 @@ template<typename Real> int MandelbrotWidget::render(int max_iter, int img_width
for(int i = 0; i < packetSize; i++)
{
buffer[4*(pix+i)] = float(pix_iter[i])*255/max_iter;
buffer[4*(pix+i)] = pix_iter[i]*255/max_iter;
buffer[4*(pix+i)+1] = 0;
buffer[4*(pix+i)+2] = 0;
}
@ -80,7 +82,7 @@ template<typename Real> int MandelbrotWidget::render(int max_iter, int img_width
void MandelbrotWidget::paintEvent(QPaintEvent *)
{
float resolution = xradius*2/width();
double resolution = xradius*2/width();
int max_iter = 64;
if(resolution < 1e-4f) max_iter += 32 * ( - 4 - std::log10(resolution));
max_iter = (max_iter/4)*4;
@ -131,8 +133,8 @@ void MandelbrotWidget::mousePressEvent(QMouseEvent *event)
if( event->buttons() & Qt::LeftButton )
{
lastpos = event->pos();
float yradius = xradius * height() / width();
center = Eigen::Vector2f(center.x() + (event->pos().x() - width()/2) * xradius * 2 / width(),
double yradius = xradius * height() / width();
center = Eigen::Vector2d(center.x() + (event->pos().x() - width()/2) * xradius * 2 / width(),
center.y() + (event->pos().y() - height()/2) * yradius * 2 / height());
draft = 16;
update();
@ -145,7 +147,7 @@ void MandelbrotWidget::mouseMoveEvent(QMouseEvent *event)
lastpos = event->pos();
if( event->buttons() & Qt::LeftButton )
{
float t = 1 + 5 * float(delta.y()) / height();
double t = 1 + 5 * double(delta.y()) / height();
if(t < 0.5) t = 0.5;
if(t > 2) t = 2;
xradius *= t;

4
demos/mandelbrot/mandelbrot.h
View File

@ -9,8 +9,8 @@ class MandelbrotWidget : public QWidget
{
Q_OBJECT
Eigen::Vector2f center;
float xradius;
Eigen::Vector2d center;
double xradius;
int size;
unsigned char *buffer;
QPoint lastpos;