paysages : Logarithmic preview scaling.

git-svn-id: https://subversion.assembla.com/svn/thunderk/paysages@305 b1fd45b6-86a6-48da-8261-f70d1f35bdcc

gui_qt/basepreview.cpp

@@ -53,7 +53,9 @@ BasePreview::BasePreview(QWidget* parent) :
     this->conf_scale_max = 1.0;
     this->conf_scale_init = 1.0;
     this->conf_scale_step = 0.0;
+    this->conf_scroll_logarithmic = false;
     this->scaling = 1.0;
+    this->scalingbase = 1.0;
     this->xoffset = 0.0;
     this->yoffset = 0.0;
     this->pixbuf = new QImage(this->size(), QImage::Format_ARGB32);
@@ -94,7 +96,7 @@ QColor BasePreview::getColor(double x, double y)
     return QColor(0, 0, 0);
 }
 
-void BasePreview::configScaling(double min, double max, double step, double init)
+void BasePreview::configScaling(double min, double max, double step, double init, bool logarithmic)
 {
     double size = (double)width();
     
@@ -104,7 +106,14 @@ void BasePreview::configScaling(double min, double max, double step, double init
         conf_scale_max = max / size;
         conf_scale_step = step / size;
         conf_scale_init = init / size;
-        scaling = init / size;
+        conf_scroll_logarithmic = logarithmic;
+        scalingbase = init / size;
+        if (conf_scroll_logarithmic && conf_scale_max - conf_scale_min > 0.0000001)
+        {
+            scalingbase = pow((scalingbase - conf_scale_min) / (conf_scale_max - conf_scale_min), 0.5) * (conf_scale_max - conf_scale_min) + conf_scale_min;
+        }
+
+        updateScaling();
         redraw();
     }
 }
@@ -235,6 +244,18 @@ void BasePreview::renderPixbuf()
     }
 }
 
+void BasePreview::updateScaling()
+{
+    if (conf_scroll_logarithmic && conf_scale_max - conf_scale_min > 0.0000001)
+    {
+        scaling = pow((scalingbase - conf_scale_min) / (conf_scale_max - conf_scale_min), 2.0) * (conf_scale_max - conf_scale_min) + conf_scale_min;
+    }
+    else
+    {
+        scaling = scalingbase;
+    }
+}
+
 void BasePreview::mousePressEvent(QMouseEvent* event)
 {
     if (event->button() == Qt::LeftButton)
@@ -355,20 +376,44 @@ void BasePreview::wheelEvent(QWheelEvent* event)
         factor = 1.0;
     }
     
+    if (event->orientation() == Qt::Vertical)
+    {
+        if (event->delta() > 0  && scalingbase > conf_scale_min)
+        {
+            scalingbase -= factor * conf_scale_step;
+            if (scalingbase < conf_scale_min)
+            {
+                scalingbase = conf_scale_min;
+            }
+        }
+        else if (event->delta() < 0  && scalingbase < conf_scale_max)
+        {
+            scalingbase += factor * conf_scale_step;
+            if (scalingbase > conf_scale_max)
+            {
+                scalingbase = conf_scale_max;
+            }
+        }
+        else
+        {
+            event->ignore();
+            return;
+        }
+    }
+    else
+    {
+        event->ignore();
+        return;
+    }
+
     old_scaling = scaling;
+    updateScaling();
+    
     width = pixbuf->width();
     height = pixbuf->height();
     
-    if (event->orientation() == Qt::Vertical)
+    if (scaling < old_scaling)
     {
-        if (event->delta() > 0  && scaling > conf_scale_min)
-        {
-            scaling -= conf_scale_step * factor;
-            if (scaling < conf_scale_min)
-            {
-                scaling = conf_scale_min;
-            }
-            
         lock_drawing->lock();
         new_width = (int)floor(((double)width) * scaling / old_scaling);
         new_height = (int)floor(((double)height) * scaling / old_scaling);
@@ -382,14 +427,8 @@ void BasePreview::wheelEvent(QWheelEvent* event)
 
         emit contentChange();
     }
-        else if (event->delta() < 0  && scaling < conf_scale_max)
+    else if (scaling > old_scaling)
     {
-            scaling += conf_scale_step * factor;
-            if (scaling > conf_scale_max)
-            {
-                scaling = conf_scale_max;
-            }
-            
         lock_drawing->lock();
         QImage part = pixbuf->scaled((int)floor(((double)width) * old_scaling / scaling), (int)floor(((double)height) * old_scaling / scaling), Qt::IgnoreAspectRatio, Qt::SmoothTransformation);
         QPainter painter(pixbuf);
@@ -401,10 +440,6 @@ void BasePreview::wheelEvent(QWheelEvent* event)
 
         emit contentChange();
     }
+    
     event->accept();
-    }
-    else
-    {
-        event->ignore();
-    }
 }

gui_qt/basepreview.h

@@ -22,7 +22,7 @@ protected:
     virtual void updateData();
     virtual QColor getColor(double x, double y);
     
-    void configScaling(double min, double max, double step, double init);
+    void configScaling(double min, double max, double step, double init, bool logarithmic=true);
     void configScrolling(double xmin, double xmax, double xinit, double ymin, double ymax, double yinit);
 
     double xoffset;
@@ -31,6 +31,7 @@ protected:
 
 private:
     void renderPixbuf();
+    void updateScaling();
 
     void resizeEvent(QResizeEvent* event);
     void paintEvent(QPaintEvent* event);
@@ -47,6 +48,8 @@ private:
     int mousex;
     int mousey;
 
+    double scalingbase;
+
     bool alive;
     bool need_restart;
     bool need_render;
@@ -62,6 +65,7 @@ private:
     double conf_scale_max;
     double conf_scale_init;
     double conf_scale_step;
+    bool conf_scroll_logarithmic;
 
 signals:
     void contentChange();