Improvements related to ColorScale and screenshots.

* ColorScale: now a pointer whenever needed. main() takes care of
  updating extents
* New class DivergentColorScale: works specifically for divergent
  scales, always has 3 colors as input: negative values, 0, positive
  values
* ManipulationHandler: ProjectionHistory no longer needed

1 files changed, 2 insertions, 0 deletions

diff --git a/colorscale.h b/colorscale.h
index 1eb8c47..ffc3439 100644
--- a/colorscale.h
+++ b/colorscale.h
@@ -25,6 +25,8 @@ public:
     template<typename OutputIterator>
     void sample(int samples, OutputIterator it) const;
 
+    static QColor lerp(const QColor &c1, const QColor &c2, float _t);
+
 protected:
     float m_min, m_max;
     QList<QColor> m_colors;