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, 24 insertions, 0 deletions

diff --git a/divergentcolorscale.h b/divergentcolorscale.h
new file mode 100644
index 0000000..9ab3be6
--- /dev/null
+++ b/divergentcolorscale.h
@@ -0,0 +1,24 @@
+#ifndef DIVERGENTCOLORSCALE_H
+#define DIVERGENTCOLORSCALE_H
+
+#include "colorscale.h"
+
+class DivergentColorScale
+    : public ColorScale
+{
+public:
+    DivergentColorScale(const QColor &color1,
+                        const QColor &colorMiddle,
+                        const QColor &color2);
+
+    enum BuiltinDivergentColorScale {
+        RedGrayBlue
+    };
+
+    QColor color(float t) const;
+
+    static DivergentColorScale builtin(BuiltinDivergentColorScale);
+    static DivergentColorScale *builtin(BuiltinDivergentColorScale, void *);
+};
+
+#endif // DIVERGENTCOLORSCALE_H