Pipette and "On Preview Widgets" branch. See issue 227

The pipette part is already working quite nice but need to be finished. The widgets part needs more work...

rtengine/labimage.cc

@@ -0,0 +1,38 @@
+#include "labimage.h"
+#include <memory.h>
+namespace rtengine {
+
+LabImage::LabImage (int w, int h) : fromImage(false), W(w), H(h) {
+
+    L = new float*[H];
+    a = new float*[H];
+    b = new float*[H];
+
+    data = new float [W*H*3];
+    float * index = data;
+    for (int i=0; i<H; i++)
+        L[i] = index + i*W;
+    index+=W*H;
+    for (int i=0; i<H; i++)
+        a[i] = index + i*W;
+    index+=W*H;
+
+    for (int i=0; i<H; i++)
+        b[i] = index + i*W;
+}
+
+LabImage::~LabImage () {
+
+    if (!fromImage) {
+        delete [] L;
+        delete [] a;
+        delete [] b;
+        delete [] data;
+    }
+}
+
+void LabImage::CopyFrom(LabImage *Img){
+	memcpy(data, Img->data, W*H*3*sizeof(float));
+}
+
+}