Comments and custom color names.

tutorials/cocoa/flower.C

-//Another demo to show transparent lines with TMultiGraph
+//Author: Timur Pocheptsov, 4/02/2014
+
+//Another demo to show transparency with TMultiGraph
 //(and the really interesting curve/equation). + point compression in
 //TPadPainter :))
-
 //You can see all three flowers ONLY with Cococa (transparency).
 
+//The equation by Paul Burke: http://paulbourke.net/geometry/
+
 #include <cassert>
 #include <vector>
 
@@ -21,6 +24,7 @@ namespace {
 typedef std::vector<Double_t> vector_type;
 typedef vector_type::size_type size_type;
 
+//______________________________________________________________________
 void create_flower(vector_type &xs, vector_type &ys, size_type nPoints, Double_t r)
 {
    assert(nPoints > 100 && "create_flower, number of points is too small");
@@ -39,16 +43,18 @@ void create_flower(vector_type &xs, vector_type &ys, size_type nPoints, Double_t
    }
 }
 
-}
+}//unnamed namespace.
 
 void flower()
 {
+   //0. Indices for custom colors.
    Int_t indices[3] = {};
    if (ROOT::CocoaTutorials::FindFreeCustomColorIndices(indices) != 3) {
       Error("flower", "failed to create custom colors");
       return;
    }
 
+   //1. I have to create a canvas to initialize gVirtualX.
    TCanvas * const cnv = new TCanvas("Chrysanthemum", "Chrysanthemum", 900, 900);
    if (gVirtualX && !gVirtualX->InheritsFrom("TGCocoa")) {
       Warning("flower", "You can see the transparency ONLY in a pdf or png output (\"File\"->\"Save As\" ->...)\n"
@@ -57,34 +63,37 @@ void flower()
 
    cnv->cd();//Just to suppress a warning if compiled.
    
-   //
    vector_type xs, ys;
 
+   //2. Create graphs and custom colors for each graph.
    create_flower(xs, ys, 300, 6);
    TGraph * const gr1 = new TGraph(Int_t(xs.size()), &xs[0], &ys[0]);
-   new TColor(indices[0], 0., 0., 0.5, "dark_red", 0.7);
+   new TColor(indices[0], 0., 0., 0.5, "custom_blue", 0.7);
    gr1->SetFillColor(indices[0]);
    gr1->SetName("part1");
    gr1->SetTitle("part1");
 
    create_flower(xs, ys, 500000, 8);
    TGraph * const gr2 = new TGraph(Int_t(xs.size()), &xs[0], &ys[0]);
-   new TColor(indices[1], 0.5, 0., 0.5, "purple", 0.5);
+   new TColor(indices[1], 0.5, 0., 0.5, "custom_purple", 0.5);
    gr2->SetFillColor(indices[1]);
    gr2->SetName("part2");
    gr2->SetTitle("part2");
 
-   create_flower(xs, ys, 100000, 12);
+   create_flower(xs, ys, 100000, 10);
    TGraph * const gr3 = new TGraph(Int_t(xs.size()), &xs[0], &ys[0]);
 
-   //If you want to see the different, change 0.2 to 1 in the next call:
-   new TColor(indices[2], 1., 0., 0.4, "magenta", 0.2);
+
+   //If you want to see the difference, change 0.2 to 1 in the next call:
+   new TColor(indices[2], 1., 0., 0.4, "custom_magenta", 0.2);
    gr3->SetFillColor(indices[2]);
    gr3->SetName("part3");
    gr3->SetTitle("part3");
 
-   //The final result.
+   //3. Create a final multigraph.
+
    //Otcveli, uzh davno ... nu ti ponEl.
+
    TMultiGraph * const flower = new TMultiGraph("Chrysanthemum", "Chrysanthemum");
    flower->Add(gr1);
    flower->Add(gr2);