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Detailed Description

Gradient fill with transparency and "SAME" option.

Requires OS X and ROOT configured with –enable-cocoa.

//Includes for ACLiC (cling does not need them).
#include "TColorGradient.h"
#include "TCanvas.h"
#include "TError.h"
#include "TColor.h"
#include "TStyle.h"
#include "TH1F.h"
void grad2(bool gl = true)
{
//Make sure canvas supports OpenGL.
//2. Check that we have a canvas with an OpenGL support.
auto cnv = new TCanvas("grad2", "gradient demo 2", 100, 100, 800, 600);
if (!cnv->UseGL() && !cnv->IsWeb())
::Warning("grad2", "This macro requires either OpenGL or Web canvas to correctly handle gradient colors");
//3. Custom colors:
// a) Custom semi-transparent red.
auto customRed = TColor::GetColor((Float_t) 1., 0., 0., 0.5);
// Custom semi-transparent green.
auto customGreen = TColor::GetColor((Float_t) 0., 1., 0., 0.5);
// 4. Linear gradient colors
// b) Gradient (from our semi-transparent red to ROOT's kOrange).
// Linear gradient is defined by: 1) angle in grad
// 2) colors (to interpolate between them),
// If necessary, TLinearGradient object can be retrieved and modified later
auto grad1 = TColor::GetLinearGradient(90., {customRed, kOrange});
//Vertical gradient fill.
auto grad2 = TColor::GetLinearGradient(90., {customGreen, kBlue});
auto hist = new TH1F("a2", "b2", 10, -2., 3.);
auto hist2 = new TH1F("c3", "d3", 10, -3., 3.);
hist->FillRandom("landau", 100000);
hist2->FillRandom("gaus", 100000);
hist->SetFillColor(grad1);
hist2->SetFillColor(grad2);
hist2->Draw();
hist->Draw("SAME");
}
float Float_t
Definition RtypesCore.h:57
@ kOrange
Definition Rtypes.h:67
@ kBlue
Definition Rtypes.h:66
void Warning(const char *location, const char *msgfmt,...)
Use this function in warning situations.
Definition TError.cxx:229
R__EXTERN TStyle * gStyle
Definition TStyle.h:433
The Canvas class.
Definition TCanvas.h:23
static Int_t GetLinearGradient(Double_t angle, const std::vector< Int_t > &colors, const std::vector< Double_t > &positions={})
Static function: Returns the linear gradient color number corresponding to specified parameters.
Definition TColor.cxx:2092
static Int_t GetColor(const char *hexcolor)
Static method returning color number for color specified by hex color string of form: "#rrggbb",...
Definition TColor.cxx:1839
1-D histogram with a float per channel (see TH1 documentation)
Definition TH1.h:621
void SetCanvasPreferGL(Bool_t prefer=kTRUE)
Definition TStyle.h:339
Author
Timur Pocheptsov

Definition in file grad2.C.