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gradients.C
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1/// \file
2/// \ingroup tutorial_cocoa
3/// This macro requires OS X and ROOT
4/// compiled with --enable-cocoa to run.
5///
6/// Features:
7/// 1. Radial and linear gradients
8/// 2. Transparent/semitransparent colours.
9/// 3. Shadows.
10///
11/// \macro_code
12///
13/// \author Timur Pocheptsov
14
15//Includes for ACLiC:
16#include "TColorGradient.h"
17#include "TVirtualX.h"
18#include "TCanvas.h"
19#include "TError.h"
20#include "TText.h"
21#include "TPie.h"
22
23//Cocoa aux. functions.
24#include "customcolor.h"
25
26void gradients()
27{
28 //Find free colour indices in the ROOT's palette for:
29 //1. A radial gradient for TPie;
30 //2. A linear gradient for TCanvas
31 //3. A fully transparent fill color for a nested pad.
32
33 Color_t colorIndices[3] = {};
35 ::Error("grad", "failed to create new custom colors");
36 return;
37 }
38
39 //Better names:
40 const Color_t &radialFill = colorIndices[0];
41 const Color_t &linearFill = colorIndices[1];
42 const Color_t &transparentFill = colorIndices[2];
43
44 //Create a canvas to check if we have a right back-end which supports gradients:
45 TCanvas * const c = new TCanvas("cpie","Gradient colours demo", 700, 700);
46 //Before we allocated any new colour or created any object:
47 if (gVirtualX && !gVirtualX->InheritsFrom("TGCocoa")) {
48 ::Error("gradients", "This macro requires OS X and ROOT built with --enable-cocoa");
49 delete c;
50 return;
51 }
52
53 //Linear gradient is defined by: 1) colors (to interpolate between them),
54 //2) coordinates for these colors along the gradient axis [0., 1.] (must be sorted!).
55 //3) Start and end points for a gradient, you specify them in some NDC rect ([0,0 - 1,1]),
56 //and this rect is either: bounding rect of your polygon/object to fill
57 //(gradient->SetCoordinateMode(TColorGradient::kObjectBoundingMode))
58 //or bounding rect of a pad (gradient->SetCoordinateMode(TColorGradient::kPadMode)).
59 //kObjectBoundingMode is the default one.
60
61
62 //Colour positions in the gradient's palette (here I place colors at the
63 //ends of 0-1):
64 const Double_t locations[] = {0., 1.};
65 //Linear gradient fill (with an axis angle == 45):
66 const Double_t rgbaData1[] = {0.2, 0.2, 0.2, 1.,/*gray*/
67 0.8, 1., 0.9, 1. /*pale green*/};
68 TLinearGradient * const gradientFill1 = new TLinearGradient(linearFill, 2, locations, rgbaData1);
69 //45 degrees:
70 gradientFill1->SetStartEnd(TColorGradient::Point(0., 0.), TColorGradient::Point(1., 1.));
71 //Set as a background color in the canvas:
72 c->SetFillColor(linearFill);
73
74 //Draw a text in the canvas (the object above the text will be
75 //semi-transparent):
76 TText * const t = new TText(0.05, 0.7, "Can you see the text?");
77 t->Draw();
78
79 //We create a nested pad on top to render a TPie in,
80 //this way we still have a text (below) + TPie with
81 //a fancy colour on top.
82 TPad * const pad = new TPad("p", "p", 0., 0., 1., 1.);
83
84 //TPad itself is fully transparent:
85 new TColor(transparentFill, 1., 1., 1., "transparent_fill_color", 0.);
86 pad->SetFillColor(transparentFill);
87 //Add our pad into the canvas:
88 pad->Draw();
89 pad->cd();
90
91 //Radial gradient fill for a TPie object:
92 const Double_t rgbaData2[] = {/*opaque orange at the start:*/1., 0.8, 0., 1.,
93 /*transparent red at the end:*/1., 0.2, 0., 0.8};
94
95 //
96 //With Quartz/Cocoa we support the "extended" radial gradient:
97 //you can specify two centers and two radiuses - the start and
98 //the end of your radial gradient (+ colors/positions as with a linear
99 //gradient).
100 //
101
102 TRadialGradient * const gradientFill2 = new TRadialGradient(radialFill, 2,
103 locations, rgbaData2);
104 //Parameters for a gradient fill:
105 //the gradient is 'pad-related' - we calculate everything in a pad's
106 //space and consider it as a NDC (so pad's rect is (0,0), (1,1)).
108 //Centers for both circles are the same point.
109 gradientFill2->SetStartEndR1R2(TColorGradient::Point(0.5, 0.5), 0.1,
110 TColorGradient::Point(0.5, 0.5), 0.4);
111
112 const UInt_t nSlices = 5;
113 //Values for a TPie (non-const, that's how TPie's ctor is declared):
114 Double_t values[nSlices] = {0.8, 1.2, 1.2, 0.8, 1.};
115 Int_t colors[nSlices] = {radialFill, radialFill, radialFill,
116 radialFill, radialFill};
117
118 TPie * const pie = new TPie("pie", "TPie:", nSlices, values, colors);
119 //One slice is slightly shifted:
120 pie->SetEntryRadiusOffset(2, 0.05);
121 //Move labels to the center (to fit the pad's space):
122 pie->SetLabelsOffset(-0.08);
123 //
124 pie->SetRadius(0.4);
125 pie->Draw("rsc");
126}
#define c(i)
Definition RSha256.hxx:101
int Int_t
Definition RtypesCore.h:45
short Color_t
Definition RtypesCore.h:92
unsigned int UInt_t
Definition RtypesCore.h:46
double Double_t
Definition RtypesCore.h:59
void Error(const char *location, const char *msgfmt,...)
Use this function in case an error occurred.
Definition TError.cxx:185
#define gVirtualX
Definition TVirtualX.h:337
Color * colors
Definition X3DBuffer.c:21
virtual void SetFillColor(Color_t fcolor)
Set the fill area color.
Definition TAttFill.h:37
The Canvas class.
Definition TCanvas.h:23
void SetCoordinateMode(ECoordinateMode mode)
Set coordinate mode.
The color creation and management class.
Definition TColor.h:21
void SetStartEnd(const Point &p1, const Point &p2)
Set end and start.
virtual void Draw(Option_t *option="")
Default Draw method for all objects.
Definition TObject.cxx:274
The most important graphics class in the ROOT system.
Definition TPad.h:28
TVirtualPad * cd(Int_t subpadnumber=0) override
Set Current pad.
Definition TPad.cxx:597
void Draw(Option_t *option="") override
Draw Pad in Current pad (re-parent pad if necessary).
Definition TPad.cxx:1268
Draw a Pie Chart,.
Definition TPie.h:23
void SetLabelsOffset(Float_t)
Set the distance between the label end the external line of the TPie.
Definition TPie.cxx:1325
void SetEntryRadiusOffset(Int_t, Double_t)
Set the distance, in the direction of the radius of the slice.
Definition TPie.cxx:1242
void SetRadius(Double_t)
Set the pie chart's radius' value.
Definition TPie.cxx:1341
void Draw(Option_t *option="l") override
Draw the pie chart.
Definition TPie.cxx:277
void SetStartEndR1R2(const Point &p1, Double_t r1, const Point &p2, Double_t r2)
Set start and end R1 and R2.
Base class for several text objects.
Definition TText.h:22
unsigned FindFreeCustomColorIndices(Color_t(&indices)[N])
Definition customcolor.h:38