/*
 * makePadsHist divides a canvas into an array of pads so that when histograms
 * are drawn in them, their borders overlap.
 *
 * Developed by Stefan KNIEGE / IKF Frankfurt
 *
 * $Id: makePadsHists.C,v 1.1 2008/11/07 16:23:20 szuba Exp $
 */

#if !defined(__CINT__) || defined(__MAKECINT__)

#include <iostream>

#include <TCanvas.h>

#endif


TObjArray *makePadsHists(const Int_t npx, const Int_t npy, const Float_t tm, const Float_t lm, TCanvas *canv = NULL, const Char_t *name = "")
{
	const Int_t npads = npx * npy;

	// calc sizes  in x and y for pads ___________
	const Float_t topsize_y = 1 / (2 + (npy - 2) * (1 - tm));
	const Float_t leftsize_x = 1 / (2 + (npx - 2) * (1 - lm));
	const Float_t midsize_y = (1 - tm) * topsize_y;
	const Float_t midsize_x = (1 - lm) * leftsize_x;

	// create canvas if necessary ________________
	TCanvas *c1 = canv;
	if (c1 == NULL) {
		Char_t canvname[256];
		sprintf(canvname, "Canv_%s", name);
		c1 = new TCanvas(canvname, canvname, npx * 150, npy * 150);
	}

	// create padarray ____________________________
	Char_t arrname[256];
	sprintf(arrname, "Arr%s", name);
	TObjArray *padarr = new TObjArray(npads);
	padarr->SetName(arrname);

	Int_t xrow, yrow;

	c1->cd();

	// create pads ________________________________
	for (Int_t np = 0; np < npads; np++) {
		Float_t px1 = 0., px2 = 0., py1 = 0., py2 = 0.;

		// row and column
		xrow = np % npx;
		yrow = np / npx;

		// xpos
		if (npy > 1) {
			if (yrow == 0) {
				py1 = 0.0;
				py2 = topsize_y;
			} else if (yrow < npy - 1) {
				py1 = topsize_y + (yrow - 1) * midsize_y;
				py2 = topsize_y + (yrow) * midsize_y;
			} else if (yrow == npy - 1) {
				py1 = topsize_y + (yrow - 1) * midsize_y;
				py2 = 1.0;
			}
		} else {
			py1 = 0.0;
			py2 = 1.0;
		}

		// ypos
		if (npx > 1) {
			if (xrow == 0) {
				px1 = 0.0;
				px2 = leftsize_x;
			} else if (xrow < npx - 1) {
				px1 = leftsize_x + (xrow - 1) * midsize_x;
				px2 = leftsize_x + (xrow) * midsize_x;
			} else if (xrow == npx - 1) {
				px1 = leftsize_x + (xrow - 1) * midsize_x;
				px2 = 1.0;
			}
		} else {
			px1 = 0.0;
			px2 = 1.0;
		}

		Char_t namep[256];
		sprintf(namep, "Pad_%s_%i", name, np);
		TPad *pad = new TPad(namep, namep, px1, py1, px2, py2, 0);
		padarr->AddAt(pad, np);
	}

	// Draw pads __________________________________ 
	for (Int_t ipad = 0; ipad < npads; ipad++) {
		xrow = ipad % npx;
		yrow = ipad / npx;

		TPad *pad = dynamic_cast<TPad *>( padarr->At(ipad) );
		pad->SetTicks();
		// margins ____________
		if (xrow == 0 && yrow == 0) {
			pad->SetBottomMargin(tm);
			pad->SetRightMargin(0.0);
			pad->SetTopMargin(0.0);
			pad->SetLeftMargin(lm);
		} else if (xrow == 0 && yrow == npy - 1.) {
			pad->SetBottomMargin(0.0);
			pad->SetRightMargin(0.0);
			pad->SetTopMargin(tm);
			pad->SetLeftMargin(lm);
		} else if (xrow == 0) {
			pad->SetBottomMargin(0.0);
			pad->SetRightMargin(0.0);
			pad->SetTopMargin(0.0);
			pad->SetLeftMargin(lm);
		} else if ((xrow > 0 && xrow < npx - 1.) && yrow == 0) {
			pad->SetBottomMargin(tm);
			pad->SetRightMargin(0.0);
			pad->SetTopMargin(0.0);
			pad->SetLeftMargin(0.0);
		} else if ((xrow > 0 && xrow < npx - 1.) && yrow == npy - 1.) {
			pad->SetBottomMargin(0.0);
			pad->SetRightMargin(0.0);
			pad->SetTopMargin(tm);
			pad->SetLeftMargin(0.0);
		} else if ((xrow > 0 && xrow < npx - 1.) && yrow == npy - 1.) {
			pad->SetBottomMargin(0.0);
			pad->SetRightMargin(0.0);
			pad->SetTopMargin(tm);
			pad->SetLeftMargin(0.0);
		} else if (xrow == npx - 1. && yrow == 0) {
			pad->SetBottomMargin(tm);
			pad->SetRightMargin(lm);
			pad->SetTopMargin(0.0);
			pad->SetLeftMargin(0.0);
		} else if (xrow == npx - 1. && yrow == npy - 1.) {
			pad->SetBottomMargin(0.0);
			pad->SetRightMargin(lm);
			pad->SetTopMargin(tm);
			pad->SetLeftMargin(0.0);
		} else if (xrow == npx - 1.) {
			pad->SetBottomMargin(0.0);
			pad->SetRightMargin(lm);
			pad->SetTopMargin(0.0);
			pad->SetLeftMargin(0.0);
		} else {
			pad->SetBottomMargin(0.0);
			pad->SetRightMargin(0.0);
			pad->SetTopMargin(0.0);
			pad->SetLeftMargin(0.0);
		}

		if (npx == 1) {
			pad->SetRightMargin(lm);
		}
		if (npy == 1) {
			pad->SetTopMargin(tm);
		}

		pad->Draw();



	}

	return padarr;
}