/* -*- C++ -*-
 * Copyright ©2008 Hugo Mills <hugo@carfax.org.uk>
 *
 * This software is distributed under the terms of the GNU GPL v3
 * For more information on the GPL, see the file COPYING or 
 * visit http://www.gnu.org/
 *
 * This software is distributed without warranty
 */

#include "magellan/contentfilled.h"

#include <algorithm>

#include "magellan/options.h"

ContentFilled::ContentFilled(
	int _minx, int _miny,
	int _maxx, int _maxy,
	bool _smooth
	)
	: minx(_minx), miny(_miny), 
	  maxx(_maxx), maxy(_maxy),
	  smooth(_smooth)
{
	init();
}

ContentFilled::ContentFilled(
	int _maxx, int _maxy,
	bool _smooth
	)
	: minx(0), miny(0), 
	  maxx(_maxx), maxy(_maxy),
	  smooth(_smooth)
{
	init();
}

ContentFilled::ContentFilled()
	: minx(0), miny(0),
	  maxx(0), maxy(0),
	  smooth(false)
{
	init();
}

void ContentFilled::init()
{
	xconv = (maxx-minx)/(2*M_PI);
	yconv = (maxy-miny)/M_PI;
}

void ContentFilled::plot(
	Output* bitmap,
	XfView* viewport,
	XfMap* projection,
	XfOrbit* orbit,
	XfSphere* sphere
	)
{
	ivec2 bm_pos;
	dvec2 map_pos;
	dvec3 shifted_pos;
	dvec3 globe_pos;
	dvec2 latlong;

	ivec3 colour;
	ivec3 c00;
	ivec3 c10;
	ivec3 c01;
	ivec3 c11;

	for(bm_pos[1] = viewport->bottom(); 
		bm_pos[1] < viewport->top(); 
		bm_pos[1]++)
	{
		for(bm_pos[0] = viewport->left(); 
			bm_pos[0] < viewport->right(); 
			bm_pos[0]++)
		{
			if(!viewport->g(map_pos, bm_pos))
				continue;

			if(projection->g(shifted_pos, map_pos)
			   && orbit->g(globe_pos, shifted_pos)
			   && sphere->g(latlong, globe_pos))
			{
				dvec2 pixelpos;
				pixelpos[0] = (latlong[0]+M_PI)*xconv;
				pixelpos[1] = (latlong[1]+M_PI_2)*yconv;

				if(smooth)
				{
					getpixel(c00, pixelpos);
					pixelpos[0]++;
					getpixel(c10, pixelpos);
					pixelpos[1]++;
					getpixel(c11, pixelpos);
					pixelpos[0]--;
					getpixel(c01, pixelpos);

					blend(colour, c00, c10, c11, c01,
						  pixelpos[0] - int(pixelpos[0]),
						  pixelpos[1] - int(pixelpos[1]));
				}
				else
				{
					getpixel(colour, pixelpos);
				}
			} else {
				colour[0] = colour[1] = colour[2] = 0;
				continue;
			}
			bitmap->setpixel(bm_pos, colour);
		}
	}
}

void ContentFilled::blend(ivec3& output,
						  const ivec3& c00, const ivec3& c10,
						  const ivec3& c11, const ivec3& c01,
						  double dx, double dy) const
{
	for(int i=0; i<3; i++)
	{
		double t0 = c00[i] + (c10[i] - c00[i]) * dx;
		double t1 = c01[i] + (c11[i] - c01[i]) * dx;
		output[i] = int(t0 + (t1 - t0) * dy);
	}
}