/* === S Y N F I G ========================================================= */

/*!	\file synfig/rendering/primitive/transformation.cpp

**	\brief Transformation

**

**	$Id$

**

**	\legal

**	......... ... 2015-2018 Ivan Mahonin

**

**	This package is free software; you can redistribute it and/or

**	modify it under the terms of the GNU General Public License as

**	published by the Free Software Foundation; either version 2 of

**	the License, or (at your option) any later version.

**

**	This package is distributed in the hope that it will be useful,

**	but WITHOUT ANY WARRANTY; without even the implied warranty of

**	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

**	General Public License for more details.

**	\endlegal

*/

/* ========================================================================= */

/* === H E A D E R S ======================================================= */

#ifdef USING_PCH

#	include "pch.h"

#else

#ifdef HAVE_CONFIG_H

#	include <config.h></config.h>

#endif

#include "transformation.h"

#endif

using namespace synfig;

using namespace rendering;

/* === M A C R O S ========================================================= */

/* === G L O B A L S ======================================================= */

/* === P R O C E D U R E S ================================================= */

/* === M E T H O D S ======================================================= */

Transformation::DiscreteBounds

Transformation::make_discrete_bounds(const Bounds &bounds)

{

	const int border_width   = 4;

	const int max_width      = 16384 - 2*border_width;

	const int max_height     = 16384 - 2*border_width;

	const int max_area_width = 4096 - 2*border_width;

	const int max_area       = max_area_width * max_area_width;

	if (!bounds.is_valid())

		return DiscreteBounds();

	const Vector raster_size_orig = bounds.rect.get_size().multiply_coords( bounds.resolution );

	Vector raster_size_float = raster_size_orig;

	if (raster_size_float[0] > max_width)

		raster_size_float[0] = max_width;

	if (raster_size_float[1] > max_height)

		raster_size_float[1] = max_height;

	VectorInt raster_size(

		std::max(1, (int)approximate_ceil(raster_size_float[0])),

		std::max(1, (int)approximate_ceil(raster_size_float[1])) );

	if (raster_size[0] * raster_size[1] > max_area) {

		const Real k = sqrt(Real(max_area)/(raster_size[0] * raster_size[1]));

		raster_size[0] = std::max(1, (int)approximate_floor(raster_size[0]*k));

		raster_size[1] = std::max(1, (int)approximate_floor(raster_size[1]*k));

	}

	const Vector border(

		border_width*raster_size_orig[0]/(bounds.resolution[0]*raster_size[0]),

		border_width*raster_size_orig[1]/(bounds.resolution[1]*raster_size[1]) );

	return DiscreteBounds(

		Rect(

			bounds.rect.get_min() - border,

			bounds.rect.get_max() + border ),

		raster_size + VectorInt(border_width, border_width) );

}

Matrix2

Transformation::derivative_vfunc(const Point &x) const

{

	const Real step = real_low_precision<real>();</real>

	const Real step_div = 1/step;

	const Point p0 = transform(x);

	const Point dx = transform(Point(x[0] + step, x[1])) - p0;

	const Point dy = transform(Point(x[0], x[1] + step)) - p0;

	return Matrix2(dx[0]*step_div, dx[1]*step_div, dy[0]*step_div, dy[1]*step_div);

}

bool

Transformation::can_merge_outer_vfunc(const Transformation&) const

	{ return false; }

bool

Transformation::can_merge_inner_vfunc(const Transformation&) const

	{ return false; }

void

Transformation::merge_outer_vfunc(const Transformation&)

	{ }

void

Transformation::merge_inner_vfunc(const Transformation&)

	{ }

Mesh::Handle

Transformation::build_mesh_vfunc(const Rect &target_rect, const Vector &precision) const

{

	typedef std::pair<int, mesh::vertex=""> GridPoint;</int,>

	Transformation::Handle back_transform = create_inverted();

	if (!back_transform)

		return Mesh::Handle();

	const Vector grid_p0 = target_rect.get_min();

	const Vector grid_p1 = target_rect.get_max();

	const Vector grid_size = grid_p1 - grid_p0;

	const int grid_side_count_x = std::max(1, (int)round(grid_size[0]/precision[0])) + 1;

	const int grid_side_count_y = std::max(1, (int)round(grid_size[1]/precision[1])) + 1;

	const Vector grid_step(

		grid_size[0]/(Real)(grid_side_count_x - 1),

		grid_size[1]/(Real)(grid_side_count_y - 1) );

	//const Real grid_step_diagonal = grid_step.mag();

	// build grid

	int visible_vertex_count = 0;

	std::vector<gridpoint> grid;</gridpoint>

	grid.reserve(grid_side_count_x * grid_side_count_y);

	for(int j = 0; j < grid_side_count_y; ++j)

		for(int i = 0; i < grid_side_count_x; ++i)

		{

			Vector p( grid_p0[0] + i*grid_step[0],

					  grid_p0[1] + j*grid_step[1] );

			Point tp = back_transform->transform(p);

			if (tp.is_valid()) {

				grid.push_back(GridPoint(visible_vertex_count, Mesh::Vertex(p, tp)));

				++visible_vertex_count;

			} else {

				grid.push_back(GridPoint(-1, Mesh::Vertex()));

			}

		}

	if (visible_vertex_count == 0)

		return Mesh::Handle();

	// copy vertices to mesh

	Mesh::Handle mesh(new Mesh());

	mesh->vertices.reserve(visible_vertex_count);

	for(std::vector<gridpoint>::const_iterator i = grid.begin(); i != grid.end(); ++i)</gridpoint>

		if (i->first >= 0) mesh->vertices.push_back(i->second);

	// build triangles

	mesh->triangles.reserve(visible_vertex_count * 2);

	for(int j = 0; j < grid_side_count_y; ++j)

	{

		for(int i = 0; i < grid_side_count_x; ++i)

		{

			int tl = grid[(j-1)*grid_side_count_x + i-1].first;

			int tr = grid[(j-1)*grid_side_count_x + i  ].first;

			int bl = grid[    j*grid_side_count_x + i-1].first;

			int br = grid[    j*grid_side_count_x + i  ].first;

			int mode = (tl >= 0 ? 1 : 0)

					 | (tr >= 0 ? 2 : 0)

					 | (bl >= 0 ? 4 : 0)

					 | (br >= 0 ? 8 : 0);

			switch(mode)

			{

			case 1|2|4|8:

				mesh->triangles.push_back(Mesh::Triangle(tl, tr, bl));

				mesh->triangles.push_back(Mesh::Triangle(bl, tr, br));

				break;

			case 2|4|8:

				mesh->triangles.push_back(Mesh::Triangle(bl, tr, br));

				break;

			case 1|4|8:

				mesh->triangles.push_back(Mesh::Triangle(tl, br, bl));

				break;

			case 1|2|8:

				mesh->triangles.push_back(Mesh::Triangle(tl, tr, br));

				break;

			case 1|2|4:

				mesh->triangles.push_back(Mesh::Triangle(tl, tr, bl));

				break;

			default:

				break;

			}

		}

	}

	return mesh;

}

Transformation*

Transformation::create_merged(const Transformation& other) const

{

	if (can_merge_inner(other)) {

		Transformation *t = clone();

		if (!t) return 0;

		if (!t->can_merge_inner(other)) return 0;

		t->merge_inner(other);

		return t;

	} else

	if (other.can_merge_outer(*this)) {

		Transformation *t = other.clone();

		if (!t) return 0;

		if (!t->can_merge_outer(*this)) return 0;

		t->merge_outer(*this);

		return t;

	}

	return 0;

}

bool

Transformation::can_merge_outer(const Transformation& other) const {

	return (bool)dynamic_cast<const transformationnone*="">(&other)</const>

		 || can_merge_outer_vfunc(other);

}

bool

Transformation::can_merge_inner(const Transformation& other) const {

	return (bool)dynamic_cast<const transformationnone*="">(&other)</const>

		 || can_merge_inner_vfunc(other);

}

bool

Transformation::merge_outer(const Transformation& other) {

	if (!can_merge_outer(other)) return false;

	merge_outer_vfunc(other);

	return true;

}

bool

Transformation::merge_inner(const Transformation& other) {

	if (!can_merge_inner(other)) return false;

	merge_inner_vfunc(other);

	return true;

}

Mesh::Handle

Transformation::build_mesh(const Rect &target_rect, const Vector &precision) const

{

	const Real epsilon = real_low_precision<real>();</real>

	if (!target_rect.is_valid())

		return Mesh::Handle();

	Vector valid_precision(fabs(precision[0]), fabs(precision[1]));

	if (std::isnan(valid_precision[0]) || std::isinf(valid_precision[0]))

		valid_precision[0] = target_rect.get_width();

	if (std::isnan(valid_precision[1]) || std::isinf(valid_precision[1]))

		valid_precision[1] = target_rect.get_height();

	if (valid_precision[0] < epsilon)

		valid_precision[0] = epsilon;

	if (valid_precision[1] < epsilon)

		valid_precision[1] = epsilon;

	return build_mesh_vfunc(target_rect, valid_precision);

}

/* === E N T R Y P O I N T ================================================= */