/* === S Y N F I G ========================================================= */
/*!	\file synfig/render.cpp
**	\brief Renderer
**
**	$Id$
**
**	\legal
**	Copyright (c) 2002-2005 Robert B. Quattlebaum Jr., Adrian Bentley
**	Copyright (c) 2012-2013 Carlos López
**
**	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>
#endif

#ifndef _WIN32
#include <unistd.h>
#include <sys/types.h>
#include <signal.h>
#endif

#include <cassert>

#include <ETL/handle>

#include "render.h"

#include "general.h"
#include <synfig/localization.h>

#include "canvas.h"
#include "cairo_renddesc.h"
#include "context.h"
#include "surface.h"
#include "target.h"


#endif

using namespace std;
using namespace synfig;
using namespace etl;

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

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

bool
synfig::parametric_render(
	Context context,
	Surface &surface,
	const RendDesc &desc,
	ProgressCallback *callback
)
{
	Point::value_type
		u,v,		// Current location in image
		su,sv,		// Starting locations
		du, dv,		// Distance between pixels
		dsu,dsv;	// Distance between subpixels

	bool
		no_clamp=!desc.get_clamp();

	int
		w(desc.get_w()),
		h(desc.get_h()),
		a(desc.get_antialias());

	Point
		tl(desc.get_tl()),
		br(desc.get_br());

	//Gamma
	//	gamma(desc.get_gamma());

	int
		x,y,		// Current location on output bitmap
		x2,y2;		// Subpixel counters

	Color::value_type
		pool;		// Alpha pool (for correct alpha antialiasing)

	// Calculate the number of channels
	//chan=channels(desc.get_pixel_format());

	// Calculate the distance between pixels
	du=(br[0]-tl[0])/(Point::value_type)w;
	dv=(br[1]-tl[1])/(Point::value_type)h;

	// Calculate the distance between sub pixels
	dsu=du/(Point::value_type)a;
	dsv=dv/(Point::value_type)a;

	// Calculate the starting points
	//su=tl[0]+(du-dsu)/(Point::value_type)2.0;
	//sv=tl[1]-(dv-dsv)/(Point::value_type)2.0;
	su=tl[0];
	sv=tl[1];

	surface.set_wh(desc.get_w(),desc.get_h());

	assert(surface);

	// Loop through all horizontal lines
	for(y=0,v=sv;y<h;y++,v+=dv)
	{
		// Set the current pixel pointer
		// to the start of the line
		Color *colordata=surface[y];

		assert(colordata);

		// If we have a callback that we need
		// to report to, do so now.
		if(callback)
			if( callback->amount_complete(y,h) == false )
			{
				// If the callback returns false,
				// then the render has been aborted.

				return false;
			}

		// Loop through every pixel in row
		for(x=0,u=su;x<w;x++,u+=du)
		{
			Color &c(*(colordata++));
			c=Color::alpha();

			// Loop through all subpixels
			for(y2=0,pool=0;y2<a;y2++)
				for(x2=0;x2<a;x2++)
				{
					Color color=context.get_color(
						Point(
							u+(Point::value_type)(x2)*dsu,
							v+(Point::value_type)(y2)*dsv
							)
						);
					if(!no_clamp)
					{
						color=color.clamped();
						c+=color*color.get_a();
						pool+=color.get_a();
					}
					else
					{
						c+=color*color.get_a();
						pool+=color.get_a();
					}
				}
			if(pool)
				c/=pool;
		}
	}

	// Give the callback one more last call,
	// this time with the full height as the
	// current line
	if(callback)
		callback->amount_complete(h,h);

	// Report our success
	return(true);
}

bool
synfig::render(
	Context context,
	Target_Scanline::Handle target,
	const RendDesc &desc,
	ProgressCallback *callback)
{
	Point::value_type
		u,v,		// Current location in image
		su,sv,		// Starting locations
		du, dv,		// Distance between pixels
		dsu,dsv;	// Distance between subpixels

	bool
		no_clamp=!desc.get_clamp();

	int
		w(desc.get_w()),
		h(desc.get_h()),
		a(desc.get_antialias());

	Point
		tl(desc.get_tl()),
		br(desc.get_br());

	//Gamma
	//	gamma(desc.get_gamma());

	int
		x,y,		// Current location on output bitmap
		x2,y2;		// Subpixel counters

	Color::value_type
		pool;		// Alpha pool (for correct alpha antialiasing)

	assert(target);

	// If we do not have a target then bail
	if(!target)
		return false;

	// Calculate the number of channels
	//chan=channels(desc.get_pixel_format());

	// Calculate the distance between pixels
	du=(br[0]-tl[0])/(Point::value_type)w;
	dv=(br[1]-tl[1])/(Point::value_type)h;

	// Calculate the distance between sub pixels
	dsu=du/(Point::value_type)a;
	dsv=dv/(Point::value_type)a;

	// Calculate the starting points
	su=tl[0]+(du-dsu)/(Point::value_type)2.0;
	sv=tl[1]-(dv-dsv)/(Point::value_type)2.0;

	// Mark the start of a new frame.
	if(!target->start_frame(callback))
		return false;

	// Loop through all horizontal lines
	for(y=0,v=sv;y<h;y++,v+=dv)
	{
		// Set the current pixel pointer
		// to the start of the line
		Color *colordata=target->start_scanline(y);

		if(!colordata)
		{
			if(callback)callback->error(_("Target panic"));
			else throw(string(_("Target panic")));
			return false;
		}

		// If we have a callback that we need
		// to report to, do so now.
		if(callback)
			if( callback->amount_complete(y,h) == false )
			{
				// If the callback returns false,
				// then the render has been aborted.
				// Exit gracefully.

				target->end_scanline();
				target->end_frame();
				return false;
			}

		// Loop through every pixel in row
		for(x=0,u=su;x<w;x++,u+=du)
		{
			Color &c(*(colordata++));
			c=Color::alpha();

			// Loop through all subpixels
			for(y2=0,pool=0;y2<a;y2++)
				for(x2=0;x2<a;x2++)
				{
					Color color=context.get_color(
						Point(
							u+(Point::value_type)(x2)*dsu,
							v+(Point::value_type)(y2)*dsv
							)
						);
					if(!no_clamp)
					{
						color=color.clamped();
						c+=color*color.get_a();
						pool+=color.get_a();
					}
					else
					{
						c+=color*color.get_a();
						pool+=color.get_a();
					}
				}
			if(pool)
				c/=pool;
		}

		// Send the buffer to the render target.
		// If anything goes wrong, cleanup and bail.
		if(!target->end_scanline())
		{
			if(callback)callback->error(_("Target panic"));
			else throw(string(_("Target panic")));
			return false;
		}
	}

	// Finish up the target's frame
	target->end_frame();

	// Give the callback one more last call,
	// this time with the full height as the
	// current line
	if(callback)
		callback->amount_complete(h,h);

	// Report our success
	return(true);
}

//////////
// Cairo_Target needs to have its RendDesc already set.
bool
synfig::cairorender(
			   Context context,
			   cairo_surface_t* surface,
			   const RendDesc &desc,
			   ProgressCallback *callback)
{
	Point::value_type
	u,v,		// Current location in image
	su,sv,		// Starting locations
	du, dv,		// Distance between pixels
	dsu,dsv;	// Distance between subpixels
	
	int
	w(desc.get_w()),
	h(desc.get_h()),
	a(desc.get_antialias());
	
	Point
	tl(desc.get_tl()),
	br(desc.get_br());
	
	//Gamma
	//	gamma(desc.get_gamma());
	
	int
	x,y,		// Current location on output bitmap
	x2,y2;		// Subpixel counters
	
	Color::value_type
	pool;		// Alpha pool (for correct alpha antialiasing)
	
	// Calculate the number of channels
	//chan=channels(desc.get_pixel_format());
	
	// Calculate the distance between pixels
	du=(br[0]-tl[0])/(Point::value_type)w;
	dv=(br[1]-tl[1])/(Point::value_type)h;
	
	// Calculate the distance between sub pixels
	dsu=du/(Point::value_type)a;
	dsv=dv/(Point::value_type)a;
	
	// Calculate the starting points
	su=tl[0]+(du-dsu)/(Point::value_type)2.0;
	sv=tl[1]-(dv-dsv)/(Point::value_type)2.0;
	
	// Create a CairoSurface from the cairo_surface_t
	CairoSurface csurface(surface);
	// map the cairo_surface_t to the etl::surface
	csurface.map_cairo_image();
	// Loop through all horizontal lines
	for(y=0,v=sv;y<h;y++,v+=dv)
	{
		// If we have a callback that we need
		// to report to, do so now.
		if(callback)
			if( callback->amount_complete(y,h) == false )
			{
				// If the callback returns false,
				// then the render has been aborted.
				// Exit gracefully.
				csurface.unmap_cairo_image();
				return false;
			}
		// Loop through every pixel in row
		for(x=0,u=su;x<w;x++,u+=du)
		{
			Color c(Color::alpha());
			// Loop through all subpixels
			for(y2=0,pool=0;y2<a;y2++)
				for(x2=0;x2<a;x2++)
				{
					Color color=Color(context.get_cairocolor(
												  Point(
														u+(Point::value_type)(x2)*dsu,
														v+(Point::value_type)(y2)*dsv
														)
												  ));
					color=color.clamped();
					c+=color*color.get_a();
					pool+=color.get_a();
				}
			if(pool)
				c/=pool;
			// Once the pixel is subsampled then I premultiply by alpha and pass
			// it to the CairoSurface
			csurface[y][x]=CairoColor(c).premult_alpha();
		}
	}
	// unmap the rendered surface to the cairo_surface_t
	csurface.unmap_cairo_image();
	
	// Give the callback one more last call,
	// this time with the full height as the
	// current line
	if(callback)
		callback->amount_complete(h,h);
	
	// Report our success
	return(true);
}
////////

bool
synfig::cairorender(Context context,
				cairo_t* cr,
				const RendDesc &desc,
				ProgressCallback *cb)
{
	RendDesc	renddesc(desc);
	
	// Untransform the render desc
	if(!cairo_renddesc_untransform(cr, renddesc))
		return false;
	const Real pw(renddesc.get_pw()),ph(renddesc.get_ph());
	const Point tl(renddesc.get_tl());
	const int w(renddesc.get_w());
	const int h(renddesc.get_h());
	cairo_surface_t *surface;
	
	surface=cairo_surface_create_similar(cairo_get_target(cr), CAIRO_CONTENT_COLOR_ALPHA, w, h);

	if(!cairorender(context, surface, renddesc, cb))
	{
		cairo_surface_destroy(surface);
		return false;
	}
	
	cairo_save(cr);
	cairo_translate(cr, tl[0], tl[1]);
	cairo_scale(cr, pw, ph);
	cairo_set_source_surface(cr, surface, 0, 0);
	cairo_set_operator(cr, CAIRO_OPERATOR_SOURCE);
	cairo_paint(cr);
	cairo_restore(cr);
	
	cairo_surface_destroy(surface);
	// Mark our progress as finished
	if(cb && !cb->amount_complete(10000,10000))
		return false;

	return true;
}



bool
synfig::render_threaded(
	Context context,
	Target_Scanline::Handle target,
	const RendDesc &desc,
	ProgressCallback *callback,
	int threads)
{
#ifndef _WIN32
    struct _render_thread
    {
		int
			pipe_read,
			pipe_write,
			pid;
		_render_thread():
			pipe_read(), pipe_write(), pid()
		{
			pipe(&pipe_read);
			pid=0;
		}
		~_render_thread()
		{
			close(pipe_read);
			close(pipe_write);
			if(pid)
			{
				kill(pid,9);
			}
		}
    } *render_thread;

    int i, mythread=-1;

	Point::value_type
		u,v,		// Current location in image
		su,sv,		// Starting locations
		du, dv,		// Distance between pixels
		dsu,dsv;	// Distance between subpixels

	bool
		no_clamp=!desc.get_clamp();

	int
		w(desc.get_w()),
		h(desc.get_h()),
		a(desc.get_antialias());

	Point
		tl(desc.get_tl()),
		br(desc.get_br());

	int
		x,y,		// Current location on output bitmap
		x2,y2;		// Subpixel counters

	Color::value_type
		pool;		// Alpha pool (for correct alpha antialiasing)

	assert(target);

	// If we do not have a target then bail
	if(!target)
		return false;

	// Calculate the distance between pixels
	du=(br[0]-tl[0])/(Point::value_type)w;
	dv=(br[1]-tl[1])/(Point::value_type)h;

	// Calculate the distance between sub pixels
	dsu=du/(Point::value_type)a;
	dsv=dv/(Point::value_type)a;

	// Calculate the starting points
	su=tl[0]+(du-dsu)/(Point::value_type)2.0;
	sv=tl[1]-(dv-dsv)/(Point::value_type)2.0;

    render_thread=new _render_thread[threads];

	// Start the forks
    for(i=0;i<threads;i++)
    {
		int pid=fork();
		if(pid==0)
		{
	    	mythread=i;
	    	goto renderthread;
		}
		render_thread[i].pid=pid;
    }

	// Mark the start of a new frame.
	if(!target->start_frame(callback))
		return false;

    for(y=0;y<h;y++)
    {
		// Set the current pixel pointer
		// to the start of the line
		Color *colordata(target->start_scanline(y));

		if(!colordata)
		{
			if(callback)callback->error(_("Target panic"));
			else throw(string(_("Target panic")));
			return false;
		}

		// If we have a callback that we need
		// to report to, do so now.
		if(callback)
			if( callback->amount_complete(y,h) == false )
			{
				// If the callback returns false,
				// then the render has been aborted.
				// Exit gracefully.

				target->end_scanline();
				target->end_frame();
				delete [] render_thread;
				return false;
			}

		read(render_thread[y%threads].pipe_read,colordata,w*sizeof(Color));

		// Send the buffer to the render target.
		// If anything goes wrong, cleanup and bail.
		if(!target->end_scanline())
		{
			delete [] render_thread;
			if(callback)callback->error(_("Target panic"));
			else throw(string(_("Target panic")));
			return false;
		}
    }

	// Finish up the target's frame
	target->end_frame();

	// Give the callback one more last call,
	// this time with the full height as the
	// current line
	if(callback)
		callback->amount_complete(h,h);

    delete [] render_thread;
    return true;

renderthread:

	// Change the random seed, so that each thread has a different one
	srand(mythread*20+threads+time(0));

	Color *buffer(new Color[w]);

	// Loop through all horizontal lines
	for(y=mythread,v=sv+dv*(Real)mythread;y<h;y+=threads,v+=dv*(Real)threads)
	{
		// Set the current pixel pointer
		// to the start of the line
		Color* colordata(buffer);

		// Loop through every pixel in row
		for(x=0,u=su;x<w;x++,u+=du)
		{
			Color &c(*(colordata++));
			c=Color::alpha();

			// Loop through all subpixels
			for(y2=0,pool=0;y2<a;y2++)
				for(x2=0;x2<a;x2++)
				{
					Color color=context.get_color(
						Point(
							u+(Point::value_type)(x2)*dsu,
							v+(Point::value_type)(y2)*dsv
							)
						);
					if(!no_clamp)
					{
						color=color.clamped();
						c+=color*color.get_a();
						pool+=color.get_a();
					}
					else
					{
						c+=color*color.get_a();
						pool+=color.get_a();
					}
				}
			if(pool)
				c/=pool;
		}

		// Send the buffer to the primary thread.
		write(render_thread[mythread].pipe_write,buffer,w*sizeof(Color));
	}

	delete [] buffer;

    _exit(0);
	return false;
#else
	return render(context, target, desc, callback);

#endif
}
