/*----------------------------------------------------------------------------*\
 | Copyright (C) 2009 - Rafael de O. Lopes Gonçalves and André Shoji Asato   |
 | This program 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 3             |
 | of the License.                                                            |
 |                                                                            |
 | This program 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.                               |
 |                                                                            |
 | You should have received a copy of the GNU General Public License          |
 | along with this program; if not, write to the Free Software                |
 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.|
\*----------------------------------------------------------------------------*/

#include <stdio.h>
#include <stdlib.h>
#include "visocor.h"

static const int LAST_FILTER = N_FILTER_VARIATIONS - 1;
static const int FIRST_FILTER = 0;
static const int FILTER_STEP = 1;

static void recalculateColorFilter(CompScreen * s) {
	VISOCOR_SCREEN(s);
	int middle;

	middle = (LAST_FILTER + FIRST_FILTER) / 2;
	if (vs->filterIntensity > middle) {
		vs->ir = ((float) vs->filterIntensity - middle)
				/ (LAST_FILTER - middle);
		vs->ig = 0;
	} else {
		vs->ig = ((float) middle - vs->filterIntensity) / (middle
				- FIRST_FILTER);
		vs->ir = 0;
	}
	vs->ib = 1.0 - vs->ig - vs->ir;
	visocorPrintf(CompLogLevelDebug, "ir = %f\tig = %f\tib = %f", vs->ir,
			vs->ig, vs->ib);
}

void visocorResetFilter(VISOCORScreen * vs) {
	int middle;

	middle = (LAST_FILTER + FIRST_FILTER) / 2;
	vs->filterIntensity = middle;
	vs->ig = 0;
	vs->ir = 0;
	vs->ib = 1;
}

Bool visocorToggleFilter(CompDisplay * d, CompAction * action,
		CompActionState state, CompOption * option, int nOption) {
	CompWindow *w;

	w = visocorFindWindow(d, option, nOption);

	if (w) {
		VISOCOR_WINDOW(w);
		if (vw->currentState != FILTER) {
			visocorToggleWindowToState(w, FILTER);
		} else {
			visocorToggleWindowToState(w, vw->lastState);
		}
	}

	return TRUE;
}

Bool visocorDecreaseFilter(CompDisplay * d, CompAction * action,
		CompActionState state, CompOption * option, int nOption) {

	int value;

	CompScreen *s;

	s = visocorFindScreen(d, option, nOption);

	if (s) {
		VISOCOR_SCREEN(s);
		value = MAX(FIRST_FILTER, vs->filterIntensity - FILTER_STEP);
		vs->filterIntensity = value;
		recalculateColorFilter(s);

		visocorDamageAllWindows(s);

		return TRUE;

	}
	return FALSE;

}

Bool visocorIncreaseFilter(CompDisplay * d, CompAction * action,
		CompActionState state, CompOption * option, int nOption) {

	CompScreen *s;

	int value;

	s = visocorFindScreen(d, option, nOption);
	if (s) {
		VISOCOR_SCREEN(s);
		value = MIN(LAST_FILTER, vs->filterIntensity + FILTER_STEP);
		vs->filterIntensity = value;
		recalculateColorFilter(s);

		visocorDamageAllWindows(s);
		return TRUE;

	}
	return FALSE;
}

int getVisocorFilterFragmentFunction(CompScreen * s, CompTexture * texture,
		int param) {
	VISOCOR_SCREEN(s);

	if (vs->visocorFunctions[FILTER][param] == 0) {
		CompFunctionData *data;
		int target;
		char filter_operation[1024];
		Bool ok = TRUE;

		visocorPrintf(CompLogLevelDebug, "criando um FILTER com a variavel %d",
				param);
		if (texture->target == GL_TEXTURE_2D)
			target = COMP_FETCH_TARGET_2D;
		else
			target = COMP_FETCH_TARGET_RECT;

		data = createFunctionData();
		if (data) {

			ok &= addTempHeaderOpToFunctionData(data, "tex");
			ok &= addTempHeaderOpToFunctionData(data, "temp");
			ok &= addFetchOpToFunctionData(data, "tex", NULL, target);
			char * format = "DP3 temp.r, tex, {1 , 0   , 0 , 0};\n"
				"DP3 temp.g, tex, {0 , 1   , 0 , 0};\n"
				"DP3 temp.b, tex, program.env[%d].xyzw;\n"
				"MOV temp.a, tex.a;";
			sprintf(filter_operation, format, param);
		}
		ok &= addDataOpToFunctionData(data, filter_operation);
		ok &= addColorOpToFunctionData(data, "output", "temp");
		if (!ok) {
			destroyFunctionData(data);
			return 0;
		}

		vs->visocorFunctions[FILTER][param] = createFragmentFunction(s,
				"visocor", data);
		;
	}

	(*s->programEnvParameter4f)(GL_FRAGMENT_PROGRAM_ARB, param, vs->ir, vs->ig,
			vs->ib, 1.0f);

	return vs->visocorFunctions[FILTER][param];

}