/*
 * Copyright 2011, Blender Foundation.
 *
 * 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 2
 * of the License, or (at your option) any later version.
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * Contributor: 
 *		Jeroen Bakker 
 *		Monique Dewanchand
 */

#include "COM_ConvertDepthToRadiusOperation.h"
#include "BLI_math.h"
#include "BKE_camera.h"
#include "DNA_camera_types.h"

ConvertDepthToRadiusOperation::ConvertDepthToRadiusOperation() : NodeOperation()
{
	this->addInputSocket(COM_DT_VALUE);
	this->addOutputSocket(COM_DT_VALUE);
	this->m_inputOperation = NULL;
	this->m_fStop = 128.0f;
	this->m_cameraObject = NULL;
	this->m_maxRadius = 32.0f;
	this->m_blurPostOperation = NULL;
}

float ConvertDepthToRadiusOperation::determineFocalDistance()
{
	if (this->m_cameraObject && this->m_cameraObject->type == OB_CAMERA) {
		Camera *camera = (Camera *)this->m_cameraObject->data;
		this->m_cam_lens = camera->lens;
		return BKE_camera_object_dof_distance(this->m_cameraObject);
	}
	else {
		return 10.0f;
	}
}

void ConvertDepthToRadiusOperation::initExecution()
{
	float cam_sensor = DEFAULT_SENSOR_WIDTH;
	Camera *camera = NULL;

	if (this->m_cameraObject && this->m_cameraObject->type == OB_CAMERA) {
		camera = (Camera *)this->m_cameraObject->data;
		cam_sensor = BKE_camera_sensor_size(camera->sensor_fit, camera->sensor_x, camera->sensor_y);
	}

	this->m_inputOperation = this->getInputSocketReader(0);
	float focalDistance = determineFocalDistance();
	if (focalDistance == 0.0f) focalDistance = 1e10f;  /* if the dof is 0.0 then set it be be far away */
	this->m_inverseFocalDistance = 1.0f / focalDistance;
	this->m_aspect = (this->getWidth() > this->getHeight()) ? (this->getHeight() / (float)this->getWidth()) : (this->getWidth() / (float)this->getHeight());
	this->m_aperture = 0.5f * (this->m_cam_lens / (this->m_aspect * cam_sensor)) / this->m_fStop;
	const float minsz = min(getWidth(), getHeight());
	this->m_dof_sp = minsz / ((cam_sensor / 2.0f) / this->m_cam_lens);    // <- == aspect * min(img->x, img->y) / tan(0.5f * fov);

	if (this->m_blurPostOperation) {
		m_blurPostOperation->setSigma(min(m_aperture * 128.0f, this->m_maxRadius));
	}
}

void ConvertDepthToRadiusOperation::executePixel(float output[4], float x, float y, PixelSampler sampler)
{
	float inputValue[4];
	float z;
	float radius;
	this->m_inputOperation->read(inputValue, x, y, sampler);
	z = inputValue[0];
	if (z != 0.f) {
		float iZ = (1.f / z);
		
		// bug #6656 part 2b, do not rescale
#if 0
		bcrad = 0.5f * fabs(aperture * (dof_sp * (cam_invfdist - iZ) - 1.0f));
		// scale crad back to original maximum and blend
		crad->rect[px] = bcrad + wts->rect[px] * (scf * crad->rect[px] - bcrad);
#endif
		radius = 0.5f * fabsf(this->m_aperture * (this->m_dof_sp * (this->m_inverseFocalDistance - iZ) - 1.f));
		// 'bug' #6615, limit minimum radius to 1 pixel, not really a solution, but somewhat mitigates the problem
		if (radius < 0.0f) radius = 0.0f;
		if (radius > this->m_maxRadius) {
			radius = this->m_maxRadius;
		}
		output[0] = radius;
	}
	else {
		output[0] = 0.0f;
	}
}

void ConvertDepthToRadiusOperation::deinitExecution()
{
	this->m_inputOperation = NULL;
}
