#include "ImageApplyAdjustColors.h"

CImageApplyAdjustColors::CImageApplyAdjustColors(void)
	: m_brightness(0)
	, m_contrast(0)
	, m_gamma(1.0f)
	, lut(1, 256, CV_8UC1)
{
	update_lutData();
}

CImageApplyAdjustColors::CImageApplyAdjustColors(int brightness, int contrast, float gamma)
	: lut(1, 256, CV_8UC1)
{
	setAdjustColors(brightness, contrast, gamma);
}

CImageApplyAdjustColors::~CImageApplyAdjustColors(void)
{

}

void CImageApplyAdjustColors::apply(cv::Mat& pDib,int side)
{
    (void)side;
    if (pDib.empty()) return;

    if (m_brightness != 0 || m_contrast != 0 || m_gamma < 0.999999f || m_gamma > 1.000001f)
        cv::LUT(pDib, lut, pDib);
}

void CImageApplyAdjustColors::apply(std::vector<cv::Mat>& mats, bool isTwoSide)
{
    (void)isTwoSide;
	int i = 0;
	for (cv::Mat& var : mats) {
		if (i != 0 && isTwoSide == false)
			break;
		if(!var.empty())
			apply(var, 0);
		i++;
	}
}

void CImageApplyAdjustColors::setAdjustColors(int brightness, int contrast, float gamma)
{
    m_brightness = cv::max(-255, cv::min(brightness, 255));
    m_contrast = cv::max(-127, cv::min(contrast, 127));
    m_gamma = cv::max(0.1f, cv::min(gamma, 5.0f));
	update_lutData();
}

void CImageApplyAdjustColors::setBrightness(int brightness)
{
	m_brightness = cv::max(-255, cv::min(brightness, 255)); 
	update_lutData();
}

void CImageApplyAdjustColors::setContrast(int contrast)
{
	m_contrast = cv::max(-127, cv::min(contrast, 127));
	update_lutData();
}

void CImageApplyAdjustColors::setGamma(float gamma)
{
	m_gamma = cv::max(0.1f, cv::min(gamma, 5.0f));
	update_lutData();
}

void CImageApplyAdjustColors::update_lutData()
{
	unsigned char* ptr = lut.data;
	//update gamma

	for (int i = 0; i < 256; i++)
	{
		//update brightness
		ptr[i] = static_cast<unsigned char>(cv::max(0, cv::min(i + m_brightness, 255)));

		//update contrast
		if (ptr[i] < 128)
            ptr[i] = static_cast<unsigned char>(cv::max(0, cv::min(ptr[i] - m_contrast, 127)));
		else
            ptr[i] = static_cast<unsigned char>(cv::max(127, cv::min(ptr[i] + m_contrast, 255)));
	}
	float g = 1.0f / m_gamma;
	for (int i = 0; i < 256; i++)
		ptr[i] = static_cast<unsigned char>(cv::min(255, static_cast<int>(cv::pow(static_cast<float>(ptr[i]) / 255.0f, g) * 255.0f + 0.5f)));
}