#include "stdfx.h"
#include "tfxparam.h"
#include "tpixelutils.h"

class Bright_ContFx : public TStandardRasterFx
{
	FX_PLUGIN_DECLARATION(Bright_ContFx)

	TRasterFxPort m_input;
	TDoubleParamP m_bright;
	TDoubleParamP m_contrast;

public:
	Bright_ContFx()
		: m_bright(0.0), m_contrast(0.0)
	{
		bindParam(this, "brightness", m_bright);
		bindParam(this, "contrast", m_contrast);
		m_bright->setValueRange(-127, 127);
		m_contrast->setValueRange(-127, 127);
		addInputPort("Source", m_input);
	}

	~Bright_ContFx(){};

	bool canHandle(const TRenderSettings &info, double frame) { return true; }

	bool doGetBBox(double frame, TRectD &bBox, const TRenderSettings &info)
	{
		if (!m_input.isConnected()) {
			bBox = TRectD();
			return false;
		}
		return m_input->doGetBBox(frame, bBox, info);
	};

	void doCompute(TTile &tile, double frame, const TRenderSettings &);
};

//===================================================================

template <typename PIXEL, typename T>
void my_compute_lut(double contrast, double brightness, vector<T> &lut)
{
	int i;
	double value, nvalue, power;

	int half_maxChannelValue = tfloor(PIXEL::maxChannelValue / 2.0);

	int lutSize = PIXEL::maxChannelValue + 1;
	for (i = 0; i < lutSize; i++) {
		value = i / double(PIXEL::maxChannelValue);
		/*brightness*/
		if (brightness < 0.0)
			value = value * (1.0 + brightness);
		else
			value = value + ((1.0 - value) * brightness);
		/*contrast*/
		if (contrast < 0.0) {
			if (value > 0.5)
				nvalue = 1.0 - value;
			else
				nvalue = value;
			if (nvalue < 0.0)
				nvalue = 0.0;
			nvalue = 0.5 * pow(nvalue * 2.0, (double)(1.0 + contrast));
			if (value > 0.5)
				value = 1.0 - nvalue;
			else
				value = nvalue;
		} else {
			if (value > 0.5)
				nvalue = 1.0 - value;
			else
				nvalue = value;
			if (nvalue < 0.0)
				nvalue = 0.0;
			power = (contrast == 1.0) ? half_maxChannelValue : 1.0 / (1.0 - contrast);
			nvalue = 0.5 * pow(2.0 * nvalue, power);
			if (value > 0.5)
				value = 1.0 - nvalue;
			else
				value = nvalue;
		}
		lut[i] = (int)(value * PIXEL::maxChannelValue);
	}
}

template <typename PIXEL, typename CHANNEL_TYPE>
void doBrightnessContrast(TRasterPT<PIXEL> ras, double contrast, double brightness)
{
	int lx = ras->getLx();
	int ly = ras->getLy();

	vector<CHANNEL_TYPE> lut(PIXEL::maxChannelValue + 1);
	my_compute_lut<PIXEL, CHANNEL_TYPE>(contrast, brightness, lut);

	int j;
	ras->lock();
	for (j = 0; j < ly; j++) {
		PIXEL *pix = ras->pixels(j);
		PIXEL *endPix = pix + lx;
		while (pix < endPix) {
			if (pix->m) {
				*pix = depremultiply(*pix);
				pix->r = lut[pix->r];
				pix->g = lut[pix->g];
				pix->b = lut[pix->b];
				pix->m = pix->m;
				*pix = premultiply(*pix);
			}
			pix++;
		}
	}
	ras->unlock();
}

void Bright_ContFx::doCompute(TTile &tile, double frame, const TRenderSettings &ri)
{
	if (!m_input.isConnected())
		return;

	m_input->compute(tile, frame, ri);

	double brightness = m_bright->getValue(frame) / 127.0;
	double contrast = m_contrast->getValue(frame) / 127.0;
	if (contrast > 1)
		contrast = 1;
	if (contrast < -1)
		contrast = -1;
	TRaster32P raster32 = tile.getRaster();
	if (raster32)
		doBrightnessContrast<TPixel32, UCHAR>(raster32, contrast, brightness);
	else {
		TRaster64P raster64 = tile.getRaster();
		if (raster64)
			doBrightnessContrast<TPixel64, USHORT>(raster64, contrast, brightness);
		else
			throw TException("Brightness&Contrast: unsupported Pixel Type");
	}
}

FX_PLUGIN_IDENTIFIER(Bright_ContFx, "brightContFx")