awesome-attractor/canvae/PNG.hpp

#ifndef PNG_HPP
#define PNG_HPP

#include <memory>
#include <vector>
#include <cassert>
#include <cmath>

#ifndef __APPLE__
	#include <array>
#else
	#include <tr1/array>
	namespace std {
		using tr1::array;
	}
#endif

#include "libpng.hpp"

#include "../Canvas.hpp"

class PNG : public Canvas {
	unsigned int width;
	unsigned int height;
	unsigned int num_colors;

	unsigned int* int_array;
	//std::shared_ptr<std::vector<unsigned int>> int_array;

public:

	double v;

	PNG(unsigned int width, unsigned int height, unsigned int num_colors = 1)
	: Canvas(2)
	, width(width)
	, height(height)
	, num_colors(num_colors)
	, int_array(0)
	, v(2.0) {

		//int_array = std::make_shared<vstd::vector<unsigned int>>(width*height*num_colors);
		int_array = new unsigned int[width*height*num_colors];
		LogInfo("PNG::PNG(): width: %d, height: %d, colors: %d\n", width, height, num_colors);

		assert(int_array != 0);

		clear();

		LogDebug("New Canvas\n");
	}

	virtual void clear() {
		std::fill_n(int_array, width*height*num_colors, 0);
	}

	virtual void plot(const double* normalizedPosition, const double* normalizedColor) {
		const double& x = normalizedPosition[0];
		const double& y = normalizedPosition[1];

		const unsigned int x_int = x*width + width*.5;
		const unsigned int y_int = y*width + height*.5;
		const unsigned int index = x_int + width * y_int;

		if(x_int < width && y_int < height) {
			if(normalizedColor[0] > 0.0){
				int_array[index]++;
			} else {
				int_array[index + width*height]++;
			}
		}
	}

	virtual void output_file(const char* filename_in) const {
		std::string filename = filename_in;
		filename += ".png";
		unsigned int* max_int = new unsigned int[num_colors];
		double* power = new double[num_colors];

		for(unsigned int i = 0; i < num_colors; ++i) {
			max_int[i] = 0;
			double cumulative = 0;
			unsigned int n = 0;

			for(unsigned int j = 0; j < width*height; j++) {
				if(max_int[i] < int_array[j+i*width*height]) {
					max_int[i] = int_array[j+i*width*height];
				}
				if(int_array[j+i* width* height] != 0) {
					cumulative += int_array[j+i*width*height];
					n++;
				}
			}


			const double average = cumulative / (double)(width*height);
			power[i] = -2.5/std::log(average/(double)max_int[i]);
			if(power[i] < 0) {
				power[i] = 1;
				LogInfo("negative power\n");
			}

			if(n < width) {
				LogInfo("not enough data in dimension %d\n", i);
				return;
			}
		}

		const double vibrancy = v;
		double averagePower = 0;
		for(unsigned int i = 0; i < num_colors; i++) {
			averagePower += power[i];
		}
		averagePower /= (double)num_colors;
		for(unsigned int i = 0; i < num_colors; i++) {
			power[i] = vibrancy*power[i] + (1.0 - vibrancy)*averagePower;
		}

		// TODO: find a way to set these things:
		//  pngFile->setcompressionlevel(9);
		//  pngFile->settext("Attractor", "Joshua Moerman", "A awesome attractor", "AwesomeAttractor");

		png::image< png::rgb_pixel > image(width, height);
		std::array<double, 6> power_matrix = {{
			1.0,	1.5,
			2.0,	2.5,
			3.0,	1.5
		}};
		std::array<double, 6> output_matrix = {{
			2.0,	2.0,
			2.0,	1.5,
			2.0,	2.0
		}};

		for(unsigned int x = 0; x < width; x++) {
			for(unsigned int y = 0; y < height; y++) {
				double r = 0.0;
				double g = 0.0;
				double b = 0.0;
				for(unsigned int c = 0; c < num_colors; c++) {
					const double norm_value = (double)int_array[x + y*width + c*width*height]/max_int[c];
					r += (std::pow(norm_value, power[c]*power_matrix[c+0]))*output_matrix[c+0];
					g += (std::pow(norm_value, power[c]*power_matrix[c+2]))*output_matrix[c+2];
					b += (std::pow(norm_value, power[c]*power_matrix[c+4]))*output_matrix[c+4];
				}
				// TODO: also clamp is below 0 ?
				r = std::min(1.0, r);
				b = std::min(1.0, b);
				g = std::min(1.0, g);
				image[y][x] = png::rgb_pixel(r*255, g*255, b*255);
			}
		}

		delete[] max_int;
		delete[] power;

		LogInfo("Writing %s\n", filename.c_str());
		image.write(filename);

		LogMoreInfo("File written");
	}
	
private:
	PNG(PNG const &);
	PNG & operator=(PNG const &);
};

#endif // PNG_HPP