awesome-attractor/canvae/PNG.hpp

#ifndef PNG_HPP
#define PNG_HPP

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

#include <png++/png.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), v(0) {

		//int_array = std::make_shared<vstd::vector<unsigned int>>(width*height*num_colors);
		int_array = new unsigned int[width*height*num_colors];

		assert(int_array != nullptr);

		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& 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) {
			int_array[index]++;
		}
	}

	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/log(average/(double)max_int[i]);
			if(power[i] < 0) {
				power[i] = 1;
				LogInfo("negative power\n");
			}


			if(n < width) {
				LogInfo("not enough data\n");
				return;
			}
		}

		const double vibrancy = 2.0;
		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);

		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];
					switch(c) {
					case 0: {
						r = (pow(norm_value, power[c]))*3.0;
						//break;
					}
					case 1: {
						g = (pow(norm_value, power[c]*2.0))*3.0;
						//break;
					}
					case 2: {
						b = (pow(norm_value, power[c]*3.0))*3.0;
						//break;
					}
					default:
						break;
					}
				}
				// 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");
	}
};

#endif // PNG_HPP