awesome-attractor/canvae/PNG.cpp

#include "../Logger.hpp"
#include <fstream>
#include <cmath>
#include <cstdlib>
#include <cassert>

#include "../pngwriter/pngwriter.h"

#include "PNG.hpp"


PNG::PNG(unsigned int width, unsigned int height, unsigned int num_colors):
		Canvas(2), width(width), height(height), num_colors(num_colors), v(0) {

	int_array = new unsigned int[width*height*num_colors];

	assert(int_array != NULL);

	clear();

	LogDebug("New Canvas\n");
}

void PNG::clear() {
	for ( unsigned int i = 0; i < width*height*num_colors; i++ ) {
		int_array[i] = 0;
	}
}

void PNG::plot(double * position) {
	const double& x = position[0];
	const double& y = position[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]++;
	}
}

/*
	I/O functions
*/

void PNG::output_file(const char * filename){
	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] ) {
				cumulative += int_array[j+i*width*height];
				n++;
			}
		}

		if ( n > 100 ) {
			const double average = cumulative / (double)n;
			power[i] = -2.5/log(average/(double)max_int[i]);
			if ( power[i] < 0 )
				power[i] = 1;
		} else {
			power[i] = 1;
		}

		if ( n <= 10 ) {
			LogInfo("not enough data\n");
		}
	}

	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;
	}

	pngwriter * pngFile = new pngwriter(width, height, 0.0, filename);
	pngFile->setcompressionlevel(9);
	pngFile->settext("Attractor", "Joshua Moerman", "A awesome attractor", "AwesomeAttractor");

	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]))*3.5;
						break;
					}
					case 1: {
						g = (pow(norm_value, power[c]))*3.0;
						break;
					}
					case 2: {
						b = (pow(norm_value, power[c]))*3.0;
						break;
					}
					default:
						break;
				}
			}
			//pngwriter clips values for me
			pngFile->plot(x, y, r, g, b);
		}
	}


	delete[] max_int;
	delete[] power;

	LogInfo("Writing %s\n", filename);

	std::ofstream file(filename);
	if ( !file ) {
		LogError("Couldn't write to file");
	}
	pngFile->close();

	LogMoreInfo("File written");

}