project: Global illumination pathtracer

Details

A simple pathtracer program, capable of producing renderings of simple bodies. The program computes global illumination, by intersecting scene objects, such as luminaries and solid bodies, with idealised surface properies.

  • last updated: August, 2018
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Screenshots

scene_3smpls.bmp scene_1smpl_dark.bmp scene_30smpls.bmp

src > bmp.cpp

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#include <fstream>
#include <sstream>
#include <string>

#include <stdlib.h>
#include <stdio.h>

#include <math.h>

#include "./color.hpp"
#include "./bmp.hpp"

using namespace std;

void outputbmp(const char* filename, int w, int h, int dpi, raytracer::color* data){
	FILE* f;
	int k= w*h;
	int s= 4*k;
	int filesize= 54+s;

	double factor= 39.375;
	int m= static_cast<int>(factor);

	int ppm= dpi* m;

	unsigned char bmpfileheader[14]= {'B','M',0,0,0,0, 0,0,0,0, 54,0,0,0};
	unsigned char bmpinfoheader[40]= {40,0,0,0, 0,0,0,0, 0,0,0,0, 1,0,24,0};

	bmpfileheader[2]= (unsigned char)(filesize);
	bmpfileheader[3]= (unsigned char)(filesize>>8);
	bmpfileheader[4]= (unsigned char)(filesize>>16);
	bmpfileheader[5]= (unsigned char)(filesize>>24);

	bmpinfoheader[4]= (unsigned char)(w);
	bmpinfoheader[5]= (unsigned char)(w>>8);
	bmpinfoheader[6]= (unsigned char)(w>>16);
	bmpinfoheader[7]= (unsigned char)(w>>24);

	bmpinfoheader[8]= (unsigned char)(h);
	bmpinfoheader[9]= (unsigned char)(h>>8);
	bmpinfoheader[10]= (unsigned char)(h>>16);
	bmpinfoheader[11]= (unsigned char)(h>>24);

	bmpinfoheader[21]= (unsigned char)(s);
	bmpinfoheader[22]= (unsigned char)(s>>8);
	bmpinfoheader[23]= (unsigned char)(s>>16);
	bmpinfoheader[24]= (unsigned char)(s>>24);

	bmpinfoheader[25]= (unsigned char)(ppm);
	bmpinfoheader[26]= (unsigned char)(ppm>>8);
	bmpinfoheader[27]= (unsigned char)(ppm>>16);
	bmpinfoheader[28]= (unsigned char)(ppm>>24);

	bmpinfoheader[29]= (unsigned char)(ppm);
	bmpinfoheader[30]= (unsigned char)(ppm>>8);
	bmpinfoheader[31]= (unsigned char)(ppm>>16);
	bmpinfoheader[32]= (unsigned char)(ppm>>24);

	f= fopen(filename, "wb");
	fwrite(bmpfileheader,1,14,f);
	fwrite(bmpinfoheader,1,40,f);

	for(int i=0; i<k; i++)
	{
		double red= (data[i].red)*255;
		double green= (data[i].green)*255;
		double blue= (data[i].blue)*255;

		unsigned char colorBytes[3]= {static_cast<unsigned char>(floor(blue)), static_cast<unsigned char>(floor(green)), static_cast<unsigned char>(floor(red))};
		fwrite(colorBytes, 1 , 3, f);
	}

	fclose(f);
};