int main (int argc, char * const argv[])
{
if( argc != 3 ) //we need 2 arguments
{
cout << "light_tracer.exe scene_description_file.txt output_image.bmp\n";
cout << "scene_description_file.txt example:\n";
cout << " width 400\n";
cout << " height 300\n";
cout << " num_spheres 3\n";
cout << " 0.0 0.0 5.0 1.0\n";
cout << " 0.1 -0.05 3.0 0.2\n";
cout << " 1.0 1.0 7.0 1.0\n";
cout << " num_triangles 2\n";
cout << " -10 -2 0 10 -2 10 10 -2 0\n";
cout << " -10 -2 0 -10 -2 10 10 -2 10\n";
cout << " num_point_lights 2\n";
cout << " 1.0 1.0 0 1.0 1.0 1.0 0.2 50\n";
cout << " -0.5 -1.5 0 0 0 1.0 0.2 50\n";
return 1;
}
Scene::Init();
ifstream indata; // indata is like cin
indata.open( argv[1] ); // opens the file
if( !indata )
{ // file couldn't be opened
return 1;
}
int w_in_pix;
string temp;
indata >> temp;
indata >> w_in_pix;
int h_in_pix;
indata >> temp;
indata >> h_in_pix;
const float aspect = (float)w_in_pix / h_in_pix;
const float fov = 0.75f;
int num_spheres;
indata >> temp;
indata >> num_spheres;
for( int i = 0; i < num_spheres; ++i )
{
Vector3 pos;
float radius;
indata >> pos.mX;
indata >> pos.mY;
indata >> pos.mZ;
indata >> radius;
Scene::Instance()->AddSphere( pos, radius );
}
int num_triangles;
indata >> temp;
indata >> num_triangles;
for( int i = 0; i < num_triangles; ++i )
{
Vector3 p1;
Vector3 p2;
Vector3 p3;
indata >> p1.mX;
indata >> p1.mY;
indata >> p1.mZ;
indata >> p2.mX;
indata >> p2.mY;
indata >> p2.mZ;
indata >> p3.mX;
indata >> p3.mY;
indata >> p3.mZ;
Scene::Instance()->AddTriangle( p1, p2, p3 );
}
int num_point_lights;
indata >> temp;
indata >> num_point_lights;
for( int i = 0; i < num_point_lights; ++i )
{
Vector3 pos;
ColourRGB colour;
float size;
int taps;
indata >> pos.mX;
indata >> pos.mY;
indata >> pos.mZ;
indata >> colour.mR;
indata >> colour.mG;
indata >> colour.mB;
indata >> size;
indata >> taps;
Scene::Instance()->AddPointLight( pos, colour, size, taps );
}
indata.close();
ImageBuffer* image = new ImageBuffer( w_in_pix, h_in_pix );
Vector3 cam_point( 0, 0, 0 );
Vector3 direction( 0, 0, 1 );
srand( (unsigned int)time(0) );
for( int y = 0; y < h_in_pix; y++ )
{
for( int x = 0; x < w_in_pix; x++ )
{
Vector3 ray_dir = direction;
ray_dir.mX = fov * aspect * ((float)x - ( (float)w_in_pix / 2.0f ))/ (float)w_in_pix; //deal with aspect ratio and fov here
ray_dir.mY = -1.0f * fov * ((float)y - ( (float)h_in_pix / 2.0f ))/ (float)h_in_pix;
ray_dir = !ray_dir;
Ray ray( cam_point, ray_dir, 0 );
image->SetPixel( x, y, Scene::Instance()->GetColour( ray ) );
}
}
image->WriteToBMP( argv[2] );
return 0;
}
void draw_triangle_pixel(int i, int j){
vec2 p0=_p0-vec2(i,j);
vec2 p1=_p1-vec2(i,j);
vec2 p2=_p2-vec2(i,j);
vector<vec2> output(3),input;
output[0]=p0;
output[1]=p1;
output[2]=p2;
// left edge
{
input=output;
output.clear();
vec2 s=input.back();
for(vec2 e : input){
if(e.x>=0){
if(s.x<0){
output.push_back(vec2(0, (s+(-s.x/(e-s).x)*(e-s)).y ));
}
output.push_back(e);
}else if(s.x>=0){
output.push_back(vec2(0, (s+(-s.x/(e-s).x)*(e-s)).y ));
}
s=e;
}
}
//right edge
{
input=output;
output.clear();
vec2 s=input.back();
for(vec2 e : input){
if(e.x<=1){
if(s.x>1){
output.push_back(vec2(1, (e+((-e.x+1)/(s-e).x)*(s-e)).y ));
}
output.push_back(e);
}else if(s.x<=1){
output.push_back(vec2(1, (e+((-e.x+1)/(s-e).x)*(s-e)).y ));
}
s=e;
}
}
for(int k=0;k<output.size();k++){
float t=output[k].x;
output[k].x=output[k].y;
output[k].y=t;
}
// left edge
{
input=output;
output.clear();
vec2 s=input.back();
for(vec2 e : input){
if(e.x>=0){
if(s.x<0){
output.push_back(vec2(0, (s+(-s.x/(e-s).x)*(e-s)).y ));
}
output.push_back(e);
}else if(s.x>=0){
output.push_back(vec2(0, (s+(-s.x/(e-s).x)*(e-s)).y ));
}
s=e;
}
}
//right edge
{
input=output;
output.clear();
vec2 s=input.back();
for(vec2 e : input){
if(e.x<=1){
if(s.x>1){
output.push_back(vec2(1, (e+((-e.x+1)/(s-e).x)*(s-e)).y ));
}
output.push_back(e);
}else if(s.x<=1){
output.push_back(vec2(1, (e+((-e.x+1)/(s-e).x)*(s-e)).y ));
}
s=e;
}
}
for(int k=0;k<output.size();k++){
float t=output[k].x;
output[k].x=output[k].y;
output[k].y=t;
}
for(vec2 e:output){
// cout<<e.x<<'\t'<<e.y<<endl;
}
float a=0;
if(!output.empty()){
for(int k=0;k<output.size()-1;k++){
a+=output[k].x*output[k+1].y;
a-=output[k].y*output[k+1].x;
}
a+=output.back().x*output.front().y;
a-=output.back().y*output.front().x;
}
a*=0.5f;
if(a<0)a*=-1;
// cout<<"pixel "<<i<<'\t'<<j<<" set "<<a<<endl;
ib.SetPixel(i,j,vec3(a,a,a));
}