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coltson n00b
Joined: 15 Oct 2005 Posts: 54

Posted: Wed Aug 07, 2013 11:10 pm Post subject: Operator overloading not resulting in the expected value 


I have this code: Code:  point intersection = viewRay.origin + t * viewRay.dir; 
Here operator overloading is used in two cases, in the multiplication between t and viewRay.dir and between viewRay.origin and the result of t * viewRay.dir
viewRay.dir is an structure of the kind Vector, which it is three floats Code:  struct Vector {
float x,y,z;
}; 
t is a float and viewRay.origin it is an structure of the kind Vector, which also it is three floats Code:  struct point {
float x,y,z;
}; 
So if viewRay.origin has it three floats with the values of 300,300 ,1000, if viewRay.dir value it is 0,0,1 and t value it is 926,4, I should have:
(300,300,1000) + 926,4 * (0,0,1) = (300,300,1000) + (0,0,926,4) = (300,300,73,5595).
However this is not the value that I am getting. Here is the output of the program for viewRay.origin being (300,300,1000): Quote:  t value it is: 926.44
viewRay.dir.x value it is: 0 viewRay.dir.y value it is: 0 viewRay.dir.z value it is: 1
viewRay.origin.x value it is: 300 viewRay.origin.x value it is: 300 viewRay.origin.z value it is: 1000
300 300 73.5595
300 300 2000 
These lines are generated by the first line that I posted in this topic followed by these: Code: 
point intersection = viewRay.origin + t * viewRay.dir; //already posted this
cout << "t value it is: " << t << endl;
cout << " viewRay.dir.x value it is: " << viewRay.dir.x << " viewRay.dir.y value it is: " << viewRay.dir.y << " viewRay.dir.z value it is: " << viewRay.dir.z << endl;
cout << " viewRay.origin.x value it is: " << viewRay.origin.x << " viewRay.origin.x value it is: " << viewRay.origin.y << " viewRay.origin.z value it is: " << viewRay.origin.z << endl;
cout << viewRay.origin.x + t*viewRay.dir.x << ' ' << viewRay.origin.y + t*viewRay.dir.y << ' ' << viewRay.origin.z + t*viewRay.dir.z << endl;
cout << intersection.x << ' ' << intersection.y << ' ' << intersection.z << endl; 
So the value being calculated by using operator overloading is . The first two values, 300,300 are correct but the last one is wrong. This 2000 is the default value of t, so I thought the t value was wrong, but it is not, as can be seen by the second line of the output
In fifth I calculate the values "manually", without operator overloading and the values calculated are corrects.
So I think the error might be in the operator overloading for the multiplication. Here is the code Code:  inline Vector operator * (float t, const Vector &v1) {
Vector v2 = {v1.x * t, v1.y * t, v1.z*t};
return v2;
} 
I can't see anything wrong there....... So anyone has an idea?
Thanks for any help. 

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MustrumR n00b
Joined: 15 Nov 2011 Posts: 71 Location: Right here

Posted: Thu Aug 08, 2013 8:50 am Post subject: 


Please post all the code. 

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steveL Watchman
Joined: 13 Sep 2006 Posts: 5080 Location: The Peanut Gallery

Posted: Thu Aug 08, 2013 6:08 pm Post subject: Re: Operator overloading not resulting in the expected value 


coltson wrote:  Code:  point intersection = viewRay.origin + t * viewRay.dir; 
Here operator overloading is used in two cases, in the multiplication between t and viewRay.dir and between viewRay.origin and the result of t * viewRay.dir
viewRay.dir is an structure of the kind Vector, which it is three floats Code:  struct Vector {
float x,y,z;
}; 
t is a float and viewRay.origin it is an structure of the kind Vector, which also it is three floats Code:  struct point {
float x,y,z;
}; 

It's not though: it's a struct point, same as intersection. 

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coltson n00b
Joined: 15 Oct 2005 Posts: 54

Posted: Sat Aug 10, 2013 1:30 am Post subject: 


MustrumR wrote:  Please post all the code. 
The code seems to be too big to post it all here at once (more than 600 lines divided into multiple files) How you suggest I shall proceed in this case?
Quote:  It's not though: it's a struct point, same as intersection. 
True, my mistake 

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Hu Moderator
Joined: 06 Mar 2007 Posts: 12490

Posted: Sat Aug 10, 2013 1:31 am Post subject: 


Concatenate it into a single file, upload it to a pastebin, and link to the pastebin from here. 

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coltson n00b
Joined: 15 Oct 2005 Posts: 54

Posted: Mon Aug 12, 2013 5:07 am Post subject: 


I did it: here is the link: http://codepad.org/64AYV50l
The lines that I mentioned here are in the first 50 lines and between the 538 and the 545 one
To run the program you also need a txt file with this content in the same dir.
Quote:  Image
Width=640;
Height=480;
bpp=32;
Material
{
Diffuse=1.0,1.0,0.0;
Reflection=0.5;
}
Material
{
Diffuse=0.0,1.0,1.0;
Reflection=0.5;
}
Material
{
Diffuse=1.0,0.0,1.0;
Reflection=0.5;
}
///////////////////////////////////////
// List of spheres //
///////////////////////////////////////
Sphere
{
Center=233.0,290.0,0.0;
Radius_Squared=10000;
Size=100.0;
MaterialId=0.0;
}
Sphere
{
Center=407.0,290.0,0.0;
Radius_Squared=10000;
Size=100.0;
MaterialId=1.0;
}
Sphere
{
Center=320.0,140.0,0.0;
Radius_Squared=10000;
Size=100.0;
MaterialId=2.0;
}
///////////////////////////////////////
// List of lights //
///////////////////////////////////////
Light
{
Position=0.0,240.0,100.0;
Intensity=1.0,1.0,1.0;
}
Light
{
Position=640.0,240.0,10000.0;
Intensity=0.6,0.7,1.0;
}



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Genone Retired Dev
Joined: 14 Mar 2003 Posts: 9217 Location: beyond the rim

Posted: Mon Aug 12, 2013 6:57 am Post subject: 


Code:  inline point operator + (const point &p1, const Vector &v1 ) {
point p2 = {p1.x + v1.x, p1.y + v1.y, p1.z + p1.z};
return p2;
}

Typo in the variable name on the zaddition. 

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coltson n00b
Joined: 15 Oct 2005 Posts: 54

Posted: Thu Aug 15, 2013 5:07 am Post subject: 


thanks 

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