It keeps repeating "The square number is" ? You're outputting i so what is i looking like when it repeats?
i just started learning about multidimensional arrays in C++
i have a couple more sets of questions like this and i have no idea to figure out what the outputs are, ive been pulling my hair out the past hour and a half trying to figure it out ><
id love it if someone could explain how these answers were gotten so i can make sense of the rest of the problems
That makes sense.. But the rest look super hard
Thanks so much!!!
I'm about to go to bed so won't be able to reply to any responses until I wake up, but this has been frustrating me for a bit and I don't know what I have done wrond and my C++ debugging skills are still quite poor.
I'm going to comment this code more properly tomorrow as well.
Essentially, we have to make a basic ray-tracer that runs on the CPU as an assignment. We've been told to do it in Java, but I asked if I could do it in C++ instead as I want to learn C++ and got told yes, so I decided to whack the following code together tonight (using Handmade Hero's framebuffer which Casey very kindly let my use). All the relevant stuff is in https://github.com/Moosichu/RayTracer/blob/master/src/ray_tracer.cpp.
However, when I run my program, nothing is being drawn to the screen
The reason I think the error is here, is because if I set the ambientFactor color to a value, the entire screen will be filled with that. It's just that no circles are being drawn which is what I want essentially as I have just implement the ambient component of spheres.
Code:Color traceRay(Ray ray, Sphere sceneObjects[], std::size_t numObjects, PointLight lights[], std::size_t numLights, int recurseDepth) { LightCollision closestCollision; closestCollision.position = {600000.0, 60000.0, 60000.0}; //TODO(Tom) Replace with max possible scalar values closestCollision.normal = {1.0, 0, 0}; closestCollision.ambientFactor = {0, 0, 0}; closestCollision.diffuseFactor = {0, 0, 0}; closestCollision.specularFactor = {0, 0, 0}; //Find the closest position for(std::size_t i = 0; i < numObjects; i++) { //TODO(Tom) Have a way of handling type of sceneObject { Sphere sphere = sceneObjects[i]; Vector3D sphereToRayOrigin = sphere.position - ray.origin; scalar a = ray.direction.dot(ray.direction); //a = |ray.direction|^2 scalar b = 2 * ray.direction.dot(sphereToRayOrigin); scalar c = sphereToRayOrigin.dot(sphereToRayOrigin) - (sphere.radius*sphere.radius); scalar d; { double intermediate = (b*b) - (4*a*c); if(intermediate < 0) { continue; //No intersection } d = sqrt(intermediate); } double s1 = (-b + d)/(2*a); double s2 = (-b - d)/(2*a); double s = s1 < s2 ? s1 : s2; //select the closest point intersection if(s < 0) { continue; } //Work out the position of the collision relateve to the camera's location Vector3D collisionOffset = ray.direction * s; if(collisionOffset.square() < closestCollision.position.square()) { //Comparing magnitudes closestCollision.position = collisionOffset; //TODO(Tom) Calculate the normal of the collision! closestCollision.ambientFactor = sphere.ambientFactor; closestCollision.diffuseFactor = sphere.diffuseFactor; closestCollision.specularFactor = sphere.specularFactor; } } } Color finalColor = closestCollision.ambientFactor; if(recurseDepth > 0) { Color diffuseComponent; Color specularComponent; //check to make sure any diffuse components actually have to be calculated if (closestCollision.diffuseFactor.red | closestCollision.diffuseFactor.green | closestCollision.diffuseFactor.blue) { //TODO(Tom) recursively calculate diffuse components and add to final color variable } //check to make sure any specular components actually have to be calculated if (closestCollision.specularFactor.red | closestCollision.specularFactor.green | closestCollision.specularFactor.blue) { //TODO(Tom) recursively calculate specular component and add to final color variable } } return finalColor; }
Sorry about this huge code dump, I'm very tired and something glaringly obvious will probably jump out in the morning, but I also have a huge fear that I will spend hours trying to track down a niggly bug.
I'm guessing the error is somewhere in my collision detection section, but I did already implement this in java and it worked fine and I have just been porting my work there to C++ so there shouldn't be any issues with the basic maths.
I'm about to go to bed so won't be able to reply to any responses until I wake up, but this has been frustrating me for a bit and I don't know what I have done wrond and my C++ debugging skills are still quite poor.
I'm going to comment this code more properly tomorrow as well.
Essentially, we have to make a basic ray-tracer that runs on the CPU as an assignment. We've been told to do it in Java, but I asked if I could do it in C++ instead as I want to learn C++ and got told yes, so I decided to whack the following code together tonight (using Handmade Hero's framebuffer which Casey very kindly let my use). All the relevant stuff is in https://github.com/Moosichu/RayTracer/blob/master/src/ray_tracer.cpp.
However, when I run my program, nothing is being drawn to the screen
The reason I think the error is here, is because if I set the ambientFactor color to a value, the entire screen will be filled with that. It's just that no circles are being drawn which is what I want essentially as I have just implement the ambient component of spheres.
Code:Color traceRay(Ray ray, Sphere sceneObjects[], std::size_t numObjects, PointLight lights[], std::size_t numLights, int recurseDepth) { LightCollision closestCollision; closestCollision.position = {600000.0, 60000.0, 60000.0}; //TODO(Tom) Replace with max possible scalar values closestCollision.normal = {1.0, 0, 0}; closestCollision.ambientFactor = {0, 0, 0}; closestCollision.diffuseFactor = {0, 0, 0}; closestCollision.specularFactor = {0, 0, 0}; //Find the closest position for(std::size_t i = 0; i < numObjects; i++) { //TODO(Tom) Have a way of handling type of sceneObject { Sphere sphere = sceneObjects[i]; Vector3D sphereToRayOrigin = sphere.position - ray.origin; scalar a = ray.direction.dot(ray.direction); //a = |ray.direction|^2 scalar b = 2 * ray.direction.dot(sphereToRayOrigin); scalar c = sphereToRayOrigin.dot(sphereToRayOrigin) - (sphere.radius*sphere.radius); scalar d; { double intermediate = (b*b) - (4*a*c); if(intermediate < 0) { continue; //No intersection } d = sqrt(intermediate); } double s1 = (-b + d)/(2*a); double s2 = (-b - d)/(2*a); double s = s1 < s2 ? s1 : s2; //select the closest point intersection if(s < 0) { continue; } //Work out the position of the collision relateve to the camera's location Vector3D collisionOffset = ray.direction * s; if(collisionOffset.square() < closestCollision.position.square()) { //Comparing magnitudes closestCollision.position = collisionOffset; //TODO(Tom) Calculate the normal of the collision! closestCollision.ambientFactor = sphere.ambientFactor; closestCollision.diffuseFactor = sphere.diffuseFactor; closestCollision.specularFactor = sphere.specularFactor; } } } Color finalColor = closestCollision.ambientFactor; if(recurseDepth > 0) { Color diffuseComponent; Color specularComponent; //check to make sure any diffuse components actually have to be calculated if (closestCollision.diffuseFactor.red | closestCollision.diffuseFactor.green | closestCollision.diffuseFactor.blue) { //TODO(Tom) recursively calculate diffuse components and add to final color variable } //check to make sure any specular components actually have to be calculated if (closestCollision.specularFactor.red | closestCollision.specularFactor.green | closestCollision.specularFactor.blue) { //TODO(Tom) recursively calculate specular component and add to final color variable } } return finalColor; }
Sorry about this huge code dump, I'm very tired and something glaringly obvious will probably jump out in the morning, but I also have a huge fear that I will spend hours trying to track down a niggly bug.
I'm guessing the error is somewhere in my collision detection section, but I did already implement this in java and it worked fine and I have just been porting my work there to C++ so there shouldn't be any issues with the basic maths.
C is even more fun...
C is so low-level that brackets [ ] are in fact just syntaxic sugar..org.apache.velocity.exception.ResourceNotFoundException: Unable to find resource
'templates/hello.vtl'
import java.util.HashMap;
import spark.ModelAndView;
import spark.template.velocity.VelocityTemplateEngine;
import static spark.Spark.*;
public class App {
public static void main(String[] args) {
staticFileLocation("public");
get("/hello", (request, response) ->{
return new ModelAndView(new HashMap(), "templates/hello.vtl");
}, new VelocityTemplateEngine());
}
}
up(int a[x][3], int 1, int 2){
if (2<2) return a[1][1+1]; //but 2 is not less than 2
cout << a[1][2] << endl; //so
return a[x][y];
}There's a cout inside the up() function if y >= 2. So you don't follow the same code path as line (d)
You only leave the function early if y<2. The code after the if statement doesn't run.
up(a, x, y) {
if (y < 2) return a[x][y+1]; // 2<2 isn't true, don't return
cout << a[x][y] << endl; // print x[1][2]
return a[x][y]; // return x[1][2] to where it was called
}
cout << x[1][2] << endl;
>6
>6Haha, yeah it will go into different functions eventually. This is just a quick and dirty way of segmenting code off.
This is very much code in progress, don't judge me on it pls
Thank you for the response!
for (auto& sceneObject: sceneObjects) { ... }
// Instead of this monstrosity from C++98
for (std::vector<SceneObject>::iterator iter = sceneObjects.begin(); iter != sceneObjects.end(); ++iter) { ... }
#include <iostream>
#include <fstream>
#include <string>
#include <vector>
using namespace std;
struct DNA{
vector<string> header;
string DNAstring;
double gcContent;
};
bool isValidDNAchar(char DNAchar_P);
//Post-condition: Returns true if char argument is one of 'a', 'c', 'g', 't'
//Otherwise returns false
bool isValidDNAstring(string DNAstring_P);
//Post-condition: Returns true if string is only made up of valid DNA characters.
//Returns false if any other character exists in the string.
int main() {
const int MAX_DNA_SIZE = 1000;
DNA dnaArray[MAX_DNA_SIZE];
ifstream dnaFile;
dnaFile.open("dna.txt");
string lineFromFile;
ofstream badDNAFile;
badDNAFile.open("badDNA.txt");
int badCount = 0;
//Read each line from file
int i = 0;
while(getline(dnaFile, lineFromFile))
{
bool valid = isValidDNAstring(lineFromFile);
//Add to header vector
if(lineFromFile[0] == '>')
{
dnaArray[i].header.push_back(lineFromFile);
}
//Check if validDNAstring
else if(valid == true)
{
dnaArray[i].DNAstring = lineFromFile;
//Move onto next element in array
i++;
}
else
{
badDNAFile << lineFromFile;
badCount++;
}
}
}
//function definitions
bool isValidDNAchar(char DNAchar_P){
if((DNAchar_P == 'a') || (DNAchar_P == 'c') || (DNAchar_P == 'g') || (DNAchar_P == 't'))
{
return true;
}
else
return false;
}
bool isValidDNAstring(string DNAstring_P)
{
for(int i=0; i < DNAstring_P.length(); i++)
{
char iChar = DNAstring_P[i];
if(!(isValidDNAchar(iChar)))
{
return false;
}
}
return true;
}I have a debugging environment in Eclipse but no idea how to really use it.
(We were taught to use another debugger in class but that's on Linux and it kind of sucks.)I have a debugging environment in Eclipse but no idea how to really use it.
But yeah, it was the '\r' character. It works now!
Eclipse was what I was told to use for Mac in my first programming class and I never really looked for alternatives.
I'll look into XCode.We're told that all the grading is done in a Linux environment and if the program doesn't work on Linux, we don't get credit. We do have access to a Linux lab, but I work at home on a Mac. This is really the first time it's ever really been a problem. Well, it seems like I'd have had the same problem on Linux anyways since the file was made on Windows.
