# PSET 4 reflection

Been stuck on reflect for a couple of hours now and can't seem to figure it out.

I've written the following code. I take the values, find what the opposite should be, put both sets into variables and then swap their pointers out. Not sure where I am going wrong here.

``````void reflect(int height, int width, RGBTRIPLE image[height][width])
{
for(int i = 0; i < height ; i++)
for(int j = 0; j < width; j++)
{

// Takes original pixel information
int B = image[i][j].rgbtBlue;
int G = image[i][j].rgbtGreen;
int R = image[i][j].rgbtRed;

// Takes image I want to swap it with
int rB = image[i][width - j].rgbtBlue;
int rG = image[i][width - j].rgbtGreen;
int rR = image[i][width - j].rgbtRed;

swap(&B , &rB);
swap(&G , &rG);
swap(&R , &rR);

//Write new values to pixels
image[i][j].rgbtBlue = B;
image[i][j].rgbtGreen = G;
image[i][j].rgbtRed = R;
image[i][width - j].rgbtBlue = rB;
image[i][width - j].rgbtGreen = rG;
image[i][width - j].rgbtRed = rR;
}

return;
}
``````

Here is my swap function.

``````void swap (int *a, int *b)
{
int temp = *a;
*a = *b;
*b = temp;
}
``````

Please help me.

## 1 Answer

Let me guess. It doesn't seem to be doing anything, right?

Without doing a deep dive analysis, one thing jumps out at me. The inner for loop runs from 0 to width. Think carefully about the practical effect of that.

From 0 to width/2, it's going to swap the left half with the right half. Then from width/2 to width, it's going to swap everything back!

If this answers your question, please click on the check mark to accept. Let's keep up on forum maintenance. ;-)

• You got it! Can't believe I didn't see it. I also needed to subtract 1 from the `image[i][width - j]` lines of code to make sure I get the initial 0 value. – Multiplify Apr 17 at 18:05
• Sometimes you have to remember the real effects of code, not just to get the code to execute. This is a perfect example of that. The code worked perfectly for what it was told to do. It was a simple oversight in the design logic that caused the failure. Happy coding! ;-) – Cliff B Apr 17 at 18:12