Thread: Adding Two 2D Arrays Together

  1. #1
    Registered User
    Join Date
    Dec 2021
    Posts
    34

    Adding Two 2D Arrays Together

    I've been trying to add two 2D arrays together with different element types: red, green and blue that point to a structure. I'm pretty sure the two arrays are read in correctly I just don't think they're added together right...
    Code:
    RGBArray = (PPMPixel **)malloc(head[1].height*sizeof(PPMPixel*)); //Points to malloc
        if((RGBArray == NULL))
        {
            printf("\tError allocating memory to the array\n");
        }
        else
        {
            printf("\tMemory allocated to the PPM array sucessfully\n"); 
        }
        for (i=0;i<head[1].height;i++)
        {
            RGBArray[i] = (PPMPixel *)malloc(head[1].width*sizeof(PPMPixel));
        }
        for (j=0;j<head[1].height;j++)
        {
            for (i=0;i<head[1].width;i++)
            {
                RGBArray[j][i].red = (AddArray1[j][i].red + AddArray2[j][i].red);
                RGBArray[j][i].green = (AddArray1[j][i].green + AddArray2[j][i].green); 
                RGBArray[j][i].blue = (AddArray1[j][i].blue + AddArray2[j][i].blue);
                //printf("%d ", RGBArray[j][i].red);
                //printf("%d ", RGBArray[j][i].green);
                //printf("%d ", RGBArray[j][i].blue);
            }     
        }

  2. #2
    Registered User
    Join Date
    Dec 2017
    Posts
    1,628
    Well, obviously you can't just add the values together since you could end up with a result that is higher than the maximum allowed value.
    A little inaccuracy saves tons of explanation. - H.H. Munro

  3. #3
    Registered User
    Join Date
    Dec 2021
    Posts
    34
    Solved it! It was just a pointer mistake. This code I sent was fine.

Popular pages Recent additions subscribe to a feed

Similar Threads

  1. Adding Arrays
    By jocdrew21 in forum C Programming
    Replies: 14
    Last Post: 08-12-2013, 10:06 AM
  2. Adding numbers with arrays
    By Oliveira in forum C Programming
    Replies: 4
    Last Post: 04-16-2009, 10:25 PM
  3. Now I need help adding arrays
    By nifear4 in forum C Programming
    Replies: 28
    Last Post: 10-30-2008, 10:18 AM
  4. Adding arrays with pointers - help
    By chip.litch in forum C Programming
    Replies: 2
    Last Post: 10-02-2008, 11:07 PM
  5. Adding Arrays and Matrices
    By dlf in forum C++ Programming
    Replies: 3
    Last Post: 11-30-2005, 02:36 PM

Tags for this Thread