Homework 2: grade report

· Annoyance:!!

o Debug folder: -5%!!!

o Cannot compile: sln and vcproj in the same folder, why? -2%

· Testing: in general worked REALLY WELL!

o Runs the entire hw with an invalid file name! -2%

o 100x1 significant difference: -2%

§ Process left/right pixels before swap

§ If only one column same pixel gets processed twice

o Significant difference for simple test image: between 5 to 10%

o Efficiency:

§ Flip image by creating a new image: flip in place!

§ Re-reading the original image multiple times instead of passing it around as a parameter

o Memory leak:

§ Forget to Deallocate after WriteImage, before ReadImage again

· Coding Style:

o INDENTATION!! Come on!!

o Use of const:

§ const int kRedModify = 17; // naming convention

o Use of function:

§ Two purposes:

· Code-ReUse: notice when you are doing cut/paste

· Readability: when code looks messy or too long (e.g., > 30 lines without a function)

§ Function should do one thing:

· FlipImage(image &theImage, int flat);

o If int = 0, flip horizontally, 1-flip vertically, 2-flip diagonally … BAD IDEA!

· byte ComputeColorChannel(const pixel &p, int flat);

o if int =0, compute red, 1-compute green, 2-compute blue … BAD IDEA!

o OK to assign a pixel to another

§ All primitive data types!

o Syntax:

§ const image &;

§ image const &; ß never seen this before, don't do this

o Use variables when you are using an expression in more than one place!!

§ if (r + (p.r % kRed) < MAX)

t.r = r + (p.r % kRed)

§ for (int i = 0; i<col; i++)

image[col-i-1] = AnotherImage[col-i-1];

§ BAD BAD BAD

o Use of {} in main():

main() {

{ my code … }

}

§ I did this to illustrate a point! DO NOT do this in general!

o Convention for instance variable!

§ Decide on one and follow!!

o Awkward coding:

if (a > 0)

continue;

else

total++;

§ Instead do this:

if (a <= 0)

total++;

o Passing int by value:

§ const int& parm

§ int parm