Difference between revisions of "Intermediate C++ Game Programming Tutorial 2"

Revision as of 23:50, 18 May 2017

In this two-part tutorial we learn all about pointers and pointer-related bullshits. Part one focuses on the basics--the most common pointer operations and the basic underlying mechanisms. In part two, we take a look at some less commonly-used but still important pointer operations (pointer arithmetic), as well as some other concepts related to pointers. This tutorial introduces a lot of new concepts and features, but is light on practical examples. In the following tutorials we will get more hands-on practice with pointers, but also make sure to experiment with them on your own after finishing Tutorial 2.

Topics Covered

Part 1

• Declaring pointers
• The addressof operator &
• The dereference (indirection) operator *
• The arrow (member of pointer) operator ->
• The indexing (subscript) operator []
• The nullptr pointer literal
• The sizeof query operator

Part 2

• Pointer Arithmetic
• Pointer const Correctness
• Pointers to Pointers
• Pointer Reinterpretation
• C++ Style Casting reinterpret_cast<>
• Linked Lists

Video Timestamp Index

Tutorial 2.1
Tutorial 2.2

Bonus Video: Red Pill [Pointers]

There is another Red Pill video that explores the actual machine instructed emitted by the compiler for pointer-related operations. Like the previous Red Pill video, this material is strictly optional and is not required to proceed with the tutorials--it will not be referenced in future tutorials. Viewer discretion is advised. The video can be found: here.

Homework

Part 1

Write a function called sum which returns the sum of all elements of an int array.
Here is the solution video: solution video.

Part 2

There are 2 assignments. Assignment 1: modify the sum function so that it uses pointer arithmetic. Assignment 2: create a new function to reverse an array of ints using pointer arithmetic techniques.

Notes

• At 24:30 in Part 1, I show the calculation for indexing off of a pointer (p[2]) as B + 2 x 4 -> B, and then a memory store operation 69 -> int@[B], but in reality (optimized or not) the index calculation would be done as part of the memory access operation, so it would end up being something like 69 -> int@[B + 2 x 4].

See also

• Next in series (Tutorial 3)
• Intermediate C++ Game Programming Series