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NASM Programming

Many of you, if you are like me, might be interested in how assembly works.  You will be very surprised that assembly is very very easy, especially after you write a couple of simple programs.  But don't get me wrong, you will be frustrated at first, however that frustration, if you channel it right, will lead to serious life long learning and will give you a deeper appreciation of the beauty of assembly. For more tutorial on assembly and visualization of these information, visit my youtube channel . Okay so lets get started. We will be using Netwide Assembler (NASM) to write our program. The general format of NASM file is this: ;This is a comment SECTION .data ;declare variable here SECTION .bss ;declare actual, dynamic variable SECTION .text ;where your program code/assembly code lives ; Working with Data Section In your .data section, you can declare variables like this: nameOfVariable: db 32 ;this declares a variable names nameOfVariable with byte valu

C++ Smart Pointer

The following is the finalized code for a simple C++ smart pointer as demonstrated by my youtube video:  here Usage: void main(){      ...     Pointer<ObjectType> pointer(new ObjectType);     ... } /*  * Pointer.h  *  *  Created on: Mar 16, 2012  *      Author: ukaku  */ #ifndef POINTER_H_ #define POINTER_H_ #include <iostream> using namespace std ; /**  * Reference represents a counter that will be incremented or decremented as  * the number of references to a pecticular pointer is made;  *  * where data means: a symbol used to point to, or associate to another object  */ class ReferenceCounter { private :     int counter ; public :     ReferenceCounter ( ) {         counter = 0 ;   //initially set to zero     }     void increase ( ) {         counter ++;   //increase it     }     int decrease ( ) {         -- counter ;   //decrease it         if ( counter < 0 ) {             cout << "ReferenceCouner is <

SAT Collision Part 2

In this collision tutorial, we will take more in detail with how exact we get the normals and how we get the intervals.  However, I will not be going in detail regarding vector math needed to understand this, although it is simple and I will eventually post blogs regarding them. Down to business.  Our shape is composed of vertices.  In the case of this rectangle, there is four vertices, in red, and four normals, in brown.  The vertices are self explanatory and the normals describe the orientation or the way a side of the triangle is facing.  Take note that the vertices are defined such that the center of the triangle, not indicated in the picture, is at position(0,0) and all vertices defining the vertex is relative to this location; just like in a normal coordinate system. Now, to get the normal for a side of the rectangle we take two vertices defining an edge of the rectangle and subtract them.  Further, we swap the x, and y components and negate the new y component.  Then we norma

Introduction to SAT

When writing games, collision detection is important, especially one that is fast and robust.  True, you can get away with having a simple rectangular collision detection where your checking if two squares overlay, but that becomes less reliable when objects in your application/game are moving fast and many I good collision detection system is SAT or  Separating axis theorem.  It says that if two convex shapes' (shapes that do not invaginate) projections along their respective normals does not overlap then the shapes do not overlay.  More clearly, if there is any project that separates the two shapes, then there is a collision. That is it. However, this requires further explanation.  A convex shape is like a rectangle, an octagon, or any shape that does not fold into itself.  When using SAT, we use its normals, denoted by brown lines, to project two convex shapes while comparing to see if the two's intervals overlap. If an overlap exist, then a collision is occurring. Her