ASM Animation
This program creates an animation using blitting with assembly after getting memory addresses of pixel information using scanline. To understand the code, you'll need some knowledge of assembly.
AI
AI Summary: This codebase represents a historical implementation of the logic described in the metadata. Our preservation engine analyzes the structure to provide context for modern developers.
Source Code
Upload
<P> </P>
<table width="467" border="0" cellspacing="0" cellpadding="0">
<tr>
<td bgcolor="#ddddcc"><font color="#000000" size="2" face="Arial, Helvetica, sans-serif"><b>Introduction</b></font></td>
</tr>
<tr>
<td>
<p><font face="Arial, Helvetica, sans-serif" size="2">If you are coming
to PHP from C++ then you can understand the need to OOP. But for the rest
of you, OOP is, in my eyes, the greatest thing to come to programming.
Classes allow you to keep track of a lot of information, and to also include
function for manipulating that information.</font></p>
<p><font face="Arial, Helvetica, sans-serif" size="2">I read something someone
wrote and I related instantly. They said that OOP is hard to grasp, but
once you understand the concept and the need, it's as bright as day. I
could never understand why we needed classes until one day I was working
on a project and it hit me.</font></p>
<p><font face="Arial, Helvetica, sans-serif" size="2">So why do you need
classes? Well, lets say you are making a game. In this game you have multiple
players. Lets say for now that the limit is 8 players. You would have
to type out and keep track of 8*x variables. x = number of attributes
a player has.</font></p>
<p><font face="Arial, Helvetica, sans-serif" size="2">Example:</font></p>
<blockquote>
<p><font face="Arial, Helvetica, sans-serif" size="1"><b><font face="Verdana, Arial, Helvetica, sans-serif">//Player
1</font></b></font><font face="Verdana, Arial, Helvetica, sans-serif"><b><font size="1"><br>
P1_NAME;<br>
P1_SCORE;<br>
P1_AMMO;</font></b></font></p>
<p><font face="Verdana, Arial, Helvetica, sans-serif"><b><font size="1">//Player
2<br>
P2_NAME;<br>
P2_SCORE;<br>
P2_AMMO;</font></b></font></p>
</blockquote>
<p><font size="2" face="Arial, Helvetica, sans-serif">Now you would have
to do this 8 times, so 8*3=24 variables you'd have to keep track of. Lets
go on. Lets say Player 2 changed his name. You would have to create a
if/else or a switch function to figure out what player he is, and then
update his variables.</font></p>
<p><font face="Arial, Helvetica, sans-serif" size="2">Example:</font></p>
<blockquote>
<blockquote>
<p><b><font face="Verdana, Arial, Helvetica, sans-serif" size="1">if(Player1)
{ </font></b></p>
<blockquote>
<p><b><font face="Verdana, Arial, Helvetica, sans-serif" size="1">P1_Name
= NewName;</font></b></p>
</blockquote>
<p><b><font face="Verdana, Arial, Helvetica, sans-serif" size="1">}
else if(Player2) {</font></b></p>
<blockquote>
<p><b><font face="Verdana, Arial, Helvetica, sans-serif" size="1">P2_Name
= NewName;</font></b></p>
</blockquote>
<p><b><font face="Verdana, Arial, Helvetica, sans-serif" size="1">}</font></b></p>
</blockquote>
</blockquote>
<p><font face="Arial, Helvetica, sans-serif" size="2">you'd have to do this
for all 8 players. What a mess!</font></p>
</td>
</tr>
</table>
<br>
<table width="467" border="0" cellspacing="0" cellpadding="0">
<tr>
<td bgcolor="#ddddcc"><font color="#000000" size="2" face="Arial, Helvetica, sans-serif"><b>The
OOP Method</b></font></td>
</tr>
<tr>
<td align="left" valign="top">
<p><font face="Arial, Helvetica, sans-serif" size="2">Lets take a look at
that scenario from an OOP point of view.</font></p>
<p><font face="Arial, Helvetica, sans-serif" size="2">You have a multi-player
game. This time you want to allow 100 players. Now from the first example
this would be a chore to keep track of all this information. But not with
OOP! First, we make a class and define an array</font></p>
<blockquote>
<p><font face="Arial, Helvetica, sans-serif" size="1"><b><font face="Verdana, Arial, Helvetica, sans-serif">//Our
class definition<br>
Class cPlayer {</font></b></font></p>
<blockquote>
<p><font face="Verdana, Arial, Helvetica, sans-serif"><b><font size="1">//Our
variables <br>
var $Name;<br>
var $Score;<br>
var $Ammo;</font></b></font></p>
<p><font face="Verdana, Arial, Helvetica, sans-serif"><b><font size="1">//Our
functions <br>
function ChangePlayerName($NewName) {</font></b></font></p>
<blockquote>
<p><font face="Verdana, Arial, Helvetica, sans-serif"><b><font size="1">$this->Name
= $NewName;</font></b></font></p>
</blockquote>
<p><font face="Verdana, Arial, Helvetica, sans-serif"><b><font size="1">}</font></b></font></p>
</blockquote>
<p><font face="Verdana, Arial, Helvetica, sans-serif"><b><font size="1">}
</font></b></font></p>
</blockquote>
<p><font face="Verdana, Arial, Helvetica, sans-serif"><b><font size="1">$PlayerCount;<br>
$Players[PlayerCount] = new cPlayer;</font></b></font></p>
<p><font face="Verdana, Arial, Helvetica, sans-serif"><b><font size="1">//Lets
change the name using OOP!<br>
$Players[PlayerID]->ChangeName("Player3456");</font></b></font></p>
<p><font face="Arial, Helvetica, sans-serif" size="2">Now how easy was that?
Less code, allows for more dynamic code and saves space and time. Lets
take a closer look at classes.</font></p>
</td>
</tr>
</table>
<br>
<table width="467" border="0" cellspacing="0" cellpadding="0">
<tr>
<td bgcolor="#ddddcc"><font color="#000000" size="2" face="Arial, Helvetica, sans-serif"><b>The
Class frame</b></font></td>
</tr>
<tr>
<td align="left" valign="top">
<p><font size="2" face="Arial, Helvetica, sans-serif">You define a class
by the <b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">class</font></b>
keyword, followed by the name of the class.</font></p>
<blockquote>
<p><font face="Verdana, Arial, Helvetica, sans-serif"><b><font size="1">class
cMyClass {</font></b></font></p>
<p><font face="Verdana, Arial, Helvetica, sans-serif"><b><font size="1">}</font></b></font></p>
</blockquote>
<p><font face="Arial, Helvetica, sans-serif" size="2">I put a 'c' in front
of my class name, just so I know its a class. You can put what you like,
but remember, the name has rules. You can not have a name beginning with
a number, or use a name that has a space and you can not use a name that
is already a keyword or a function name. </font></p>
<p><font face="Arial, Helvetica, sans-serif" size="2">You define a variable
of type <b><font face="Verdana, Arial, Helvetica, sans-serif" size="1">cMyClass</font></b>
like so:</font></p>
<blockquote>
<p><font face="Arial, Helvetica, sans-serif" size="1"><b><font face="Verdana, Arial, Helvetica, sans-serif">$myClass
= new cMyClass;</font></b></font></p>
</blockquote>
<p><font face="Arial, Helvetica, sans-serif" size="2">This says that we
want <b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">$myClass</font></b>
to be of type <b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">cMyClass</font></b>.
Now we can use <b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">$myClass</font></b>
to access the variables inside of <b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">cMyClass</font></b>.</font></p>
</td>
</tr>
</table>
<br>
<table width="467" border="0" cellspacing="0" cellpadding="0">
<tr>
<td bgcolor="#ddddcc"><font color="#000000" size="2" face="Arial, Helvetica, sans-serif"><b>The
Class guts - Variables</b></font></td>
</tr>
<tr>
<td align="left" valign="top">
<p><font size="2" face="Arial, Helvetica, sans-serif">Having a class is
no good if you don't have something inside of it. So with this in mind,
we add some variables. To add variables, we first identify the variable
by putting the<b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">
var</font></b> keyword in front of our variable name.</font></p>
<blockquote>
<p><font size="1"><b><font face="Verdana, Arial, Helvetica, sans-serif">class
cMyClass {</font></b></font></p>
<blockquote>
<p><font face="Verdana, Arial, Helvetica, sans-serif"><b><font size="1">var
$myVariable;</font></b></font></p>
</blockquote>
<p><font face="Verdana, Arial, Helvetica, sans-serif"><b><font size="1">}</font></b></font></p>
</blockquote>
<p><font size="2" face="Arial, Helvetica, sans-serif">Now we have a variable
that we can access. To access this variable you can use the variable we
defined for <b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">cMyClass</font></b>.</font></p>
<blockquote>
<p><font size="1"><b><font face="Verdana, Arial, Helvetica, sans-serif">$myClass->myVariable
= "My Class";</font></b></font></p>
</blockquote>
<p><font size="1" face="Arial, Helvetica, sans-serif"><b><font face="Verdana, Arial, Helvetica, sans-serif">$myVariable</font></b></font><font size="2" face="Arial, Helvetica, sans-serif">
inside of <b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">cMyClass</font></b>
is now set to <i>"My Class"</i>. Now, lets say we want to view
what is in the variable. You'd assume (as I did) that you can do it this
way</font></p>
<blockquote>
<p><font size="1" face="Verdana, Arial, Helvetica, sans-serif"><b>echo
$myClass->myVariable;</b></font></p>
</blockquote>
<p><font size="2" face="Arial, Helvetica, sans-serif">Well, unfortunately,
this does not work. Those coming from C++ will be disappointed to hear
that you will need to define a function inside of the class to print the
value of the variable. See the next section for functions.</font></p>
</td>
</tr>
</table>
<br>
<table width="467" border="0" cellspacing="0" cellpadding="0">
<tr>
<td bgcolor="#ddddcc"><font color="#000000" size="2" face="Arial, Helvetica, sans-serif"><b>The
Class guts - Functions / Constructors</b></font></td>
</tr>
<tr>
<td align="left" valign="top">
<p><font size="2" face="Arial, Helvetica, sans-serif">The ability to have
functions that are specific to your class is great. It is also needed.
The first function we will talk about will be the <b><i>constructor</i></b>.
The constructor is a function that gets called when we create a variable
defined as being of type <b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">cMyClass</font></b>.
This constructor function has the same name as the class.</font></p>
<blockquote>
<p><font size="1"><b><font face="Verdana, Arial, Helvetica, sans-serif">class
cMyClass {</font></b></font></p>
<blockquote>
<p><font face="Verdana, Arial, Helvetica, sans-serif"><b><font size="1">var
$myVariable;</font></b></font></p>
<p><b><font face="Verdana, Arial, Helvetica, sans-serif" size="1">function
cMyClass() {</font></b></p>
<p><b><font face="Verdana, Arial, Helvetica, sans-serif" size="1">}</font></b></p>
</blockquote>
<p><font face="Verdana, Arial, Helvetica, sans-serif"><b><font size="1">}</font></b></font></p>
</blockquote>
<p><font size="2" face="Arial, Helvetica, sans-serif">So what do we do with
this constructor? Well, nothing if you dont need it. But, lets say that
you want to define <b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">$myVariable</font></b>
as having a default value.</font></p>
<blockquote>
<p><font size="1"><b><font face="Verdana, Arial, Helvetica, sans-serif">class
cMyClass {</font></b></font></p>
<blockquote>
<p><font face="Verdana, Arial, Helvetica, sans-serif"><b><font size="1">var
$myVariable = "This is a default value";</font></b></font></p>
<p><b><font face="Verdana, Arial, Helvetica, sans-serif" size="1">function
cMyClass() {</font></b></p>
<p><b><font face="Verdana, Arial, Helvetica, sans-serif" size="1">}</font></b></p>
</blockquote>
<p><font face="Verdana, Arial, Helvetica, sans-serif"><b><font size="1">}</font></b></font></p>
</blockquote>
<p><font size="2" face="Arial, Helvetica, sans-serif">This does not work.
It will give an error. So this is where our constructor functions comes
in. We can set the default value of <b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">$myVariable</font></b>
inside this function.</font></p>
<blockquote>
<p><font size="1"><b><font face="Verdana, Arial, Helvetica, sans-serif">class
cMyClass {</font></b></font></p>
<blockquote>
<p><font face="Verdana, Arial, Helvetica, sans-serif"><b><font size="1">var
$myVariable;</font></b></font></p>
<p><b><font face="Verdana, Arial, Helvetica, sans-serif" size="1">function
cMyClass() {</font></b></p>
<blockquote>
<p><font face="Verdana, Arial, Helvetica, sans-serif"><b><font size="1">
$this->myVariable = "This is a default value";</font></b></font></p>
</blockquote>
<p><b><font face="Verdana, Arial, Helvetica, sans-serif" size="1">}</font></b></p>
</blockquote>
<p><font face="Verdana, Arial, Helvetica, sans-serif"><b><font size="1">}</font></b></font></p>
</blockquote>
<p><font face="Arial, Helvetica, sans-serif" size="2">Now, when we define
<font face="Verdana, Arial, Helvetica, sans-serif"> <font size="1"> <b>$myClass
= new cMyClass;</b></font></font> our constructor will be called and the
value of <b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">$myVariable</font></b>
will be set.</font></p>
<p><font face="Arial, Helvetica, sans-serif" size="2">Creating your own
functions is just as easy. Just identify our function by putting the <b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">function</font></b>
keyword in front of the function name.</font></p>
<blockquote>
<p><font size="1"><b><font face="Verdana, Arial, Helvetica, sans-serif">class
cMyClass {</font></b></font></p>
<blockquote>
<p><font face="Verdana, Arial, Helvetica, sans-serif"><b><font size="1">var
$myVariable;</font></b></font></p>
<p><b><font face="Verdana, Arial, Helvetica, sans-serif" size="1">function
cMyClass() {</font></b></p>
<blockquote>
<p><font face="Verdana, Arial, Helvetica, sans-serif"><b><font size="1">
$this->myVariable = "This is a default value";</font></b></font></p>
</blockquote>
<p><b><font face="Verdana, Arial, Helvetica, sans-serif" size="1">}</font></b></p>
<p><b><font face="Verdana, Arial, Helvetica, sans-serif" size="1">function
MyFunction() {</font></b></p>
<blockquote>
<p><b><font face="Verdana, Arial, Helvetica, sans-serif" size="1">return
$this->myVariable; </font></b></p>
</blockquote>
<p><b><font face="Verdana, Arial, Helvetica, sans-serif" size="1">}</font></b></p>
</blockquote>
<p><font face="Verdana, Arial, Helvetica, sans-serif"><b><font size="1">}</font></b></font></p>
</blockquote>
<p><font face="Arial, Helvetica, sans-serif" size="2">in our new function
that we just defined, we return the value of <b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">$myVariable</font></b>.
Now, you should have a good understanding of how we add functions and
variables. Lets take a look at how to access these class members.</font></p>
</td>
</tr>
</table>
<br>
<table width="467" border="0" cellspacing="0" cellpadding="0">
<tr>
<td bgcolor="#ddddcc"><font color="#000000" size="2" face="Arial, Helvetica, sans-serif"><b>Accessing
class members</b></font></td>
</tr>
<tr>
<td align="left" valign="top">
<p><font size="2" face="Arial, Helvetica, sans-serif">You access class members
by using the <b><font face="Verdana, Arial, Helvetica, sans-serif" size="1">-></font></b>
symbol.</font></p>
<blockquote>
<p><font size="2" face="Arial, Helvetica, sans-serif"><b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">$myClass->myVariable;</font></b></font></p>
</blockquote>
<p><font size="2" face="Arial, Helvetica, sans-serif">When accessing class
members, you do not need to include the <b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">$</font></b>
infront of variable names.</font></p>
<blockquote>
<p><font face="Arial, Helvetica, sans-serif" size="1"><b><font face="Verdana, Arial, Helvetica, sans-serif">$myClass->$myVariable
= "This is wrong";</font></b></font></p>
<p><font face="Verdana, Arial, Helvetica, sans-serif"><b><font size="1">$myClass->myVariable
= "This is correct";</font></b></font></p>
</blockquote>
<p><font face="Arial, Helvetica, sans-serif" size="2">When accessing class
members from inside the class, you will need to use the <b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">$this</font></b>
keyword. Follow the same rules as above when accessing the class members
from inside the class.</font></p>
<blockquote>
<p><font face="Verdana, Arial, Helvetica, sans-serif" size="1"><b>$this->myVariable
= "Accessing it from inside";</b></font></p>
</blockquote>
<p><font face="Arial, Helvetica, sans-serif" size="2">Accessing our members
is not hard. You just need to know how.</font></p>
</td>
</tr>
</table>
<br>
<table width="467" border="0" cellspacing="0" cellpadding="0">
<tr>
<td bgcolor="#ddddcc"><font color="#000000" size="2" face="Arial, Helvetica, sans-serif"><b>Nested
classes </b></font></td>
</tr>
<tr>
<td align="left" valign="top">
<p><font face="Arial, Helvetica, sans-serif" size="2">At some point, you
will want to have nested classes. Nested classes are classes defined inside
another class. Take a look at this example:</font></p>
<blockquote>
<p><font size="1" face="Verdana, Arial, Helvetica, sans-serif"><b>class
cMyClass {</b></font></p>
<blockquote>
<p><b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">var
$myVariable;</font></b></p>
<p><b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">function
cMyClass() {</font></b></p>
<blockquote>
<p><b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">$this->myVariable
= "Hello";</font></b></p>
</blockquote>
<p><b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">}</font></b></p>
<p><b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">function
MyFunction() {</font></b></p>
<blockquote>
<p><b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">return
$this->myVariable;</font></b></p>
</blockquote>
<p><b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">}</font></b></p>
</blockquote>
<p><b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">}</font></b></p>
<p><b><font face="Verdana, Arial, Helvetica, sans-serif" size="1">class
cNewClass {</font></b></p>
<blockquote>
<p><b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">var
$newVariable;<br>
var $myClass;</font></b></p>
<p><font size="1" face="Verdana, Arial, Helvetica, sans-serif"><b>function
cNewClass() {</b></font></p>
<blockquote>
<p><font size="1"><b><font face="Verdana, Arial, Helvetica, sans-serif">
$newVariable = "Nothing for now";</font></b></font><br>
<b><font face="Verdana, Arial, Helvetica, sans-serif" size="1">$myClass
= new cMyClass;</font></b></p>
</blockquote>
<p><font size="1" face="Verdana, Arial, Helvetica, sans-serif"><b>}</b></font></p>
<p><font size="1" face="Verdana, Arial, Helvetica, sans-serif"><b>function
NewFunction() {</b></font></p>
<blockquote>
<p><font size="1"><b><font face="Verdana, Arial, Helvetica, sans-serif">
$newVariable = $this->myClass->MyFunction();</font></b></font></p>
</blockquote>
<p><font size="1" face="Verdana, Arial, Helvetica, sans-serif"><b>}</b></font></p>
</blockquote>
<p><b><font face="Verdana, Arial, Helvetica, sans-serif" size="1">}</font></b></p>
</blockquote>
<p><font face="Arial, Helvetica, sans-serif" size="2">Now to sort out your
confusion. What happened here was this, first, we defined our class <b><font face="Verdana, Arial, Helvetica, sans-serif" size="1">cMyClass</font></b>.
Then we define our new class <b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">cNewClass</font></b>.
Inside of <b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">cNewClass</font></b>
we defined a variable <b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">$myClass</font></b>.
Then in the constructor for <b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">cNewClass</font></b>
we decalred <b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">myClass</font></b>
as <b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">cMyClass</font></b>.
Now, we have access to the members of <b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">cMyClass</font></b>
from <b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">cNewClass</font></b>.</font></p>
<p><font face="Arial, Helvetica, sans-serif" size="2">In our <b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">NewClass</font></b>
function we set our <b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">$newVariable</font></b>
to the value of <b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">cMyClass</font></b>.
We do this by calling the member function <b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">MyFunction()</font></b>
of <b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">cMyClass</font></b>
to return the value of <b><font face="Verdana, Arial, Helvetica, sans-serif" size="1">myVariable</font></b>.
You can also do this from outside of the class like so:</font></p>
<p><font face="Arial, Helvetica, sans-serif" size="2"><b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">$NewClass
= </font><font face="Arial, Helvetica, sans-serif" size="2"><b><font size="1" face="Verdana, Arial, Helvetica, sans-serif">new
cNewClass;<br>
<br>
$NewClass->newVariable = $NewClass->myClass->MyFunction();</font></b></font></b></font></p>
</td>
</tr>
</table>
<br>
<table width="467" border="0" cellspacing="0" cellpadding="0">
<tr>
<td bgcolor="#ddddcc"><font color="#000000" size="2" face="Arial, Helvetica, sans-serif"><b>Conclusion</b></font></td>
</tr>
<tr>
<td align="left" valign="top"><font size="2" face="Arial, Helvetica, sans-serif">Hopefully
I didn't leave out too much information. I tried to cover the basics. OOP
is such a great thing that if you are not using it, you are missing out.
It allows for easy coding and also allows for more dynamic coding. If you
don't understand OOP, I suggest learning.</font></td>
</tr>
</table>
Upload
Original Comments (3)
Recovered from Wayback Machine