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Introduction to Direct Draw (Tutorial)
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Visual Basic 5 Visual Basic 6
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This code has been viewed 91174 times. Note: To use Direct Draw or any other component of DirectX, get the library if you haven't already. You can download it from Microsoft. You should end up with a .Zip file on your hard disk. Use a program like winzip to extract the file. Place the file (dx7vb.dll) in your windows\system\ folder, normally C:\windows\system\dx7vb.dll, then add a reference to it in your VB project.
Theory
It is important that you understand
the theory behind DirectDraw before attempting to make any
programs using it.
DirectDraw is the 2D component of directX, it is best used in
multimedia (where intense drawing is needed) applications or
platformer games. DirectDraw allows you to gain direct access to
the memory on the video card, where you can compose scenes and
frames, or store bitmaps. There are certain things that you
should know about before I launch into things:
| Term |
Meaning |
| Buffer |
A buffer is
used to store graphical information, ie: a bitmap. |
| Primary
Buffer |
Represents
the screen. Anything that goes in here appears on the
screen. |
| Blitting |
Blitting is
the process of copying from one surface to another,
similiar to the bitblt API call. |
| Display Mode
|
The
resolution that your program runs at. In fullscreen mode
it represents the size of the screen. 640x480 is a
display mode. |
| Colour Depth
|
This is the
number of colours that are displayed on the screen. fewer
colours will take less memory, and look a lot worse. 8bit=256
colours 16bit=65536 colours 24bit=16million & 32bit=16.7million.
This is set at the same time as the Display Mode. |
| Frames Per
Second (FPS) |
This is the
number of times the screen is being updated every second.
The human eye cannot see above 33FPS, for optimal quality
try to keep close to or above this speed. |
˙
Every
DirectDraw application follows a similiar pattern:
Create Everything
Start Loop
Blt to screen
End Loop
Destroy Everything
Surfaces
Surfaces are one of the most important things to understand. A
surface is used like a picturebox control in a normal visual
basic application, it holds graphical data. For example: you are
making a game, you have a level, some graphics and a sprite. You
can load your sprite bitmap into one surface, your level graphics
into another, then compose the level onto the backbuffer; which
then appears on the screen. The primary buffer and back buffer
are special types of surfaces.
¸2000 Jack Hoxley -˙All rights
reserved.
The material on this page may be
reproduced as long as credit is˙given to myself
"Jack˙Hoxley"
The author can be e-mailed at jollyjeffers@greenonions.netscapeonline.co.uk.
His web site is http://members.dencity.com/dx4vb/
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