GFX

With trigonometry functions such as sine and cosine, it is very easy to compute for the value of x and y for any given radius and teta.

We've all learned this from highschool and college class and it will not be tacked in this article. However, drawing a circle using these functions requires the usage of floating-point numbers which is slow, not to mention the typecasting from floating-point to integers as plotting a pixel requires such datatype.

If you've ever worked with Adobe Photoshop or any image processing tool, you've probably resized an image to a certain frame or dimension. Suppose the original image dimension is 600x800 (3:4 aspect ratio) and you want to fit everything in a 500x750 (2:3 aspect ratio) frame. What you will do is to shrink the width from 600 to 500 and stretch the height from 800 to 750. This process of resizing is called image scaling in computer graphics.

Noise is another special effect to emulate an old TV without a signal. A naive approach to do this graphic effect is to create a double for-loop and randomize the color of the pixel being placed on each of the coordinates of the screen.

for (y = 0; y < MAX_SCREEN_HEIGHT; ++y)
    for (x = 0; x < MAX_SCREEN_WIDTH; ++x)
        putPixel(x, y, RBGA(rand()%256, rand()%256, rand()%256, rand()%256));

This will work but not as fast as we would like it to be due to the following reasons:

Melt is a technique I've been using when developing 2D games to demonstrate the illusion of melting objects. This effect is something that you cannot just do in Photoshop. Some things are better done the hard way giving you more control of the parameters and function behavior. This is another Throwback Thursday's article so I've written it using QBASIC.

The Technique is simple, you can apply it to any bitmap/canvass of any modern graphic libraries that you are using. The basic idea is, given an object you need to: