Rolling and Rotating scrolltext (Old School VIII)

I made today a little Monkey X Pro demonstration: Rolling and rotating scrolltext (Old School VIII). Now it works perfectly. Like in Old School VII, the letters fade in and out at the bottom of the circle of letters. I have used my Font 2 PNG program to grab individual characters of a ttf-font to png-images for the program. Perhaps I will later share the source code of the demonstration…

Enjoy the nostalgia! 🙂

The idea behind the code of the rolling and rotating scrolltext:

  • At every update frame 30 characters (png-images) from the scrolltext are drawn in a form of a circle, each character with 12 degrees step (12 *30 = 360), let angle related to this angle be angle1
  • When drawing the character images, the angle that increases in 12 steps is added to each character in addition to this angle is added other angle variable, let this be angle2, that is decreased (the direction of rolling and rotating) by 1 degrees at every update frame
  • Because of my (probably clumsy but working 🙂 )implementation:
  • in DrawImage method rotation angle is angle1 + angle2 + constant that adjusts the letters to the right place on the circle

As to he fade out and fade in for the letter images, you may adjust the letters with alpha values as you best you see it is sensible, probably somewhere at the bottom of the circle.

That’s it! Do try to make make your own version with programming language of your choice. I recommend my Font 2 PNG program for the font.

Good luck!

Bouncing of the ball when it touches the Bat (80s Krakout style)

It’s night when I’m writing this. I came up with a little Monkey X tutorial on how to program the bouncing of the ball, when it touches the bat in the “old school way” — like in the popular C64 game Krakout in the 80s.

In the video for the tutorial you can see, that as the ball touches the bat for the first time, delta y doesn’t change. This is because both the ball and the bat are uneven as height in pixels; now both the ball and the bat have a middle point.

This is just a short piece of code, that doesn’t handle the case, when the ball is at the horizontal top or bottom of the bat. There’s some extra work for anyone who wants to make an 80s style Krakout game. 🙂

The delta y for the ball is calculated simply how the ball’s y-position is related to the middle point to the bat. The “scale” variable is used to adjust the max y-speed of the ball. If you are new to Monkey X, remember that with Pro version, you can compile the code to the Android target among many other targets. See the Store page.

Source code below:

Feel free to use and improve the source above in your own projects.

Here’s the graphics to download (license: public domain), except the background picture:



The bat is 32 x 73 pixels as size, the ball is 16 x 17 pixels.


For comparing to the C64’s popular Krakout, see the video below:

Many years ago I started to program Krakout style game in the spirit of the good old Commodore 64, but as usual, something went wrong. Three months work with multiple levels and a level editor programmed in Blitz3D were lost because I hadn’t taken backups of the files, when I, well, “fixed” the Windows installation I had at the time…

3D Stars With Controlled Center Point

Just little changes to old post on 3D stars with Mojo2… Now on the projection from 3D space to 2D space (screen), the center point can be controlled, just touch the screen or keep the left mouse button pushed down to control the stars… The code should compile as such to any target on Monkey X Pro.

Source code license: Public Domain.

Scrolling a Picture Larger Than Visible Area in Monkey X

A little tutorial on scrolling a picture that is larger than the visible area of the screen in Monkey X.

In this example we will be using a picture of 1280 x 960 pixels in “native” resolution of 640 x 480 pixels. The source is primarily meant to Android target but works for example to desktop target too.

The picture is scrolled by moving a finger on the Android device. In order to avoid the picture to “jump” after not scrolling the picture, variables related to scrolling speed must be set to zero.

Lets have a look at the source code:

Examine the source code and learn. Source code license: Public Domain.

Below is a video related to this post:


Missile Attack in Monkey X

Again, some nostalgia. In older blog post I presented a shortened version of my old implementation of Amiga’s “Missile Attack”. This night I made the game in Monkey X and the source can be directly compiled to Android target.

The game is quite simple one: Just shoot the missiles before they get to the bottom of the screen.

If a missile goes to the left or right side of the screen, you see the colors of the background changing — and also when you fire a shot. This gives the game more life. 🙂

Below is the source code:

Source code license: GNU General Public License 3.0.

Below is the video of the game on Android tablet and on computer screen:

I may make a better version of the game later on this summer…

How to Make a Worm Game Part 2

(Updated 03/05/2017 with improved source code and new video)

A little update to older post. As the title of the post says we’re making a worm game (in Monkey X). In this version the worm is controlled by touching the screen keeping in mind that the game is really aimed to Android.

I’ll explain here how the worm is controlled.

If you move your finger ”up” from the worm’s head, the worm goes to that direction and respectively to other directions.

See the video below:

The direction is determined by comparing two subsequent update rounds’ TouchX() and TouchY() coordinates.

The test can’t be straightforward TouchX() or TouchY() test, because the player probably won’t move his/her finger absolutely to one of the four directions the worm is to be controlled.

This is why there is another test in controlling the worm: The absolute values of difference of the two subsequent update round’s TouchX() and TouchY() coordinates. If the player wants to control the worm ”up”, the player probably has moved his/her finger more vertically than horizontally.

See the source code:

Source code license: Public domain.

Notice, that in this code one part of the worm’s “body” is 17 x 17 pixels, but the worm moves with step of one pixel and can be controlled with accuracy of one pixel. The example code above is simple implementation of this kind of worm game. The down side of the code is, that the sizes of the arrays for x– and y-coordinates depend of the length of the worm in pixels.

I may come back later with some implementation with different concept of moving the worm of which “body” is built with “blocks” of different size than one pixel, but the worm is controlled  with accuracy of one pixel, without using arrays of which lengths depend on the size of the worm in pixels.

Scaling Bitmap Font Made with Font 2 PNG in Monkey X part 2

Just a quick update to old code, this one can be compiled to Android target.

Source code copyright: public domain.

Below is a YouTube video of this post:


Touching a real time scaled and middle handled image in Monkey X

One of my Android projects is getting further every now and then… I’d like to share here something that is related to that project: Touching a real time scaled middle handled image. This version uses Mojo2 and OpenGL2. OpenGL2 is only needed for storing the pixel information of the image (LoadImageData).

You may want check the video:

The image that the program uses, has transparent pixels. Touching the image is done by checking is the alpha component of image’s pixel <> 0. If it is, the image has been touched. With mojo2 every image is middle handled by default. This is good for real time scaling and rotation.

The program below tests if pre-loaded image has been touched while it is real time scaled.

If you want to see the above code in practice, please check the video above. And as always, feel free to use this code as you wish.

Old School V – A Weird Sine Wave Scroller Made in Monkey X

This is getting to be a nightmare, this is the 5th Old School demonstration made in Monkey X. Probably the last in the series. I must have be bitten by a nostalgia bug.

In this version the lightning effect affects the font too — see the better quality video with new music:

Below is the source code:

The strange variable coefficient causes the weird sine wave effect.

In order to get the lightning effect working for the font, one must create in addition to font.png file files font_n.png and font_s.png. The Mojo2 renderer does the job from that on.

File font.png is light blue as color, font_n.png is graphically the same but white. Font_s.png is darkened version of font_n.png.

As mentioned in the first Old School post, n stands for normal, s stands for specular.

I hope you get the same nostalgic feeling from the video as I get… As always, feel free to use the source.

Old School IV – Yet Another Sine Wave Scroller made in Monkey X

Yet another sine wave scroller. Now the wave moves also — just like in the most traditional Amiga demos. 🙂

Below is the video (new version with smoother movement):

The angle for sin function is calculated from the x-coordinate again. 360 is divided by the screen width = 640 pixels, the quotient is 0.5625. The screen position (in pixels) from 0 to 640 – 1 is multiplied by this quotient which makes the sine wave to be positioned to full screen width.

That’s the idea. In the code the starting position can be negative (minus character’s width).

The variable addAngle is added to the screen position for the sin function, which makes the wave move. If the value of addAngle is negative, the wave moves to the other direction.

Below is the code:

Check the other Old School posts for more info and feel free to use this code.