Smooth 8 way scroll (Project Horizon Engine part)

[sovenyimre]

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Project Horizon - simple 8 way Scroll Engine part
Created by
Electric Black Sheep
Soveny Laszlo, Soveny Imre
(2021.12.30.)
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Simple, fast, adjustable TOME.Map Viewer.
I think it is a good base for any game.
AMOS PRO 2.0 Extensions: TOME, AMCAF, TURBO PLUS 2.15

How it works:
Any screen and tile size and scroll speed can be used.
The rest of the parameters are calculated automatically, so no further calculation is required.
The size of screen is as big as the visible scren and the size of a tile (ex: 320 * 256-> 352 * 288) Within this area, the camera follow.
The essence of the scroll is that the player moves inside a predefined area of the screen (middle).
If it moves or stays inside the middle frame, the visible area is centered (with speed 1). ...I know it is not simpler but nicer than a simle scroll stop.
If you exit the middle frame by moving, the coordinate system will follow.
I use screen offset command so it is 32x32 hw scroll. (or 16x16 if the tile size is 16x16)
If we reach the edge of the 32x32 scroll area when moving, then the following things happen:
1. turn off the bobs
2. copy the visible screen in the opposite side direction to the direction of movement
3. replace the missing tile parts (stripes)in the direction ahead of us.
4. check movement and I start again if necessary until double buffer is identical.
This is necessary because if I exit the field at a corner point, an error may occur and the two buffers may be different at the end.
So all of this is done at least twice because displaying flicker-free bobs requires a double buffered screen with the same content
and turning off the bobs is necessary because if I dont, bob will (blink) appear in bad position after screen copy and the previous image is being restored bellow th bob when it moves (causing visual errors).
On the one hand, to be fast and on the other hand more handy (not to cause any trouble), so I turned off a couple of automated systems.
Screen copy is slow but almost invisible at 25 FPS and there is enough CPU time left for other things (the background processes of a game), You just
only have to insert in the correct place (like Gosub DUMMY).
Could run faster than 25 fps but in that case because of the speed difference, Screen copy is visible.
For faster results, I used Turbo Plus Icons instead of AMOS icons and Turbo Plus Scene command instead TOME.(TOME editor can be used, the program will convert the map to scene format)
I'm not a professional programmer. I just had an idea of ??how such a system could work and I share the above because I haven’t found fast/working solution I can use.
If anyone has an idea of ??what could be improved or simplified, I look forward to your comments.

[idrougge]

Could you explain a bit about how it works?

[sovenyimre]

Originally Posted by idrougge

Could you explain a bit about how it works?

For explanation, I edited the description.

[Predseda]

Sovenybros rock!

[idrougge]

Originally Posted by sovenyimre

For explanation, I edited the description.

Thanks!

[sovenyimre]

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Project Horizon - simple 8 way Scroll Engine part (+Light/Shadow)
Created by
Electric Black Sheep
Soveny Laszlo, Soveny Imre
(2022.02.05.)
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Light+Shadow:

How it works:
It is not raycast! Imagine a circle divided into predefined angles.
The program checks each tile in a predefined spiral path (from inside->out) to see if its value is below a certain value (I use 0...161 values for Walls),
if so, it calculates its angle and distance from the flame.
If the angle of a tile not already "in shadow", it means that its distance is less than the smallest distance stored for the angle, I update one belonging data to the angle.
The result is a "distorted circle"?!
like this toy: https://www.google.com/search?q=Grap...+Puzzle+Boards
The drawing is quite simple.
Palette use 16 normal color and 16 half tone color.
I use blitter lines on the last bitplane to draw the circle and fill it.
So watever is under this area.... it will be darker.

The demo:
- arrow keys to move the flame
- +/- keys to adjust shadow resolution

Anyone who is curious can see how a game looks like if we use this.
https://electricblacksheep.itch.io/p...ready-to-play-

I wanted to share it because I want to use it in my game.
The drawing is fast but the calculation itself is pretty slow.
The program must check 80 tiles, generating 3 points inside to fill gaps in angles, so that the result does not look like a hedgehog.
Since I am not a professional or a mathematician this came to my mind as the best solution but I am sure there is a better one as well.
If anyone has a suggestion, please comment.

(2022.02.20)
Also extended with a program to convert maps from Tome to Tiled (.MAP to .TMX), and Tiled maps back to Tome (.TMX to .MAP).
I used a "simple approach" and Since it is also the first time I used Tiled , I dont know that it will work in every case.