Scorpion Engine

[acidbottle]

Really cool new update!

Have an "interesting" bug that developed on the previous update. I try to compile the project directly into winuae, which was working flawlessly. As of last night I get a wall of error codes doing so, can obtain a screenie of needed later. I didnt change much in my code so unsure what caused this!

Advice needed again to ..

Am trying to shift a scrolling player which is fine, I can increase the xspeed and xcamera by moving the control to the right, it has reduced speed when controls left. When I want to slow down though am finding changing to -xspeed or -xcamera is not making difference. Any help appreciated I do often find my explanations of issues really bad after I read back, think here is no different! Have tried various player attribute changes (left/right speed etc) not working also.

edit: to simplify, need a scrolling player to speedup when control moves right, staying constant speed when left and slowing down when moving left!

[earok]

Daily check in time:

- Renamed "double speed" to "double smooth" (I figured this was a little clearer since the point of it is not to double the speed of gameplay but double the smoothness of it)

- Fixes for acceleration with double smooth that hopefully resolve gravity bug (thanks Mixel)

- New "control_scroll" option designed more or less just for scrolling shooters. Set the Scroll X or Scroll Y value (not both) and the camera will scroll from one side of the level to the other, moving the player along with it. This was all possible already of course but only with timers and codeblocks, this is a little easier and more efficient since no custom codeblock logic is required to get a scrolling shooter working.

Note that since this is brand new, there's probably a lot of work that needs to be done to get it to work. I've only tested it in vertical mode (negative Y scroll) so far.

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@acidbottle apologies, I don't quite follow, but in any case you should be able to control everything via codeblocks. You should be able to set actor_x, actor_y, camera_x and camera_y in a timer_expired codeblock (using conditions based on control1_x) to get the effect that you want.

@viddi cheers! I may need to try out two player mode with a Tales of Gorluth game

@kaizen35 good to see you again! Would be interested to see that car game going with the new rotation option

[acidbottle]

Cheers earok, I knew it was an on expire timer code and just had an extra camera_x variable set, which I removed and always completely forget about the control1_x var. A quick 10 minute tinker this morning had solved a couple hours of head banging and the effect I have is near spot on!

This is a significant development to as it was the last major part of the Wonderboy mechanics resolved.

As for all the recent scrolling and shooter improvements to the core engine, absolutely stellar work. The sky is the limit for what can be achieved, though wondering if you got any further with less restrictive cpu_path movement, that would be a game changer for sure!

[Lemming880]

A cpu_platform actor with collision set to none does not fall through slopes while it does through solid tiles. Can this be made possible? In my case I have coins that should drop to the bottom of the screen but they keep laying on the slopes.

And will you add an option for actor flash? You know, when a player or enemy gets hit it briefly flashes. What I did until now is make a white silhouette for each actor and used that for a single flash. But it's quite cumbersome.

[earok]

Thanks Acidbottle, good to hear!

@Lemming880 hmm.. does CPU_Accel work instead? If it's only going up and down, CPU_Accel might be a better option (and since it doesn't test for slopes, it shouldn't land on one)

Re: Flash, that's something on the backlog but I haven't quite thought of the best way to solve it. It will come sooner or later though.

[acidbottle]

Did you not add a palette change feature than could replicate a kind of flashing effect in a recent build? Might be thinking of something else to be honest ...

[Lemming880]

Originally Posted by earok

...does CPU_Accel work instead?...

With cpu_accel the coin flies to the top of the screen because it first gets pushed up and then should drop down with gravity. And cpu-platform is the only one with gravity. But I can think of other solutions like showing a sparkle when picking up a coin. I'll think of something. And I'll wait for flash then. Thanks.

[earok]

@lemming880 I did bit of an experiment, this setup should work (if actor set to up as the default direction).



- Accelerate is designed to keep accelerating until the speed limit in the direction it's going
- However, you can feed it a negative value
- Therefore, we slow it down to zero when it's moving up, and keep accelerating when it's moving down (but no more than the maximum down speed)


@acidbottle there is a palette change option but it's not the same as what Lemming880 is asking for (the palette change will change the color for everything, whereas a flash effect, if implemented, would allow a single actor to flash a single color)

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Today's experimental update is simply that the movement type selection is in a pop-up rather than a drop-down. This is partly because there's a lot of them so it'll make it easier to find a particular one, but it also gives me the opportunity to give each movement type some basic documentation.

[Mixel]

That’s an excellent change, I still sometimes pick the wrong one.

One thing that would be neat, for effects (in some cases “flashing” etc) is if you could set bitplane settings (and only sprite on/off) in codeblocks rather than it just being baked in by animation. That would give a lot of flexibility for effects depending on how your palette was set up. You can get some neat translucent/trippy effects even when the palette isn’t set up specifically for it. I can imagine some neat looking things if you can cycle through the bitplane options with codeblocks, but I don’t know how practical that’d be!

Also looking at wonderboy and other old arcade machines I think some sort of colour cycling on panels would be great, it’s weird how common that used to be.

[saimon69]

Originally Posted by Mixel

Also looking at wonderboy and other old arcade machines I think some sort of colour cycling on panels would be great, it’s weird how common that used to be.

Since was pretty light on CPU timing it was used often to have almost free animation

[acidbottle]

I love the new change, sometimes small additions like that help massively.

Definitely second the motion for colour cycling on a panel, though am getting the impression it may not be as easy at it sounds ha!

On the subject of panels, we have a top and bottom panel, are there any plan to introduce left or right side panels to?

[saimon69]

Ok, once in a while i come with those questions that might give a headache to Eric but is because have something in mind and so want to see the feasibility:
Does the engine actually use global text variables and allows to parse and modify it (like a text in a string "textarea" and then read or change letter 4 of it) plus can i read this global text from an actor and enable it/disable it according to the text value? (like if the string was 'textarea' i change the letter 4 to 'u', and make the actor do some actions ONLY if the fourth letter is 'u') since might come handy to set statuses and progresses for some game styles

[Mixel]

I don’t think you can do that.. But I don’t quite understand what occasion you’d want to, either?

I just use tons of numeric variables.

[saimon69]

Originally Posted by Mixel

I don’t think you can do that.. But I don’t quite understand what occasion you’d want to, either?

I just use tons of numeric variables.

Well i did not put my hands on Scorpion yet but was checking on the idea of progressive power up and to use a string to define which power up and at what level i have it, then use IF statements (or a switch one if available) on the actor to have different interactions whether the character is set or not and which character - i would have used a system like that in ZX BASIC if i was going to work on the spectrum - that or use binary digits on a byte; i admit might sound wasteful

[Mixel]

Oh no, doesn’t sound wasteful at all you could do that which a bunch of ifs and global variables though for sure. You can set as many custom variables as you like so you can have weapon strength, type, level, ammo, etc.. the projectiles themselves can contain variables too.

[UltraNarwhal]

Nice updates, but noticed sprites now flicker in builds after multiplexing was introduced (31st August). Easy to see in Duckstroma once you enter tree, then lay an egg.
May not affect games that use parallax, due to not using last three sprite colours.

[earok]

There's nothing yet in the way of string manipulation, some string manipulation will come at some point (eg, the ability to format strings like "you have {var_coins} coins") but I'm not sure it'll include conditionals on individual characters.


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Minor experimental check in should fix (or at least significantly reduce) sprite issues as reported in Duckstroma (There was a bug where an actor being destroyed would consume sprite channels for a frame, it happened that the egg would spawn a second version of the egg and while that first egg still existed in memory, it was still consuming sprite channels).


A further optimization tweak is that, all frames with an animation time of 0 are not animated (which is to say, if a frame has an animation time of 0 essentially has an infinite frame time). This should be ideal for bullets and such where there's simply no second frame to animate.

[Lemming880]

Originally Posted by earok

@lemming880 I did bit of an experiment, this setup should work (if actor set to up as the default direction).

It works in free air. The coin jumps up and then goes down just like it used to. But when there are solid tiles above the coin it somehow keeps jumping up until the solid tiles end and then falls down. And when the solid tiles reach the top of the screen the coin will leave the top of the screen. I've used cpu_accelerate and your settings. And in the codeblock I make the coin jump up with actor yspeed -3.

[UltraNarwhal]

Originally Posted by earok

Minor experimental check in should fix (or at least significantly reduce) sprite issues as reported in Duckstroma (There was a bug where an actor being destroyed would consume sprite channels for a frame, it happened that the egg would spawn a second version of the egg and while that first egg still existed in memory, it was still consuming sprite channels).

Thanks, all seems fine now in Duckstroma and Abbey of the Dead

[Mixel]

I have a really dumb seeming request.. can I get player control types that rotate the joystick inputs 90degrees, 180degrees, 270degrees? Or even a modifier you could change in codeblocks?

This is partly an idea for a spell in wizonk but mostly for another experimental project. (I wonder who can make the first(/only?) tate mode scorpion game? Lol)