※ Danmakufu Q&A/Problem thread 3 ※

[Sparen]

And which function can I use to make the alpha of the boss texture white? (I mean to make the boss all white, but with the opacity)

I recommend taking a render target of the boss, and applying a shader that sets every pixel to your desired color while maintaining the alpha channel value

[Zinochan]

I recommend taking a render target of the boss, and applying a shader that sets every pixel to your desired color while maintaining the alpha channel value

How can I do that?(I don't know about neither shaders nor render targets)

[Helepolis]

How can I increase playing field's size using camera zoom without changing STG frame?

Not sure if this is possible. There is no "zoom out" for 2D cam afaik.

[FlareDragon]

How can I increase playing field's size using camera zoom without changing STG frame?

Not sure if this is possible. There is no "zoom out" for 2D cam afaik.

While it is possible to zoom in and out using Set2DCameraRatio (or using Set2DCameraRatioX or Set2DCameraRatioY), it doesn't affect the playing field (I think you'd have to use SetStgFrame somehow). Haven't been able to figure it quite out, but I'm sure it's there somewhere.
EDIT: So I was playing around with it, and I've gotten somewhere with it: Code for zooming task
Biggest issues I'm having so far, though, is it doesn't seem to quite render the frame properly (though the collision is certainly working properly).

Images: Default Zoom(1), Zoomed Out(0.75), Zoomed In(1.2)

Any idea why?
(Also, default collision for shots seem to stop working beyond a certain x- and y-postion, though boss collision definitely works. Seemed interesting enough to note)

[AlexKerb]

Maybe with some workarounds and improvements it will work properly? Anyway, thanks for help. And yes, with some workarounds I made 0.7 zoom and it works quite good (no hitbox bugs, just little issues with vision, playable).
https://pastebin.com/t9LPeX8B.

[Zinochan]

There is a tutorial explaining render targets? Where can I found it?

[Arcvasti]

There's one here, but it might be outdated now. You don't need to use render targets or shaders for the aura effect at all, just normal 2D sprite objects and the ObjRender_SetColor function.

[IIe4eNiIIIe]

So, I'm trying to implement a continue system. I made a menu appear after pleyer's last life, and after pressing "continue" the game continues, player gets 3 additional lives, but still doesn't revive. It seems that player's state is still at STATE_END and doesn't change even after gaining new lives. What can I do?

[Sparen]

So, I'm trying to implement a continue system. I made a menu appear after pleyer's last life, and after pressing "continue" the game continues, player gets 3 additional lives, but still doesn't revive. It seems that player's state is still at STATE_END and doesn't change even after gaining new lives. What can I do?

You just never let the player lose all their lives.

This is what I do:

Code: [Select]

    case(EV_PLAYER_SHOOTDOWN){ //To disable continue system, block comment this case.
            if(GetPlayerLife < 0){ //If equals 0, still have a life left (IE using last life)
                SetPlayerLife(0.123); //Copied from Arby, should prevent STATE_END.
                ContinueSystem;
            }
    }


[Zinochan]

I've managed to learn how to use render targets, and I need to know if I can transform a black image to a white image (I've set the HSV color 0,0,0 and that make the texture black)

Edit:Nevermind, learned how to make a shader.

[Drake]

HSV (0,0,0) is black and (0,0,100) is white.

[IIe4eNiIIIe]

Hm, I never thought you can use anything but integers in life value. Thanks for the help

[Sparen]

Hm, I never thought you can use anything but integers in life value. Thanks for the help

No problem. It's not intuitive, but it works.

[Zinochan]

I've created the aura effect, but now the aura keeps 'escaping' the boss. What can I do to prevent this?
https://pastebin.com/y5jAuUzP
edit:Nevermind again, I was setting the source rect just once.

[AlexKerb]

How can I receive x and y coordinates of the laser's end?

[Sparen]

How can I receive x and y coordinates of the laser's end?

One end of the laser is at ObjMove_GetX/Y. The other can be calculated using the length and angle of the laser just as you would do any other radial position calculation: X + length*cos(angle), Y + length*sin(angle).

[IIe4eNiIIIe]

Can someone provide me with a working example of replaye save scene? I tried using the default one without any changes, but after I enter the name of replay and press "done"(or whatever this means 終了) error on the first picture appears. Than I tried to change the default script a bit, and I end up with error on second picture and I don't even know what it means. After some manual change in texts that appear, I managed to surpass that problem (just kinda. I made it go away, but the intended result is also unreachable that way), but the first one still appears after that. Here is my replay save script, which is almost fully copied default version https://pastebin.com/nZBKDhAM

[Sparen]

Can someone provide me with a working example of replaye save scene? I tried using the default one without any changes, but after I enter the name of replay and press "done"(or whatever this means 終了) error on the first picture appears. Than I tried to change the default script a bit, and I end up with error on second picture and I don't even know what it means. After some manual change in texts that appear, I managed to surpass that problem (just kinda. I made it go away, but the intended result is also unreachable that way), but the first one still appears after that. Here is my replay save script, which is almost fully copied default version https://pastebin.com/nZBKDhAM

I see that you are using "[" and "]"

I recommend escaping these ("[osb]" and "[csb]"? "&osb;" and "&csb;"?) to avoid Danmakufu trying to execute them.

Refer to https://sparen.github.io/ph3tutorials/ph3u2l21.html

[Zinochan]

How can I stop the player from retrying a script with the backspace button?

[Kinedyme]

I'm getting some kind of error code on the log window when I try to output calculated values:

1.#INF00 for a number
-1.#IND00 for a different number
1.#QNAN0 for a trigonometric function that essentially takes the sum of the above numbers

What do these warnings mean, and what is likely the problem?

Thanks in advance

[Sparen]

I'm getting some kind of error code on the log window when I try to output calculated values:

#INF00 for a number
#IND00 for a different number
#QNAN0 for a trigonometric function that essentially takes the sum of the above numbers

What do these warning mean, and what is likely the problem?

Thanks in advance

Please provide the code you are using, the actual error, and more context.

[Kinedyme]

Please provide the code you are using, the actual error, and more context.

The first number is intended to be angular acceleration of a bullet, calculated by the function

function CalcAngleAccel1(a1,a2,l1,l2,g,m1,m2,a_v1,a_v2){
      let part1 = -1*g*(2*m1 + m2)*sin(a1);
      let part2 = -1*m2*g*sin(a1 - 2*a2);
      let part3 = -2*sin(a1 - a2)*m2;
      let part4 = a_v2*a_v2*l2 + a_v1*a_v1*l1*cos(a1 - a2);
      let part5 = l1*(2*m1 + m2 - m2*cos(2*a1 - 2*a2));
      let ans = (part1 + part2 + part3*part4)/part5;
      WriteLog(ans);
      return ans;
   }
In which a1 and a2 are a set of angles, a_v1 and a_v2 are those angles' respective angular velocities in the previous frame, and l, g and m are constant variables.

This value is then added to the angular velocity (a_v1), which is then added to the angle (a1).
WriteLog(a1) gives the second value.

The third value is provided by WriteLog(sin(-a1))

The intention is to make a bullet follow a path dictated by polar coordinates using this angle, imitating the movement of a double pendulum. At present, the bullet appears to follow an incorrect path, and then vanish (perhaps moving to (0,0)?) when these errors appear.

[Kinedyme]

Oh, and prior to this, the three numbers begin spiralling out of control, with respect to their magnitudes.

The very last frame before these errors appear also returns a value less than -1 for the trigonometric expression as well.

[Sparen]

EDIT: Oops; read l as |. @Kinedyme: Please use the [ code ] [ / code] tags (no spaces)

I'm getting some kind of error code on the log window when I try to output calculated values:

1.#INF00 for a number
-1.#IND00 for a different number
1.#QNAN0 for a trigonometric function that essentially takes the sum of the above numbers

What do these warnings mean, and what is likely the problem?

Refer to:
https://stackoverflow.com/questions/347920/what-do-1-inf00-1-ind00-and-1-ind-mean
https://stackoverflow.com/questions/29210975/1-qnan0-output-when-calculating-standard-deviation-c

[Kinedyme]

Okay, I'll remember that next time

Thank you, I'll try to add a limit onto the angular acceleration.

[Sparen]

Okay, I'll remember that next time

Thank you, I'll try to add a limit onto the angular acceleration.

If you angles are the ones exploding, it may help to normalize (angle = angle % 360)

[MugenCC]

I've tried to use variable pointers the way they're used in C/C++ but it doesn't work. Is there any way to use them in Danmakufu?

[Drake]

Definitely not, unfortunately. Objects are not accessed by pointer, but by an integer ID that Danmakufu will then manage internally. Arguments to functions are also passed by value, not by reference.
Are there other particular use cases that you were considering?

[MugenCC]

I was thinking of functions that used the variables themselves as parameters, as opposed to the values the variables hold at the time.  For example, I wanted to try to make a "Wait until" function, so instead of writing

Code: [Select]

while(!boolean){yield;}, I'd write

Code: [Select]

WaitUntil(boolean);.

[Drake]

Yeah, no can do. Technically you can use scope to accomplish this in some sense, i.e.

Code: [Select]

task a(){
  let bool = false;
  function WaitUntilFlag(){
    while(!bool){ yield; }
  }

  task b(){
    // stuff
    bool = true;
  }
  b();

  WaitUntilFlag();

  // finish
}
But that isn't quite the same.