Some trig, and packer dimensions are screwed up.

Some trig, and packer dimensions are screwed up. - Printable Version

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+--- Thread: Some trig, and packer dimensions are screwed up. (/showthread.php?tid=423839)

Some trig, and packer dimensions are screwed up. - Misiur - 19.03.2013

There is basic idea. Let's create SetVehiclePos which works with front bumper position, not center of vehicle (front wheels aren't good either). So I've begun

pawn Код:

SetVehicleFrontBumperPos(vid, Float:x, Float:y, Float:z, Float:angle) {
    new 
        Float:sin = floatsin(-angle, degrees), 
        Float:cos = floatcos(angle, degrees),
        model = GetVehicleModel(vid),
        Float:fD[3];
    
    GetVehicleModelInfo(model, VEHICLE_MODEL_INFO_SIZE, fD[0], fD[1], fD[2]);
    
    //Let's get half of vehicle length
    //x /= 2 won't work for floats
    fD[0] = fD[0] / 2;
    fD[1] = fD[1] / 2;
    x -= (fD[0] * cos) - (fD[1] * sin);
    y -= (fD[1] * cos) - (fD[0] * sin);
    
    SetVehicleZAngle(vid, angle);
    return SetVehiclePos(vid, x, y, z);
}

I'm testing with angle = 175, so the x coords are completely screwed up, but y work quite nicely. After commenting the x axis I got something like http://imgur.com/a/ZWTkv - damnit, packer is screwed up. It's longer in the back than in the front. Any idea how to fix this? (_not_ using front wheel position, as it won't be the same)

Re: Some trig, and packer dimensions are screwed up. - Misiur - 19.03.2013

I hope that's only exception. Now - I'd like the function to work properly for any angle provided - I had trigonometry in school, and I know how to use it, but somehow GTA Units are diffrent from stuff I know.

The light blue line is fD[1] / 2 - half of the vehicle length

pawn Код:

GetVehicleModelInfo(model, VEHICLE_MODEL_INFO_SIZE, fD[0], fD[1], fD[2]);
    fD[0] = fD[0] / 2;
    fD[1] = fD[1] / 2 - (443 == model ? 4.2 : 0.0);
    x -= fD[1] * sin;
    y -= fD[1] * cos;

Should I change anything in here?

Re: Some trig, and packer dimensions are screwed up. - Stylock - 19.03.2013

The second code should work, but you need to use negative angle in both floatsin and floatcos.

Re: Some trig, and packer dimensions are screwed up. - Misiur - 19.03.2013

I tried following https://sampforum.blast.hk/showthread.php?tid=416752 thread, but I don't know which theory is right in the end. I assumed that version with swapped Y angle (0 <=> 270) is correct, but I still don't get all those angles swapping ways (yeah, I'm one of those guys who copy all equations without looking at them)

Re: Some trig, and packer dimensions are screwed up. - Stylock - 19.03.2013

I don't know anything about swapped Y angles. This is how GTA SA rotations are:

Код:

        north (0)
           |
(90) west-   -east (270)
           |
        south (180)

https://sampwiki.blast.hk/wiki/SetPlayerFacingAngle

Re: Some trig, and packer dimensions are screwed up. - Misiur - 19.03.2013

I meant to say Y axis, sorry. And I promise I won't eat shredded wheat. Well, swapping cosine as well makes sense. Thanks

#e:
@****** I meant that I never paid attention to functions using trigonometry, sheesh