Blargel's Danmakufu Corner (Ikareimu Revival? and Contest)

[Blargel]

Arrrrrrrrrgh, stop making my head hurt! :colonveeplusalpha:

Your code is still incorrect I believe. Just because the two points of one line segment are on opposite ends of the other line segments doesn't mean they intersect because they're line segments. For example, a situation like this:

                      |
-----------           |
                      |
                      |
                      |
                      |

The two points on the vertical line are above and below the horizontal line, but the segments obviously don't intersect. Of course, maybe I didn't read your code carefully enough since I only read the comments and glimpsed the code a little (it's hard to read on the forum and I was too lazy to copy it to Notepad++) and maybe you did catch that. Your Collision_Box_Laser is similar to how I was planning to do the collision detection eventually, but there are a lot of other issues I need to work out later as well. Anyways, like I said on IRC, I already generally know how I'm going to solve this problem and the line to line collision detection is probably gonna be handled differently than how you have it. More math, less if-else construction.

[Kylesky]

Your code is still incorrect I believe.

yeah... I noticed that after I left... :V

here's a very much simplified version of that block of code

Code: [Select]

function PointSideFromLine(x1, y1, x2, y2, x3, y3)
{
    let lineangle=atan2(y3-y2, x3-x2);
    let slope=(y3-y2)/(x3-x2);
    let x4=(y2-y1)/slope+x1; //hope this makes sense... tried morphing y=mx+b into x=(y-b)/m
    if(x1<=x4 || x3-x2==0){return "LEFT";}else{return "RIGHT";}
}

function Collision_Segment_Line(x1, y1, x2, y2, x3, y3, x4, y4)
{
    if(PointSideFromLine(x1, y1, x3, y3, x4, y4)=="LEFT"){
        if(PointSideFromLine(x2, y2, x3, y3, x4, y4)=="RIGHT"){return true;}else{return false;}
    }else{
        if(PointSideFromLine(x2, y2, x3, y3, x4, y4)=="LEFT"){return true;}else{return false;}
    }
}

function Collision_Segment_Segment(x1, y1, x2, y2, x3, y3, x4, y4) //either do this, or find a way to make a GetPOI function (point of intersection) and use Collision_Line_Circle to check if it's on both segments... these 2 things both make sure that it checks segment to segment and not segment to line
{
    if(Collision_Segment_Line(x1, y1, x2, y2, x3, y3, x4, y4)==true && Collision_Segment_Line(x3, y3, x4, y4, x1, y1, x2, y2)==true)
    {
    return true;
    }else{
    return false;
    }
}

function Collision_Box_Line(x1, y1, x2, y2, x3, y3, x4, y4, x5, y5, x6, y6)
{
    if(Collision_Segment_Segment(x1, y1, x3, y3, x5, y5, x6, y6)==true || Collision_Segment_Segment(x2, y2, x4, y4, x5, y5, x6, y6)==true)
    {
    return true;
    }else{
    return false;
    }
}

function Collision_Box_Laser(centx, centy, x1, y1, x2, y2, x3, y3, x4, y4, x5, y5, x6, y6, width)
{
    if(PointSideFromLine(centx, centy, x5, y5, x6, y6)=="LEFT"){
        if(Collision_Box_Line(x1, y1, x2, y2, x3, y3, x4, y4, x5-width/2, y5-width/2, x6-width/2, y6-width/2)==true){return true;}else{return false;}
    }else{
        if(Collision_Box_Line(x1, y1, x2, y2, x3, y3, x4, y4, x5+width/2, y5+width/2, x6+width/2, y6+width/2)==true){return true;}else{return false;}
    }
}

most comments are gone :V (by the way... this also works for curvy lasers :V the only problem is measuring the length to cut the laser, and I doubt if you're gonna even bother doing that)

Also, the reason why I'm trying to perfect this function/s is cause I'm also gonna use them... (in the future)

[Blargel]

Ikareimu Fucking What Contest
My goal for this is really just to get exposure so I might be able to get a spriter and/or composer to help me with this and future games.