Graal Forums - Checking for polygon wall

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Checking for polygon wall

I've been having an issue trying to do this for a while now, and I thought I'd ask here for a hand.
Okay, so I have these 7 variables:

PHP Code:


		
			
 this.game_height_b = (GraalControl.height/2)+150; 

 this.char_top_x = (GraalControl.width/2);

 this.char_top_y = this.game_height_b - 12;

 this.char_left_x = (GraalControl.width/2)-12;

 this.char_left_y = this.game_height_b - 2;

 this.char_right_x = (GraalControl.width/2)+12;

 this.char_right_y = this.game_height_b - 2;

These control a moveable character, all except this.game_height_b.
Now, I also have a wall of small polygons all down the left side of my screen, each polygon with 4 coordinates, so it's basically a small wall of rectangles of different lengths.
What I would like to do is take each this.char x variable and try to see if it is less than the innermost polygon's x coordinate on each char's y coordinate.

(NOTE: These polygons are continually moving down the left side of my screen, so I have little way of knowing the index of each polygon as it is always changing.)
Any suggestions?

You could do something like...

PHP Code:


		
			
if (this.char_x in |this.wall_x, this.wall_x + this.wall_width| &&

    this.char_y in |this.wall_y, this.wall_y + this.wall_height|) {



    // In Wall



}

You'd benefit more from searching 'polygon collision' and seeing how it's implemented in other programming/scripting languages and then port/adapt it to GS2.

I have some geometry stuff written which I could release, like

checking if a point is in a triangle;
checking if a point is in a polygon;
forming a convex polygon around a set of points (using the gift wrap algorithm); and
forming a bounding rectangle around a polygon.

However, I don't have a polygon-polygon intersection checker, though I could probably write one if multiple people think it'd be useful.

Quote:

Originally Posted by WhiteDragon (Post 1659151)

I have some geometry stuff written which I could release, like

checking if a point is in a triangle;
checking if a point is in a polygon;
forming a convex polygon around a set of points (using the gift wrap algorithm); and
forming a bounding rectangle around a polygon.

You should!