Checking for polygon wall

[iBeatz]

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?

[fowlplay4]

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.

[WhiteDragon]

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.

[fowlplay4]

Originally Posted by WhiteDragon

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!