package Helper

	import Terrain
	import Filter
	
	public int array pow2
	
	constant rot45 = 0.707106
	constant nrot45 = -0.707106
	
	init
		for int i = 0 to 31
			pow2[i] = R2I(Pow(2, I2R(i)))
	
	public function getPathingNormal(vec2 pos) returns vec2
		int numberOfTests = 15
		real radius = 64
		vec2 addedVecs = vec2(0, 0)
		for int i = 1 to numberOfTests
			vec2 direction = vec2(0,0).polarOffset((i*2*bj_PI/numberOfTests).asAngleRadians(), radius)
			vec2 testPoint = pos + direction
			if IsTerrainPathable(testPoint.x, testPoint.y, PATHING_TYPE_WALKABILITY)
				addedVecs += direction
		if addedVecs.length() == 0.0
			print(pos.toString())
		return addedVecs.setLength(1.) * (-1.)
		
	public function getBounceVec(vec2 vel, vec2 nor) returns vec2
		if vel.dot(nor) < 0
			vec2 u = (vel.dot(nor)) * nor
			return (vel - u) - u
		return vel
		
	public function getLastPathablePoint(vec2 pos1, vec2 pos2) returns vec2
		vec2 p1 = pos1
		vec2 p2 = pos2
		for int i = 1 to 8
			vec2 h = p1 - p2
			vec2 toTest = p2 + vec2(h.x / 2, h.y / 2)
			if not IsTerrainPathable(toTest.x, toTest.y, PATHING_TYPE_WALKABILITY)
				p1 = toTest
			else
				p2 = toTest
		return p1
		
	public function checkForPathing(vec2 pos, vec2 vel, real radius) returns vec2
		vec2 test = vel.setLength(radius)
		if IsTerrainPathable(pos.x + test.x, pos.y + test.y, PATHING_TYPE_WALKABILITY)
			return vec2(pos.x + test.x, pos.y + test.y)
		if IsTerrainPathable(pos.x - test.x, pos.y - test.y, PATHING_TYPE_WALKABILITY)
			return vec2(pos.x - test.x, pos.y - test.y)
		if IsTerrainPathable(pos.x - test.y, pos.y + test.x, PATHING_TYPE_WALKABILITY)
			return vec2(pos.x - test.y, pos.y + test.x)
		if IsTerrainPathable(pos.x + test.y, pos.y + test.x, PATHING_TYPE_WALKABILITY)
			return vec2(pos.x + test.y, pos.y + test.x)
		test *= rot45
		if IsTerrainPathable(pos.x + (test.x - test.y), pos.y + (test.x + test.y), PATHING_TYPE_WALKABILITY)
			return vec2(pos.x + (test.x - test.y), pos.y + (test.x + test.y))
		if IsTerrainPathable(pos.x - (test.x - test.y), pos.y - (test.x + test.y), PATHING_TYPE_WALKABILITY)
			return vec2(pos.x - (test.x - test.y), pos.y - (test.x + test.y))
		if IsTerrainPathable(pos.x - (test.x + test.y), pos.y + (test.x - test.y), PATHING_TYPE_WALKABILITY)
			return vec2(pos.x - (test.x + test.y), pos.y + (test.x - test.y))
		if IsTerrainPathable(pos.x + (test.x + test.y), pos.y - (test.x - test.y), PATHING_TYPE_WALKABILITY)
			return vec2(pos.x + (test.x + test.y), pos.y - (test.x - test.y))
		return vec2(0,0)
			
			
	/**	Same as dot product */
	public function vec2.op_mult(vec2 v) returns real
		return this.x * v.x + this.y + v.y
				
	public function int.asFourchar() returns string
		string charMap = ".................................!.#$%&'()*+,-./0123456789:;<=>.@ABCDEFGHIJKLMNOPQRSTUVWXYZ[.]^_`abcdefghijklmnopqrstuvwxyz{|}~................................................................................................................................."
		string result = ""
		int remainingValue = this
		int charValue
		for int byteno = 0 to 3
			charValue = ModuloInteger(remainingValue, 256)
			remainingValue = remainingValue div 256
			result = SubString(charMap, charValue, charValue + 1) + result
		return result
		

endpackage