OpenDiablo2/d2common/math.go

package d2common

import "math"

func MinInt(a, b int) int {
	if a < b {
		return a
	}
	return b
}

func MaxInt(a, b int) int {
	if a > b {
		return a
	}
	return b
}

// Min returns the lower of two values
func Min(a, b uint32) uint32 {
	if a < b {
		return a
	}
	return b
}

// Max returns the higher of two values
func Max(a, b uint32) uint32 {
	if a > b {
		return a
	}
	return b
}

// MaxInt32 returns the higher of two values
func MaxInt32(a, b int32) int32 {
	if a > b {
		return a
	}
	return b
}

func AbsInt32(a int32) int32 {
	if a < 0 {
		return -a
	}
	return a
}

// MinInt32 returns the higher of two values
func MinInt32(a, b int32) int32 {
	if a < b {
		return a
	}
	return b
}

// BytesToInt32 converts 4 bytes to int32

// IsoToScreen converts isometric coordinates to screenspace coordinates

// ScreenToIso converts screenspace coordinates to isometric coordinates

// GetAngleBetween returns the angle between two points. 0deg is facing to the right.
func GetAngleBetween(p1X, p1Y, p2X, p2Y float64) int {
	deltaY := p1Y - p2Y
	deltaX := p2X - p1X

	result := math.Atan2(deltaY, deltaX) * (180 / math.Pi)
	iResult := int(result)
	for iResult < 0 {
		iResult += 360
	}
	for iResult >= 360 {
		iResult -= 360
	}
	return iResult
}

// GetRadiansBetween returns the radians between two points. 0rad is facing to the right.
func GetRadiansBetween(p1X, p1Y, p2X, p2Y float64) float64 {
	deltaY := p2Y - p1Y
	deltaX := p2X - p1X

	return math.Atan2(deltaY, deltaX)
}

// AlmostEqual returns true if two values are within threshold from each other
func AlmostEqual(a, b, threshold float64) bool {
	return math.Abs(a-b) <= threshold
}