Move to Point > 2D

package main

import (
	"math"

	rl "github.com/gen2brain/raylib-go/raylib"
)

/* MORE RAYLIB GO EXAMPLES ARE AVAILABLE HERE:

https://github.com/unklnik/raylib-go-more-examples

*/

var (
	scrW, scrH              int          // SCREEN WIDTH & HEIGHT
	player, cnt, clickPoint rl.Vector2   //PLAYER, SCREEN CENTER, MOUSE CLICK VECTOR2
	nextPosition            rl.Rectangle //COLLISION RECTANGLE FOR MOVE TO POINT
	playerSpeed             = float32(8) //MAX SPEED PLAYER MOVES
	playerDirX, playerDirY  float32      //X & Y DIRECTION SPEEDS
)

func main() {

	rl.InitWindow(0, 0, "move to point - raylib go - https://github.com/unklnik/raylib-go-more-examples")
	scrW, scrH = rl.GetScreenWidth(), rl.GetScreenHeight() // GET SCREEN SIZES
	rl.SetWindowState(rl.FlagBorderlessWindowedMode)       //SET WINDOW STATE
	rl.SetWindowSize(scrW, scrH)                           // SET WINDOW SIZE

	//rl.ToggleFullscreen() // UNCOMMENT IF YOU HAVE DISPLAY ISSUES WITH OVERLAPPING WINDOW BARS

	camera := rl.Camera2D{} // DEFINES THE CAMERA
	camera.Zoom = 1.0       //SETS CAMERA ZOOM

	cnt = rl.NewVector2(float32(scrW/2), float32(scrH/2)) //SCREEN CENTER
	player, clickPoint = cnt, cnt                         //SET INITIAL PLAYER & CLICKPOINT POSITIONS

	rl.SetTargetFPS(60) // NUMBER OF FRAMES DRAWN IN A SECOND

	for !rl.WindowShouldClose() {

		//IF LEFT MOUSE CLICKED CREATE COLLISION RECTANGLE FROM CLICK POINT
		if rl.IsMouseButtonPressed(rl.MouseButtonLeft) {
			size := float32(16)
			clickPoint = rl.GetMousePosition()
			nextPosition = rl.NewRectangle(clickPoint.X-size/2, clickPoint.Y-size/2, size, size)
		}

		//IF CLICK POINT IS NOT CENTER & PLAYER IS NOT COLLIDING WITH NEXT POSITION RECTANGLE MOVE
		if clickPoint != cnt && !rl.CheckCollisionPointRec(player, nextPosition) {

			player.X += playerDirX //MOVE X DIRECTION
			player.Y += playerDirY //MOVE Y DIRECTION

			diffX := absdiff(player.X, clickPoint.X) //ABSOLUTE DISTANCE BETWEEN X POINTS
			diffY := absdiff(player.Y, clickPoint.Y) //ABSOLUTE DISTANCE BETWEEN Y POINTS

			if diffX > diffY { //IF X DISTANCE IS LARGER THAN Y DISTANCE
				//DIRECTION X SPEED = PLAYER MAX SPEED
				playerDirX = playerSpeed
				//DIRECTION Y SPEED = Y DISTANCE DIVIDED BY (X DISTANCE DIVIDED BY MAX SPEED)
				playerDirY = diffY / (diffX / playerSpeed)
			} else {
				playerDirY = playerSpeed
				playerDirX = diffX / (diffY / playerSpeed)
			}

			//CHANGES TO NEGATIVE IF CLICKPOINT X IS LEFT OF PLAYER
			if clickPoint.X < player.X {
				playerDirX = -playerDirX
			}
			//CHANGES TO NEGATIVE IF CLICKPOINT Y IS ABOVE PLAYER
			if clickPoint.Y < player.Y {
				playerDirY = -playerDirY
			}

		}

		rl.BeginDrawing()

		rl.ClearBackground(rl.Black)

		rl.BeginMode2D(camera)

		if clickPoint != cnt {
			rl.DrawRectangleLinesEx(nextPosition, 2, rl.Magenta) //DRAW COLLISION RECTANGLE
		}

		rl.DrawCircleV(player, 32, rl.Fade(rl.Green, 0.4)) //DRAW PLAYER CIRCLE

		rl.DrawText("LEFT MOUSE CLICK ON THE SCREEN TO MOVE TO POINT", 10, 10, 20, rl.White)

		rl.EndMode2D()

		rl.EndDrawing()
	}

	rl.CloseWindow()
}

// FUNCTION TO CALCULATE ABSOLUTE DIFFERENCE BETWEEN TWO VALUES FOR NEGATIVE VALUES
func absdiff(num1, num2 float32) float32 {
	num := float32(0)
	if num1 == num2 {
		num = 0
	} else {
		if num1 <= 0 && num2 <= 0 {
			num1 = getabs(num1)
			num2 = getabs(num2)
			if num1 > num2 {
				num = num1 - num2
			} else {
				num = num2 - num1
			}
		} else if num1 <= 0 && num2 >= 0 {
			num = num2 + getabs(num1)
		} else if num2 <= 0 && num1 >= 0 {
			num = num1 + getabs(num2)
		} else if num2 >= 0 && num1 >= 0 {
			if num1 > num2 {
				num = num1 - num2
			} else {
				num = num2 - num1
			}
		}
	}
	return num
}

// FUNCTION TO CALCULATE ABSOLUTE VALUE FOR NEGATIVE VALUES
func getabs(value float32) float32 {
	value2 := float64(value)
	value = float32(math.Abs(value2))
	return value
}