package main

import (
	"fmt"
	"github.com/gen2brain/raylib-go/raylib"
	"github.com/ojrac/opensimplex-go"
)

func main() {

	const (
		screenWidth  = 2200
		screenHeight = 1200
	)

	rl.InitWindow(screenWidth, screenHeight, "sumi sierpinski arrow")

	var camera rl.Camera2D
	camera.Zoom = 1.0

	rl.SetTargetFPS(60)

	angles := make([]float32, 1000)
	noise := opensimplex.NewNormalized(0)
	for i := range len(angles) {
		angles[i] = float32(noise.Eval2(float64(i)*0.0001, 0.00)) * 2 - 1
		fmt.Printf("angles[%d] = %.2f\n", i, angles[i])
	}

	frameNum := 0

	for !rl.WindowShouldClose() {

		frameNum++

		if rl.IsMouseButtonDown(rl.MouseRightButton) {
			delta := rl.GetMouseDelta()
			delta = rl.Vector2Scale(delta, -1.0/camera.Zoom)
			camera.Target = rl.Vector2Add(camera.Target, delta)
		}

		// Zoom based on mouse wheel
		wheel := rl.GetMouseWheelMove()
		if wheel != 0 {
			// Get the world point that is under the mouse
			mouseWorldPos := rl.GetScreenToWorld2D(rl.GetMousePosition(), camera)

			// Set the offset to where the mouse is
			camera.Offset = rl.GetMousePosition()

			// Set the target to match, so that the camera maps the world space point
			// under the cursor to the screen space point under the cursor at any zoom
			camera.Target = mouseWorldPos

			// Zoom increment
			const zoomIncrement float32 = 0.125

			camera.Zoom += (wheel * zoomIncrement)
			if camera.Zoom < zoomIncrement {
				camera.Zoom = zoomIncrement
			}
		}

		rl.BeginDrawing()
		rl.ClearBackground(rl.RayWhite)

		rl.BeginMode2D(camera)

		rl.PushMatrix()
		rl.Translatef(screenWidth/2, screenHeight/2, 0);

		// initial transform by halfway again through angle array

		angleIndex := frameNum%len(angles)
		angle := angles[angleIndex]

		initAngle := angles[(angleIndex + len(angles)/2)%len(angles)]
		rl.Rotatef(250*initAngle, 0, 0, 1)
		rl.Translatef(100*initAngle, 100*initAngle, 0)

		for range 1000 {
			rl.DrawLine(0, 0, 10, 0, rl.Black)
			rl.Translatef(10, 0, 0)
			rl.Rotatef(angle, 0, 0, 1)
			angleIndex++
			angleIndex = angleIndex%len(angles)
			angle += angles[angleIndex]
		}
		rl.PopMatrix()

		/*
		rl.PushMatrix()
		rl.Translatef(0, 25*50, 0)
		rl.Rotatef(90, 1, 0, 0)
		rl.DrawGrid(100, 50)
		rl.PopMatrix()
		*/

		rl.EndMode2D()

		rl.DrawText("Mouse right button drag to move, mouse wheel to zoom", 10, 10, 20, rl.White)

		rl.EndDrawing()
	}

	rl.CloseWindow()
}