sumi/main.go

package main

import (
	"fmt"
	"log"
	"math"
	"os"
	"time"

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

func clamp01(v float64) float64 {
	if v < 0 {
		return 0
	}
	if v > 1 {
		return 1
	}
	return v
}

func GrayCurve(v, k float64) rl.Color {
	v = math.Pow(clamp01(v), k) // k < 1 boosts highlights, k > 1 boosts shadows
	c := uint8(v * 255)
	return rl.Color{R: c, G: c, B: c, A: 255}
}

const (
	screenWidth  = 1400
	screenHeight = 700
	displayScale = 2
	snapshotsDir = "snapshots"
)

func main() {

	os.MkdirAll(snapshotsDir, 0755)

	log := log.New(os.Stdout, "", log.Ldate|log.Ltime|log.Lshortfile)

	storage, err := NewStorage(snapshotsDir)
	if err != nil {
		log.Printf("Error loading storage: %v\n", err)
		os.Exit(1)
	}

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

	log.Printf("screen=%dx%d render=%dx%d",
		rl.GetScreenWidth(), rl.GetScreenHeight(),
		rl.GetRenderWidth(), rl.GetRenderHeight(),
	)


	w := rl.GetRenderWidth()
	h := rl.GetRenderHeight()

	angles := make([]float32, 1000)
	noise := opensimplex.NewNormalized(0)
	r := 0.75
	dtheta := 360.0/float64(len(angles))
	for i := range len(angles) {
		rad := float64(i) * dtheta * math.Pi / 180.0
		x := r * math.Cos(rad)
		y := r * math.Sin(rad)
		angles[i] = float32(noise.Eval2(x, y) * 360.0)
	}

	sketches := []Sketch{
		&SierpinskiArrow{},
		&Worm{
			position: rl.Vector2 { X: 50, Y: 50 },
			angles: angles,
			angleIndex: 0,
			stepSize: 2,
		},
	}

	var camera = rl.Camera2D{
		Target:   rl.Vector2{X: 0, Y: 0},
		Offset:   rl.Vector2{X: float32(w) / 2, Y: float32(h) / 2},
		Rotation: 0,
		Zoom:     1.0,
	}

	rl.SetTargetFPS(60)

	t0 := time.Now()

	ports := MakePorts()
	ports["sierpinskiArrowLength"] = Const{
		V: 1200,
	}

	ports["sierpinskiArrowDepth"] = Const{
		V: 7,
	}

	ports["sierpinskiArrowAngle"] = Sine{
		Amp:  120,
		Bias: 100,
		Freq: 0.1,
	}

	for !rl.WindowShouldClose() {
		updateCamera(&camera)

		// begin drawing
		rl.BeginDrawing()
		rl.ClearBackground(rl.RayWhite)
		rl.BeginMode2D(camera)

		t := time.Since(t0).Seconds()

		// set up RenderCtx
		renderCtx := &RenderCtx{
			Width:  int32(w),
			Height: int32(h),
			Time:   t,
			Ports:  ports.Eval(t),
		}

		/**
		MAIN DRAWING
		 **/

		for _, s := range sketches {
			rl.PushMatrix()
			s.Draw(renderCtx)
			rl.PopMatrix()
		}

		if rl.IsKeyDown(rl.KeySpace) {
			if _, err := storage.Save(); err != nil {
				log.Printf("Error saving snapshot: %v\n", err)
			}
		}

		rl.EndMode2D()

		rl.DrawLine(10, 10, int32(w-10), int32(h-10), rl.Black)

		// HUD
		rl.DrawText("Mouse right button drag to move, mouse wheel to zoom", 10, 10, 20, rl.Black)
		rl.EndDrawing()
	}

	rl.CloseWindow()
}

func updateCamera(camera *rl.Camera2D) {
	// Get the world point that is under the mouse
	mouseVec2 := rl.GetMousePosition()

	if rl.IsMouseButtonDown(rl.MouseRightButton) {
		// get mouse delta from last frame
		delta := rl.GetMouseDelta()
		// compute the amount to move scaled by the camera zoom
		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 {
		mouseWorldPos := rl.GetScreenToWorld2D(mouseVec2, *camera)

		// Set the offset to where the mouse is
		camera.Offset = mouseVec2

		// 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
		}
	}
}

type Worm struct {
	position rl.Vector2
	angles []float32
	angleIndex int
	stepSize int
}

func (w *Worm) Draw(ctx *RenderCtx) {
	rl.PushMatrix()
	rl.Translatef(w.position.X, w.position.Y, 0)
	lastAngle := float32(0.0)
	for i := range w.angles {
		ii := (i + w.angleIndex) % len(w.angles)
		angle := w.angles[ii]
		rl.Rotatef(angle - lastAngle, 0, 0, 1)
		rl.DrawLine(0, 0, int32(w.stepSize), 0, rl.Black)
		rl.Translatef(float32(w.stepSize), 0, 0)
		lastAngle = angle
	}
	rl.PopMatrix()
	w.angleIndex = (w.angleIndex + 1) % len(w.angles)
}

type SierpinskiArrow struct{}

func (s *SierpinskiArrow) Draw(ctx *RenderCtx) {
	sierpinskiArrow(ctx, int(ctx.Ports["sierpinskiArrowDepth"]), ctx.Ports["sierpinskiArrowLength"])
}

func sierpinskiArrow(ctx *RenderCtx, order int, length float64) {
	if order == 0 {
		curve(ctx, order, length, ctx.Ports["sierpinskiArrowAngle"])
	} else {
		rl.Rotatef(float32(ctx.Ports["sierpinskiArrowAngle"]), 0, 0, 1)
		curve(ctx, order, length, -ctx.Ports["sierpinskiArrowAngle"])
	}
}

func curve(ctx *RenderCtx, order int, length float64, angle float64) {
	if order == 0 {
		len := int32(length)
		rl.DrawLine(0, 0, len, 0, rl.Black)
		rl.Translatef(float32(length), 0, 0)
	} else {
		curve(ctx, order-1, length/2, -angle)
		rl.Rotatef(float32(angle), 0, 0, 1)
		curve(ctx, order-1, length/2, angle)
		rl.Rotatef(float32(angle), 0, 0, 1)
		curve(ctx, order-1, length/2, -angle)
	}
}

func main2() {
	angles := make([]float32, 1000)
	noise := opensimplex.NewNormalized(0)
	for i := range len(angles) {
		angles[i] = float32(noise.Eval2(float64(i)*0.05, 0.00))*0.1 - 0.05
	}
	frameNum := 0
	for !rl.WindowShouldClose() {
		frameNum++
		// initial transform by halfway again through angle array
		angleIndex := (frameNum / 10) % len(angles)
		angle := angles[angleIndex]
		initAngle := angles[(angleIndex+len(angles)/2)%len(angles)]
		rl.Rotatef(2500*initAngle, 0, 0, 1)
		rl.Translatef(100*initAngle, 100*initAngle, 0)
		fmt.Printf("%.3f", angle)
		rl.EndMode2D()
	}
}