Blocks rendered by Ebiten with gfx.

ebiten-gfx-blocks.go

package main

import (
	"github.com/hajimehoshi/ebiten"
	"github.com/peterhellberg/gfx"
)

const (
	title    = "Ebiten GFX Blocks"
	scale    = 4
	w, h     = 256, 128
	fw, fh   = float64(w), float64(h)
	fw2, fh2 = fw / 2, fh / 2
)

var (
	pix           = make([]uint8, w*h*4)
	scaler        = gfx.NewLinearScaler().Range(6, 0.5).Domain(0, fh)
	flipY         = gfx.V(1, -1)
	bounds        = gfx.R(0, 0, fw, fh)
	defaultPos    = gfx.V3(fw2, fh2, 0)
	defaultOrigin = bounds.Center().ScaledXY(flipY).Vec3(1)
	origin        = defaultOrigin
	pos           = defaultPos
	blocks        = createBlocks()
)

func createBlocks() (blocks gfx.Blocks) {
	for j := -6.0; j < 6; j++ {
		for i := -6.0; i < 6; i++ {
			aj, ai := gfx.MathAbs(j), gfx.MathAbs(i)

			p := pos.AddXYZ(-fw2+(i*10), -fh2+(j*10), 0)
			s := gfx.V3(3+aj, 3+ai, 3*ai+aj)
			c := gfx.BlockColors[int(ai+aj)%8]

			blocks.AddNewBlock(p, s, c)
			blocks.AddNewBlock(p.AddXYZ(0, 0, -7*(ai+aj)), s.AddXYZ(-3, -3, 0), gfx.BlockColorBlack)
		}
	}

	return blocks
}

func render() {
	dst := gfx.NewImage(w, h, gfx.BlockColorBlack.Dark)

	var drawCount int

	for i := len(blocks) - 1; i >= 0; i-- {
		b := blocks[i]

		if shape, top, left, _ := b.Polygons(origin); bounds.Overlaps(shape.Rect()) {
			drawCount += shape.Fill(dst, b.Color.Medium)
			drawCount += left.Fill(dst, b.Color.Dark)
			drawCount += top.Fill(dst, b.Color.Light)
		}

		drawCount++
	}

	gfx.Log("drawCount: %d", drawCount)

	pix = dst.Pix
}

func main() {
	render()

	ebiten.SetWindowDecorated(false)
	ebiten.Run(func(screen *ebiten.Image) error {
		if ebiten.IsKeyPressed(ebiten.KeyEscape) {
			return gfx.ErrDone
		}

		if ebiten.IsDrawingSkipped() {
			return nil
		}

		if updatePos(pos, origin) {
			render()
		}

		return screen.ReplacePixels(pix)
	}, w, h, scale, title)
}

func updatePos(oldPos, oldOrigin gfx.Vec3) bool {
	if ebiten.IsKeyPressed(ebiten.KeyH) {
		pos.Y += 0.6 // Diagonal up left
	}
	if ebiten.IsKeyPressed(ebiten.KeyL) {
		pos.X += 0.6 // Diagonal up right
	}
	if ebiten.IsKeyPressed(ebiten.KeyJ) {
		pos.X -= 0.6 // Diagonal down left
	}
	if ebiten.IsKeyPressed(ebiten.KeyK) {
		pos.Y -= 0.6 // Diagonal down right
	}
	if ebiten.IsKeyPressed(ebiten.KeyW) {
		pos.Z += 0.5 // Straight up
	}
	if ebiten.IsKeyPressed(ebiten.KeyS) {
		pos.Z -= 0.5 // Straight down
	}
	if ebiten.IsKeyPressed(ebiten.KeyA) {
		origin.X -= 1 // Straight left
	}
	if ebiten.IsKeyPressed(ebiten.KeyD) {
		origin.X += 1 // Straight right
	}
	if ebiten.IsKeyPressed(ebiten.KeyC) {
		pos, origin = defaultPos, defaultOrigin // Reset pos and origin
	}
	if ebiten.IsKeyPressed(ebiten.KeyX) && origin.Z > 0.5 {
		origin.Z -= 0.05 // Scale down
	}
	if ebiten.IsKeyPressed(ebiten.KeyZ) && origin.Z < 10 {
		origin.Z += 0.05 // Scale up
	}
	if ebiten.IsMouseButtonPressed(ebiten.MouseButtonLeft) {
		origin.X, origin.Y = gfx.IV(ebiten.CursorPosition()).ScaledXY(flipY).XY()
	}

	switch touches := ebiten.Touches(); len(touches) {
	case 1:
		origin.X, origin.Y = gfx.IV(touches[0].Position()).ScaledXY(flipY).XY()
	case 2:
		tv := gfx.IV(touches[1].Position())
		origin.Z = scaler.ScaleFloat64(tv.Y)
		origin.X, origin.Y = gfx.IV(touches[0].Position()).ScaledXY(flipY).XY()
	}

	return pos != oldPos || origin != oldOrigin
}