it works :)

chatgpt.go

@@ -0,0 +1,147 @@
+package main
+
+import (
+	"image"
+	"image/color"
+	"image/draw"
+	"math"
+
+	"git.niplace.ru/XoxJlopeZi4BB/dev/fb"
+)
+
+var Width, Height = fb.Resolution()
+const (
+	cubeSize     = 50
+	Zoom         = 1000.0
+	FOV          = 350
+	frameCount   = 120
+	rotationStep = math.Pi / 60
+)
+
+type Point3D struct {
+	X, Y, Z float64
+}
+
+type Point2D struct {
+	X, Y int
+}
+
+func rotateX(p Point3D, angle float64) Point3D {
+	cosA := math.Cos(angle)
+	sinA := math.Sin(angle)
+	return Point3D{
+		X: p.X,
+		Y: p.Y*cosA - p.Z*sinA,
+		Z: p.Y*sinA + p.Z*cosA,
+	}
+}
+
+func rotateY(p Point3D, angle float64) Point3D {
+	cosA := math.Cos(angle)
+	sinA := math.Sin(angle)
+	return Point3D{
+		X: p.X*cosA + p.Z*sinA,
+		Y: p.Y,
+		Z: -p.X*sinA + p.Z*cosA,
+	}
+}
+
+func project(p Point3D) Point2D {
+	scale := Zoom / (p.Z + FOV)
+	return Point2D{
+		X: int(p.X*scale + float64(Width)/2),
+		Y: int(p.Y*scale + float64(Height)/2),
+	}
+}
+
+func drawLine(img *image.Paletted, p1, p2 Point2D, col color.Color) {
+	dx := abs(p2.X - p1.X)
+	dy := abs(p2.Y - p1.Y)
+	sx := -1
+	if p1.X < p2.X {
+		sx = 1
+	}
+	sy := -1
+	if p1.Y < p2.Y {
+		sy = 1
+	}
+	err := dx - dy
+
+	for {
+		img.Set(p1.X, p1.Y, col)
+		if p1.X == p2.X && p1.Y == p2.Y {
+			break
+		}
+		e2 := 2 * err
+		if e2 > -dy {
+			err -= dy
+			p1.X += sx
+		}
+		if e2 < dx {
+			err += dx
+			p1.Y += sy
+		}
+	}
+}
+
+func abs(x int) int {
+	if x < 0 {
+		return -x
+	}
+	return x
+}
+
+/*
+func Map[S, T any](v S, f func(T) T) S {
+}
+*/
+
+func main() {
+	// Define the vertices of the cube
+	vertices := []Point3D{
+		{-cubeSize, -cubeSize, -cubeSize},
+		{cubeSize, -cubeSize, -cubeSize},
+		{cubeSize, cubeSize, -cubeSize},
+		{-cubeSize, cubeSize, -cubeSize},
+		{-cubeSize, -cubeSize, cubeSize},
+		{cubeSize, -cubeSize, cubeSize},
+		{cubeSize, cubeSize, cubeSize},
+		{-cubeSize, cubeSize, cubeSize},
+	}
+
+	// Define the edges of the cube
+	edges := [][2]int{
+		{0, 1}, {1, 2}, {2, 3}, {3, 0},
+		{4, 5}, {5, 6}, {6, 7}, {7, 4},
+		{0, 4}, {1, 5}, {2, 6}, {3, 7},
+	}
+
+	// Palette for the GIF
+	palette := []color.Color{color.Black, color.White}
+
+	// Generate frames
+	for i := 0; i < frameCount; i++ {
+		angle := float64(i) * rotationStep
+		img := image.NewPaletted(image.Rect(0, 0, Width, Height), palette)
+		draw.Draw(img, img.Bounds(), &image.Uniform{color.Black}, image.Point{}, draw.Src)
+
+		// Rotate and project vertices
+		projVertices := make([]Point2D, len(vertices))
+		for j, v := range vertices {
+			rotated := rotateY(rotateX(v, angle), angle)
+			projVertices[j] = project(rotated)
+		}
+
+		// Draw edges
+		for _, edge := range edges {
+			p1 := projVertices[edge[0]]
+			p2 := projVertices[edge[1]]
+			drawLine(img, p1, p2, color.White)
+		}
+
+		err := fb.Draw(img)
+		if err != nil {
+			panic(err)
+		}
+	}
+}

go.mod

@@ -0,0 +1,5 @@
+module git.niplace.ru/XoxJlopeZi4BB/cube
+
+go 1.23.4
+
+require git.niplace.ru/XoxJlopeZi4BB/dev v0.0.0-20250126033838-b2021445b668

go.sum

@@ -0,0 +1,4 @@
+git.niplace.ru/XoxJlopeZi4BB/dev v0.0.0-20250126033410-5c05476970ae h1:anDr2+KuivGQ2TnZogDlGxWFU6FTeZIkqcRin/drkjQ=
+git.niplace.ru/XoxJlopeZi4BB/dev v0.0.0-20250126033410-5c05476970ae/go.mod h1:7YjlidjZZr0+dNjfgYgy5hPfdE3pV1bBT5UcNvz5LjY=
+git.niplace.ru/XoxJlopeZi4BB/dev v0.0.0-20250126033838-b2021445b668 h1:Kh9BL+0ia8Lo+lvIsZ3a5pYqzq9ZYwk0+gho7L7BASI=
+git.niplace.ru/XoxJlopeZi4BB/dev v0.0.0-20250126033838-b2021445b668/go.mod h1:7YjlidjZZr0+dNjfgYgy5hPfdE3pV1bBT5UcNvz5LjY=

readme

@@ -0,0 +1,2 @@
+example of working with /dev/fb0 device
+cube animation is done by chatgpt