init

internal/engine/transform.go

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+package engine
+
+import "math"
+
+// Matrix represents a 2D transformation matrix in the form:
+// | A C E |
+// | B D F |
+// | 0 0 1 |
+type Matrix struct {
+	A, B, C, D, E, F float64
+}
+
+// NewIdentityMatrix creates an identity matrix
+func NewIdentityMatrix() Matrix {
+	return Matrix{
+		A: 1, B: 0, C: 0,
+		D: 1, E: 0, F: 0,
+	}
+}
+
+// Translate creates a translation matrix
+func Translate(x, y float64) Matrix {
+	return Matrix{
+		A: 1, B: 0, C: 0,
+		D: 1, E: x, F: y,
+	}
+}
+
+// Rotate creates a rotation matrix for the given angle in radians
+func Rotate(angle float64) Matrix {
+	cos := math.Cos(angle)
+	sin := math.Sin(angle)
+	return Matrix{
+		A: cos, B: sin, C: -sin,
+		D: cos, E: 0, F: 0,
+	}
+}
+
+// Scale creates a scaling matrix
+func Scale(sx, sy float64) Matrix {
+	return Matrix{
+		A: sx, B: 0, C: 0,
+		D: sy, E: 0, F: 0,
+	}
+}
+
+// Multiply multiplies two matrices
+func (m Matrix) Multiply(other Matrix) Matrix {
+	return Matrix{
+		A: m.A*other.A + m.C*other.B,
+		B: m.B*other.A + m.D*other.B,
+		C: m.A*other.C + m.C*other.D,
+		D: m.B*other.C + m.D*other.D,
+		E: m.A*other.E + m.C*other.F + m.E,
+		F: m.B*other.E + m.D*other.F + m.F,
+	}
+}
+
+// Transform represents a geometric transformation
+type Transform struct {
+	x, y, size float64
+	rotation   int // 0 = 0 rad, 1 = 0.5π rad, 2 = π rad, 3 = 1.5π rad
+}
+
+// NewTransform creates a new Transform
+func NewTransform(x, y, size float64, rotation int) Transform {
+	return Transform{
+		x:        x,
+		y:        y,
+		size:     size,
+		rotation: rotation,
+	}
+}
+
+// TransformIconPoint transforms a point based on the translation and rotation specification
+// w and h represent the width and height of the transformed rectangle for proper corner positioning
+func (t Transform) TransformIconPoint(x, y, w, h float64) Point {
+	right := t.x + t.size
+	bottom := t.y + t.size
+	rotation := t.rotation % 4
+
+	switch rotation {
+	case 1: // 90 degrees
+		return Point{X: right - y - h, Y: t.y + x}
+	case 2: // 180 degrees
+		return Point{X: right - x - w, Y: bottom - y - h}
+	case 3: // 270 degrees
+		return Point{X: t.x + y, Y: bottom - x - w}
+	default: // 0 degrees
+		return Point{X: t.x + x, Y: t.y + y}
+	}
+}
+
+// ApplyTransform applies a transformation matrix to a point
+func ApplyTransform(point Point, matrix Matrix) Point {
+	return Point{
+		X: matrix.A*point.X + matrix.C*point.Y + matrix.E,
+		Y: matrix.B*point.X + matrix.D*point.Y + matrix.F,
+	}
+}
+
+// NoTransform represents an identity transformation
+var NoTransform = NewTransform(0, 0, 0, 0)