func NewText(x0, y0 int, text, color string) *Text {
	return &Text{x0, y0, text, color}
}
NewText returns a new text annotation at (x0, y0) with the given color.
package canvas
import (
	"reflect"
	"strings"
	"github.com/fogleman/gg"
)
type Point struct {
	x, y int
}
func NewPoint(x, y int) *Point {
	return &Point{x, y}
}
type Line struct {
	x0, y0 int
	start  string
	x1, y1 int
	end    string
	color  string
}
func NewLine(x0, y0 int, start string, x1, y1 int, end string, color string) *Line {
	return &Line{x0, y0, start, x1, y1, end, color}
}
type Text struct {
	x0, y0 int
	text   string
	color  string
}