Golint contentstream draw (#426)

* Fix draw package golint notices.

pdf/contentstream/draw/bezier_curve.go

@@ -21,6 +21,7 @@ type CubicBezierCurve struct {
 	P3 Point // Final point.
 }
 
+// NewCubicBezierCurve returns a new cubic Bezier curve.
 func NewCubicBezierCurve(x0, y0, x1, y1, x2, y2, x3, y3 float64) CubicBezierCurve {
 	curve := CubicBezierCurve{}
 	curve.P0 = NewPoint(x0, y0)
@@ -45,6 +46,7 @@ func (curve CubicBezierCurve) AddOffsetXY(offX, offY float64) CubicBezierCurve {
 	return curve
 }
 
+// GetBounds returns the bounding box of the Bezier curve.
 func (curve CubicBezierCurve) GetBounds() model.PdfRectangle {
 	minX := curve.P0.X
 	maxX := curve.P0.X
@@ -84,21 +86,25 @@ func (curve CubicBezierCurve) GetBounds() model.PdfRectangle {
 	return bounds
 }
 
+// CubicBezierPath represents a collection of cubic Bezier curves.
 type CubicBezierPath struct {
 	Curves []CubicBezierCurve
 }
 
+// NewCubicBezierPath returns a new empty cubic Bezier path.
 func NewCubicBezierPath() CubicBezierPath {
 	bpath := CubicBezierPath{}
 	bpath.Curves = []CubicBezierCurve{}
 	return bpath
 }
 
+// AppendCurve appends the specified Bezier curve to the path.
 func (p CubicBezierPath) AppendCurve(curve CubicBezierCurve) CubicBezierPath {
 	p.Curves = append(p.Curves, curve)
 	return p
 }
 
+// Copy returns a clone of the Bezier path.
 func (p CubicBezierPath) Copy() CubicBezierPath {
 	bpathcopy := CubicBezierPath{}
 	bpathcopy.Curves = []CubicBezierCurve{}
@@ -108,6 +114,7 @@ func (p CubicBezierPath) Copy() CubicBezierPath {
 	return bpathcopy
 }
 
+// Offset shifts the Bezier path with the specified offsets.
 func (p CubicBezierPath) Offset(offX, offY float64) CubicBezierPath {
 	for i, c := range p.Curves {
 		p.Curves[i] = c.AddOffsetXY(offX, offY)
@@ -115,6 +122,7 @@ func (p CubicBezierPath) Offset(offX, offY float64) CubicBezierPath {
 	return p
 }
 
+// GetBoundingBox returns the bounding box of the Bezier path.
 func (p CubicBezierPath) GetBoundingBox() Rectangle {
 	bbox := Rectangle{}
 

pdf/contentstream/draw/path.go

@@ -10,15 +10,19 @@ type Path struct {
 	Points []Point
 }
 
+// NewPath returns a new empty path.
 func NewPath() Path {
 	return Path{}
 }
 
+// AppendPoint adds the specified point to the path.
 func (p Path) AppendPoint(point Point) Path {
 	p.Points = append(p.Points, point)
 	return p
 }
 
+// RemovePoint removes the point at the index specified by number from the
+// path. The index is 1-based.
 func (p Path) RemovePoint(number int) Path {
 	if number < 1 || number > len(p.Points) {
 		return p
@@ -29,10 +33,13 @@ func (p Path) RemovePoint(number int) Path {
 	return p
 }
 
+// Length returns the number of points in the path.
 func (p Path) Length() int {
 	return len(p.Points)
 }
 
+// GetPointNumber returns the path point at the index specified by number.
+// The index is 1-based.
 func (p Path) GetPointNumber(number int) Point {
 	if number < 1 || number > len(p.Points) {
 		return Point{}
@@ -40,6 +47,7 @@ func (p Path) GetPointNumber(number int) Point {
 	return p.Points[number-1]
 }
 
+// Copy returns a clone of the path.
 func (p Path) Copy() Path {
 	pathcopy := Path{}
 	pathcopy.Points = []Point{}
@@ -49,6 +57,7 @@ func (p Path) Copy() Path {
 	return pathcopy
 }
 
+// Offset shifts the path with the specified offsets.
 func (p Path) Offset(offX, offY float64) Path {
 	for i, pt := range p.Points {
 		p.Points[i] = pt.Add(offX, offY)
@@ -56,6 +65,7 @@ func (p Path) Offset(offX, offY float64) Path {
 	return p
 }
 
+// GetBoundingBox returns the bounding box of the path.
 func (p Path) GetBoundingBox() BoundingBox {
 	bbox := BoundingBox{}
 
@@ -93,6 +103,7 @@ func (p Path) GetBoundingBox() BoundingBox {
 	return bbox
 }
 
+// BoundingBox represents the smallest rectangular area that encapsulates an object.
 type BoundingBox struct {
 	X      float64
 	Y      float64

pdf/contentstream/draw/point.go

@@ -11,15 +11,18 @@ import (
 	"github.com/unidoc/unidoc/pdf/internal/transform"
 )
 
+// Point represents a two-dimensional point.
 type Point struct {
 	X float64
 	Y float64
 }
 
+// NewPoint returns a new point with the coordinates x, y.
 func NewPoint(x, y float64) Point {
 	return Point{X: x, Y: y}
 }
 
+// Add shifts the coordinates of the point with dx, dy and returns the result.
 func (p Point) Add(dx, dy float64) Point {
 	p.X += dx
 	p.Y += dy

pdf/contentstream/draw/shapes.go

@@ -171,6 +171,7 @@ func (rect Rectangle) Draw(gsName string) ([]byte, *pdf.PdfRectangle, error) {
 // The currently supported line ending styles are None, Arrow (ClosedArrow) and Butt.
 type LineEndingStyle int
 
+// Line ending styles.
 const (
 	LineEndingStyleNone  LineEndingStyle = 0
 	LineEndingStyleArrow LineEndingStyle = 1
@@ -180,6 +181,7 @@ const (
 // LineStyle refers to how the line will be created.
 type LineStyle int
 
+// Line styles.
 const (
 	LineStyleSolid  LineStyle = 0
 	LineStyleDashed LineStyle = 1

pdf/contentstream/draw/vector.go

@@ -7,11 +7,13 @@ package draw
 
 import "math"
 
+// Vector represents a two-dimensional vector.
 type Vector struct {
 	Dx float64
 	Dy float64
 }
 
+// NewVector returns a new vector with the direction specified by dx and dy.
 func NewVector(dx, dy float64) Vector {
 	v := Vector{}
 	v.Dx = dx
@@ -19,6 +21,8 @@ func NewVector(dx, dy float64) Vector {
 	return v
 }
 
+// NewVectorBetween returns a new vector with the direction specified by
+// the subtraction of point a from point b (b-a).
 func NewVectorBetween(a Point, b Point) Vector {
 	v := Vector{}
 	v.Dx = b.X - a.X
@@ -26,6 +30,8 @@ func NewVectorBetween(a Point, b Point) Vector {
 	return v
 }
 
+// NewVectorPolar returns a new vector calculated from the specified
+// magnitude and angle.
 func NewVectorPolar(length float64, theta float64) Vector {
 	v := Vector{}
 
@@ -34,12 +40,14 @@ func NewVectorPolar(length float64, theta float64) Vector {
 	return v
 }
 
+// Add adds the specified vector to the current one and returns the result.
 func (v Vector) Add(other Vector) Vector {
 	v.Dx += other.Dx
 	v.Dy += other.Dy
 	return v
 }
 
+// Rotate rotates the vector by the specified angle.
 func (v Vector) Rotate(phi float64) Vector {
 	mag := v.Magnitude()
 	angle := v.GetPolarAngle()
@@ -57,16 +65,19 @@ func (v Vector) Flip() Vector {
 	return v
 }
 
+// FlipY flips the sign of the Dy component of the vector.
 func (v Vector) FlipY() Vector {
 	v.Dy = -v.Dy
 	return v
 }
 
+// FlipX flips the sign of the Dx component of the vector.
 func (v Vector) FlipX() Vector {
 	v.Dx = -v.Dx
 	return v
 }
 
+// Scale scales the vector by the specified factor.
 func (v Vector) Scale(factor float64) Vector {
 	mag := v.Magnitude()
 	theta := v.GetPolarAngle()
@@ -76,10 +87,13 @@ func (v Vector) Scale(factor float64) Vector {
 	return v
 }
 
+// Magnitude returns the magnitude of the vector.
 func (v Vector) Magnitude() float64 {
 	return math.Sqrt(math.Pow(v.Dx, 2.0) + math.Pow(v.Dy, 2.0))
 }
 
+// GetPolarAngle returns the angle the magnitude of the vector forms with the
+// positive X-axis going counterclockwise.
 func (v Vector) GetPolarAngle() float64 {
 	return math.Atan2(v.Dy, v.Dx)
 }