go-chart/renderer.go
Will Charczuk de6df027fc updates
2017-05-17 16:01:23 -07:00

87 lines
2.0 KiB
Go

package chart
import (
"io"
"github.com/golang/freetype/truetype"
"github.com/wcharczuk/go-chart/drawing"
)
// Renderer represents the basic methods required to draw a chart.
type Renderer interface {
// ResetStyle should reset any style related settings on the renderer.
ResetStyle()
// GetDPI gets the DPI for the renderer.
GetDPI() float64
// SetDPI sets the DPI for the renderer.
SetDPI(dpi float64)
// SetStrokeColor sets the current stroke color.
SetStrokeColor(drawing.Color)
// SetFillColor sets the current fill color.
SetFillColor(drawing.Color)
// SetStrokeWidth sets the stroke width.
SetStrokeWidth(width float64)
// SetStrokeDashArray sets the stroke dash array.
SetStrokeDashArray(dashArray []float64)
// MoveTo moves the cursor to a given point.
MoveTo(x, y int)
// LineTo both starts a shape and draws a line to a given point
// from the previous point.
LineTo(x, y int)
// QuadCurveTo draws a quad curve.
// cx and cy represent the bezier "control points".
QuadCurveTo(cx, cy, x, y int)
// ArcTo draws an arc with a given center (cx,cy)
// a given set of radii (rx,ry), a startAngle and delta (in radians).
ArcTo(cx, cy int, rx, ry, startAngle, delta float64)
// Close finalizes a shape as drawn by LineTo.
Close()
// Stroke strokes the path.
Stroke()
// Fill fills the path, but does not stroke.
Fill()
// FillStroke fills and strokes a path.
FillStroke()
// Circle draws a circle at the given coords with a given radius.
Circle(radius float64, x, y int)
// SetFont sets a font for a text field.
SetFont(*truetype.Font)
// SetFontColor sets a font's color
SetFontColor(drawing.Color)
// SetFontSize sets the font size for a text field.
SetFontSize(size float64)
// Text draws a text blob.
Text(body string, x, y int)
// MeasureText measures text.
MeasureText(body string) Box2d
// SetTextRotatation sets a rotation for drawing elements.
SetTextRotation(radians float64)
// ClearTextRotation clears rotation.
ClearTextRotation()
// Save writes the image to the given writer.
Save(w io.Writer) error
}