go-chart/renderer.go
2016-07-08 17:57:14 -07:00

67 lines
1.5 KiB
Go

package chart
import (
"image/color"
"io"
"github.com/golang/freetype/truetype"
)
// RendererProvider is a function that returns a renderer.
type RendererProvider func(int, int) (Renderer, error)
// Renderer represents the basic methods required to draw a chart.
type Renderer interface {
// SetDPI sets the DPI for the renderer.
SetDPI(dpi float64)
// SetStrokeColor sets the current stroke color.
SetStrokeColor(color.RGBA)
// SetFillColor sets the current fill color.
SetFillColor(color.RGBA)
// SetStrokeWidth sets the stroke width.
SetStrokeWidth(width 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)
// 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(color.RGBA)
// 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) (width int, height int)
// Save writes the image to the given writer.
Save(w io.Writer) error
}