initial commit.

defaults.go

@@ -0,0 +1,69 @@
+package chart
+
+import (
+	"image/color"
+	"sync"
+
+	"github.com/golang/freetype/truetype"
+)
+
+const (
+	// DefaultChartHeight is the default chart height.
+	DefaultChartHeight = 400
+	// DefaultChartWidth is the default chart width.
+	DefaultChartWidth = 200
+	// DefaultPadding is the default gap between the image border and
+	// chart content (referred to as the "canvas").
+	DefaultPadding = 10
+	// DefaultLineWidth is the default chart line width.
+	DefaultLineWidth = 2.0
+	//DefaultDPI is the default dots per inch for the chart.
+	DefaultDPI = 120.0
+	// DefaultMinimumFontSize is the default minimum font size.
+	DefaultMinimumFontSize = 8.0
+)
+
+var (
+	// DefaultBackgroundColor is the default chart background color.
+	// It is equivalent to css color:white.
+	DefaultBackgroundColor = color.RGBA{R: 255, G: 255, B: 255, A: 255}
+	// DefaultCanvasColor is the default chart canvas color.
+	// It is equivalent to css color:white.
+	DefaultCanvasColor = color.RGBA{R: 255, G: 255, B: 255, A: 255}
+	// DefaultTextColor is the default chart text color.
+	// It is equivalent to #333333.
+	DefaultTextColor = color.RGBA{R: 51, G: 51, B: 51, A: 255}
+	// DefaultAxisColor is the default chart axis line color.
+	// It is equivalent to #333333.
+	DefaultAxisColor = color.RGBA{R: 51, G: 51, B: 51, A: 255}
+	// DefaultBorderColor is the default chart border color.
+	// It is equivalent to #efefef.
+	DefaultBorderColor = color.RGBA{R: 239, G: 239, B: 239, A: 255}
+	// DefaultLineColor is the default (1st) series line color.
+	// It is equivalent to #0074d9.
+	DefaultLineColor = color.RGBA{R: 0, G: 217, B: 116, A: 255}
+	// DefaultFillColor is the default fill color.
+	// It is equivalent to #0074d9.
+	DefaultFillColor = color.RGBA{R: 0, G: 217, B: 116, A: 255}
+)
+
+var (
+	_defaultFontLock sync.Mutex
+	_defaultFont     *truetype.Font
+)
+
+// GetDefaultFont returns the default font (Roboto-Medium).
+func GetDefaultFont() (*truetype.Font, error) {
+	if _defaultFont == nil {
+		_defaultFontLock.Lock()
+		defer _defaultFontLock.Unlock()
+		if _defaultFont == nil {
+			font, err := truetype.Parse(roboto)
+			if err != nil {
+				return nil, err
+			}
+			_defaultFont = font
+		}
+	}
+	return _defaultFont, nil
+}