88 lines
1.6 KiB
Markdown
88 lines
1.6 KiB
Markdown
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# Go Graphics
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`gg` is a library for rendering 2D graphics in pure Go.
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## Installation
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go get github.com/fogleman/gg
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## Hello, Circle!
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```go
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package main
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import "github.com/fogleman/gg"
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func main() {
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// create a new 1000x1000 pixel image
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dc := gg.NewContext(1000, 1000)
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// draw a circle at the center with radius 400
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// nothing is drawn yet, we have to call Stroke or Fill
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dc.DrawCircle(500, 500, 400)
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// use black and 10px stroke width
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dc.SetRGB(0, 0, 0)
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dc.SetLineWidth(10)
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dc.Stroke()
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// write the result to file
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dc.SavePNG("out.png")
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}
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```
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## Drawing Functions
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Ever used a graphics library that didn't have functions for drawing rectangles
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or circles? What a pain!
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```go
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DrawLine(x1, y1, x2, y2 float64)
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DrawRectangle(x, y, w, h float64)
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DrawEllipticalArc(x, y, rx, ry, angle1, angle2 float64)
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DrawEllipse(x, y, rx, ry float64)
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DrawArc(x, y, r, angle1, angle2 float64)
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DrawCircle(x, y, r float64)
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DrawImage(im image.Image, x, y int)
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DrawString(x, y float64, s string)
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MoveTo(x, y float64)
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LineTo(x, y float64)
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QuadraticTo(x1, y1, x2, y2 float64)
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ClosePath()
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ClearPath()
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Clear()
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Stroke()
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Fill()
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StrokePreserve()
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FillPreserve()
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```
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## Color Functions
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Colors can be set in several different ways for your convenience.
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```go
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SetColor(c color.Color)
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SetHexColor(x string)
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SetRGBA255(r, g, b, a int)
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SetRGB255(r, g, b int)
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SetRGBA(r, g, b, a float64)
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SetRGB(r, g, b float64)
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```
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## Transformation Functions
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```go
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Identity()
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Translate(x, y float64)
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Scale(x, y float64)
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Rotate(angle float64)
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RotateAbout(angle, x, y float64)
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Shear(x, y float64)
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TransformPoint(x, y float64) (tx, ty float64)
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Push()
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Pop()
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```
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