58 lines
1.4 KiB
Go
58 lines
1.4 KiB
Go
package main
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import (
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"bytes"
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"fmt"
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"image"
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"image/color"
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"image/draw"
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"image/png"
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)
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func main() {
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// A rectangle from 0,0 to 300,240.
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r := image.Rect(0, 0, 300, 240)
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// Create an image
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im := image.NewNRGBA(r)
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// set some color variables for convience
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var (
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red = color.RGBA{0xff, 0x00, 0x00, 0xff}
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blue = color.RGBA{0x00, 0x00, 0xff, 0xff}
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)
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// Fill with a uniform color
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draw.Draw(im, r, &image.Uniform{red}, image.ZP, draw.Src)
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// Set individual pixels
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im.Set(10, 20, blue)
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im.Set(20, 30, color.Black)
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im.Set(30, 40, color.RGBA{0x10, 0x20, 0x30, 0xff})
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// Get the values of specific pixels as color.Color types.
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// The color will be in the color.Model of the image (in this
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// case color.NRGBA) but color models can convert their values
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// to other models.
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c1 := im.At(0, 0)
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c2 := im.At(10, 20)
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// or directly as RGB components (scaled values)
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redc, greenc, bluec, _ := c1.RGBA()
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redc, greenc, bluec, _ = im.At(30, 40).RGBA()
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// Images can be read and writen in various formats
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var buf bytes.Buffer
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err := png.Encode(&buf, im)
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if err != nil {
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fmt.Println(err)
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}
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fmt.Println("Image size:", im.Bounds().Dx(), "×", im.Bounds().Dy())
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fmt.Println(buf.Len(), "bytes when encoded as PNG.")
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fmt.Printf("Pixel at %7v is %v\n", image.Pt(0, 0), c1)
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fmt.Printf("Pixel at %7v is %#v\n", image.Pt(10, 20), c2) // %#v shows type details
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fmt.Printf("Pixel at %7v has R=%d, G=%d, B=%d\n",
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image.Pt(30, 40), redc, greenc, bluec)
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}
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