145 lines
3.6 KiB
Go
145 lines
3.6 KiB
Go
package render
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import (
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"image"
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"image/color"
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"math"
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"golang.org/x/image/draw"
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)
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// Pattern provides infinite algorithmically generated Patterns and implements
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// the image.Image interface.
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type Pattern struct {
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Size image.Point
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}
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// Image interface
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func (c *Pattern) ColorModel() color.Model { return color.NRGBAModel }
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func (c *Pattern) At(x, y int) color.Color { return color.Transparent }
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func (c *Pattern) Bounds() image.Rectangle {
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return image.Rectangle{image.Point{-1e9, -1e9}, image.Point{1e9, 1e9}}
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}
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func (p *Pattern) ToFixedImage(bounds image.Rectangle) *image.NRGBA {
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img := image.NewNRGBA(bounds)
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// TODO: allow setting a mask?
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// override size for pattern?
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p.Size = bounds.Size() // override size for this Pattern
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draw.Draw(img, bounds, p, image.Point{}, draw.Src)
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return img
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}
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type StripePattern struct {
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Pattern
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Palette color.Palette
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}
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func (c *StripePattern) At(x, y int) color.Color {
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n := len(c.Palette)
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if n == 0 {
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return color.Transparent
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}
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pxPerStripe := c.Size.Y / n
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if pxPerStripe <= 0 {
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pxPerStripe = 1
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}
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stripeIndex := y / pxPerStripe % n // FIXME: y - c.Size? -> negative modulo fix
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return c.Palette[stripeIndex]
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}
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func NewPrideImage(p color.Palette, bounds image.Rectangle) image.Image {
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Pattern := StripePattern{Palette: p}
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return Pattern.ToFixedImage(bounds)
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}
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var PrideFlags = map[string]color.Palette{
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"lgbti": color.Palette{
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color.NRGBA{0xe4, 0x03, 0x03, 0xff},
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color.NRGBA{0xff, 0x8c, 0x00, 0xff},
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color.NRGBA{0xff, 0xed, 0x00, 0xff},
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color.NRGBA{0x00, 0x80, 0x26, 0xff},
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color.NRGBA{0x00, 0x4d, 0xff, 0xff},
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color.NRGBA{0x75, 0x07, 0x87, 0xff},
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},
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"nonbinary": color.Palette{
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color.NRGBA{0x9c, 0x5c, 0xd4, 0xff},
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color.NRGBA{0xfc, 0xfc, 0xfc, 0xff},
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color.NRGBA{0xfc, 0xf4, 0x34, 0xff},
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color.NRGBA{0x2c, 0x2c, 0x2c, 0xff},
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},
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"trans": color.Palette{
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color.NRGBA{0x5b, 0xde, 0xfa, 0xff},
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color.NRGBA{0xf5, 0xa9, 0xb8, 0xff},
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color.NRGBA{0xff, 0xff, 0xff, 0xff},
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color.NRGBA{0xf5, 0xa9, 0xb8, 0xff},
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color.NRGBA{0x5b, 0xde, 0xfa, 0xff},
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},
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}
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type DynamicPattern struct {
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Pattern
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Color func(x, y int, p *DynamicPattern) (float64, float64, float64) // should return rgb in [0,1] range
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Luma float64 // color parameter
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Freq float64 // frequency parameter
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Phase float64 // phase parameter
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Brightness float64 // additive base brightness
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ColFactor float64 // Pattern intensity
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}
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func (c *DynamicPattern) At(x, y int) color.Color {
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col := color.NRGBA{}
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if c.ColFactor == 0.0 && c.Brightness == 0.0 {
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c.ColFactor = 1.0
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}
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if c.Color != nil {
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r, g, b := c.Color(x, y, c)
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col.R = uint8(r * c.ColFactor * 255)
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col.G = uint8(g * c.ColFactor * 255)
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col.B = uint8(b * c.ColFactor * 255)
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}
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if c.Freq == 0.0 {
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c.Freq = 1.0
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}
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col.R = col.R + uint8(255*c.Brightness)
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col.G = col.G + uint8(255*c.Brightness)
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col.B = col.B + uint8(255*c.Brightness)
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col.A = 0xff
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return col
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}
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var DynPatterns = map[string]image.Image{
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"rbow": &DynamicPattern{
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Color: func(x, y int, p *DynamicPattern) (float64, float64, float64) {
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xx := float64(x) / 26.0 // TODO: dynamic sizing
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yy := float64(y) / 13.0
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r := 0.5 + 0.5*math.Cos(xx+p.Phase)
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g := 0.5 + 0.5*math.Sin(yy+p.Phase)
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b := 0.5 + 0.5*math.Sin(xx+p.Phase)*math.Cos(yy+p.Phase)
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return r, g, b
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},
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},
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"pastel": &DynamicPattern{
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Brightness: 0.5, // TODO: expose these params?
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ColFactor: 0.5,
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Freq: 5.0,
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Color: func(x, y int, p *DynamicPattern) (float64, float64, float64) {
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offset := 0.0
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v := math.Atan2(float64(x)-offset, float64(y)-offset) + p.Phase
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r := 0.5 + 0.5*math.Sin(v*p.Freq)
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g := 0.5 + 0.5*math.Cos(v*p.Freq)
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b := 0.5 + 0.5*math.Sin(v*p.Freq+6.28318/p.Luma)
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return r, g, b
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},
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},
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}
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