rework color parsing & dynamic palettes

This commit is contained in:
Norwin Roosen 2020-12-29 16:42:47 +01:00
parent 8f18af72f7
commit 82f09db519
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GPG Key ID: 24BC059DE24C43A3
2 changed files with 89 additions and 34 deletions

View File

@ -8,27 +8,31 @@ import (
"golang.org/x/image/draw" "golang.org/x/image/draw"
) )
// pattern provides infinite algorithmically generated patterns and implements // Pattern provides infinite algorithmically generated Patterns and implements
// the image.Image interface. // the image.Image interface.
type pattern struct{} type Pattern struct {
Size image.Point
}
// Image interface // Image interface
func (c *pattern) ColorModel() color.Model { return color.NRGBAModel } func (c *Pattern) ColorModel() color.Model { return color.NRGBAModel }
func (c *pattern) At(x, y int) color.Color { return color.Transparent } func (c *Pattern) At(x, y int) color.Color { return color.Transparent }
func (c *pattern) Bounds() image.Rectangle { func (c *Pattern) Bounds() image.Rectangle {
return image.Rectangle{image.Point{-1e9, -1e9}, image.Point{1e9, 1e9}} return image.Rectangle{image.Point{-1e9, -1e9}, image.Point{1e9, 1e9}}
} }
func (p *pattern) ToFixedImage(bounds image.Rectangle) *image.NRGBA { func (p *Pattern) ToFixedImage(bounds image.Rectangle) *image.NRGBA {
img := image.NewNRGBA(bounds) img := image.NewNRGBA(bounds)
// TODO: allow setting a mask?
// override size for pattern?
p.Size = bounds.Size() // override size for this Pattern
draw.Draw(img, bounds, p, image.Point{}, draw.Src) draw.Draw(img, bounds, p, image.Point{}, draw.Src)
return img return img
} }
type StripePattern struct { type StripePattern struct {
pattern Pattern
Palette color.Palette Palette color.Palette
Size int
} }
func (c *StripePattern) At(x, y int) color.Color { func (c *StripePattern) At(x, y int) color.Color {
@ -37,7 +41,7 @@ func (c *StripePattern) At(x, y int) color.Color {
return color.Transparent return color.Transparent
} }
pxPerStripe := c.Size / n pxPerStripe := c.Size.Y / n
if pxPerStripe <= 0 { if pxPerStripe <= 0 {
pxPerStripe = 1 pxPerStripe = 1
} }
@ -46,8 +50,8 @@ func (c *StripePattern) At(x, y int) color.Color {
} }
func NewPrideImage(p color.Palette, bounds image.Rectangle) image.Image { func NewPrideImage(p color.Palette, bounds image.Rectangle) image.Image {
pattern := StripePattern{Palette: p, Size: bounds.Dy()} Pattern := StripePattern{Palette: p}
return pattern.ToFixedImage(bounds) return Pattern.ToFixedImage(bounds)
} }
var PrideFlags = map[string]color.Palette{ var PrideFlags = map[string]color.Palette{
@ -74,27 +78,67 @@ var PrideFlags = map[string]color.Palette{
}, },
} }
type SineColorPattern struct { type DynamicPattern struct {
pattern Pattern
Luma uint8
Freq float64 Color func(x, y int, p *DynamicPattern) (float64, float64, float64) // should return rgb in [0,1] range
Phase float64
Luma float64 // color parameter
Freq float64 // frequency parameter
Phase float64 // phase parameter
Brightness float64 // additive base brightness
ColFactor float64 // Pattern intensity
} }
func (c *SineColorPattern) At(x, y int) color.Color { func (c *DynamicPattern) At(x, y int) color.Color {
TAU := 6.28318
offset := 0.5
scale := 0.5
v := math.Atan2(float64(x), float64(y))
col := color.NRGBA{} col := color.NRGBA{}
col.R = uint8((offset+scale*math.Sin(v/c.Freq*TAU))*128 + 128)
col.G = uint8((offset+scale*math.Sin(v/c.Freq*TAU+TAU/3))*128 + 128) if c.ColFactor == 0.0 && c.Brightness == 0.0 {
col.B = uint8((offset+scale*math.Sin(v/c.Freq*TAU+TAU/1.5))*128 + 128) c.ColFactor = 1.0
}
if c.Color != nil {
r, g, b := c.Color(x, y, c)
col.R = uint8(r * c.ColFactor * 255)
col.G = uint8(g * c.ColFactor * 255)
col.B = uint8(b * c.ColFactor * 255)
}
if c.Freq == 0.0 {
c.Freq = 1.0
}
col.R = col.R + uint8(255*c.Brightness)
col.G = col.G + uint8(255*c.Brightness)
col.B = col.B + uint8(255*c.Brightness)
col.A = 0xff col.A = 0xff
// col.R = c.Luma
// col.G = uint8(math.Sin(float64(x)/c.Freq+c.Phase) * 128 + 128)
// col.B = uint8(math.Cos(float64(y)/c.Freq+c.Phase) * 128 + 128)
return col return col
} }
var DynPatterns = map[string]image.Image{
"rbow": &DynamicPattern{
Color: func(x, y int, p *DynamicPattern) (float64, float64, float64) {
xx := float64(x) / 26.0 // TODO: dynamic sizing
yy := float64(y) / 13.0
r := 0.5 + 0.5*math.Cos(xx+p.Phase)
g := 0.5 + 0.5*math.Sin(yy+p.Phase)
b := 0.5 + 0.5*math.Sin(xx+p.Phase)*math.Cos(yy+p.Phase)
return r, g, b
},
},
"pastel": &DynamicPattern{
Brightness: 0.5, // TODO: expose these params?
ColFactor: 0.5,
Freq: 5.0,
Color: func(x, y int, p *DynamicPattern) (float64, float64, float64) {
offset := 0.0
v := math.Atan2(float64(x)-offset, float64(y)-offset) + p.Phase
r := 0.5 + 0.5*math.Sin(v*p.Freq)
g := 0.5 + 0.5*math.Cos(v*p.Freq)
b := 0.5 + 0.5*math.Sin(v*p.Freq+6.28318/p.Luma)
return r, g, b
},
},
}

View File

@ -128,16 +128,27 @@ func RunREPL(f Fluter) {
// alternatively treat it as palette name. If both fail, // alternatively treat it as palette name. If both fail,
// give image.Transparent // give image.Transparent
func parseColorOrPalette(input string) image.Image { func parseColorOrPalette(input string) image.Image {
if col, err := hex.DecodeString(input); err == nil { if input == "w" {
return image.NewUniform(color.White)
} else if input == "b" {
return image.NewUniform(color.Black)
} else if input == "t" {
return image.Transparent
} else if col, err := hex.DecodeString(input); err == nil && len(col) >= 3 {
var alpha byte = 0xff var alpha byte = 0xff
if len(col) == 4 { if len(col) == 4 {
alpha = col[3] alpha = col[3]
} }
return image.NewUniform(color.NRGBA{col[0], col[1], col[2], alpha}) return image.NewUniform(color.NRGBA{col[0], col[1], col[2], alpha})
} else if pal := render.PrideFlags[input]; len(pal) != 0 { }
return &render.StripePattern{Palette: pal, Size: 13}
} else { if pal := render.PrideFlags[input]; len(pal) != 0 {
return &render.SineColorPattern{Luma: 0xf0, Freq: 1} return &render.StripePattern{Palette: pal}
}
if p, ok := render.DynPatterns[input]; ok {
return p
}
return image.Transparent return image.Transparent
} }
}