doodle/pkg/level/palette.go
Noah Petherbridge eb24858830 Brush Pattern Textures
Palette swatches gain a new property: Pattern.

Patterns are grayscale textures that the swatch color will sample
against when drawing pixels to the level, by taking the world coordinate
modulo a value inside the texture.

A few algorithms were tried (Screen, Overlay), this branch lands on one
that tries to cast the color from grayscale which comes out rather dark;
to get a patterned color to look black while still seeing the pattern,
the color needs to be as bright as #777 to get the effect.
2021-06-09 22:36:32 -07:00

137 lines
2.8 KiB
Go

package level
import (
"fmt"
"git.kirsle.net/go/render"
)
// DefaultPalette returns a sensible default palette.
func DefaultPalette() *Palette {
return &Palette{
Swatches: []*Swatch{
&Swatch{
Name: "solid",
Color: render.Black,
Solid: true,
},
&Swatch{
Name: "decoration",
Color: render.Grey,
},
&Swatch{
Name: "fire",
Color: render.Red,
Fire: true,
},
&Swatch{
Name: "water",
Color: render.RGBA(0, 0, 255, 180),
Water: true,
},
},
}
}
// NewBlueprintPalette returns the blueprint theme's color palette.
// DEPRECATED in favor of DefaultPalettes.
func NewBlueprintPalette() *Palette {
return &Palette{
Swatches: []*Swatch{
&Swatch{
Name: "solid",
Color: render.RGBA(254, 254, 254, 255),
Solid: true,
},
&Swatch{
Name: "decoration",
Color: render.Grey,
},
&Swatch{
Name: "fire",
Color: render.RGBA(255, 80, 0, 255),
Fire: true,
},
&Swatch{
Name: "water",
Color: render.RGBA(0, 153, 255, 255),
Water: true,
},
&Swatch{
Name: "electric",
Color: render.RGBA(255, 255, 0, 255),
Solid: true,
},
},
}
}
// NewPalette initializes a blank palette.
func NewPalette() *Palette {
return &Palette{
Swatches: []*Swatch{},
byName: map[string]int{},
}
}
// Palette holds an index of colors used in a drawing.
type Palette struct {
Swatches []*Swatch `json:"swatches"`
// Private runtime values
ActiveSwatch *Swatch `json:"-"` // name of the actively selected color
byName map[string]int // Cache map of swatches by name
}
// Inflate the palette swatch caches. Always call this method after you have
// initialized the palette (i.e. loaded it from JSON); this will update the
// "color by name" cache and assign the index numbers to each swatch.
func (p *Palette) Inflate() {
p.update()
}
// AddSwatch adds a new swatch to the palette.
func (p *Palette) AddSwatch() *Swatch {
p.update()
var (
index = len(p.Swatches)
name = fmt.Sprintf("color %d", len(p.Swatches))
)
p.Swatches = append(p.Swatches, &Swatch{
Name: name,
Color: render.Magenta,
index: index,
})
p.byName[name] = index
return p.Swatches[index]
}
// Get a swatch by name.
func (p *Palette) Get(name string) (result *Swatch, exists bool) {
p.update()
if index, ok := p.byName[name]; ok && index < len(p.Swatches) {
result = p.Swatches[index]
exists = true
}
return
}
// update the internal caches and such.
func (p *Palette) update() {
// Initialize the name cache if nil or if the size disagrees with the
// length of the swatches available.
if p.byName == nil || len(p.byName) != len(p.Swatches) {
// Initialize the name cache.
p.byName = map[string]int{}
for i, swatch := range p.Swatches {
swatch.index = i
p.byName[swatch.Name] = i
}
}
}