From 0ede282b73905c90ebb6342731d1b7d6e17a516c Mon Sep 17 00:00:00 2001
From: Norwin Roosen <git@nroo.de>
Date: Mon, 28 Dec 2020 01:14:26 +0100
Subject: [PATCH] fixup! changes??? idk anymore

---
 render/pattern.go | 100 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 100 insertions(+)
 create mode 100644 render/pattern.go

diff --git a/render/pattern.go b/render/pattern.go
new file mode 100644
index 0000000..fb2deca
--- /dev/null
+++ b/render/pattern.go
@@ -0,0 +1,100 @@
+package render
+
+import (
+	"image"
+	"image/color"
+	"math"
+
+	"golang.org/x/image/draw"
+)
+
+// pattern provides infinite algorithmically generated patterns and implements
+// the image.Image interface.
+type pattern struct{}
+
+// Image interface
+func (c *pattern) ColorModel() color.Model { return color.NRGBAModel }
+func (c *pattern) At(x, y int) color.Color { return color.Transparent }
+func (c *pattern) Bounds() image.Rectangle {
+	return image.Rectangle{image.Point{-1e9, -1e9}, image.Point{1e9, 1e9}}
+}
+
+func (p *pattern) ToFixedImage(bounds image.Rectangle) *image.NRGBA {
+	img := image.NewNRGBA(bounds)
+	draw.Draw(img, bounds, p, image.Point{}, draw.Src)
+	return img
+}
+
+type StripePattern struct {
+	pattern
+	Palette color.Palette
+	Size    int
+}
+
+func (c *StripePattern) At(x, y int) color.Color {
+	n := len(c.Palette)
+	if n == 0 {
+		return color.Transparent
+	}
+
+	pxPerStripe := c.Size / n
+	if pxPerStripe <= 0 {
+		pxPerStripe = 1
+	}
+	stripeIndex := y / pxPerStripe % n // FIXME: y - c.Size? -> negative modulo fix
+	return c.Palette[stripeIndex]
+}
+
+func NewPrideImage(p color.Palette, bounds image.Rectangle) image.Image {
+	pattern := StripePattern{Palette: p, Size: bounds.Dy()}
+	return pattern.ToFixedImage(bounds)
+}
+
+var PrideFlags = map[string]color.Palette{
+	"lgbti": color.Palette{
+		color.NRGBA{0xe4, 0x03, 0x03, 0xff},
+		color.NRGBA{0xff, 0x8c, 0x00, 0xff},
+		color.NRGBA{0xff, 0xed, 0x00, 0xff},
+		color.NRGBA{0x00, 0x80, 0x26, 0xff},
+		color.NRGBA{0x00, 0x4d, 0xff, 0xff},
+		color.NRGBA{0x75, 0x07, 0x87, 0xff},
+	},
+	"nonbinary": color.Palette{
+		color.NRGBA{0x9c, 0x5c, 0xd4, 0xff},
+		color.NRGBA{0xfc, 0xfc, 0xfc, 0xff},
+		color.NRGBA{0xfc, 0xf4, 0x34, 0xff},
+		color.NRGBA{0x2c, 0x2c, 0x2c, 0xff},
+	},
+	"trans": color.Palette{
+		color.NRGBA{0x5b, 0xde, 0xfa, 0xff},
+		color.NRGBA{0xf5, 0xa9, 0xb8, 0xff},
+		color.NRGBA{0xff, 0xff, 0xff, 0xff},
+		color.NRGBA{0xf5, 0xa9, 0xb8, 0xff},
+		color.NRGBA{0x5b, 0xde, 0xfa, 0xff},
+	},
+}
+
+type SineColorPattern struct {
+	pattern
+	Luma  uint8
+	Freq  float64
+	Phase float64
+}
+
+func (c *SineColorPattern) 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.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)
+	col.B = uint8((offset+scale*math.Sin(v/c.Freq*TAU+TAU/1.5))*128 + 128)
+	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
+}