add gradient banner functions to isogrids package #67 (f44ba95e) · Commits · blackheaven / tinygraphs

controllers/isogrids/gradient.go

+3 −4

Original line number	Diff line number	Diff line
		@@ -5,18 +5,17 @@ import (
		"net/http"

		"github.com/taironas/tinygraphs/colors"
		"github.com/taironas/tinygraphs/draw/squares"
		"github.com/taironas/tinygraphs/extract"
		"github.com/taironas/tinygraphs/write"
		)

		// Gradient handler for "labs/squares/banner/gradient"
		// Gradient handler for "labs/isogrids/banner/gradient"
		// generates a color gradient random grid image.
		func BannerGradient(w http.ResponseWriter, r *http.Request) {

		width := extract.Width(r)
		height := extract.Height(r)
		xsquares := extract.XSquares(r)
		xtriangles := extract.XTriangles(r)
		numColors := extract.NumColors(r)
		gv := extract.GradientVector(r, uint8(0), uint8(0), uint8(width), uint8(0))

		@@ -40,5 +39,5 @@ func BannerGradient(w http.ResponseWriter, r *http.Request) {
		}

		write.ImageSVG(w)
		squares.RandomGradientSVG(w, colors, gColors, gv, width, height, xsquares)
		isogrids.RandomGradientSVG(w, colors, gColors, gv, width, height, xtriangles)
		}

draw/isogrids/gradient.go

0 → 100644

+67 −0

Original line number	Diff line number	Diff line
		package isogrids

		import (
		"image/color"
		"math"
		"net/http"

		"github.com/ajstarks/svgo"
		"github.com/taironas/tinygraphs/colors"
		"github.com/taironas/tinygraphs/draw"
		)

		// RandomGradientSVG builds an image.
		func RandomGradientSVG(w http.ResponseWriter, colors, gColors []color.RGBA, gv colors.GradientVector, width, height, xsquares int) {

		var gradientColors []svg.Offcolor
		gradientColors = make([]svg.Offcolor, len(gColors))
		percentage := uint8(100 / len(gColors))

		step := uint8(100 / len(gColors))
		for i, c := range gColors {
		gradientColors[i] = svg.Offcolor{percentage, RGBToHex(c.R, c.G, c.B), 1}
		percentage += step
		}

		canvas := svg.New(w)
		canvas.Start(width, height)
		canvas.Def()
		canvas.LinearGradient("gradientColors", gv.X1, gv.Y1, gv.X2, gv.Y2, gradientColors)
		canvas.DefEnd()
		canvas.Rect(0, 0, width, height, "fill:url(#gradientColors)")

		squares := xsquares
		quadrantSize := width / squares
		middle := math.Ceil(float64(squares) / float64(2))
		colorMap := make(map[int]color.RGBA)
		colorIndex := make(map[int]int)
		for yQ := 0; yQ < squares; yQ++ {
		y := yQ * quadrantSize
		colorMap = make(map[int]color.RGBA)
		colorIndex = make(map[int]int)
		for xQ := 0; xQ < squares; xQ++ {
		x := xQ * quadrantSize
		fill := ""
		if _, ok := colorMap[xQ]; !ok {
		if float64(xQ) < middle {
		colorIndex[xQ] = draw.RandomIndexFromArray(colors)
		colorMap[xQ] = colors[colorIndex[xQ]]
		} else if xQ < squares {
		colorIndex[xQ] = colorIndex[squares-xQ-1]
		colorMap[xQ] = colorMap[squares-xQ-1]
		} else {
		colorIndex[xQ] = colorIndex[0]
		colorMap[xQ] = colorMap[0]
		}
		}
		if colorIndex[xQ] != 0 {
		fill = "fill:none"
		} else {
		fill = draw.FillFromRGBA(colorMap[xQ])

		}
		canvas.Rect(x, y, quadrantSize, quadrantSize, fill)
		}
		}
		canvas.End()
		}