Commit 614be378 authored by santiaago's avatar santiaago
Browse files

fix bug on isogrid images by centering and showing extra triangles 

Fixes #43
parent d05d612a

draw/isogrids/isogrids.go

+7 −8
Original line number Diff line number Diff line
@@ -15,24 +15,23 @@ func Isogrids(w http.ResponseWriter, key string, colors []color.RGBA, size, line 


	fringeSize := size / lines

	distance := distanceTo3rdPoint(fringeSize)

	fringeSize = distance

	lines = size / fringeSize



	offset := ((fringeSize - distance) * lines) / 2

	// triangle grid here:

	for xL := 0; xL < lines/2; xL++ {

		for yL := 0; yL < lines; yL++ {

	for xL := -1; xL < lines/2; xL++ {

		for yL := -1; yL <= lines; yL++ {

			var x1, x2, y1, y2, y3 int

			if (xL % 2) == 0 {

				x1, y1, x2, y2, _, y3 = right1stTriangle(xL, yL, fringeSize, distance)

			} else {

				x1, y1, x2, y2, _, y3 = left1stTriangle(xL, yL, fringeSize, distance)

			}

			xs := []int{x2, x1, x2}

			xs := []int{x2 + offset, x1 + offset, x2 + offset}

			ys := []int{y1, y2, y3}

			fill1 := draw.FillFromRGBA(draw.PickColor(key, colors, (xL+3*yL+lines)%15))

			canvas.Polygon(xs, ys, fill1)



			xsMirror := mirrorCoordinates(xs, lines, fringeSize, 0)

			xsMirror := mirrorCoordinates(xs, lines, distance, offset*2)

			canvas.Polygon(xsMirror, ys, fill1)



			var x11, x12, y11, y12, y13 int
@@ -48,12 +47,12 @@ func Isogrids(w http.ResponseWriter, key string, colors []color.RGBA, size, line 
				// we make sure that the previous triangle and this one touch each other in this point.

				y12 = y1 + fringeSize

			}

			xs1 := []int{x12, x11, x12}

			xs1 := []int{x12 + offset, x11 + offset, x12 + offset}

			ys1 := []int{y11, y12, y13}

			fill2 := draw.FillFromRGBA(draw.PickColor(key, colors, (xL+3*yL+1+lines)%15))

			canvas.Polygon(xs1, ys1, fill2)



			xs1 = mirrorCoordinates(xs1, lines, fringeSize, 0)

			xs1 = mirrorCoordinates(xs1, lines, distance, offset*2)

			canvas.Polygon(xs1, ys1, fill2)

		}

	}

draw/isogrids/triangles.go

+12 −12
Original line number Diff line number Diff line
@@ -12,44 +12,44 @@ func distanceTo3rdPoint(AC int) int { 


// right1stTriangle computes a right oriented triangle '>'

func right1stTriangle(xL, yL, fringeSize, distance int) (x1, y1, x2, y2, x3, y3 int) {

	x1 = xL * fringeSize

	x2 = xL*fringeSize + distance

	x1 = xL * distance

	x2 = xL*distance + distance

	x3 = x1

	y1 = yL * fringeSize

	y2 = y1 + fringeSize/2

	y3 = yL*fringeSize + distance

	y3 = yL*fringeSize + fringeSize

	return

}



// left1stTriangle computes the coordinates of a left oriented triangle '<'

func left1stTriangle(xL, yL, fringeSize, distance int) (x1, y1, x2, y2, x3, y3 int) {

	x1 = xL*fringeSize + distance

	x2 = xL * fringeSize

	x1 = xL*distance + distance

	x2 = xL * distance

	x3 = x1

	y1 = yL * fringeSize

	y2 = y1 + fringeSize/2

	y3 = yL*fringeSize + distance

	y3 = yL*fringeSize + fringeSize

	return

}



// left2ndTriangle computes the coordinates of a left oriented triangle '<'

func left2ndTriangle(xL, yL, fringeSize, distance int) (x1, y1, x2, y2, x3, y3 int) {

	x1 = xL*fringeSize + distance

	x2 = xL * fringeSize

	x1 = xL*distance + distance

	x2 = xL * distance

	x3 = x1

	y1 = yL*fringeSize + fringeSize/2

	y2 = y1 + fringeSize/2

	y3 = yL*fringeSize + distance + fringeSize/2

	y3 = yL*fringeSize + fringeSize + fringeSize/2

	return

}



// right2ndTriangle computes the coordinates of a right oriented triangle '>'

func right2ndTriangle(xL, yL, fringeSize, distance int) (x1, y1, x2, y2, x3, y3 int) {

	x1 = xL * fringeSize

	x2 = xL*fringeSize + distance

	x1 = xL * distance

	x2 = xL*distance + distance

	x3 = x1

	y1 = yL*fringeSize + fringeSize/2

	y2 = yL + fringeSize

	y3 = yL*fringeSize + fringeSize/2 + distance

	y3 = yL*fringeSize + fringeSize/2 + fringeSize

	return

}