Function newChartScaleY

gui/chart.go:536–575

newChartScaleY creates and returns a pointer to a new chartScaleY for the specified chart, number of lines and color

(chart *Chart, lines int, color *math32.Color)

// newChartScaleY creates and returns a pointer to a new chartScaleY for the specified
// chart, number of lines and color
func newChartScaleY(chart *Chart, lines int, color *math32.Color) *chartScaleY {

	if lines < 2 {
		lines = 2
	}
	sy := new(chartScaleY)
	sy.chart = chart
	sy.lines = lines
	sy.uniBounds.Init("Bounds")

	// Appends left vertical line
	positions := math32.NewArrayF32(0, 0)
	positions.Append(0+deltaLine, 0, 0, 0+deltaLine, -1, 0)

	// Appends horizontal lines
	step := 1 / float32(lines-1)
	for i := 0; i < lines; i++ {
		ny := -1 + float32(i)*step
		if i == 0 {
			ny += deltaLine
		}
		if i == lines-1 {
			ny -= deltaLine
		}
		positions.Append(0, ny, 0, 1, ny, 0)
	}

	// Creates geometry and adds VBO
	geom := geometry.NewGeometry()
	geom.AddVBO(gls.NewVBO(positions).AddAttrib(gls.VertexPosition))

	// Initializes the panel with this graphic
	gr := graphic.NewGraphic(sy, geom, gls.LINES)
	sy.mat.Init(color)
	gr.AddMaterial(sy, &sy.mat, 0, 0)
	sy.Panel.InitializeGraphic(chart.ContentWidth(), chart.ContentHeight(), gr)

	sy.recalc()
	return sy
}

// recalc recalculates the position and size of this scale inside its parent
func (sy *chartScaleY) recalc() {