Greyscale bars/Display: Difference between revisions

=={{header|Wren}}==

{{libheader|DOME}}

<lang ecmascript>import "graphics" for Canvas, Color

import "dome" for Window

import "math" for Math

class GreyBars {

construct new(width, height) {

Window.title = "Grey bars example"

Window.resize(width, height)

Canvas.resize(width, height)

_w = width

_h = height

}

init() {

drawBars()

}

drawBars() {

var run = 0

var colorComp = 0 // component of the color

var columnCount = 8

while (columnCount < 128) {

var colorGap = 255 / (columnCount - 1) // by this gap we change the background color

var columnWidth = (_w / columnCount).floor

var columnHeight = (_h / 4).floor

if (run % 2 == 0) { // switches color directions with each iteration of while loop

colorComp = 0

} else {

colorComp = 255

colorGap = -colorGap

}

var ystart = columnHeight * run

var xstart = 0

for (i in 0...columnCount) {

var iColor = Math.round(colorComp)

var nextColor = Color.rgb(iColor, iColor, iColor)

Canvas.rectfill(xstart, ystart, xstart + columnWidth, ystart + columnHeight, nextColor)

xstart = xstart + columnWidth

colorComp = colorComp + colorGap

}

run = run + 1

columnCount = columnCount * 2

}

}

update() {}

draw(alpha) {}

}

var Game = GreyBars.new(640, 320)</lang>