main.lua

@@ -0,0 +1,144 @@
+function lerp(x0, x1, t)
+    return x0*(1-t) + x1*t
+end
+
+function blendExp(x0, x1, t)
+	return x0^(1-t)*x1^t
+end
+
+local sw = 640
+local sh = 480
+
+local font
+local fs = 12
+
+local coordsA = {}
+local coordsB = {}
+local coordsAL = {}
+local coordsBL = {}
+
+local input = {
+	0.9013,
+	1.3685,
+	1.1046,
+	1.1633,
+	0.7332,
+	0.8603,
+}
+
+local win = {
+	T = 1.5,
+	B = -0.5,
+	L = 0,
+	R = 1,
+	stepX = 0.1,
+	stepY = 0.25,
+}
+win.scaleX = 1/(win.L - win.R)
+win.scaleY = 1/(win.T - win.B)
+
+local precision = 32
+
+function screenX(x)
+	return sw*(win.L-x)*win.scaleX
+end
+
+function screenY(y)
+	return sh*(win.T-y)*win.scaleY
+end
+
+function addPoint(coords, x, y)
+	coords[#coords+1] = screenX(x)
+	coords[#coords+1] = screenY(y)
+end
+
+function interpolate(x, values, interpolator)
+	local x = (x*#values) % #values
+	local x0 = math.floor(x)
+	local x1 = (x0 + 1) % #values
+	return interpolator(values[x0+1], values[x1+1], x - x0)
+end
+
+function love.load()
+	if not love.graphics.setMode(sw, sh) then
+		error("couldn't setMode ("..sw.." by "..sh..")")
+	end
+
+	love.graphics.setCaption("hey it's a graph")
+
+	--font = love.graphics.newFont("DejaVuSansMono.ttf", fs)
+	--love.graphics.setFont(font)
+
+	local lines = #input * precision
+	local seg = 1/lines
+
+	for n=1, lines+1 do
+		local x = (n-1)*seg
+		local hue = (n-1)/lines
+
+		local y = interpolate(hue, input, lerp)
+		addPoint(coordsA, x, y)
+		addPoint(coordsAL, x, math.log(y))
+
+		y = interpolate(hue, input, blendExp)
+		addPoint(coordsB, x, y)
+		addPoint(coordsBL, x, math.log(y))
+	end
+end
+
+function love.keypressed(key)
+	if key == "escape" then
+		love.event.push("quit")
+	end
+end
+
+local drawCoords = love.graphics.line
+local drawText = love.graphics.print
+
+function color(hex)
+	local r = tonumber(string.sub(hex, 1,2), 16)
+	local g = tonumber(string.sub(hex, 3,4), 16)
+	local b = tonumber(string.sub(hex, 5,6), 16)
+	love.graphics.setColor(r,g,b)
+end
+
+function drawVert(x)
+	drawCoords(x, 0, x, sh)
+end
+
+function drawHoriz(y)
+	drawCoords(0, y, sw, y)
+end
+
+function love.draw()
+	love.graphics.setBackgroundColor(255,255,255)
+	love.graphics.clear()
+
+	for x=win.L, win.R, win.stepX do
+		color("d3e2e7")
+		local rx = screenX(x)
+		drawVert(rx)
+		color("808080")
+		drawText(tostring(x), rx, sh - fs)
+	end
+
+	for y=win.B, win.T, win.stepY do
+		color("c6cce3")
+		local ry = screenY(y)
+		drawHoriz(ry)
+		color("808080")
+		drawText(tostring(y), 0, ry)
+	end
+
+	color("404040")
+	drawVert(screenX(0))
+	drawHoriz(screenY(0))
+
+	color("57C1BB")
+	drawCoords(coordsA)
+	drawCoords(coordsAL)
+
+	color("9F65C5")
+	drawCoords(coordsB)
+	drawCoords(coordsBL)
+end