gists/main.lua
2013-03-11 15:09:01 +00:00

144 lines
2.5 KiB
Lua

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