Here’s a little crappy plasma globe demo I made today. It was inspired by some code I found for implementing a simple electricity effect at http://krazydad.com/bestiary/bestiary_lightning.html . If you change the display mode to STANDARD you can tweak all of the various parameters for it. With a some effort this could be made a lot less crappy, but since I’m just playing around I don’t really care to do anymore to it.
function setup()
displayMode(FULLSCREEN)
supportedOrientations(LANDSCAPE_ANY)
iparameter("minBolts", 1, 50, 5)
iparameter("maxBolts", 1, 50, 10)
iparameter("minLineWidth", 1, 20, 3)
iparameter("maxLineWidth", 1, 20, 5)
iparameter("minDetail", 1, 30, 5)
iparameter("maxDetail", 1, 30, 20)
iparameter("minDisplacement", 1, 1000, 100)
iparameter("maxDisplacement", 1, 1000, 200)
touches = {}
center = vec2(WIDTH*0.5, HEIGHT*0.5)
diameter = math.min(WIDTH, HEIGHT)
radius = diameter * 0.5
end
function touched(touch)
if touch.state == BEGAN or touch.state == MOVING then
local tp = vec2(touch.x, touch.y)
if center:distSqr(tp) <= radius*radius then
touches[touch.id] = tp
else
local v = (tp - center):normalize() * (radius-8)
touches[touch.id] = center + v
end
elseif touch.state == ENDED then
touches[touch.id] = nil
end
end
-- ported from code at http://krazydad.com/bestiary/bestiary_lightning.html
function drawLightning(x1, y1, x2, y2, displace, detail)
if displace < detail then
line(x1, y1, x2, y2)
else
local midx = (x2+x1) * 0.5
local midy = (y2+y1) * 0.5
midx = midx + (math.random() - 0.5) * displace
midy = midy + (math.random() - 0.5) * displace
drawLightning(x1, y1, midx, midy, displace * 0.5, detail)
drawLightning(x2, y2, midx, midy, displace * 0.5, detail)
end
end
function draw()
background(0)
-- swap max and mins if necessary
local minB = math.min(minBolts, maxBolts)
local maxB = math.max(minBolts, maxBolts)
local minW = math.min(minLineWidth, maxLineWidth)
local maxW = math.max(minLineWidth, maxLineWidth)
local minDt = math.min(minDetail, maxDetail)
local maxDt = math.max(minDetail, maxDetail)
local minDp = math.min(minDisplacement, maxDisplacement)
local maxDp = math.max(minDisplacement, maxDisplacement)
-- count touch points
local numTouchBolts = 0
for k,v in pairs(touches) do numTouchBolts = numTouchBolts + 1 end
-- draw thin bolts
lineCapMode(PROJECT)
stroke(64, 64, 255)
local numBolts = math.random(minB, maxB)
local mb = math.random(0, 1)
numBolts = math.max(mb, numBolts - numTouchBolts*4)
for i = 1, numBolts do
local detail = math.random(minDt, maxDt)
local displace = math.random(minDp, maxDp)
local angle = math.rad(math.random(0, 360))
local rv = vec2(0, 1):rotate(angle) * radius
local p = center + rv
strokeWidth(math.random(minW, maxW))
drawLightning(center.x, center.y, p.x, p.y, displace, detail)
end
-- draw thicker bolts to touch points
lineCapMode(ROUND)
strokeWidth(maxW * 3)
stroke(256, 0, 128)
for k,v in pairs(touches) do
local detail = math.random(minDt, maxDt)
local displace = math.random(minDp, maxDp) * 0.5
drawLightning(center.x, center.y, v.x, v.y, displace, detail)
end
-- draw the ball edge
strokeWidth(5)
stroke(128)
fill(0, 0, 0, 0)
ellipse(WIDTH/2, HEIGHT/2, diameter)
-- draw the ball center
noStroke()
fill(192, 0, 128)
ellipse(WIDTH/2, HEIGHT/2, 50)
end
