Code:
visible vPolyT = dim(64)
set window "Burning polygon mess", screenw()/screenh()*512, 512, true
set redraw off
set color 0, 8, 32
cls
particles = []
while not keydown(KEY_ESCAPE)
i = 0
while i < sizeof(particles)
if particles[i].Update() i = i + 1
else free key particles, i
wend
particles[sizeof(particles)] = FireParticle(width(primary)/2, height(primary) - 64)
set color 0, 8, 32, 96
cls
set additive true
foreach p in particles p.Draw()
set additive false
redraw
fwait 60
wend
function FireParticle(x, y)
p = []
p.pts = []
for i = 1 to 3 + rnd(4)
p.pts[sizeof(p.pts)] = (rnd() - 0.5)*48
p.pts[sizeof(p.pts)] = (rnd() - 0.5)*48
next
p.x = x + rnd(32) - 16; p.y = y + rnd(32) - 16
p.a = rnd(2*PI); p.as = (rnd() - 0.5)*0.2
p.dx = (rnd() - 0.5)*2; p.dy = (rnd() - 0.75)*2
p.r = 96; p.g = 80; p.b = 64
p.fi = 0; p.p = 0
p.Update = function()
.x = .x + .dx; .y = .y + .dy
.r = 8 + (.r - 8)*0.98; .g = 8 + (.g - 8)*0.96; .b = 8 + (.b - 8)*0.9
.dx = .dx*0.975; .dy = max(.dy - 0.01, - 4)
.a = .a + .as
.fi = min(.fi + 0.05, 1); .p = .p + 0.003
if .p >= 1 return false
return true
endfunc
p.Draw = function()
set color .r, .g, .b, .fi*(1 - .p)*255
DrawPolyXForm(.pts, .x, .y, (1 - .p)*2, 2, .a, false)
endfunc
return p
endfunc
' n7 needs something like this in its core: 'draw poly xform', 'draw poly image xform'
function DrawPolyXForm(points, x, y, sx, sy, a, scaleFirst)
if scaleFirst
for i = 0 to sizeof(points)/2 - 1
px = points[i*2]*sx; py = points[i*2 + 1]*sy
vPolyT[i*2] = x + px*cos(a) - py*sin(a)
vPolyT[i*2 + 1] = y + py*cos(a) + px*sin(a)
next
else
for i = 0 to sizeof(points)/2 - 1
px = points[i*2]; py = points[i*2 + 1]
vPolyT[i*2] = x + (px*cos(a) - py*sin(a))*sx
vPolyT[i*2 + 1] = y + (py*cos(a) + px*sin(a))*sy
next
endif
draw poly vPolyT, true, sizeof(points)/2
endfunc
