Instead of working on the map editor for that "3d thing", I started playing around with the code I posted here.
If you think, rather than just write lines of code more or less by random (that's what I did), it's possible that you can make something interesting of this. I added lots of code to be able to add polygons that can be repositioned and rotated. The 'PushOut' function handles collision between an object (circle) and all the lines in the scene. It also sets a direction (obj.pdx and obj.pdy) which is the "average push out direction". With my random lines of code, I try to use that direction to determine when the object (player) is standing on something (then he can jump), when it hits something from below etc. And ... ugh ... never mind.
If you think, rather than just write lines of code more or less by random (that's what I did), it's possible that you can make something interesting of this. I added lots of code to be able to add polygons that can be repositioned and rotated. The 'PushOut' function handles collision between an object (circle) and all the lines in the scene. It also sets a direction (obj.pdx and obj.pdy) which is the "average push out direction". With my random lines of code, I try to use that direction to determine when the object (player) is standing on something (then he can jump), when it hits something from below etc. And ... ugh ... never mind.
Code:
' Experiment.
set window "Collision", 640, 480
set redraw off
#win32
' List of lines that objects can collide with.
lines = []
' Add a square using Polygon and add its lines to lines.
square = Polygon([-50, -50, 50, -50, 50, 50, -50, 50], 320, 240, true)
square.AddTo(lines)
' Add a star using Polygon.
star = Polygon([0, -100, 25, -25, 100, 0, 25, 25, 0, 100, -25, 25, -100, 0, -25, -25], 425, 100, true)
star.AddTo(lines)
' Add another star ...
star2 = Polygon([0, -100, 25, -25, 100, 0, 25, 25, 0, 100, -25, 25, -100, 0, -25, -25], 175, 125, true)
star2.AddTo(lines)
' Add two static rectangle using rectangle.
tmp = Rectangle(64, 480 - 64, 640 - 128, 32)
tmp.AddTo(lines)
tmp = Rectangle(32, 32, 32, 200)
tmp.AddTo(lines)
' Add a rectangle that will spin.
rectangle = Rectangle(110, 300, 130, 32)
rectangle.AddTo(lines)
' Add some borders.
lines[sizeof(lines)] = Line(0, 0, 639, 0)
lines[sizeof(lines)] = Line(639, 0, 639, 479)
lines[sizeof(lines)] = Line(639, 479, 0, 479)
lines[sizeof(lines)] = Line(0, 479, 0, 0)
' Player.
obj = Object(100, 100, 16)
obj.dx = 0
obj.dy = 0
while not keydown(KEY_ESCAPE, true)
' Rotate obstacles.
square.SetAngle(square.Angle() + rad(0.5))
star.SetAngle(star.Angle() + rad(0.25))
star2.SetAngle(star2.Angle() - rad(0.5))
rectangle.SetAngle(rectangle.Angle() - rad(0.25))
if keydown(KEY_LEFT) obj.dx = max(obj.dx - 0.5, -3)
elseif keydown(KEY_RIGHT) obj.dx = min(obj.dx + 0.5, 3)
obj.x = obj.x + obj.dx
obj.y = obj.y + obj.dy
PushOut(obj, lines)
' obj.pdx and obj.pdy has now been set to the average "push direction" caused by all lines
' pushing the object around.
' Push direction y < 0 means the object is being pushed UP. In that case, set dy to 0.
if obj.pdy < 0
obj.dy = 0
' If push direction y < -0.25, let the player jump.
if obj.pdy < -0.25 and keydown(KEY_UP, true)
obj.dy = -5
endif
elseif obj.pdy > 0
obj.dy = max(obj.dy, obj.pdy)
endif
' Apply gravity.
obj.dy = min(obj.dy + 0.1, 6)
' So ... stuff to dx.
obj.dx = obj.dx + obj.pdx*0.25 ' I have no idea
obj.dx = obj.dx*0.95
set color 0, 0, 0
cls
set color 255, 255, 255
DrawLines(lines)
obj.Draw()
set caret width(primary)/2, 16
center "Use the arrow keys to move left and right and jump"
redraw
fwait 60
wend
function DrawLines(lines)
foreach ln in lines draw line ln[0], ln[1], ln[2], ln[3]
endfunc
function Object(x, y, r)
return [x: x, y: y, r: r, rsqr: r*r, pdx: 0, pdy: 0,
Draw: function(); draw ellipse .x, .y, .r, .r, false; endfunc]
endfunc
' Pushout
' -------
function PushOut(obj, lines)
tests = 4
obj.pdx = 0
obj.pdy = 0
for i = 1 to tests
col = false
foreach ln in lines
dp = max(0, min(ln[6], (obj.x - ln[0])*ln[4] + (obj.y - ln[1])*ln[5]))
px = ln[0] + dp*ln[4]; py = ln[1] + dp*ln[5]
dx = obj.x - px; dy = obj.y - py
d = dx*dx + dy*dy
if d < obj.rsqr
k = 1/sqr(d)
obj.x = px + dx*k*obj.r
obj.y = py + dy*k*obj.r
obj.pdx = obj.pdx + dx*k
obj.pdy = obj.pdy + dy*k
col = true
endif
next
if not col break
next
if obj.pdx or obj.pdy
k = 1/sqr(obj.pdx*obj.pdx + obj.pdy*obj.pdy)
obj.pdx = obj.pdx*k
obj.pdy = obj.pdy*k
endif
endfunc
' Polygon
' -------
' Return polygon at position x, y.
function Polygon(points, x, y, closed)
p = [trans: unset, org: [], x: x, y: y, a: 0, cx: 0, cy: 0]
pcount = sizeof(points)/2
centerX = 0
centerY = 0
if closed n = pcount - 1
else n = pcount - 2
for i = 0 to n
j = (i + 1)%pcount
p.org[sizeof(p.org)] = Line(
points[i*2], points[i*2 + 1],
points[j*2], points[j*2 + 1])
next
for i = 0 to pcount - 1
p.cx = p.cx + points[i*2]; p.cy = p.cy + points[i*2 + 1]
next
p.cx = p.cx/pcount; p.cy = p.cy/pcount
p.trans = copy(p.org)
' AddTo
' -----
' Add to list of lines.
p.AddTo = function(lines)
foreach ln in .trans lines[sizeof(lines)] = ln
endfunc
' X
' -
' Return x coordinate.
p.X = function()
return .x
endfunc
' Y
' -
' Return y coordinate.
p.Y = function()
return .y
endfunc
' Angle
' -----
' Return angle.
p.Angle = function()
return .a
endfunc
' SetTransform
' ------------
' Set position and angle and apply.
p.SetTransform = function(x, y, angle)
.x = x
.y = y
.a = angle
.Transform()
endfunc
' SetPosition
' -----------
' Set position and apply.
p.SetPosition = function(x, y)
.x = x
.y = y
.Transform()
endfunc
' SetAngle
' --------
' Set angle and apply.
p.SetAngle = function(angle)
.a = angle
.Transform()
endfunc
' Transform
' ---------
' Update transformed polygon.
p.Transform = function()
RotateLines(.org, .trans, .cx, .cy, .a)
foreach ln in .trans
ln[0] = ln[0] + .x; ln[1] = ln[1] + .y
ln[2] = ln[2] + .x; ln[3] = ln[3] + .y
ln[4] = (ln[2] - ln[0])/ln[6]; ln[5] = (ln[3] - ln[1])/ln[6]
next
endfunc
p.Transform()
return p
' RotateLines
' -----------
' Helper.
function RotateLines(srcLines, dstLines, aroundX, aroundY, angle)
c = cos(angle); s = sin(angle)
for i = 0 to sizeof(srcLines) - 1
srcLn = srcLines[i]; dstLn = dstLines[i]
x = srcLn[0] - aroundX; y = srcLn[1] - aroundY
dstLn[0] = aroundX + x*c - y*s; dstLn[1] = aroundY + y*c + x*s
x = srcLn[2] - aroundX; y = srcLn[3] - aroundY
dstLn[2] = aroundX + x*c - y*s; dstLn[3] = aroundY + y*c + x*s
next
endfunc
endfunc
' Rectangle
' ---------
function Rectangle(x, y, w, h)
w = w - 1
h = h - 1
return Polygon([0, 0, w, 0, w, h, 0, h], x, y, true)
endfunc
' Line
' ----
' Return a new line.
function Line(x0, y0, x1, y1)
ln = [x0, y0, x1, y1]
dx = ln[2] - ln[0]; dy = ln[3] - ln[1]
ln[6] = sqr(dx*dx + dy*dy)
ln[4] = dx/ln[6]
ln[5] = dy/ln[6]
return ln
endfunc