I just had to convert a cool "homing example" by Jeppe Nielsen from BlitzBasic to PureBasic.
It isn't perfect in any way! I did a fast conversion and it can improved in a 1000 ways.
but here it is...
Code: Select all
; Homing example, by Jeppe Nielsen 2003
;
; Original code from BlitzBasic Community
; http://www.blitzbasic.com
;
; Converted from BlitzBasic to PureBasic by Techjunkie 2004
Global playerx.l
Global playery.l
Global distance.f
Global fcolor.l
distance = 100
Structure enemy
x.l
y.l
vx.f
vy.f
ax.f
ay.f
vmax.f
amax.f
EndStructure
Global e.enemy
Global Dim e.enemy(1000)
Global enemy_count.l
enemy_count = 0
Procedure enemynew(x.f, y.f, vmax.f, amax.f)
e(enemy_count)\x = x
e(enemy_count)\y = y
e(enemy_count)\vmax = vmax
e(enemy_count)\amax = amax
enemy_count + 1
EndProcedure
Procedure enemyupdate()
For i = 0 To enemy_count
dx.f = (playerx - e(i)\x)
dy.f = (playery - e(i)\y)
l.f = Sqr(dx.f * dx.f + dy.f * dy.f)
dx.f =( dx.f / l.f) * e(i)\amax
dy.f = (dy.f / l.f) * e(i)\amax
;if close enough escape target
If l.f <= distance.f
dx.f = -dx.f
dy.f = -dy.f
EndIf
;check against all other enemies, to avoid them
dxx.f = 0
dyy.f = 0
co = 0
For j = 0 To enemy_count
If j <> i
dex.f = (e(i)\x - e(j)\x)
dey.f = (e(i)\y - e(j)\y)
l.f = Sqr(dex.f * dex.f + dey.f * dey.f)
dxx.f = dxx.f + (dex.f / l.f) * e(i)\amax
dyy.f = dyy.f + (dey.f / l.f) * e(i)\amax
co + 1
EndIf
Next
dxx.f = dxx.f / co
dyy.f = dyy.f / co
dx.f = (dx.f + dxx.f) / 2.0
dy.f = (dy.f + dyy.f) / 2.0
e(i)\ax = e(i)\ax + dx.f
e(i)\ay = e(i)\ay + dy.f
acc.f = Sqr(e(i)\ax * e(i)\ax + e(i)\ay * e(i)\ay)
;Check if current acceleration is more than allowed
If acc.f > e(i)\amax
e(i)\ax = (e(i)\ax / acc.f) * e(i)\amax
e(i)\ay = (e(i)\ay / acc.f) * e(i)\amax
EndIf
e(i)\vx = e(i)\vx + e(i)\ax
e(i)\vy = e(i)\vy + e(i)\ay
vel.f = Sqr(e(i)\vx * e(i)\vx + e(i)\vy * e(i)\vy)
;Check if current velocity is more than allowed
If vel.f > e(i)\vmax
e(i)\vx = (e(i)\vx / vel.f) * e(i)\vmax
e(i)\vy = (e(i)\vy / vel.f) * e(i)\vmax
EndIf
; add velocity to position
e(i)\x = e(i)\x + e(i)\vx
e(i)\y = e(i)\y + e(i)\vy
Next
EndProcedure
If InitMouse() = 0 Or InitSprite() = 0 Or InitKeyboard() = 0
MessageRequester("Error", "Can't open DirectX", 0)
End
EndIf
If (OpenScreen(800, 600, 16, "Homing Example") = 0)
MessageRequester("Error", "Impossible to open a 800*600 16 bit screen",0)
End
EndIf
;create ten enemies at random locations
For i = 1 To 10
enemynew(Random(800.0), Random(600.0), (4.0*Random(1000)/1000) + 0.5, (0.08*Random(1000)/1000) + 0.02)
Next
; BackColor(RGB(0, 0, 0))
click = 0
fcolor = RGB(255,255,255)
Repeat
FlipBuffers()
ClearScreen(RGB(0,0,0))
ExamineKeyboard()
ExamineMouse()
StartDrawing(ScreenOutput())
DrawingMode(2|4)
text.s = "Enemies = " + Str(enemy_count)
; Locate(10,10)
; DrawText(text)
; Locate(10,30)
; DrawText("Move player with mouse")
; Locate(10,50)
; DrawText("LMB - Resize allowed distance to player")
; Locate(10,70)
; DrawText("RMB - Add enemies")
; Locate(10,90)
; DrawText("ESC - Quit")
StopDrawing()
If click = 0
playerx = MouseX()
playery = MouseY()
EndIf
If (MouseButton(1) And click = 0)
click = 1
clickx = MouseX()
clicky = MouseY()
EndIf
If (MouseButton(1) And click = 1)
dx = (MouseX() - clickx)
dy = (MouseY() - clicky)
distance = Sqr(dx * dx + dy * dy)
EndIf
If (MouseButton(1) = 0 And click = 1)
click = 0
EndIf
If (MouseButton(2))
If (enemy_count < 1000)
enemynew(Random(800.0), Random(600.0), 2.5, (0.08 * Random(1000)/1000) + 0.02)
EndIf
EndIf
enemyupdate()
StartDrawing(ScreenOutput())
DrawingMode(2|4)
For i = 0 To enemy_count
Box(e(i)\x - 3, e(i)\y - 3, 6, 6, fcolor)
Next
Box(playerx - distance, playery - distance, 10, 10, fcolor)
Circle(playerx - distance , playery - distance, distance * 2, fcolor)
StopDrawing()
Until KeyboardPushed(#PB_Key_Escape)
End
It's rather cool, but thank Jeppe Nielsen too. He's done a lot of cool stuff in BlitzBasic. I'm about to convert more examples.