Snowball Gravity

Blitz3D Forums/Blitz3D Beginners Area/Snowball Gravity

Happy Llama

(Posted 2012) [#1]

I want to add gravity to the snowballs. I have made a Field gravity and decrease it by 0.001 in a For Next loop. When I try to move the snowball by gravity, it won't go down. Any suggestions on how to fix this? Thanks.

Happy Llama


Graphics3D 800,600,0,2
SetBuffer BackBuffer()

Global snowballtimer=MilliSecs()

;variables
Global spacebar=57,escape=1,leftkey=208,rightkey=205
Global gravity=0.3
Global cam_y#=-3
Global cam_x#=0 
Global magazine=10
Global playerhealth=100
Global enemyhealth=100
Global score = 0
Global enemyalive=0
Global collision_id
Global collision_entitiy
Global frametimer = 0

HidePointer

shoosh=LoadSound("swoosh.wmv")

;Types

Type snowball
	Field mesh	
	Field id	
	Field damage
	Field yspeed
End Type

Const type_player=1
Const type_enemy=2
Const type_playersnowball=3
Const type_enemysnowball=4
Const type_1fort=5
Const type_2fort=6

AmbientLight 255,255,255

;Light
sun=CreateLight()


;Player
player=CreateCamera()
CameraFogRange player,0.1,400
CameraFogMode player,True
CameraClsColor player,100,130,150
CameraFogColor player,100,130,150
EntityType player,type_player

;Terrain
Global ground=CreatePlane()
PositionEntity ground,0,-5,0
EntityColor ground,200,200,200


;Sky
Global sky=CreatePlane()
PositionEntity sky,0,100,0
RotateEntity sky,-180,0,0
;Sky texture
Global skytex=LoadTexture("sky.jpg")
EntityTexture sky,skytex
ScaleTexture skytex,5,5
ScaleTexture skytex,500,500

;Load the enemy

Global enemy=LoadMesh("enemy.3ds")
PositionEntity enemy,0,-4,27
ScaleEntity enemy,0.4,0.4,0.4
EntityType enemy,type_enemy

;Create the bullets
Global snowball=CreateSphere()
ScaleEntity snowball,0.5,0.5,0.5
HideEntity snowball



;Make the snow forts:

;Fort 1
Global fort1=LoadMesh("snowfort.3ds")
PositionEntity fort1,0,-3.5,4
EntityColor fort1,255,255,255
ScaleEntity fort1,1,1,2.5
RotateEntity fort1,0,-90,0
EntityType fort1, type_fort1

;Fort 2
Global fort2=CreateCube()
PositionEntity fort2,0,-4,25
EntityColor fort2,255,255,255
ScaleEntity fort2,2,1,1
EntityType fort1, type_fort2

Global aimer=LoadImage("Aimer.png")
MaskImage aimer,255,255,255
ScaleImage aimer,0.3,0.3
MidHandle aimer


;Making it snow!

;Dim snowflake(1000)

;For p=0 To 1000

;snowflake(p)=CreateSphere()

;ScaleEntity snowflake(p),0.05,0.05,0.05

;PositionEntity snowflake(p),Rnd(-50,50),Rnd(1,100),Rnd(-50,50)

;Next

Collisions type_playersnowball, type_enemy, 2,2
Collisions type_enemysnowball, type_player,1,2

;###############
;#  Main Loop  #
;###############
While Not KeyDown (escape)


;player snowballs
If MouseHit(1) And magazine > 0	And cam_y=-3.0
	s.snowball = New snowball 		
	s\mesh = CopyEntity(snowball)		
	s\id = 1						
	s\damage = 5
	s\yspeed# = 0
	yspeed=yspeed-0.01				
	PositionEntity s\mesh,EntityX(player),EntityY(player),EntityZ(player)			
	RotateEntity s\mesh, EntityPitch(player),EntityYaw(player),EntityRoll(player)	
	magazine = magazine -1
	EntityType s\mesh,type_playersnowball
	EntityRadius s\mesh, 2			
End If 


For s.snowball = Each snowball	
	MoveEntity s\mesh,0,yspeed,1
	If Abs(EntityZ(s\mesh)) > 400 	
	    FreeEntity s\mesh			
		Delete s					
	End If
Next

If KeyHit(18)And magazine < 1 Then 
	magazine = 10
EndIf 

If magazine < 0 Then
	Text 100,100,"Press E to Reload"
EndIf  

;Enemy snowballs
ThrowSnowballs()

;Collisions:

psnowball_collisions()
esnowball_collisions()


;Move the snow downwards
;For l=0 To 1000
;MoveEntity snowflake(l),0,Rnd(-0.002,-0.1),0
;Next

;duck 

If KeyDown(57) Then  
cam_y=-3.7
Else
cam_y=-3
EndIf

PositionEntity player,cam_x,cam_y,3

;straffting  

If KeyDown(30) Then cam_x=cam_x-0.1

If KeyDown(32) Then cam_x=cam_x+0.1


If cam_x > 0.5 Then cam_x=0.5
If cam_x < -0.5 Then cam_x=-0.5 

;point the enemy at the player
If enemyhealth > 0
	PointEntity enemy,player
End If 

;FPS Camera Stuff
mx#=mx#+MouseXSpeed()
my#=my#+MouseYSpeed()

If mx# > 100 Then mx# = 100
If mx# < -100 Then mx# = -100

If my# > 40 Then my# = 40
If my# < -80 Then my# = -80

RotateEntity player,my#,-mx#,0








RenderWorld

UpdateWorld 

Color 0,0,0

Rect 10,10,170,70,False

Text 20,20,"Snowballs left: "+ magazine
Text 20,40,"Health: "+ playerhealth
Text 20,60,"Score: " + score

DrawImage aimer,GraphicsWidth()/2,GraphicsHeight()/2

Flip




Wend



End


Function psnowball_collisions()	
	For s.snowball = Each snowball						
		For collision_id = 1 To CountCollisions(s\mesh)	
			collision_entity = CollisionEntity(s\mesh, collision_id)
				If GetEntityType(collision_entity) = type_enemy		
					enemyhealth = enemyhealth - s\damage				
						DebugLog "enemyhealth " + enemyhealth
						score = score + 1
						FreeEntity s\mesh	
						Delete s			
							If enemyhealth <= 0 Then FreeEntity enemy	
						Exit
				End If
		Next
	Next
End Function 


Function esnowball_collisions()	
	For a.snowball = Each snowball						
		For collision_id = 1 To CountCollisions(a\mesh)	
			collision_entity = CollisionEntity(a\mesh, collision_id)
				If GetEntityType(collision_entity) = type_player		
					enemyhealth = enemyhealth - a\damage				
						DebugLog "playerhealth " + playerhealth
						playerhealth=playerhealth-a\damage
						FreeEntity a\mesh	
						Delete a				
						Exit
				End If
		Next
	Next
End Function 
				


Function ThrowSnowballs()


   If MilliSecs() >= snowballtimer + 1000
        snowballtimer = MilliSecs() 
        a.snowball = New snowball
	a\mesh = CopyEntity(snowball)
	a\id = 2
	a\damage = 5
	PositionEntity a\mesh,EntityX(enemy),EntityY(enemy),EntityZ(enemy)
	RotateEntity a\mesh, EntityPitch(enemy),EntityYaw(enemy),EntityRoll(enemy)
	EntityType a\mesh,type_enemysnowball
   EndIf


End Function

Last edited 2012

Yasha

(Posted 2012) [#2]

Firstly, you're not using the "yspeed" field for anything. You use a local in the main loop that's also called "yspeed" - is this intentional? The only thing you do to the field of the same name in the main loop is zero it (since you zero it directly above the line manipulating the local... if that was supposed to be the field, it wouldn't do anything anyway). It's not entirely clear what your intention is in this part of the code.

Secondly, both the local and the field are defaulting to integers, not floats, and therefore trying to modify them by 0.01 (note: not 0.001 in the actual code) will round to zero and have no effect.

Line 138 by the way highlights a bug in Blitz3D: it should really complain that you've used the float sigil on an integer field, but for some reason doesn't (sigils don't do anything after the line where the variable was declared - best avoid them except in declarations). The presence of the float sigil here is therefore not changing the fact that that field holds an integer.

(I should take a moment to recommend the editor IDEal, which helpfully highlighted all of these errors in red for me!)

Matty

(Posted 2012) [#3]

Changed as follows:

For s.snowball = Each snowball	
	MoveEntity s\mesh,0,s\yspeed,1 ;LINE MODIFIED - s\yspeed used instead of yspeed
	;NEW LINE HERE ADDED BY MATTY
	s\yspeed = s\yspeed - gravity
	If Abs(EntityZ(s\mesh)) > 400 	
	    FreeEntity s\mesh			
	    Delete s					
	End If
Next

Note I haven't read the rest of your code so no idea if the rest works as you want it to but hopefully that should put you on the right track...

Last edited 2012

Happy Llama

(Posted 2012) [#4]

thanks