Torch Light Effect

BlitzMax Forums/BlitzMax Programming/Torch Light Effect

therevills

(Posted 2009) [#1]

Hi All,

I'm trying to achieve a torch light effect around some sprites.

I've tried using SetBlend SHADEBLEND and this works okay, as long as I dont have a background image.... but I want a background image!

Heres some code:

SuperStrict
Graphics 800,600,0
SeedRnd MilliSecs()

Const MAPWIDTH:Int = 800/32
Const MAPHEIGHT:Int = 600/32

Global map:Int[MAPWIDTH, MAPHEIGHT]

Cls
'create player
SetColor 1,1,1
DrawOval 0,0,30,30
SetColor 255,255,255
DrawOval 3,3,24,24
SetColor 255,0,0
DrawOval 5,5,20,20
Global player:TImage=CreateImage(30,30,1,DYNAMICIMAGE|MASKEDIMAGE)
GrabImage player,0,0

Cls
' Create background
For Local i% = 0 To 100
	SetColor Rand(255),Rand(255),Rand(255)
	DrawLine Rand(0,800),Rand(0,600),Rand(0,800),Rand(0,600)
Next
Global background:TImage=CreateImage(800,600,1,DYNAMICIMAGE|MASKEDIMAGE)
GrabImage background,0,0

Cls
' Create background 1
For Local i% = 0 To 1000
	SetColor Rand(255),Rand(255),Rand(255)
	DrawOval Rand(0,800),Rand(0,600),Rand(10,100),Rand(10,100)
Next
Global background1:TImage=CreateImage(800,600,1,DYNAMICIMAGE|MASKEDIMAGE)
GrabImage background1,0,0

Cls
' create tile
SetColor 100,30,0
DrawRect 0,0,16,16
DrawRect 16,16,16,16
SetColor 147,70,0
DrawRect 16,0,16,16	
DrawRect 0,16,16,16
Global tile:TImage=CreateImage(32,32,1,DYNAMICIMAGE|MASKEDIMAGE)
GrabImage tile,0,0

Cls

MidHandleImage player
ReadLevelData()

Global px%=400,py%=300,px1%=100,py1%=100,px2%=200,py2%=200
Global bx%,by%,bg_on%,bg1_on%
Global angle:Float=Rand(0,359)
Global spd:Float=6
Global dx:Float = Cos(angle) * spd
Global dy:Float = Sin(angle) * spd

SetColor 255,255,255
SetClsColor 50,50,50

While Not AppTerminate()=1 And Not KeyHit(KEY_ESCAPE)
	'controls
	If KeyDown(KEY_RIGHT) px:+5
	If KeyDown(KEY_LEFT) px:-5
	If KeyDown(KEY_UP) py:-5
	If KeyDown(KEY_DOWN) py:+5
	
	If KeyHit(KEY_F1)
		If bg_on Then bg_on = False Else bg_on = True
	EndIf
	If KeyHit(KEY_F2)
		If bg1_on Then bg1_on = False Else bg1_on = True
	EndIf
	
	' move background 1
	bx:-1
	If bx < - 800 bx = 0	
	
	' bounce the other player around
	px1:+ dx
	py1:+ dy
	If (px1+dx)<10 Or px1+dx>GraphicsWidth()-10 Then dx = - dx 
	If (py1+dy)<10 Or py1+dy>GraphicsHeight()-10 Then dy = - dy	
	
	'draw
	Cls
		'draw light
		SetBlend SOLIDBLEND
		DrawOval px-100,py-100,200,200
		DrawOval px1-100,py1-100,200,200
		
		'draw background		
		SetBlend SHADEBLEND
		If bg_on Then DrawImage background,0,0
		If bg1_on Then
			SetAlpha 0.2
			DrawImage Background1, bx, by
			DrawImage Background1, bx+800, by
			SetAlpha 1
		EndIf
		'draw tile
		DrawMap()
		DrawImage player,px2,py2
		'draw player
		SetBlend ALPHABLEND
		DrawImage player,px,py
		DrawImage player,px1,py1
	Flip 1
Wend

Function ReadLevelData()
	For Local y:Int = 0 To MAPHEIGHT - 1
		For Local x:Int = 0 To MAPWIDTH - 1
			Local Data:Int
			ReadData Data
			map[x, y]= Data
		Next
	Next
End Function

Function DrawMap()
	For Local x:Int = 0 To MAPWIDTH - 1
		For Local y:Int = 0 To MAPHEIGHT - 1
			Select map[x, y]
				Case 1
					DrawImage Tile, x * 32, y * 32
			End Select
		Next
	Next
End Function

DefData 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 0, 0, 0, 2, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 0, 1, 0, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1
DefData 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1

When you first run it, you can see the desired effect (although the player at px2,py2 should have alpha too...). Then place F1 and F2 to turn on the backgrounds.

When the backgrounds are on the tiles become transparent which I dont want and the light effect is ruined... any solutions?

Thanks

Nate the Great

(Posted 2009) [#2]

is this what you are trying to do?

SuperStrict
Graphics 800,600,0
SeedRnd MilliSecs()

Const MAPWIDTH:Int = 800/32
Const MAPHEIGHT:Int = 600/32

Global map:Int[MAPWIDTH, MAPHEIGHT]

Cls
'create player
SetColor 1,1,1
DrawOval 0,0,30,30
SetColor 255,255,255
DrawOval 3,3,24,24
SetColor 255,0,0
DrawOval 5,5,20,20
Global player:TImage=CreateImage(30,30,1,DYNAMICIMAGE|MASKEDIMAGE)
GrabImage player,0,0

Cls
' Create background
For Local i% = 0 To 100
	SetColor Rand(255),Rand(255),Rand(255)
	DrawLine Rand(0,800),Rand(0,600),Rand(0,800),Rand(0,600)
Next
Global background:TImage=CreateImage(800,600,1,DYNAMICIMAGE|MASKEDIMAGE)
GrabImage background,0,0

Cls
' Create background 1
For Local i% = 0 To 1000
	SetColor Rand(255),Rand(255),Rand(255)
	DrawOval Rand(0,800),Rand(0,600),Rand(10,100),Rand(10,100)
Next
Global background1:TImage=CreateImage(800,600,1,DYNAMICIMAGE|MASKEDIMAGE)
GrabImage background1,0,0

Cls
' create tile
SetColor 100,30,0
DrawRect 0,0,16,16
DrawRect 16,16,16,16
SetColor 147,70,0
DrawRect 16,0,16,16	
DrawRect 0,16,16,16
Global tile:TImage=CreateImage(32,32,1,DYNAMICIMAGE|MASKEDIMAGE)
GrabImage tile,0,0

Cls

MidHandleImage player
ReadLevelData()

Global px%=400,py%=300,px1%=100,py1%=100,px2%=200,py2%=200
Global bx%,by%,bg_on%,bg1_on%
Global angle:Float=Rand(0,359)
Global spd:Float=6
Global dx:Float = Cos(angle) * spd
Global dy:Float = Sin(angle) * spd

SetColor 255,255,255
SetClsColor 50,50,50

While Not AppTerminate()=1 And Not KeyHit(KEY_ESCAPE)
	'controls
	If KeyDown(KEY_RIGHT) px:+5
	If KeyDown(KEY_LEFT) px:-5
	If KeyDown(KEY_UP) py:-5
	If KeyDown(KEY_DOWN) py:+5
	
	If KeyHit(KEY_F1)
		If bg_on Then bg_on = False Else bg_on = True
	EndIf
	If KeyHit(KEY_F2)
		If bg1_on Then bg1_on = False Else bg1_on = True
	EndIf
	
	' move background 1
	bx:-1
	If bx < - 800 bx = 0	
	
	' bounce the other player around
	px1:+ dx
	py1:+ dy
	If (px1+dx)<10 Or px1+dx>GraphicsWidth()-10 Then dx = - dx 
	If (py1+dy)<10 Or py1+dy>GraphicsHeight()-10 Then dy = - dy	
	
	'draw
	Cls
		
		
		'draw background		
		SetBlend lightblend
		If bg_on Then DrawImage background,0,0
		If bg1_on Then
			SetAlpha 0.2
			DrawImage Background1, bx, by
			DrawImage Background1, bx+800, by
			SetAlpha 1
		EndIf
		SetBlend solidblend
		'draw tile
		DrawMap()
		DrawImage player,px2,py2
		'draw player
		SetBlend ALPHABLEND
		DrawImage player,px,py
		DrawImage player,px1,py1
		
		'draw light
		SetBlend lightBLEND
		SetAlpha .2
		DrawOval px-100,py-100,200,200
		DrawOval px1-100,py1-100,200,200
		SetAlpha 1
	Flip 1
Wend

Function ReadLevelData()
	For Local y:Int = 0 To MAPHEIGHT - 1
		For Local x:Int = 0 To MAPWIDTH - 1
			Local Data:Int
			ReadData Data
			map[x, y]= Data
		Next
	Next
End Function

Function DrawMap()
	For Local x:Int = 0 To MAPWIDTH - 1
		For Local y:Int = 0 To MAPHEIGHT - 1
			Select map[x, y]
				Case 1
					DrawImage Tile, x * 32, y * 32
			End Select
		Next
	Next
End Function

DefData 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 0, 0, 0, 2, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 0, 1, 0, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1
DefData 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1

therevills

(Posted 2009) [#3]

Thanks Nate, but not quite. I actually tried that way first. It doesnt shade the level tiles and it looks light the brightness is wrong on the lighted part...

Any other ideas?

matibee

(Posted 2009) [#4]

A bit more like this...

Drawing a light/shadowmap over the whole scene. In this example it's grabbed at 1/10th scale for performance. Using an image with blending edges for the highlight will improve the look of it.

SuperStrict
Graphics 800,600,0
SeedRnd MilliSecs()

Const MAPWIDTH:Int = 800/32
Const MAPHEIGHT:Int = 600/32

Global map:Int[MAPWIDTH, MAPHEIGHT]

Cls
'create player
SetColor 1,1,1
DrawOval 0,0,30,30
SetColor 255,255,255
DrawOval 3,3,24,24
SetColor 255,0,0
DrawOval 5,5,20,20
Global player:TImage=CreateImage(30,30,1,DYNAMICIMAGE|MASKEDIMAGE)
GrabImage player,0,0

Cls
' Create background
For Local i% = 0 To 100
	SetColor Rand(255),Rand(255),Rand(255)
	DrawLine Rand(0,800),Rand(0,600),Rand(0,800),Rand(0,600)
Next
Global background:TImage=CreateImage(800,600,1,DYNAMICIMAGE|MASKEDIMAGE)
GrabImage background,0,0

Cls
' Create background 1
For Local i% = 0 To 1000
	SetColor Rand(255),Rand(255),Rand(255)
	DrawOval Rand(0,800),Rand(0,600),Rand(10,100),Rand(10,100)
Next
Global background1:TImage=CreateImage(800,600,1,DYNAMICIMAGE|MASKEDIMAGE)
GrabImage background1,0,0

Cls
' create tile
SetColor 100,30,0
DrawRect 0,0,16,16
DrawRect 16,16,16,16
SetColor 147,70,0
DrawRect 16,0,16,16	
DrawRect 0,16,16,16
Global tile:TImage=CreateImage(32,32,1,DYNAMICIMAGE|MASKEDIMAGE)
GrabImage tile,0,0

Cls

MidHandleImage player
ReadLevelData()

Global px%=400,py%=300,px1%=100,py1%=100,px2%=200,py2%=200
Global bx%,by%,bg_on%,bg1_on%
Global angle:Float=Rand(0,359)
Global spd:Float=6
Global dx:Float = Cos(angle) * spd
Global dy:Float = Sin(angle) * spd

SetColor 255,255,255
SetClsColor 50,50,50

Local lightMap:TImage = CreateImage( 80,60,1,DYNAMICIMAGE|MASKEDIMAGE )

While Not AppTerminate()=1 And Not KeyHit(KEY_ESCAPE)
	'controls
	If KeyDown(KEY_RIGHT) px:+5
	If KeyDown(KEY_LEFT) px:-5
	If KeyDown(KEY_UP) py:-5
	If KeyDown(KEY_DOWN) py:+5
	
	If KeyHit(KEY_F1)
		If bg_on Then bg_on = False Else bg_on = True
	EndIf
	If KeyHit(KEY_F2)
		If bg1_on Then bg1_on = False Else bg1_on = True
	EndIf
	
	' move background 1
	bx:-1
	If bx < - 800 bx = 0	
	
	' bounce the other player around
	px1:+ dx
	py1:+ dy
	If (px1+dx)<10 Or px1+dx>GraphicsWidth()-10 Then dx = - dx 
	If (py1+dy)<10 Or py1+dy>GraphicsHeight()-10 Then dy = - dy	
	
	'draw
	Cls
		SetBlend SOLIDBLEND
		DrawOval (px-100)/10,(py-100)/10,20,20
		DrawOval (px1-100)/10,(py1-100)/10,20,20
		'DrawOval 80,60,20,20
		
		GrabImage( lightMap, 0, 0 )
		
		Cls 	

		'draw background		
		SetBlend SHADEBLEND
		If bg_on Then DrawImage background,0,0
		If bg1_on Then
			SetAlpha 0.2
			DrawImage Background1, bx, by
			DrawImage Background1, bx+800, by
			SetAlpha 1
		EndIf
		'draw tile
		SetBlend SOLIDBLEND
		DrawMap()
		
		'draw light
		SetBlend SOLIDBLEND
		'DrawOval px-100,py-100,200,200
		'DrawOval px1-100,py1-100,200,200
		
		DrawImage player,px2,py2
		'draw player
		SetBlend ALPHABLEND
		SetAlpha 1.0
		
		DrawImage player,px,py
		DrawImage player,px1,py1
		
		SetBlend SHADEBLEND
		SetAlpha 0.5
		SetScale 10,10
		DrawImage lightMap, 0, 0
		SetScale 1, 1
	Flip 1
Wend

Function ReadLevelData()
	For Local y:Int = 0 To MAPHEIGHT - 1
		For Local x:Int = 0 To MAPWIDTH - 1
			Local Data:Int
			ReadData Data
			map[x, y]= Data
		Next
	Next
End Function

Function DrawMap()
	For Local x:Int = 0 To MAPWIDTH - 1
		For Local y:Int = 0 To MAPHEIGHT - 1
			Select map[x, y]
				Case 1
					DrawImage Tile, x * 32, y * 32
			End Select
		Next
	Next
End Function

DefData 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 0, 0, 0, 2, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 0, 1, 0, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1
DefData 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1

therevills

(Posted 2009) [#5]

Excellent! Thanks alot matibee!

Would never have thought of doing it that way!

therevills

(Posted 2009) [#6]

Tided the code up a bit and added an "image" with blended images (but looks like grab image doesnt grab the alpha correctly at the edges) - Thanks again matibee!

SuperStrict
Graphics 800,600,0
SeedRnd MilliSecs()

Const MAPWIDTH:Int = 800/32
Const MAPHEIGHT:Int = 600/32

Global map:Int[MAPWIDTH, MAPHEIGHT]
Global lightimg:TImage, player:TImage, background:TImage, background1:TImage, Tile:TImage

CreateGameGraphics()

ReadLevelData()

Global px%=400,py%=300,px1%=100,py1%=100,px2%=200,py2%=200
Global bx%,by%,bg_on% = 1 ,bg1_on% = 1
Global angle:Float=Rand(0,359)
Global spd:Float=6
Global dx:Float = Cos(angle) * spd
Global dy:Float = Sin(angle) * spd

SetColor 255,255,255
SetClsColor 20,20,20

Local lightMap:TImage = CreateImage( 160,120,1,DYNAMICIMAGE|MASKEDIMAGE )

While Not AppTerminate()=1 And Not KeyHit(KEY_ESCAPE)
	'controls
	If KeyDown(KEY_RIGHT) px:+5
	If KeyDown(KEY_LEFT) px:-5
	If KeyDown(KEY_UP) py:-5
	If KeyDown(KEY_DOWN) py:+5
	
	If KeyHit(KEY_F1)
		If bg_on Then bg_on = False Else bg_on = True
	EndIf
	If KeyHit(KEY_F2)
		If bg1_on Then bg1_on = False Else bg1_on = True
	EndIf
	
	' move background 1
	bx:-1
	If bx < - 800 bx = 0	
	
	' bounce the other player around
	px1:+ dx
	py1:+ dy
	If (px1+dx)<10 Or px1+dx>GraphicsWidth()-10 Then dx = - dx 
	If (py1+dy)<10 Or py1+dy>GraphicsHeight()-10 Then dy = - dy	
	
	'draw
	Cls
		SetBlend ALPHABLEND
		DrawImage lightimg,(px-100)/5,(py-100)/5
		DrawImage lightimg,(px1-100)/5,(py1-100)/5		
		GrabImage( lightMap, 0, 0 )
		
		Cls 	
		If bg_on Then DrawImage background,0,0
		If bg1_on Then
			SetAlpha 0.6
			DrawImage Background1, bx, by
			DrawImage Background1, bx+800, by
			SetAlpha 1
		EndIf
		'draw map
		DrawMap()
		
		'draw player
		SetBlend ALPHABLEND
		SetAlpha 1.0
		DrawImage player,px2,py2
		DrawImage player,px,py
		DrawImage player,px1,py1
		
		SetBlend SHADEBLEND
		SetAlpha 0.8
		SetScale 5,5
		DrawImage lightMap, 0, 0
		SetScale 1, 1
		SetAlpha 1		
	Flip 1
Wend

Function ReadLevelData()
	For Local y:Int = 0 To MAPHEIGHT - 1
		For Local x:Int = 0 To MAPWIDTH - 1
			Local Data:Int
			ReadData Data
			map[x, y]= Data
		Next
	Next
End Function

Function DrawMap()
	For Local x:Int = 0 To MAPWIDTH - 1
		For Local y:Int = 0 To MAPHEIGHT - 1
			Select map[x, y]
				Case 1
					DrawImage Tile, x * 32, y * 32
			End Select
		Next
	Next
End Function

DefData 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 0, 0, 0, 2, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 0, 1, 0, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
DefData 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1
DefData 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1

Function CreateGameGraphics()
	Cls
	createLight()
	createPlayer()
	createBackgrounds()
	createTile()
	Cls
	MidHandleImage player
End Function

Function createLight()
	Cls
	'create light
	SetBlend ALPHABLEND
	SetColor 255,255,255
	Local s#=0
	For Local i%=0 To 20
	SetAlpha 0.2
	DrawOval 0+s,0+s,40-s-s,40-s-s
	s:+0.5
	Next
	lightimg:TImage=CreateImage(40,40,1,DYNAMICIMAGE|MASKEDIMAGE)
	GrabImage lightimg,0,0
	SetAlpha 1
End Function

Function createPlayer()
	Cls
	'create player
	SetColor 1,1,1
	DrawOval 0,0,30,30
	SetColor 255,255,255
	DrawOval 3,3,24,24
	SetColor 255,0,0
	DrawOval 5,5,20,20
	player:TImage=CreateImage(30,30,1,DYNAMICIMAGE|MASKEDIMAGE)
	GrabImage player,0,0
End Function

Function createBackgrounds()
	Cls
	SetLineWidth 10
	' Create background
	For Local i% = 0 To 100
		SetColor Rand(255),Rand(255),Rand(255)
		DrawLine Rand(0,800),Rand(0,600),Rand(0,800),Rand(0,600)
	Next
	background:TImage=CreateImage(800,600,1,DYNAMICIMAGE|MASKEDIMAGE)
	GrabImage background,0,0
	
	Cls
	' Create background 1
	For Local i% = 0 To 1000
		SetColor Rand(255),Rand(255),Rand(255)
		DrawOval Rand(0,800),Rand(0,600),Rand(10,100),Rand(10,100)
	Next
	background1:TImage=CreateImage(800,600,1,DYNAMICIMAGE|MASKEDIMAGE)
	GrabImage background1,0,0
End Function

Function createTile()
	Cls
	' create tile
	SetColor 100,30,0
	DrawRect 0,0,16,16
	DrawRect 16,16,16,16
	SetColor 147,70,0
	DrawRect 16,0,16,16	
	DrawRect 0,16,16,16
	tile:TImage=CreateImage(32,32,1,DYNAMICIMAGE|MASKEDIMAGE)
	GrabImage tile,0,0
End Function

matibee

(Posted 2009) [#7]

Happy to help :)

I'm a bit rusty with my blend modes, but I think I've fixed your other issues too..

GrabImage won't grab any alpha values since there's no alpha stored on the rendertarget (IIRC). To get round that, draw the light image in various shades of grey without any alpha involved.

Function CreateLight()
	Cls
	'create light
	SetBlend SOLIDBLEND
	Local s#=0
	For Local i%=0 To 20
	Local grey% = Min ( i * i, 255 )
	SetColor grey, grey, grey
	DrawOval 0+s,0+s,40-s-s,40-s-s
	s:+0.5
	Next
	lightimg:TImage=CreateImage(40,40,1,DYNAMICIMAGE|MASKEDIMAGE)
	GrabImage lightimg,0,0
End Function

Now when you draw them to your lightmap, draw them in LIGHTBLEND mode and when you draw the lightmap, there's no need to set/unset any alpha values since there's no alpha involved with the shadeblend.

Cls
		SetBlend LIGHTBLEND
		DrawImage lightimg,(px-100)/5,(py-100)/5
		DrawImage lightimg,(px1-100)/5,(py1-100)/5		
		GrabImage( lightMap, 0, 0 )
		
		Cls 
		SetBlend ALPHABLEND 	
		If bg_on Then DrawImage background,0,0
		If bg1_on Then
			SetAlpha 0.6
			DrawImage Background1, bx, by
			DrawImage Background1, bx+800, by
			SetAlpha 1
		EndIf
		'draw map
		DrawMap()
		
		'draw player
		SetBlend ALPHABLEND
		SetAlpha 1.0
		DrawImage player,px2,py2
		DrawImage player,px,py
		DrawImage player,px1,py1
		
		SetBlend SHADEBLEND
		SetScale 5,5
		DrawImage lightMap, 0, 0
		SetScale 1, 1
	Flip 1

Finally, if you want the two lights to interact, try turning down the maximum grey value in the CreateLight function

Local grey% = Min ( i * i, 128 )

Personally I think there should be more of a drop off in light values as it moves away from the centre, so experiment a little more with the CreateLight func (or I'd have used in image I could get right in Photoshop).

therevills

(Posted 2009) [#8]

Thanks again matibee!

I'm a bit rusty with my blend modes

Ive only really used ALPHABLEND and LIGHTBLEND the blend modes...

Cool example using LIGHTBLEND to use the grey to fade out, although in my game Ive actually created an image with alpha, but Ill see which is better :)

matibee

(Posted 2009) [#9]

One other thing I wanted to try..

If your tiles are 32x32, and you make the shadow map 1/8 th scale, you could occlude the lights using 4x4 rects of solid black drawn onto the lightmap after the lights have been drawn.

If you had a quick visibility test, you could fill in all the 4x4 cells that are not visible from the light position, creating a very cool dynamic lighting effect :)