2d tile lighting

BlitzMax Forums/BlitzMax Programming/2d tile lighting

Diablo (Posted 2005) [#1]

Ok so I've been working on this code of a while with a mate of mine and got this far. ' Lighting Demo ' NOTE - RIPED From WIP, so sorry for the map types etc... ' ============================================ ' Created By Stefan J Lulham ' Const's Const iTileWidth:Int = 17 Const iTileHeight:Int = 17 ' Globals Global iXOffset:Int = 0 Global iYOffset:Int = 0 Global iDMX:Int = 0 Global iDMY:Int = 0 ' Map ' Info about a map Type Map ' Properties Field m_sName:String ' Name of the map Field m_iWidth:Int ' Width of the map Field m_iHeight:Int ' Height of the map ' Special Properties Field m_kTile:Tile[0, 0] Field m_kAreaList:TList = CreateList() ' Create a map Function Create:Map(sName:String, iWidth:Int, iHeight:Int) ' Create a local map Local kMap:Map = New Map kMap.m_sName = sName kMap.m_iWidth = iWidth kMap.m_iHeight = iHeight kMap.m_kTile = New Tile[iWidth + 1, iHeight + 1] ' Setup the map tiles For iX = 0 To iWidth For iY = 0 To iHeight kMap.m_kTile[iX, iY] = New Tile kMap.m_kTile[iX, iY].m_iFloor = 0 kMap.m_kTile[iX, iY].m_iWall = -1 kMap.m_kTile[iX, iY].m_iWallType = 0 kMap.m_kTile[iX, iY].m_iDarkness = 255 kMap.m_kTile[iX, iY].m_bWindow = False kMap.m_kTile[iX, iY].m_bDoor = False kMap.m_kTile[iX, iY].m_bDoorOpen = False kMap.m_kTile[iX, iY].m_bFoged = False kMap.m_kTile[iX, iY].m_bExplored = False kMap.m_kTile[iX, iY].m_bLit = 0 kMap.m_kTile[iX, iY].m_iRed = 255 kMap.m_kTile[iX, iY].m_iGreen = 255 kMap.m_kTile[iX, iY].m_iBlue = 255 Next Next Return kMap ' Return the local map End Function ' Render the map Method Render() For iX = 0 To m_iWidth For iY = 0 To m_iHeight If m_kTile[iX, iY].m_bFoged = False Then ' Set the colour for the tile based on the darkness iRed = m_kTile[iX, iY].m_iRed - m_kTile[iX, iY].m_iDarkness If iRed < 0 Then iRed = 0 If iRed > 255 Then iRed = 255 iGreen = m_kTile[iX, iY].m_iGreen - m_kTile[iX, iY].m_iDarkness If iGreen < 0 Then iGreen = 0 If iGreen > 255 Then iGreen = 255 iBlue = m_kTile[iX, iY].m_iBlue - m_kTile[iX, iY].m_iDarkness If iBlue < 0 Then iBlue = 0 If iBlue > 255 Then iBlue = 255 ' Calculate the offset iXOffset = (GraphicsWidth() / 2) - (iDMX * 17) iYOffset = (GraphicsHeight() / 2) - (iDMY * 17) SetColor iRed, iGreen, iBlue DrawRect (iX * iTileWidth) + (iXOffset), (iY * iTileWidth) + (iYOffset), 17, 17'DrawImage kFloorImg, (iX * iTileWidth) + (iXOffset), (iY * iTileWidth) + (iYOffset), m_iFloor SetColor 255, 255, 255 EndIf Next Next End Method ' Update the map Method Update() For iX = 0 To m_iWidth For iY = 0 To m_iHeight m_kTile[iX, iY].m_bFoged = True m_kTile[iX, iY].m_iDarkness = 255 m_kTile[iX, iY].m_bLit = 0 Next Next End Method ' Light an area of a map Method LightArea(iCenterX:Int, iCenterY:Int, iFactor:Int = 4, fIntesity:Float = .1, iRed = 255, iGreen = 255, iBlue = 255) 'iFactor = 8 For iAngle:Int = 1 To 360 For k = 1 To 30 iDarkness:Int = 255 tempx = (iCenterX * iTileWidth) + k * iFactor * Cos(iAngle) tempy = (iCenterY * iTileHeight) + k * iFactor * Sin(iAngle) 'If k * iFactor > (30*fIntesity*iFactor) And k * iFactor <= (30 *iFactor) Then iDarkness = (Abs(((30-k)/(30-30*(fIntesity/2))) * 255)) 'EndIf 'DrawText iDarkness, 10, 24 + (k * 12) iDarkness:-255 iDarkness:* -1 ttempx = tempx - tempx Mod iTileWidth ttempx = (ttempx / iTileWidth) + 1 ttempy = tempy - tempy Mod iTileHeight ttempy = (ttempy / iTileHeight) + 1 If ttempx >= 0 And ttempx <= m_iWidth And ttempy >= 0 And ttempy <= m_iHeight Then If m_kTile[ttempx , ttempy].m_bLit = 0 Then ' Darkness Adding m_kTile[ttempx, ttempy].m_iDarkness = (m_kTile[ttempx, ttempy].m_iDarkness + iDarkness) - 255 If m_kTile[ttempx, ttempy].m_iDarkness < 0 Then m_kTile[ttempx, ttempy].m_iDarkness = 0 If m_kTile[ttempx, ttempy].m_iDarkness > 255 Then m_kTile[ttempx, ttempy].m_iDarkness = 255 ' Colour Adding ' - Red m_kTile[ttempx , ttempy].m_ired = ((m_kTile[ttempx , ttempy].m_ired + ired)) If m_kTile[ttempx , ttempy].m_ired =< 0 Then m_kTile[ttempx , ttempy].m_ired = 0 If m_kTile[ttempx , ttempy].m_ired => 255 Then m_kTile[ttempx , ttempy].m_ired = 255 ' - Green m_kTile[ttempx , ttempy].m_igreen = ((m_kTile[ttempx , ttempy].m_igreen + igreen)) If m_kTile[ttempx , ttempy].m_igreen =< 0 Then m_kTile[ttempx , ttempy].m_igreen =0 If m_kTile[ttempx , ttempy].m_igreen => 255 Then m_kTile[ttempx , ttempy].m_igreen = 255 ' - Blue m_kTile[ttempx , ttempy].m_iblue = ((m_kTile[ttempx , ttempy].m_iblue + iblue)) If m_kTile[ttempx , ttempy].m_iblue=< 0 Then m_kTile[ttempx , ttempy].m_iblue= 0 If m_kTile[ttempx , ttempy].m_iblue=> 255 Then m_kTile[ttempx , ttempy].m_iblue= 255 ' Tile has had manip done already m_kTile[ttempx , ttempy].m_bLit = 1 EndIf 'If map[ttempx , ttempy].iWindow = -1 Then ' If map[ttempx , ttempy].iWall > -1 Then ' map[ttempx , ttempy].bFoged = False ' map[ttempx, ttempy].bExplored = True ' Goto goto1 ' EndIf 'EndIf m_kTile[ttempx , ttempy].m_iRed = iRed m_kTile[ttempx , ttempy].m_iGreen = iGreen m_kTile[ttempx , ttempy].m_iBlue = iBlue m_kTile[ttempx , ttempy].m_bFoged = False 'map[ttempx, ttempy].bExplored = True Else Goto a001 End If Next #a001 Next For x = 0 To m_iWidth For y = 0 To m_iHeight m_kTile[x , y].m_bLit = False Next Next End Method End Type ' Tile ' Holds info about a single map tile Type Tile ' Properties Field m_iFloor:Int ' Floor image frame used Field m_iWall:Int ' Wall image frame used (includes Windows, Doors) Field m_iWallType:Byte ' The kind of wall (Wooden, Brick, etc.) Field m_iDarkness:Int ' The darkness of the tile ' Flags Field m_bWindow:Byte ' Is it a window Field m_bDoor:Byte ' Is it a door Field m_bDoorOpen:Byte ' Is the door open Field m_bLit:Byte ' Has it been Lit Field m_bExplored:Byte ' Has it been explored Field m_bFoged:Byte ' Is it foged ' Colour Field m_iRed:Byte ' Red part Field m_iGreen:Byte ' Geen part Field m_iBlue:Byte ' Blue part End Type ' Area ' Holds info about any "area's" Type Area ' Properties Field m_sName:String ' Name of the area Field m_iX:Int ' X position Field m_iY:Int ' y position Field m_iWidth:Int ' Width of the area Field m_iHeight:Int ' Height of the area ' Lighting properties Field m_iRed:Byte ' Red part Field m_iGreen:Byte ' Geen part Field m_iBlue:Byte ' Blue part Field m_iPower:Byte ' Power of the light End Type Graphics 640, 480, 32 SetMaskColor 255, 0, 255 SetBlend ALPHABLEND 'Global kFloorImg = LoadAnimImage("gfx/floor.bmp", iTileWidth, iTileHeight, 0, 1) Global kCurrentMap:Map = Map.Create("Noob", 200, 200) Intesity# = .1 Lightness = 10 While Not KeyHit(Key_Escape) Cls If KeyHit(Key_Up) Or MouseY() <= 3 Then iDMY:- 1 If KeyHit(Key_Down) Or MouseY() >= GraphicsHeight() - 3 Then iDMY:+ 1 If KeyHit(Key_Left) Or MouseX() <= 3 Then iDMX:- 1 If KeyHit(Key_Right) Or MouseX() >= GraphicsWidth() - 3 Then iDMX:+ 1 If KeyDown(Key_Q) Then Lightness:- 1 If KeyDown(Key_W) Then Lightness:+ 1 If Lightness > iTileWidth Then Lightness = iTileWidth If Lightness < 0 Then Lightness = 0 If KeyDown(Key_A) Then Intesity#:- .01 If KeyDown(Key_S) Then Intesity#:+ .01 kCurrentMap.Update() kCurrentMap.LightArea(iDMX, iDMY, Lightness, Intesity#) kCurrentMap.LightArea((((MouseX() - (GraphicsWidth() / 2)) / 17)) + iDMX, (((MouseY() - (GraphicsHeight() / 2)) / 17)) + iDMY, 5, Intesity#, 255, 155, 0)'iDMX, iDMY, Lightness, Intesity#) kCurrentMap.Render() SetColor 255, 255, 255 DrawText "DIABLO'S LIGHTING DEMO", 10, 10 + (1 * 12) DrawText "======================", 10, 10 + (2 * 12) DrawText "Lightness: " + Lightness + " (Use 'Q' & 'W' to change)", 10, 10 + (3 * 12) DrawText "Intesity:" + Intesity# + " (Use 'A' & 'S' to change)", 10, 10 + (4 * 12) 'DrawText (MouseX() / 17) + ", " + (MouseY() / 17), 10, 34 Flip FlushMem Wend EndGraphics End It works fine its just i wanted to know if there was a better of doing the lighting because its going to get pretty slow with 4+ light points. also i wanted to know if there is a better way that i can blend the colours together (Without using alpha blend, too slow). thx for any help.

K@li (Posted 2009) [#2]

cool !

Sanctus (Posted 2009) [#3]

I used images with LIGHTBLEND. It does the trick for me if I use a good image.

Arowx (Posted 2009) [#4]

I found a great article about lighting here! in effect it's about creating a shadow casting system that is very fast. I've tried it and managed to add 32 lights and get realistic looking shadows but it depends upon the size of the tilemap on screen, and I have not yet done any speed tests! If your interested in the code I can post?