Dynamic 2D Landscape

BlitzMax Forums/BlitzMax Programming/Dynamic 2D Landscape

Scaremonger (Posted 2012) [#1]

Hi all, I've been looking to rewrite a game I produced in the 80's which requires a landscape that is dynamic. Think "Defender" and you'll get a rough idea, the difference is that the landscape at the bottom is solid instead of a line. One feature of the game is a crawling mass of "Red Weed" that transforms the landscape from Green to Red. In the early version, the landscape was blocks of colour held in an array but today's graphics require a higher resolution than this. I have tried using 4x4 pixel blocks in an array and have tried the same size objects in a Tlist (and an array so they can reference their neighbours to spread), but storing the landscape in "active-pixels" is a few hundred thousand objects at best and slows down the FPS to the point of being un-useable. Does anyone have any suggestions on how I should approach this? My test code: SuperStrict Graphics 800, 600 SeedRnd( MilliSecs() ) SetBlend( ALPHABLEND ) AutoMidHandle( True ) Global GW% = GraphicsWidth() Global GH% = GraphicsHeight() New TScape.Generate() Global player:TPlayer = New TPlayer.Create() '# Initialise timers Local fliptimer:Int Global pause:Int = False '#Game Loop Timing ' Deltatime Global Now:Int ' Used by deltatime calculations Global DELTATIME:Float Global LastTime:Int=MilliSecs() ' Used by deltatime calculations ' Cycles per second Global cps:Int Global cps_count:Int Global cps_time:Int = MilliSecs() ' Frames per second Global fps:Int Global fps_count:Int Global fps_time:Int = MilliSecs() '# Game loop While Not KeyHit( KEY_ESCAPE ) And Not AppTerminate() Now = MilliSecs() DELTATIME = Float( Now - LastTime ) /60 LastTime = Now '# Cycles per second cps_count:+ 1 Local elapsed:Int = now-cps_time If elapsed >= 1000 Then cps_time = now cps = cps_count cps_count = 0 End If If Not pause Then TBase.refresh() If fliptimer < Now Then fliptimer = Now + 16 Cls TBase.paint() '# Frames per second fps_count:+ 1 Local elapsed:Int = now-fps_time If elapsed >= 1000 Then fps_time = now fps = fps_count fps_count = 0 End If SetColor 255,255,255 DrawText "FPS: " + fps , 0 , 0 DrawText "CPS: " + cps , 0 , 15 Flip 0 Delay 1 End If Wend '########################################################### Type TBase '# OBJECT LIST VARIABLES Global list:TList = CreateList() '# Object List Field ListLink:TLink '# LInk to object in list Field r%=255, g%=255, b%=255 '# GAME OBJECT VARIABLES Field x:Float , y:Float Field angle:Float; Field dx:Float, dy:Float Field timer:float '# Used to time short lived objects Field speed:Float '# Speed of object '------------------------------------------------------------ Method addToList() listlink = ListAddLast(list,Self) End method '------------------------------------------------------------ Method colour( r%, g%, b% ) Self.r = r Self.g = g Self.b = b End Method '------------------------------------------------------------ Function refresh() For Local item:TBase = EachIn list item.update() Next End Function '------------------------------------------------------------ Function paint() For Local item:TBase = EachIn list item.draw() Next End Function '------------------------------------------------------------ Method die() RemoveLink( Self.listlink ) End Method '------------------------------------------------------------ Method update() ; End Method Method draw() ; End Method End Type '################### Type TScape Extends TBase Global scape:TScape[60000 , 60] Field status% = 0 Field px% , py% '# Status: '# 0 = Grass '# 1 = Infected '# 2 = Red (Infectious) '------------------------------------------------------------ Method generate() Local h% = Rand( 5 , 40) Local i% For Local n% = 1 To GW /4 For i% = 1 To h scape[n,i] = New TScape.Create( n, i ) Next h = h + Rand( - 1 , 1 ) If h > 60 Then h = 60 If h < 1 Then h = 1 Next scape[1, 1].status = 2 scape[1, 1].colour( 255,0,0 ) End Method '------------------------------------------------------------ Method Create:TScape( px%, py% ) listlink = ListAddLast(list , Self) Self.x = px*4 Self.y = GH - 60 - py * 4 Self.px = px Self.py = py Self.colour( 0,255,0 ) timer = 10 Return Self End Method '------------------------------------------------------------ Method draw() SetColor( r, g , b ) DrawRect( x,y,3,3) End Method '------------------------------------------------------------ Method update() Select status Case 0 ; Return Case 1 timer :- DELTATIME If timer <= 0 Then colour( 255 , 0 , 0) status = 2 timer = 10 End If Case 2 timer :- DELTATIME If timer <= 0 Then timer :+ 10 Local ex% = Rand( -1,1 ) Local ey% = Rand( - 1 , 1 ) If px + ex < 0 Then ex = 0 If px + ex >GW Then ex = 0 If py + ey < 0 Then ey = 0 If py + ey > 60 Then ey = 0 If Not (ex = 0 And ey = 0) And scape[px + ex , py + ey] And scape[px + ex , py + ey] .status = 0 Then scape[px + ex , py + ey].infect() End If End Select End Method '------------------------------------------------------------ Method infect() status = 1 timer = 50 colour( 255,255,0 ) End Method End Type '################ Type TPlayer Extends TBase '------------------------------------------------------------ Method Create:TPlayer() addtolist() Self.x = 100 Self.y = GH-200 Return Self End Method '------------------------------------------------------------ Method draw() SetColor( 255,0,0) DrawText( ">", x, y ) End Method '------------------------------------------------------------ Method update() If KeyDown( KEY_UP) Then y = Y - 15 * DELTATIME If KeyDown( KEY_DOWN) Then y = Y + 15 * DELTATIME End Method End Type Last edited 2012

slenkar (Posted 2012) [#2]

how did worms do it? the only way i can think of is using polygons that form and split with the landscape but that seems very complicated

Kryzon (Posted 2012) [#3]

You need to delegate this to the hardware. Worms used masking. If we were in Blitz3D, you'd draw black circles over your environment image where the projectiles hit. Since black is masked automatically in Blitz3D, the circle would "chop" out a piece of the environment and the pixel-perfect collision system would consider that as empty space, and using DrawImage would draw the environment with transparent holes where the projectiles hit. With BlitzMax, under the hood, masking is done with alpha blending. You need to get the pointer to your pixmap's pixels and manually set their alpha value to zero in a radius or whatever shape you want - just make sure you don't try to read outside the limits. You can also use WritePixel and set a value of ARGB [255,0,0,0] so these pixels are considered empty space when drawn with ALPHABLEND or when processed with ImagesCollide(). Also make sure to clean any loose pixels left (like a single pixel floating in air) just to avoid having ugly chunks flying in mid air, potentially causing bugged collisions. Study Pixmaps, they're the way to go. Last edited 2012

InvisibleKid (Posted 2012) [#4]

i only skimmed over the posts but saw mention of worms, and remembered a tiny test example i put together a few years ago that may or may not be relivant. either way your welcome to check it out and take from it what you will. Old Post Here

therevills (Posted 2012) [#5]

I did a quick worms clone awhile ago: http://www.blitzbasic.com/Community/posts.php?topic=89848#1021110

Scaremonger (Posted 2012) [#6]

I think my title for this post may have been mis-understood. Although having a dynamically created landscape is part of my project, the problem I am having is more to do with the landscape being dynamic AFTER it is created. For example, red weed that spreads, things that grow and die. Using an object for each pixel in the landscape is a huge Tlist.. There must be a better way.

Kryzon (Posted 2012) [#7]

Try using arrays instead of TLists of objects. That is, arrays representing the full landscape. One array for the class of objects, one for the attributes of objects etc. Last edited 2012

Jesse (Posted 2012) [#8]

why don't you create them in groups of pixels as in an organism being developed. maybe a square of 8x8 10x10 16x16 pixels etc... of which each pixel don't have to be created at the same time. treat them as a bunch of mini maps being connected together. When a pixel is grown into the edge of the square it can spread into another square. also when the square is full(mature) you can ignore the individual pixels for a certain time until it starts to die or your desired condition. Just an idea. Last edited 2012

SLotman (Posted 2012) [#9]

Have 2 maps. One for dynamic things, other for "static" things. Just update the dynamic ones. If something happens, and turn a "static" tile into a dynamic one, just move it to the second list. If a dynamic tile "dies", move it to a static, and so on. This should help a little bit :)

Scaremonger (Posted 2012) [#10]

Thanks guys; thats given me some ideas to try out. :)