GetSpriteRect

Status = GetSpriteRect(SpriteIndex, RectPointer)

Parameters:     SpriteIndex = The index of the sprite you wish to query     RectPointer = Pointer to a Rectangle structure.

Returns:     Status = Returns a 0 when it failed, other wise it'll return one

The GetSpriteRect function returns the bounding coordinates that surround a rotated and scaled sprite. GetSpriteRect acts as a short cut to manually querying the sprite via the GetSpriteVertexX and GetSPriteVertexY commands. However, unlike other sprite commands which only return a single value, GetSpriteRect requires we pass it a pointer to suitabel formatted RECT structure. A RECT structure is just a type with four integer fields. The command treats the first pair of fields as the top left XY coordinate and the second pair is the bottom right XY coordinate. It works this way so we can avoid numerous functions calls to the sprite, which can be fairly time consuming. FACTS:       * GetSpriteRect can't validate the Rect pointer you give it is legayc or not. So if you pass a pointer that doesn't exist, it'll most likely crash.       * Also see GetSpriteX,GetSpriteY, GetSpriteVertexX,GetSpriteVertexY Example #1:       Create a sprite, set it's XYZ positions, then read and display its position to the screen.            SetFPS 60      // locate the help files media folder   Path$=ProgramDir$()+"Help\Commands/Media/"      // Load the bubble image   BallImage     =LoadNewImage(Path$+"bubble_64x64.bmp",2)            Type MyRect      x1,y1      x2,y2   EndType      // define a pointer to this rect structre   Dim BoundingBox As MyRect Pointer      // allocate / create an instance of this structure   BoundingBox = New MyRect         // CReate sprite for us to query   Sprite=NewSprite(400,300,BallImage)   SpriteDrawMode Sprite,2   ScaleSprite Sprite,2            // Main Loop   Do      // Clear the screen to the default colour      Cls            // turn the sprite 1 degree      TurnSprite Sprite,1            // draw all the sprites      DrawAllSprites            // Query the sprites bounding box      If GetSpriteRect(Sprite,BoundingBox)=true                  // read the sprites vertex manually         x1=GetSpriteVertexX(Sprite,0)         y1=GetSpriteVertexY(Sprite,0)         x2=GetSpriteVertexX(Sprite,1)         y2=GetSpriteVertexY(Sprite,1)         x3=GetSpriteVertexX(Sprite,2)         y3=GetSpriteVertexY(Sprite,2)         x4=GetSpriteVertexX(Sprite,3)         y4=GetSpriteVertexY(Sprite,3)                  // Connect the egdes in red         LineC x1,y1,x2,y2,$ff0000         LineC x2,y2,x3,y3,$ff0000         LineC x3,y3,x4,y4,$ff0000         LineC x4,y4,x1,y1,$ff0000                           // draw the bounding box in GREEN         BoxC BoundingBox.X1,BoundingBox.Y1,BoundingBox.X2,BoundingBox.Y2,false, $00ff00               EndIf            Sync   Loop       Example #2:       The following shows a more complex usage where the bounding area of a sprite is used to selective refresh the displays backdrop picture. This particular example creates a back drop image, converts that into a MAP, then prior to each frame being drawn it only restores the blocks on the screen that were drawn over last frame. The idea of such approach is to reduce the amount of the drawing the program does. Many classic games use this type of rendering loop to keep the speed up as high as possible, it's still very useful today !

Example Source: Download This Example   LoadFont  "arial",1,16,0,8         // -----------------------------------------------------------   // Size the Map blocks we'll use.   // -----------------------------------------------------------   Constant TileWidth   =32   Constant TileHeight   =32      // -----------------------------------------------------------   // Make the Backdrop image.  This buffer is also used for the 'FX surface'   // -----------------------------------------------------------   BackDropFX =MakeBackdropImage()         // -----------------------------------------------------------   // Make a blob image to represent the sprites in the scene   // -----------------------------------------------------------   Blob= MakeBlobImage(64,64)         // -----------------------------------------------------------   // Define our RECT structure to hold the bounds of each sprite   // -----------------------------------------------------------      Type tRect      x1,y1      x2,y2   EndType      // -----------------------------------------------------------   // Define a type to simulate some characters in the scene.   // -----------------------------------------------------------   Type tAlien      Sprite      speed#      direction#      Rect As tRect   EndType      // ------------------------------------------------------   // Dim a list called Character to hold the objects   // ------------------------------------------------------   Dim Character As TAlien List         // ------------------------------------------------------   // Set the clip zone of the object   // ------------------------------------------------------   clipSize=64   ViewportX1=-clipSize   ViewportX2=GetScreenWidth()+clipSize   ViewportY1=-clipSize   ViewportY2=GetScreenHeight()+clipSize         // ------------------------------------------------------   // MAKE MAP / LEVEL / BLOCKS from our backdrop picture   // ------------------------------------------------------      Map,OriginalLevel,RefreshLevel=Make_Map_FRom_Image(BackDropFX)             ;*=-----------------------------------------------------------------------------=* ;         >> Main Loop << ;*=-----------------------------------------------------------------------------=*         Screen=NewImage(GetScreenWidth(),GetScreenHeight(),2)         Do            // Add new charcter to scene if the space key is being pressed      If SpaceKey()  Or  LastTime<Timer()                  LastTime=Timer()+50         Add_Random_Character(Blob)               EndIf                  // Process and render to the objects in the character list      RenderToImage Screen                  // Draw the refresh level to our FX image screen      DrawMap Map,RefreshLevel,0,0            // reset the refresh level      ClearLevel Map,RefreshLevel,0                  // Process our list of characters      For Each Character()                  ThisSprite=Character.Sprite         Speed#          =Character.speed#         Angle#          =Character.direction#                  MoveSprite ThisSprite,CosRadius(angle#,speed#),SinRadius(angle#,speed#)                ; Check if the character is inside the screen ?         If RectHitSprite(ViewportX1,ViewportY1,ViewportX2,ViewportY2,ThisSprite)=false            DeleteSprite Sprite            Character=null            Continue         EndIf                  // Get the rect around this sprite         If GetSpriteRect(ThisSprite,Character.Rect)            // Convert Pixels coordinates to Map Tile positions            x1=Character.Rect.x1/TileWidth            y1=Character.Rect.y1/TileHeight            x2=Character.Rect.x2/TileWidth            y2=Character.Rect.y2/TileHeight            CopyLevel   Map,OriginalLevel,x1,y1,x2+1,y2+1,Map,RefreshLevel,TilePad+x1,TilePad+y1         EndIf      Next                  // Draw the Sprite List to the FX buffer image      DrawAllSprites                  // Direct rendering to the PB display      RenderToScreen            // Draw the current state of the Backdrop to the SCREEN      DrawImage Screen,0,0,false            // Draw the info to the screen for the viewer      Text 0, 0,"Refresh %:"+CalcRefreshPercentage(Map,RefreshLevel)      Text 0,20,"Fps:"+Str$(FPS())            Sync   Loop             ;*=-----------------------------------------------------------------------------=* ;                        >> Add Random Character << ;*=-----------------------------------------------------------------------------=* ; ;  This function adds a new character to our liost and fills it with random ; position and speed data.    ;*=-----------------------------------------------------------------------------=*       Psub Add_Random_Character(ThisImage)      Character             = New tAlien   x         =Rnd(GetScreenWidth())   y           =Rnd(GetScreenHeight())   Character.Sprite          =NewSprite(X,y,ThisIMage)   Character.Speed      =RndRange(1,5)   Character.direction# =Rnd(360)    EndPsub          ;*=-----------------------------------------------------------------------------=* ;                        >> Calc ReFresh Percentage << ;*=-----------------------------------------------------------------------------=* ; ;  This function converts an image into the array of tiles representing this ; image.  Each cell in the array contains the image handle of that 'sector' ; of the original image.   This is used to refresh the image during refresh. ; ;*=-----------------------------------------------------------------------------=*       Psub CalcRefreshPercentage(Map,Level)   Count=0   Width=GetLevelWidth(Map,Level)   Height=GetLevelHeight(Map,Level)      Total = (Width+1)*(Height+1)      For ylp=0 To Height      For xlp=0 To Width         Tile=PeekLevelTile(Map,Level,xlp,ylp)         Count+=Tile<>0      Next   Next      p#=Float(Count)/Total      s$=Str$(p#*100   )    EndPsub s$                   ;*=-----------------------------------------------------------------------------=* ;                           >> Make Blob image << ;*=-----------------------------------------------------------------------------=* ; ;    This function makes a Blob (circle/ellipse) image with alpha channel, which ; is used to represent a hand drawn sprite in your game. ; ;*=-----------------------------------------------------------------------------=*       Function MakeBlobImage(width,height)      oldsurface=GetSurface()   Thisimage=GetFreeImage()   CreateFXImageEx ThisImage,Width,Height,32   RenderToImage Thisimage   radiusX=Width/2   radiusY=Height/2      LockBuffer   EllipseC (width/2),(height/2),radiusX,radiusY,true,RGB(255,255,255)      nullpixel=Point(0,0)   For ylp=0 To height-1      A=Float(ylp)/height*255      A=LSL32(a,24)      For xlp=0 To width-1         ThisPixel=FastPoint(xlp,ylp) And $00ffffff         If ThisPixel            FastDot xlp,ylp,ThisPixel Or A         EndIf      Next   Next   UnLockBuffer   PrepareAFXImage ThisImage   RenderToImage oldsurface EndFunction ThisImage          ;*=-----------------------------------------------------------------------------=* ;                           >> Make Backdrop image << ;*=-----------------------------------------------------------------------------=* ; ;   This function create a backdrop image.  It's a bit of mess, but it'll do for ; the sake of the demo.  In a real game you'd obviously load your own backdrop. ;*=-----------------------------------------------------------------------------=*       Function MakeBackdropImage()      // Make the backdrop   sw=GetScreenWidth()   sh=GetScreenHeight()   backdrop=NewImage(sw,sh,2)   RenderToImage backdrop   c1=ARGB(255,0,0,100)   c2=ARGB(255,70,50,0)   c3=ARGB(255,0,200,0)   c4=ARGB(255,0,0,0)   ShadeBox 0,0,sw,sh,c1,c2,c3,c4   LoadFont  "Arial",2,64,0      SetFont 2   For lp=0 To 200      Ink RndRGB()| $ff000000      CenterText Rnd(sw),Rnd(sh),"<>"   Next      Ink ARGB(255,55,55,55)   x=sw/2   y=sh*0.4   CenterText x-2,y-2,"Game Backdrop Image"   Ink ARGB(255,255,255,255)   CenterText x,y,"Game Backdrop Image"   SetFont 1   DeleteFont 2   RenderToScreen    EndFunction BackDrop          Function Make_Map_FRom_Image(ThisIMage)      // ------------------------------------------------------   // MAKE MAP / LEVEL / BLOCKS from our backdrop picture   // ------------------------------------------------------      Map=NewMap(10)      IMageWidth   =GetImageWidth(ThisIMage)   IMageHeight   =GetImageHeight(ThisIMage)      TilesWide   =IMageWidth/TileWidth   TilesHigh   =IMageHeight/TileHeight      If (TilesWide*TileWidth)>ImageWidth Then TilesWide++   If (TilesHigh*TileHeight)>ImageHieght Then TilesHigh++      BlockCount=(TilesWide*TilesHigh)+1   CreateMapGFX Map,TileWidth,TileHeight,BlockCount,RGB(0,0,0),2      OriginalLevel=NewLevel(Map,TilesWide-1,TilesHigh-1)      RenderToImage ThisImage      // ----------------------------------   // Build map representation of this image   // ----------------------------------   Index=1   For ylp=0 To TilesHigh-1      For xlp=0 To TilesWide-1         Xpos=xlp*TileWidth         Ypos=ylp*TileHeight         GetMapBlk Map,Index,Xpos,Ypos         PokeLevelTile Map,OriginalLevel, Xlp,ylp,Index         Index++      Next   Next         RefreshLevel   =NewLevel(Map,TilesWide-1,TilesHigh-1)      PasteLevel map,OriginalLevel,Map,RefreshLevel,0,0,0      LevelTransparent  Map,RefreshLevel,0       EndFunction Map,OriginalLevel,RefreshLevel

Related Info:	GetSpriteOldX | GetSpriteOldY | GetSpriteOldZ | GetSpriteX | GetSpriteY | GetSpriteZ | MoveSprite | MoveSpriteX | MoveSpriteY | MoveSpriteZ | PositionSprite | PositionSpriteX | PositionSpriteXYZ | PositionSpriteY | PositionSpriteZ :

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