[bb] B2D-->B3D by John Pickford [ 1+ years ago ]

[BlitzBot]

Title : B2D-->B3D
Author : John Pickford
Posted : 1+ years ago

Description : A system for drawing 2D sprites in B3D.  The plan is to make it 99% compatible tith B2D commands so porting B2D games will be trivial.

So far I have emulated LoadAnimImage and DrawImage which are the most common commands.

There are a couple of known issues:

If B3D resisizes and image   exture on loading then this code will not notice and get the UV's wrong.  I'm looking for an elegant fix for this.

Transparent color must be 0,0,0 which appears to be a limitation of B3D at the moment.

How does it work?
Replace every drawImage and LoadAnimImage command in your code with a call to my functions.  You also need an extra call to ClearDisplayList at the start of each frame (and of course Renderworld before FLIP).

Each time you draw a sprite a quad will be added to a mesh which will be drawn at renderworld.  There's no need to worry about cameras or managing entities - existing code should work.

SPEED:  Seems a fair bit slower than B2D.  Hopefully I'll find a way to improve this.

FUTURE:  I intend to add extra parameters to DrawImage which support scaling, rotation and variable alpha(tranlucency).  This is ultimately the main reason for moving a 2D game to B3D - access to better rendering features.

A side effect of all this is future-proofing code as future editions of DirectX are dropping support for 2D.

Code :

Code (blitzbasic) Select Expand

;*******************************************************************
;
; 2Din3D By J.Pickford - Freeware!
;..........................................
;
; A set of 2D sprite functions implemented in B3D
;
; Functions are intended to be VERY close to B2D commands to make
; conversion of B2D games easy
;
;
;
; This code is a work-in-progress. I hope to emulate more of the B2D
; functionality in future versions.
;
; Future Enhancements: Sprite Scaling, Rotation, Variable Alpha
;
;********************************************************************

Const maxframes=1000 ;max number of animation frames allowed in a single texture

Type texturebank

Field t_texture
Field t_brush
Field t_sx#[maxframes]
Field t_sy#[maxframes]
Field t_width#
    Field t_height#
    Field t_maxframe
Field t_totalwidth#
Field t_totalheight#

End Type

Const width#=640 ;Screensize
Const height#=480


Graphics3D width,height
SetBuffer BackBuffer()

Global camera=CreateCamera()
Global pivot=CreateCamera()
Global displaylist=CreateMesh(camera)
Global lasttexture.texturebank



Global alien.texturebank=loadanimimageb3d ("alien.bmp",64,64)  ;Just an example



clock#=0

While Not MouseHit(2)



ClearDisplayList() ;This resets the display list - ESSENTIAL!


;"Draw" some stuff-------------------------------Actual drawing takes place at Renderworld()

For f#=1 To 360 Step 5

drawimageb3d (alien,width/2+width/2*Sin(clock/4)*Cos(clock+f),height/2+Cos(clock/5)*height/2*Sin(clock+f),(f/5) Mod 64)

Next

;should be at opposite corners of the screen

drawimageb3d (alien,0,0,(clock/5)Mod 64)
drawimageb3d (alien,width-64,height-64,(clock/7)Mod 64)

;-------------------------------------------------

RenderWorld() ;Actual drawing takes place
Color 255,255,255
Text 100,10,"Click Right Mouse Button to Quit"
Flip

clock=clock+1

Wend


End

;--------------------------------------
; Call this at the start of each frame


Function ClearDisplayList()

FreeEntity displaylist
displaylist=CreateMesh(camera)
PositionEntity displaylist,-width/2,-height/2,width/2
lasttexture=Null

End Function

;------------------------------------------------------------------------
; LoadAnimImageB3D
;...................
;
;  Intended to be compatible with B2D command "LoadAnimImage"
;
;  Known problems: If B3D resizes texture because it's too big then
;                  the UV's will be wrong.  Looking for a neat fix...
;
;   The transparent colour must be 0,0,0
;-------------------------------------------------------------------------


Function LoadAnimImageB3D.texturebank (file$,swidth#,sheight#)

this.texturebank=New texturebank
this _texture=LoadTexture (file$,1+4) ;color + masked
this _brush=CreateBrush()
BrushTexture this _brush,this _texture
    BrushFX this _brush,1 ;Full bright - no lighting needed

this _totalwidth=TextureWidth (this _texture)
this _totalheight=TextureHeight (this _texture)
this _width=swidth
this _height=sheight

frame=0
sy#=0

;Create the UV coords for each animation frame (just for speed later on)

While sy<this _totalheight

sx#=0

While sx<this _totalwidth

this _sx[frame]=sx/this _totalwidth
this _sy[frame]=sy/this _totalheight
frame=frame+1
sx=sx+swidth

Wend

sy=sy+sheight

Wend


this _maxframe=frame-1

Return this

End Function


;--------------------------------------------------------------------------------
; DrawImageB3D (Simple sprite with no fancy functions)
;......................................................
;
;
; Intended to be compatible with the B2D equivelant (DrawImage)
; The only enhancement being x,y are floats allowing sub-pixel positioning
;
;--------------------------------------------------------------------------------

Function DrawImageB3D (texture.texturebank,x#,y#,frame)

y=height-y ;in B3D y is up - in B2D y is down

;use existing surface except when switching source textures

If texture=lasttexture Then surface=FindSurface (displaylist,texture _brush)
If Not surface Then surface=CreateSurface (displaylist,texture _brush)
lasttexture=texture

w#=texture _width-1 ;size of image (pixels)
h#=texture _height-1
tw#=w/texture _totalwidth ;size of image (texture coords)
th#=h/texture _totalheight
sx#=texture _sx[frame] ;position of image within texture (texture coords)
sy#=texture _sy[frame]

; four vertices represent four corners of sprite

v1=AddVertex (surface,x,y,0,sx,sy)
v2=AddVertex (surface,x+w,y,0,sx+tw,sy)
v3=AddVertex (surface,x,y-h,0,sx,sy+th)
v4=AddVertex (surface,x+w,y-h,0,sx+tw,sy+th)

AddTriangle (surface,v1,v2,v3) ;two triangle make rectangular up image
AddTriangle (surface,v2,v4,v3)

End Function

Comments :


thelizardking(Posted 1+ years ago)

 pretty nice