B-ASIC

B-Asic is a set of RSX commands allowing to use the Amstrad CPC Plus features from BASIC. It was written by Longshot of Logon System.

SpriteNumber=[0..15] XZoom=[0..3] YZoom=[0..3]
Define sprite zoom for specified sprite.
If XZoom or YZoom is zeroed, sprite is not displayed
Zoom value of 1 is no magnify.
Note : Sprite must be activated by SPRON instruction to be displayed on screen
Example : SPRZOOM,2,2,1 define the sprite 2 magnification to 2x horiz. and 1x vertically

SPRXY,SpriteNumber,XPos,YPos

SpriteNumber=[0..15] XPos=[-256..767] YZoom=[-256..255]
Define sprite position on screen according a mode 2 definition
Note : Sprite must be activated by SPRON instruction to be displayed on screen
Example : SPRXY,2,100,80 define sprite 2 position at 100,80 coordinates

SPRTDEF,SpriteNumber,Address,DurationPer,WaitingPer

SpriteNumber=[0..15] Address=[0..65535] DurationPer=[0..65535] WaitingPer=[0..65535]
Periods are defined by period of 0,02 second (e.g. 50 = 1 second)
Define a path for the specified sprite.
The path is defined by screen positions, given by a set of x,y coordinates defined in memory.
Each coordinate is defined on 2 bytes (4 bytes for a screen position) in the memory
The coordinate must be stored on a little endian method, e.g. the less significant byte
in first and the most significant byte in second position in memory.
The last x coordinate must take the value F0F0 (hexa) to indicate the path end definition
DurationPer indicates the time while the sprite will run on the path (at the last position
the path start again at the fist position).
If DurationPer is zeroed, so the duration is infinite.
WaitingPer indicate the start period which occurs when the path will be activated
(see SPRTON and SPRTOFF instructions)
Note : A same path can be used by one or more sprites.
Example : SPRTDEF,3,&3000,0,100 to define for sprite 3 a path defined in &3000 with an infinite
loop of the path after 2 seconds of start delay after SPRTON,3 instruction.

SPRTON,SprNb1,SprNb2,...,SprNbx

SprNbx=[O..15]
Start the path simultanously for the specified sprites.
Note : An undefined path for the sprite may occur an erratic behaviour of the sprite started.
Example : SPRTON,1,5,7 start the path for sprites 1, 5 and 7 simultaneously

SPRTOFF,SprNb1,SprNb2,...,SprNbx

SprNbx=[0..15]
Stop the path simultaneously for the specified sprites
Example : SPRTOFF,1,7 stop the path for sprites 1 and 7 simultanously

SPRSWAP,SpriteNumber1,SpriteNumber2

SpriteNumberx=[0..15]
Exchange the sprite content of two sprites.
Note : If SpriteNumber1=SpriteNumber2 it results just a waste of time.
Example : SPRSWAP,1,5 exchange the graphics data of sprites 1 and 5

SPRPLOT,SpriteNumber,XPos,YPos,SpritePen

SpriteNumber=[0..15] XPos=[0..15] YPos=[0..15] SpritePen=[0..15]
Plot a pixel in the specified sprite at specified coordinates
Note : SpritePen=0 means the transparent pen for sprite
Example : SPRPLOT,3,10,9,4 plot a pixel pen 4 at coordinates 10,9 of sprite 3

SPRCOPY,SpriteOrg,SpriteDst

SpriteOrg=[0..15], SpriteDst=[0..15]
Copy the content of SpriteOrg to SpriteDst.
Example : SPRCOPY,1,2 copy the content of sprite 1 to sprite 2

SPRTURNX,SpriteNumber

SpriteNumber=[0..15]
Flip the sprite specified on horizontal axis
Example : SPRTURNX,1

SPRTURNY,SpriteNumber

SpriteNumber=[0..15]
Flip the sprite specified on vertical axis
Example : SPRTURNY,1

SPRFILL,SpriteNumber,SpritePen

SpriteNumber=[0..15] SpritePen=[0..15]
Fill the specified sprite with the specified pen
Note : SpritePen=0 means the transparent pen for sprite
Example : SPRFILL,1,12 fill the sprite 1 with pen 12

SPRSAVE,[SpriteNumber,] BlocNumber, Filename

SpriteNumber=[0..15] BlocNumber=[0..4] Filename=Name of file in Amsdos standard
Save a sprite or a set of 16 sprites (defined as one Block) to disk
B-Asic can store 64 sprites definitions more than the usal sprite contained in asic ram.
These 64 sprites are organised as 4 sets of 16 sprites named "Block".
Bloc 1 : sprites 0 to 15, Bloc 2 : sprites 16 to 31, Bloc 3 : sprites 32 to 47 and
Bloc 4 : sprites 48 to 63
Bloc 0 is used for the 16 "real" asic sprites.
If SpriteNumber is not precised in the instruction, so a complete block is saved
If SpriteNumber is precised, only the specified sprite of the block is saved
Note : Sprites are not optimised (e.g. 1 pixel=1 byte)
Example : SPRSAVE,3,2,"SPR3BLK1.BIN" save the sprite 3 of the Bloc 2 (e.g. sprite 18/63)
in the file named "SPR3BLK1.BIN"
Example : SPRSAVE,0,"SPRASIC.BIN" save the content of block 0 (e.g. 16 asic sprites)

SPRLOAD,[SpriteNumber,] BlocNumber, Filename

SpriteNumber=[0..15] BlocNumber=[0..4] Filename=Name of file in Amsdos standard
Load a sprite or a set of 16 sprites (defined as one Block) from disk
B-Asic can store 64 sprites definitions more than the usal sprite contained in asic ram.
These 64 sprites are organised as 4 sets of 16 sprites named "Block".
Bloc 1 : sprites 0 to 15, Bloc 2 : sprites 16 to 31, Bloc 3 : sprites 32 to 47 and
Bloc 4 : sprites 48 to 63
Bloc 0 is used for the 16 "real" asic sprites.
If SpriteNumber is not precised in the instruction, so a complete block is loaded
If SpriteNumber is precised, only the specified sprite of the block is loaded
Note : Sprites are not optimised (e.g. 1 pixel=1 byte)
Note : If the file specified has an invalid size, an error is displayed
Example : SPRLOAD,3,2,"SPR3BLK1.BIN" load the sprite 3 of the Bloc 2 (e.g. sprite 18/63)

from the file "SPR3BLK1.BIN"

Example : SPRLOAD,3,"RAAHHHHH.SPR" load the block 3 (e.g. sprites 32 to 47) from file "RAAHHHHH.SPR"

SPRTORAM,SpriteAsic,SpriteRam

SpriteAsic=[0..15] SpriteRam=[0..63]
Copy the content of the current asic sprite in the sprite ram specified
See SPRLOAD/SPRSAVE instruction for block oragnisation.
Example : SPRTORAM,1,17 copy sprite asic 1 to sprite 17 of ram (e.g.in Block 2)

RAMTOSPR,SpriteRam,SpriteAsic

SpriteRam=[0..63] SpriteAsic=[0..15]
Copy the content of the sprite in ram in the current asic sprite specified
See SPRLOAD/SPRSAVE instruction for block oragnisation.
Example : RAMTOSPR,17,1 copy sprite sprite 17 of ram (2nd of bloc 2) in sprite asic 1

CATCH,SpriteNumber,XPos,YPos

SpriteNumber=[0..15] XPos=[0..143] YPos=[0..183]
Get a sprite from mode 0 screen at specified coordinates (coordinates top/left).
Note : This instruction runs only in graphic mode 0
Example : CATCH,3,120,100 catch the pixels from 120,100 to 135,115 in sprite 3

INKCOPY

Copy the whole colour screen palette to sprite palette.

SPRLINK,SpriteNumber1,SpriteNumber2,Xrel,Yrel

SpriteNumberx=[0..15] XRel=[-256..767] YRel=[-256..255]
Link a sprite (2) to another sprite (1) with a relative position.
That means if sprite (1) is moved, then sprite (2) is moved too.
So if sprite 1 is moved in X1,Y1 then the sprite 2 will be moved automatically in X1+Xrel,Y1+Yrel
It's possible to link all the sprites in all combinations to create one or more "super sprites"
Note : A sprite cannot be linked to itself.
Example : SPRLINK,1,2,16,0 link sprite 2 to sprite 1 with a relative x position of 16 pixels
Example : SPRLINK,2,5,0,16 link sprite 5 to sprite 2 with a relative y position of 16 pixels
[ so move the sprite 1 signify to move sprite 2 and 5 ]

SPRUNLINK,SpriteNumber1,SpriteNumber2

SpriteNumberx=[0..15]
Unlink a sprite from anoter sprite.
Example : SPRUNLINK,2,5 erase the link between sprite 2 and 5

ERALINK

Erase all link

DEFORGXY,SpriteNumber,XPos,YPos

SpriteNumber=[0..15] XPos=[-256..767] YPos=[-256..255]
Define absolute origin position of the specified sprite
That means that real sprite position take care of this defined coordinates.
Example : DEFORGXY,1,10,20:SPRXY,1,5,3 display sprite at 15,23
Note : It's possible to define an origin position for a sprite following a path (see SPRTDEF)
The default of origin at B-Asic reset is 0,0

DEFORGSPR,SpriteSlave,SpriteMaster

SpriteSlave=[0..15] SpriteMaster=[0..15]
Define the origin position of SpriteSlave with the position of SpriteMaster.
Note : It's possible to define a sprite relative position for a sprite following a path (see SPRTDEF)
It's possible to generate complex definitions of sprites movments.
If a sprite 1 use a path 1 and a sprite 2 use a path 2, if the sprite 2 is the slave of sprite 1, then
the path 2 will be relative to path 1.
To erase the slavery of a sprite, use DEFORGXY instruction

SPRWHERE,SpriteNumber,@varx%,@vary%

SpriteNumber=[0..15] varx=Name of x variable vary=Name of y variable
Get the x,y coordinates of the specified sprite
Important note : varx and vary must be defined first like integer (declaration in basic with '%') and
they must be given to the instruction "by address" ('@' before the variable name). The * declaration must
be respected to avoid unpredictibles results.
Example : 10 VARX%=0: VARY%=0 : SPRWHERE,1,@VARX%,@VARY%: PRINT VARX%,VARY%

OTHERS INSTRUCTIONS SET POKEASIC,Address,val1,...,valx

Address=[&4000..&7FFF] Valx=[&00..&FF]
Poke one or more bytes in Asic I/O page
Instruction reserved to experimented users.

POKEVR,Address,val1,...,valn

Address=[&4000..&7FFF] Valx=[&00..&FF]
Poke one or more bytes in second video page
Instruction reserved to experimented users.

ERROR MESSAGES

Bad arguments number

Bad number of arguments used in the instruction

Invalid Argument

An invalid value is used in one or more arguments of the instruction

Invalid Filename

A bad filename was used in a SPRSAVE or SPRLOAD instruction

Disc Error

An I/O error has occured in a SPRSAVE or SPRLOAD instruction.
Disc is missing, or the disk has a wrong or damaged format.

Not a Sprite file

The size of the file specified in SPRLOAD is not correct.
See if you do no use the SPRLOAD with a block instead of a single sprite (or the opposite)

Same Sprites Numbers

An instruction SPRLINK or SPRUNLINK is attempted with 2 identical sprite numbers.

Bad Graphic Mode

Instruction CATCH is not used in MODE 0

Invalid Moving List

An invalid table is created for SPRTDEF
(e.g. the first coordinate is the path end)

Link Table Full

The link table is full.
Normally this error cannot occur in a well built program.

Sprites not Linked

Instruction SPRUNLINK is used with sprites not linked.

B-ASIC

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