{{htmlmetatags>metatag-robots=()
metatag-title=(IMAGE BLITTING BASIC MASKING | ugBASIC User Manual)
metatag-keywords=(ugBASIC,Commodore 64,Commodore PLUS/4,ZX Spectrum)
metatag-description=(An isomorphic language for retrocomputers)
metatag-media-og:image=(:ugbasic:logo-ugbasic-fb.png)
metatag-og:title=(IMAGE BLITTING BASIC MASKING | ugBASIC User Manual) 
metatag-og:description=(An isomorphic language for retrocomputers)
}}

====== ugBASIC User Manual ======

===== IMAGE BLITTING BASIC MASKING =====

==== PURPOSE ====
 A classic use for blitting is to render transparent sprites onto a background. In this example a background image, a sprite, and a 1-bit mask are used.  

==== SOURCE CODE ====
   
   
   
   PROCEDURE example ON ALL BUT VIC20, VG5000
   
   	BITMAP ENABLE(16)
   	
   	DEFINE PALETTE NOT PRESERVE
   	
   	CLS BLACK
   	
   	mask := LOAD IMAGE("blit_mask.png") EXACT TRANSPARENCY BLACK OPACITY LIGHT WHITE
   	background := LOAD IMAGE("blit_background.png")
   	sprite := LOAD IMAGE("blit_sprite.png")
   	
   	CONST x = ( SCREEN WIDTH - IMAGE WIDTH(background) ) \ #2
   	CONST y = ( SCREEN HEIGHT - IMAGE HEIGHT(background) ) \ #2
   	
   	PUT IMAGE background AT x,y
   	
   	REM In the first blit, the mask is blitted onto the background using 
   	REM the raster operator AND. Because any value ANDed with 0 equals 0, 
   	REM and any value ANDed with 1 is unchanged, black areas are created 
   	REM where the actual sprites will appear, while leaving the rest of 
   	REM the background alone.
   	
   	BLIT bop1 AS ( ( SOURCE ) AND ( DESTINATION ) )
   	BLIT IMAGE mask AT x+10,y+10 WITH bop1
   	
   	REM In the second blit, the sprite is blitted onto the newly altered 
   	REM background using the raster operator of OR. Because any value 
   	REM ORed with 0 is unchanged, the background is unaffected and the 
   	REM black areas are filled with the actual sprite image.
   	
   	BLIT bop2 AS ( ( ( INVERSE ( SOURCE 2 ) ) AND ( SOURCE 1 ) ) OR ( DESTINATION ) )
   	BLIT IMAGES sprite, mask AT x+10,y+10 WITH bop2
   	
   END PROC
   
   CALL example ON ALL BUT VIC20, VG5000
   	
   	
   	
   


==== SOURCE FILE ====
  * ''[[https://github.com/spotlessmind1975/ugbasic/tree/main/examples/blit_basic_mask.bas|blit_basic_mask.bas]]''
==== HOW TO COMPILE AND RUN ====
The instructions here refer to compiling the example from the command line. For Microsoft Windows users we suggest using **[[https://spotlessmind1975.itch.io/ugbasic-ide|UGBASIC-IDE]]**, which allows you to compile the example with just one click.=== ATARI 400/800 family ===
In order to compile and run the example, you need to have the Altirra emulator, and in particular that the ''altirra'' executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.atari blit_basic_mask.bas -o example.xex
   altirra example.xex
   
   # Windows 
   ugbc.atari.exe blit_basic_mask.bas -o example.xex
   altirra example.xex
=== ATARI 600XL/800XL/1200XL/XG(SE) family ===
In order to compile and run the example, you need to have the Altirra emulator, and in particular that the ''altirra'' executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.atarixl blit_basic_mask.bas -o example.xex
   altirra example.xex
   
   # Windows 
   ugbc.atarixl.exe blit_basic_mask.bas -o example.xex
   altirra example.xex
=== Commodore 64 ===
In order to compile and run the example, you need to have the VICE emulator, and in particular that the ''x64sc'' executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.c64 blit_basic_mask.bas -o example.prg
   x64sc example.prg
   
   # Windows 
   ugbc.c64.exe blit_basic_mask.bas -o example.prg
   x64sc example.prg
=== Commodore 64+REU ===
In order to compile and run the example, you need to have the VICE emulator, and in particular that the ''x64sc'' executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.c64reu blit_basic_mask.bas -o example.prg
   x64sc -reu example.prg
   
   # Windows 
   ugbc.c64reu.exe blit_basic_mask.bas -o example.prg
   x64sc -reu example.prg
=== Commodore PLUS/4 ===
== Using YAPE ==
In order to run the example, you need to have the YAPE emulator. In particular that the ''yape'' executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.plus4 blit_basic_mask.bas -o example.prg
   yape example.prg
   
   # Windows 
   ugbc.plus4.exe blit_basic_mask.bas -o example.prg
   yape example.prg
== Using VICE ==
In order to run the example, you need to have the VICE emulator. In particular that the ''xplus4'' executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.plus4 blit_basic_mask.bas -o example.prg
   xplus4 example.prg
   
   # Windows 
   ugbc.plus4.exe blit_basic_mask.bas -o example.prg
   xplus4 example.prg
=== Dragon 32 ===
In order to compile and run the example, you need to have the XROAR emulator, and in particular that the ''xroar'' executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.d32 blit_basic_mask.bas -o example.bin
   xroar -rompath (your rom path) example.bin
   
   # Windows 
   ugbc.d32.exe blit_basic_mask.bas -o example.bin
   xroar.exe -rompath (your rom path) example.bin
=== Dragon 64 ===
In order to compile and run the example, you need to have the XROAR emulator, and in particular that the ''xroar'' executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.d64 blit_basic_mask.bas -o example.bin
   xroar -rompath (your rom path) example.bin
   
   # Windows 
   ugbc.d64.exe blit_basic_mask.bas -o example.bin
   xroar.exe -rompath (your rom path) example.bin
=== PC128 Olivetti Prodest ===
In order to compile and run the example, you need to have the DCMOTO emulator, and in particular that the ''dcmoto'' executable is accessible.

Then, type this command on the command line and on the emulator:

   # Linux 
   ugbc.pc128op blit_basic_mask.bas -o example.k7
   dcmoto
   (choose BASIC 128)
   CLEAR,&H2FFF: LOADM"CASS:",R: EXEC
   
   # Windows 
   ugbc.pc128op.exe blit_basic_mask.bas -o example.k7
   dcmoto
   (choose example.k7)
   (choose BASIC 128)
   CLEAR,&H2FFF: LOADM"CASS:",R: EXEC
=== Thomson MO5 ===
In order to compile and run the example, you need to have the DCMOTO emulator, and in particular that the ''dcmoto'' executable is accessible.

Then, type this command on the command line and on the emulator:

   # Linux 
   ugbc.pc128op blit_basic_mask.bas -o example.k7
   dcmoto
   (choose BASIC 128)
   CLEAR,&H2FFF: LOADM"CASS:",R: EXEC
   
   # Windows 
   ugbc.pc128op.exe blit_basic_mask.bas -o example.k7
   dcmoto
   (choose example.k7)
   (choose BASIC 128)
   CLEAR,&H2FFF: LOADM"CASS:",R: EXEC
=== Commodore VIC-20 ===
In order to compile and run the example, you need to have the VICE emulator, and in particular that the ''xvic'' executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.vic20 blit_basic_mask.bas -o example.prg
   xvic --memory 24k example.prg
   
   # Windows 
   ugbc.vic20.exe blit_basic_mask.bas -o example.prg
   xvic --memory 24k example.prg
=== ZX Spectrum ===
In order to compile and run the example, you need to have the Speccy emulator, and in particular that the ''speccy'' executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.zx blit_basic_mask.bas -o example.tap
   Speccy example.tap
   
   # Windows 
   ugbc.zx.exe blit_basic_mask.bas -o example.tap
   Speccy example.tap
=== MSX ===
In order to compile and run the example, you need to have the openMsx or the BlueMSX emulator, and in particular that its executable is accessible.

Then, type this command on the command line:

== openMSX ==
   # Linux 
   ugbc.msx1 blit_basic_mask.bas -o example.rom
   openmsx -cart example.rom
   
   # Windows 
   ugbc.msx1.exe blit_basic_mask.bas -o example.rom
   openmsx -cart example.rom
== blueMSX ==
   # Linux 
   ugbc.msx1 blit_basic_mask.bas -o example.rom
   bluemsx example.rom
   
   # Windows 
   ugbc.msx1.exe blit_basic_mask.bas -o example.rom
   bluemsx example.rom
=== ColecoVision ===
In order to compile and run the example, you need to have the openMsx or the BlueMSX emulator, and in particular that its executable is accessible.

Then, type this command on the command line:

== openMSX ==
   # Linux 
   ugbc.coleco blit_basic_mask.bas -o example.rom
   openmsx -machine \"COL - ColecoVision\" -cart example.rom
   
   # Windows 
   ugbc.coleco.exe blit_basic_mask.bas -o example.rom
   bluemsx -machine \"COL - ColecoVision\" example.rom
== blueMSX ==
   # Linux 
   ugbc.coleco blit_basic_mask.bas -o example.rom
   bluemsx /machine \"COL - ColecoVision\" /rom1 example.rom
   
   # Windows 
   ugbc.coleco.exe blit_basic_mask.bas -o example.rom
   bluemsx  /machine \"COL - ColecoVision\" /rom1 example.rom
=== SEGA SC-3000 ===
In order to compile and run the example, you need to have the BlueMSX emulator, and in particular that its executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.sc3000 blit_basic_mask.bas -o example.rom
   bluemsx /machine \"SEGA - SC-3000\" /rom1 example.rom
   
   # Windows 
   ugbc.sc3000.exe blit_basic_mask.bas -o example.rom
   bluemsx  /machine \"SEGA - SC-3000\" /rom1 example.rom
=== SEGA SG-1000 ===
In order to compile and run the example, you need to have the BlueMSX emulator, and in particular that its executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.sg1000 blit_basic_mask.bas -o example.rom
   bluemsx /machine \"SEGA - SG-1000\" /rom1 example.rom
   
   # Windows 
   ugbc.sg1000.exe blit_basic_mask.bas -o example.rom
   bluemsx  /machine \"SEGA - SG-1000\" /rom1 example.rom
==== ANY PROBLEM? ====
If you have found a problem trying to run this example, if you think there is a bug or, more simply, you would like it to be improved, [[https://github.com/spotlessmind1975/ugbasic/issues/new?title=IMPROVE IMAGE BLITTING BASIC MASKING|open an issue]] for this example on GitHub. Thank you!===== POWERED BY =====

[[:ugbasic:user:examples|{{ :ugbasic:user:logo-ugbasic.png?nolink&600 |}}]]