' (2)
 	OPTION EXPLICIT
 
 	' (3)
 	DIM p AS FLOAT
 	DIM q AS INT
 	DIM xp AS FLOAT, yp AS FLOAT, zp AS FLOAT
 	DIM xf AS FLOAT, yf AS FLOAT, zf AS FLOAT
 	DIM xr AS FLOAT, yr AS FLOAT, zr AS FLOAT
 	DIM xt AS FLOAT, yt AS FLOAT, zt AS FLOAT
 	DIM xx AS FLOAT, yy AS FLOAT, zz AS FLOAT
 	DIM zi AS INTEGER
 	DIM p1 AS INTEGER
 	DIM zt AS FLOAT
 	DIM xl AS INTEGER, yl AS INTEGER
 	DIM x1 AS INTEGER, y1 AS INTEGER
 	
 	' (4)
 	BITMAP ENABLE (320,200,16)
 	
 	CLS BLACK
 	
 	p1=160
 	q=100
 	xp=144
 	xr=01.5*PI
 	yp=56
 	yr=01
 	
 	zp=64
 	xf=xr/xp
 	yf=yp/yr
 	zf=xr/zp
 	
 	FOR zi=-q TO q-1
 	
 		IF zi<-zp OR zi>zp THEN GOTO endloop
 		
 		zt=zi*xp/zp
 		zz=zi
 		xl=INT(.5+SQR((xp*xp)-(zt*zt)))
 		
 		FOR xi=-xl TO xl
 			DEGREE
 			xt=(SQR(xi*xi+zt*zt)*xf)*180/PI:xx=xi
 			yy=(SIN (xt)+.4*SIN (3*xt))*yf
 			GOSUB continue
 		NEXT
 endloop:
 	NEXT
 loop:
 	GOTO loop
 
 continue:
 	x1=xx+zz+p1
 	' (10)
 	' PRINT "yy = ";yy;" zz = ";zz;" q = ";q
 	y1=INT(yy-zz+q)
 	' (11)
 	' PRINT "y1 = ";y1
 	' (5)
 	
 	PLOT x1,y1,GREEN
 	' (12)
 	' PRINT "PLOT AT ";x1;",";y1
 	
 	IF y1=0 THEN GOTO draw_line
 	
 	' Fix? (1)
 	' RETURN
 	
 draw_line:
 	' (6)
 	INK YELLOW
 	' (7)
 	LINE x1,y1-1 TO x1,0
 	' PRINT "LINE ";x1;"-";y1;" TO ";x1;",0"
 	RETURN

• bug2.bas

The instructions here refer to compiling the example from the command line. For Microsoft Windows users we suggest using UGBASIC-IDE, which allows you to compile the example with just one click.

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 bug2.bas -o example.xex
 altirra example.xex
 
 # Windows 
 ugbc.atari.exe bug2.bas -o example.xex
 altirra example.xex

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 bug2.bas -o example.xex
 altirra example.xex
 
 # Windows 
 ugbc.atarixl.exe bug2.bas -o example.xex
 altirra example.xex

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 bug2.bas -o example.prg
 x64sc example.prg
 
 # Windows 
 ugbc.c64.exe bug2.bas -o example.prg
 x64sc example.prg

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 bug2.bas -o example.prg
 x64sc -reu example.prg
 
 # Windows 
 ugbc.c64reu.exe bug2.bas -o example.prg
 x64sc -reu example.prg

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 bug2.bas -o example.prg
 yape example.prg
 
 # Windows 
 ugbc.plus4.exe bug2.bas -o example.prg
 yape example.prg

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 bug2.bas -o example.prg
 xplus4 example.prg
 
 # Windows 
 ugbc.plus4.exe bug2.bas -o example.prg
 xplus4 example.prg

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 bug2.bas -o example.bin
 xroar -rompath (your rom path) example.bin
 
 # Windows 
 ugbc.d32.exe bug2.bas -o example.bin
 xroar.exe -rompath (your rom path) example.bin

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 bug2.bas -o example.bin
 xroar -rompath (your rom path) example.bin
 
 # Windows 
 ugbc.d64.exe bug2.bas -o example.bin
 xroar.exe -rompath (your rom path) example.bin

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 bug2.bas -o example.k7
 dcmoto
 (choose BASIC 128)
 CLEAR,&H2FFF: LOADM"CASS:",R: EXEC
 
 # Windows 
 ugbc.pc128op.exe bug2.bas -o example.k7
 dcmoto
 (choose example.k7)
 (choose BASIC 128)
 CLEAR,&H2FFF: LOADM"CASS:",R: EXEC

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 bug2.bas -o example.k7
 dcmoto
 (choose BASIC 128)
 CLEAR,&H2FFF: LOADM"CASS:",R: EXEC
 
 # Windows 
 ugbc.pc128op.exe bug2.bas -o example.k7
 dcmoto
 (choose example.k7)
 (choose BASIC 128)
 CLEAR,&H2FFF: LOADM"CASS:",R: EXEC

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 bug2.bas -o example.prg
 xvic --memory 24k example.prg
 
 # Windows 
 ugbc.vic20.exe bug2.bas -o example.prg
 xvic --memory 24k example.prg

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 bug2.bas -o example.tap
 Speccy example.tap
 
 # Windows 
 ugbc.zx.exe bug2.bas -o example.tap
 Speccy example.tap

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:

 # Linux 
 ugbc.msx1 bug2.bas -o example.rom
 openmsx -cart example.rom
 
 # Windows 
 ugbc.msx1.exe bug2.bas -o example.rom
 openmsx -cart example.rom

 # Linux 
 ugbc.msx1 bug2.bas -o example.rom
 bluemsx example.rom
 
 # Windows 
 ugbc.msx1.exe bug2.bas -o example.rom
 bluemsx example.rom

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:

 # Linux 
 ugbc.coleco bug2.bas -o example.rom
 openmsx -machine \"COL - ColecoVision\" -cart example.rom
 
 # Windows 
 ugbc.coleco.exe bug2.bas -o example.rom
 bluemsx -machine \"COL - ColecoVision\" example.rom

 # Linux 
 ugbc.coleco bug2.bas -o example.rom
 bluemsx /machine \"COL - ColecoVision\" /rom1 example.rom
 
 # Windows 
 ugbc.coleco.exe bug2.bas -o example.rom
 bluemsx  /machine \"COL - ColecoVision\" /rom1 example.rom

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 bug2.bas -o example.rom
 bluemsx /machine \"SEGA - SC-3000\" /rom1 example.rom
 
 # Windows 
 ugbc.sc3000.exe bug2.bas -o example.rom
 bluemsx  /machine \"SEGA - SC-3000\" /rom1 example.rom

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 bug2.bas -o example.rom
 bluemsx /machine \"SEGA - SG-1000\" /rom1 example.rom
 
 # Windows 
 ugbc.sg1000.exe bug2.bas -o example.rom
 bluemsx  /machine \"SEGA - SG-1000\" /rom1 example.rom

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, open an issue for this example on GitHub. Thank you!