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Volhout
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Joined: 05/03/2018
Location: Netherlands
Posts: 5807

Posted: 08:18am 22 Feb 2026

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Hi javavi,

Wauw. This is beautifull. I did not have VGA system at hand, so I converted it to Game*Mite (any color LCD would do). But this is amazing. It feels like we could convert the whole of the universe into a few lines of MMBasic. Thank you. Between your demo's there are some real gems, pure diamond, and this is one of them.

dim cmap(15)'MODE 2
cMap(1)=RGB(Red)
cMap(2)=RGB(Yellow)
cMap(3)=RGB(White)
'Map set

For N=0 To 239
For M=0 To 319
X=0:Y=-.1:Z=3
U=(M-159.5)/160:V=(N-117.5)/160
W=1/Sqr(U*U+V*V+1):U=U*W:V=V*W
I=Sgn(U):G=1
Do
E=X-I:F=Y-I:P=U*E+V*F-W*Z
D=P*P-E*E-F*F-Z*Z+1
If D>0 Then
T=-P-Sqr(D)
If T>0 Then
X=X+T*U:Y=Y+T*V:Z=Z-T*W:E=X-I:F=Y-I:G=Z
P=2*(U*E+V*F-W*G):U=U-P*E:V=V-P*F:W=W+P*G:I=-I
Loop
EndIf
EndIf
If V<0 Then
P=(Y+2)/V:V=-V*((Int(X-U*P)+Int(Z-W*P)And 1)/2+.3)+.2
EndIf
Color cMap(3-(48*Sqr(V)+(7*(M+4*N))Mod 16)\16)
Pixel M,240-N
Next
Next

Volhout

PicomiteVGA PETSCII ROBOTS

Martin H.

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Joined: 04/06/2022
Location: Germany
Posts: 1427

Posted: 10:24am 22 Feb 2026

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Fascinating. I have no idea how the programme works, but Harms version also runs smoothly in mode 7 under mmbasic for Windows.
Here in 640x480 Picomite HDMI Mode 3 or CMM2/MMBASIC4Windows Mode 1

cls:Mode 1' Mode 3 PICO HDMI
dim cmap(15)
cMap(1)=RGB(Red)
cMap(2)=RGB(Yellow)
cMap(3)=RGB(White)
For N=0 To 479
For M=0 To 639
X=0:Y=-.1:Z=3
U=(M-319.5)/320 : V=(N-237.5)/320
W=1/Sqr(U*U+V*V+1):U=U*W:V=V*W
I=Sgn(U):G=1
Do
E=X-I:F=Y-I:P=U*E+V*F-W*Z
D=P*P-E*E-F*F-Z*Z+1
If D>0 Then
T=-P-Sqr(D)
If T>0 Then
X=X+T*U:Y=Y+T*V:Z=Z-T*W:E=X-I:F=Y-I:G=Z
P=2*(U*E+V*F-W*G):U=U-P*E:V=V-P*F:W=W+P*G:I=-I
Loop
End If
End If
If V<0 Then
P=(Y+2)/V:V=-V*((Int(X-U*P)+Int(Z-W*P)And 1)/2+.3)+.2
EndIf
Color cMap(3-(48*Sqr(V)+(7*(M+4*N))Mod 16)\16)
Pixel M,480-N
Next
Next

Cheers
Martin
Edited 2026-02-22 20:45 by Martin H.

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JanVolk
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Joined: 28/01/2023
Location: Netherlands
Posts: 326

Posted: 11:10am 22 Feb 2026

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And also on the RP2040-GEEK.

' - RP2040-GEEK -
'MODE 2
Dim cmap(15)
cMap(1)=RGB(Red)
cMap(2)=RGB(Yellow)
cMap(3)=RGB(White)
'Map set

For N=0 To 134 '239->134 'ILI9341=320x240 ST7789_135=240x135
For M=0 To 239 '319->239
X=0:Y=-.1:Z=3
U=(M-119.5)/120:V=(N-67)/120 '159.5->119.5 117.5->67 160->120
W=1/Sqr(U*U+V*V+1):U=U*W:V=V*W
I=Sgn(U):G=1
Do
E=X-I:F=Y-I:P=U*E+V*F-W*Z
D=P*P-E*E-F*F-Z*Z+1
If D>0 Then
T=-P-Sqr(D)
If T>0 Then
X=X+T*U:Y=Y+T*V:Z=Z-T*W:E=X-I:F=Y-I:G=Z
P=2*(U*E+V*F-W*G):U=U-P*E:V=V-P*F:W=W+P*G:I=-I
Loop
EndIf
EndIf
If V<0 Then
P=(Y+2)/V:V=-V*((Int(X-U*P)+Int(Z-W*P)And 1)/2+.3)+.2
EndIf
Color cMap(3-(48*Sqr(V)+(7*(M+4*N))Mod 16)\16)
Pixel M,135-N '240->135
Next
Next

Jan.

twofingers

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Joined: 02/06/2014
Location: Germany
Posts: 1729

Posted: 01:18pm 27 Feb 2026

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Hi Martin(/Harm/Vadim),
I hope you don't mind that I modified your code. I was playing around with it a bit (along with AI, since I don't really understand the code ;-)).
My goal was to explore the possibilities for speed optimization in pure BASIC.
For a faster speed (now 44 seconds on 640x480 display), I halved the resolution (using double pixels)!

MODE 3:CLS :Map RESET:Timer =0
Dim Float x,y,z,u,v,w,e,f,p,d,t,uo,vo,tp,v2,xi,zi,i3=1/320
Dim Integer m,n,k,o,c,uc=320,vc=240
Dim Integer G(15)=(0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15)
Colour Map G(),G()
For n=0 To 479:vo=(n-vc)*i3:v2=vo*vo+1:o=28*n
For m=1 To 640 Step 2
x=0:y=-.1:z=3.8:uo=(m-uc)*i3:w=1/Sqr(uo*uo+v2):u=uo*w:v=vo*w:i=Sgn(u)
Do
e=x-i:f=y-i:p=u*e+v*f-w*z:d=p*p-e*e-f*f-z*z+1:If d<=0 Then Exit Do
t=-p-Sqr(d):If t<0 Then Exit Do
Inc x,t*u:Inc y,t*v:Inc z,-t*w:e=x-i
p=2*(u*e+v*(y-i)-w*z):Inc u,-p*e:Inc v,-p*(y-i):Inc w,p*z:i=-i
Loop
If v<0 Then
tp=(y+2)/v:xi=x-u*tp:zi=z-w*tp
k=((xi+4096)+Int(zi+4096))And 1
c=10-k*10
Else
c=Int(14-v*25+((7*m+o)Mod 16)\2)
EndIf
c=c*(c>0 And c<15)+15*(c>=15)
Line m,480-n,m+1,480-n,,G(c):Next
Next
Print Timer

Functional Block Description

1. Initialization & Setup (Lines 1-8)
The code sets the display MODE 3 and resets the color Map. It initializes
all necessary variables and the G() array, which maps indices 0-15 to
the system's color palette.

2. Ray Normalization & Viewport Mapping (Lines 9-11)
Inside the nested loops, the code converts screen pixels (m, n) into
3D ray slopes (uo, vo). Line 11 is critical: it calculates the unit
vector components (u, v, w) using the Pythagorean normalization
formula to prepare for accurate physical reflections.

3. Reflection Loop (Lines 12-17)
The Do...Loop handles the ray-sphere intersections.

Lines 13-14: Calculate the discriminant 'd' and distance 't' to
check if a sphere is hit.

Lines 15-16: If hit, the position is updated (Inc x, y, z) and
the ray's direction (u, v, w) is mathematically reflected.

Line 17: Toggles 'i' to check the other sphere in the next iteration.

4. Floor and Horizon Logic (Lines 18-23)

Floor (Lines 19-21): If the ray points down (v < 0), the floor
intersection (tp) and checkerboard coordinates (xi, zi) are calculated.
Your optimized '10-k*10' logic assigns colors without 'If' branches.

Sky (Lines 22-23): If the ray points up, a dithered gradient color
is calculated based on the vertical slope.

5. Boolean Clamping & Output (Lines 25-26)

Line 25: The high-performance Boolean expression clamps 'c' between
0 and 15 without using the slower 'If' or 'Min/Max' commands.

Line 26: The 'Line' command outputs a 2-pixel segment to the screen.

Regards
Michael

causality ≠ correlation ≠ coincidence

tritonium
Newbie

Joined: 16/06/2018
Location: United Kingdom
Posts: 24

Posted: 02:37pm 06 Mar 2026

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Hi Javavi

I love this vga imagery but I cant get anything to work properly with map in it.
I have a pico 2530A with vga adapter and options as follows

PicoMiteVGA MMBasic RP2350A Edition V6.01.00
OPTION FLASH SIZE 4194304
OPTION COLOURCODE ON
OPTION KEYBOARD US
OPTION RESOLUTION 640x480 @ 252000KHz

All those not using MAP work just fine

should I be using HDMI ?

Dave

Bleep
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Joined: 09/01/2022
Location: United Kingdom
Posts: 776

Posted: 02:58pm 06 Mar 2026

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Hi Dave,
The answer is yes, the VGA colours are fixed in hardware to 16 fixed colours, fixed resitor values, so cannot be changed, whereas the HDMI can be mapped to give any colour, depending on mode there may still only be 16 colours, but they can be mapped to any 16 colours.

stanleyella

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Joined: 25/06/2022
Location: United Kingdom
Posts: 2793

Posted: 05:13pm 06 Mar 2026

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Bleep said Hi Dave,
The answer is yes, the VGA colours are fixed in hardware to 16 fixed colours, fixed resitor values, so cannot be changed, whereas the HDMI can be mapped to give any colour, depending on mode there may still only be 16 colours, but they can be mapped to any 16 colours.

I never thought about that. I've been using pico usb hdmi for a while and assumed as it was in vga demo it worked on pico vga. doh.

javavi

Guru

Joined: 01/10/2023
Location: Ukraine
Posts: 541

Posted: 05:29pm 08 Mar 2026

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SinePoly

MODE 2
Dim integer xp(255),yp(255)
Dim integer s(255),c(255)
r0=63:a0=0:b0=0
di=217:db=1:da=1
For i=0 To 255
s(i)=Int(r0*Sin(i*Pi/128))
c(i)=Int(r0*Cos(i*Pi/128))
Next

Do
si=220
Inc di:Inc si,-di
If di=220 Then di=0
If di=0 Then
db=(db+1)And 255:si=(si+1)And 65535:Inc di,2
Do : fc=Int(Rnd*16):bc=Int(Rnd*16): Loop While fc=bc
EndIf
a0=(a0+2)And 255:b0=(b0+2)And 255
a=a0:b=b0
For i=0 To 255
x=(si*c(a)+c(b)*di):y=(si*s(a)+S(b)*di)
a=(a+da)And 255:b=(b+db)And 255
xp(i)=160+x\128:yp(i)=120+y\128
Next

CLS Map(bc):Color Map(fc)
Polygon 256,xp(),yp()
Pause 20
Loop While Inkey$=""

Edited 2026-03-09 06:24 by javavi

Martin H.

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Joined: 04/06/2022
Location: Germany
Posts: 1427

Posted: 10:47am 10 Mar 2026

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A small old demo that I wrote about 35 years ago in GFA Basic on the Atari ST, converted here for PICOMITE VGA/HDMI.

' Vectorball by Martin H. 1991-2026
Dim x1(20),y1(20),y(20),coor%(20,4)
FRAMEBUFFER create
FRAMEBUFFER layer create
init
FRAMEBUFFER write f
Do
co%=0
For f=0 To 359 Step 10
CLS
p=f+4
p1=f+8
p2=f+160
For n=1 To 20
x1(n)=160+coor%(n,2)*Sin(((f+coor%(n,3))/180)*Pi)
y1(n)=(coor%(n,2))*Cos((f+coor%(n,3))/180*Pi)
Next n
For w=25 To -25 Step -1
For n=1 To 20
If Int(y1(n))=w Then
Sprite write 1,x1(n) , 100+coor%(n,1)
EndIf
Next n
Next w
schatten
Inc co%
FRAMEBUFFER write n
Sprite scroll -1,0
FRAMEBUFFER write f
' page copy 1,0
FRAMEBUFFER copy f,l
Next f
Loop

Sub schatten
'water reflection (kind of)
For fx=0 To 23
l0=7*Sin(((fx+co%)/3.5)*Pi)
Blit 130,164-fx*3,130+l0,177+fx,64,1
Next fx
End Sub
Sub init
CLS
For l= 1 To 70
Pixel Rnd*320,Rnd*180,RGB(white)
Next l

Restore coords
For f=1 To 20
For n=1 To 3
Read coor%(f,n)
Next n
Next f
Restore BLL
Open "ball.spr" For output As #1
For f=1 To 17
Read a$:Print #1,a$
Next
Close #1
Sprite load "ball.spr"
End Sub
coords:
' coord y, x, degree: The figure
' Y is logical
' X is the radius from the centre point
' Degree is the deviation from zero degrees in a circle (cf. Z).
Data 0,12,45
Data 8,8,45
Data 8, 4,180
Data 8, 4,200
Data 10,18,22
Data 16,4,45
Data 16, 9,170
Data 19,23,10
Data 24, 4,45
Data 24, 15,160
Data 28,24,20
Data 32, 4,0
Data 40,12,-10
Data 40,4,175
Data 48,20,-20
Data 48,10,170
Data 56,24,-25
Data 56,12,160
Data 64,24,-30
Data 64,12,160
End Sub
BLL:
Data "16,1,16"
Data "0000011111100000"
Data "0001111111111000"
Data "0011111991111100"
Data "0111199999911110"
Data "0111999B99991110"
Data "111193773B991111"
Data "1119B7777B999111"
Data "1119B7777BB99111"
Data "1111B3773B991111"
Data "11119BBBBB991111"
Data "1111199B99911111"
Data "0111111991111110"
Data "0111111111111110"
Data "0011111111111100"
Data "0001111111111000"
Data "0000011111100000"

Back then, I had to cache all the frames, but today, on the Pico, it runs in real time.
Have Fun
Martin
Edited 2026-03-10 20:54 by Martin H.

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Volhout
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Joined: 05/03/2018
Location: Netherlands
Posts: 5807

Posted: 10:58am 10 Mar 2026

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Nice !!

Volhout

PicomiteVGA PETSCII ROBOTS

stanleyella

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Joined: 25/06/2022
Location: United Kingdom
Posts: 2793

Posted: 04:25pm 10 Mar 2026

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I got
[39] Blit 130,164-fx*3,130+l0,177+fx,64,1
Error : Not enough Heap memory
PicoMiteHDMI MMBasic USB RP2350A Edition V6.01.00b11
OPTION SERIAL CONSOLE COM2,GP20,GP21
OPTION FLASH SIZE 4194304
OPTION COLOURCODE ON
OPTION KEYBOARD UK, 0, 0, 600, 150
OPTION RESOLUTION 640x480 @ 315000KHz
OPTION DISPLAY 20, 40
OPTION SDCARD GP2, GP6, GP7, GP4
OPTION AUDIO GP0,GP1', ON PWM CHANNEL 0
OPTION DEFAULT FONT 3, 1
> stan

Martin H.

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Joined: 04/06/2022
Location: Germany
Posts: 1427

Posted: 04:44pm 10 Mar 2026

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Sure, the program uses all 3 screens, but the difference between our systems doesn't seem that big.

Quote PicoMiteHDMI MMBasic USB RP2350A Edition V6.02.01RC1
OPTION SERIAL CONSOLE COM1,GP0,GP1
OPTION FLASH SIZE 4194304
OPTION COLOURCODE ON
OPTION KEYBOARD US
OPTION RESOLUTION 640x480 @ 252000KHz
OPTION DISPLAY 30, 53
OPTION HDMI PINS 1, 3, 7, 5
OPTION SDCARD GP22, GP6, GP7, GP4
OPTION AUDIO GP26,GP27', ON PWM CHANNEL 5
OPTION MODBUFF ENABLE 192
OPTION PLATFORM OLIMEX USB

Quote Program:
2K ( 0%) Program (108 lines)
182K (100%) Free

Saved Variables:
16K (100%) Free

RAM:
3K ( 1%) 16 Variables
0K ( 0%) General
227K (99%) Free

I can only guess, since it doesn't cause any problems for me.
Make sure that you are in Mode 2
in mode 1 I get the same message
so simply add a MODE 2 at the start of the Programm
Edited 2026-03-11 03:27 by Martin H.

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javavi

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Joined: 01/10/2023
Location: Ukraine
Posts: 541

Posted: 05:23pm 17 Mar 2026

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The Sphere of the Question

MODE 2
CX=MM.HRES\2
CY=MM.VRES\2
N=314:F=1
FRAMEBUFFER CREATE
FRAMEBUFFER WRITE F
Do
CLS
For P=0 To N
Y=1-2*P/N
R=Sqr(1-Y*Y)
T=F*P
X=R*Cos(T)
Z=R*Sin(T)
If Z<0 Then Color RGB(Blue) Else Color RGB(Cyan)
Print @(CX+X*CY,CY+Y*CY) "?";
Next
FRAMEBUFFER COPY F,N,B
Pause 50
Inc F,0.001
Loop While Inkey$=""

stanleyella

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Joined: 25/06/2022
Location: United Kingdom
Posts: 2793

Posted: 09:05pm 18 Mar 2026

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Looks nice! Thanks.

stanleyella

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Joined: 25/06/2022
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Posts: 2793

Posted: 09:16pm 18 Mar 2026

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@Martin H. yes, add mode 2 and it works. impressive.

javavi

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Joined: 01/10/2023
Location: Ukraine
Posts: 541

Posted: 06:53pm 21 Mar 2026

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SinePrint

MODE 2
T$="PicoMite HDMI USB"
LT=Len(T$)*MM.FONTWIDTH
YB=MM.VRES-MM.FONTHEIGHT
XRL=MM.HRES-LT-MM.FONTWIDTH
XLL=MM.FONTWIDTH
XS=YLL
DIR=0
P=0
Do
X=XS+Sin(P)*MM.FONTWIDTH
Color Map(1+Int(Rnd*15))
Print @(X,YB)T$
If XS<=XLL Then DIR=1
If XS>=XRL Then DIR=-1
Inc XS,DIR
Inc P,.3
Pause 60
Loop While Inkey$=""

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