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vegipete

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Joined: 29/01/2013
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Posted: 04:08am 09 Jan 2024

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To test some things, I bashed this together for the PicoMiteVGA. It shows some potential.
(Delete the first 2 lines if you are not transferring via AUTOSAVE.)

I am puzzled by something, though. When you pilot the ship slowly off the top or left edges, the intensity drops. It appears normal everywhere else. Hmmm. (It might be related to framebuffer copying. If you hit ctrl-C while the ship is in the dim zone, it goes back to full intensity.)
(PicoMiteVGA MMBasic Version 5.07.08RC21)
Edited 2024-01-09 14:15 by vegipete

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Volhout
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Posted: 02:41pm 09 Jan 2024

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Hi Vegipete,

I see no "rocks" yet...only the spaceship.
But when I accelerate it gets warp speed 10.... Wauw.

You are busy with a zillion projects at the same time. Need any help to finish one of them ? LR, RIS, Qbert ... ?

Volhout

P.S. I wonder if the "vector graphics" resolution of the arcade game could be implemented in mode 1 (640x480) using a "tile" to color the plane if you like. But the original game was B/W only.
Edited 2024-01-10 01:16 by Volhout

PicomiteVGA PETSCII ROBOTS

stanleyella

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Posted: 05:26pm 09 Jan 2024

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I looked at the code cos asteroids was a favourite and not tried but looks interesting.
I was thinking of polygons not sprites and no trig.
the original arcade used phosphor fade and the rocks were drawn not erased

vegipete

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Posted: 06:57pm 09 Jan 2024

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As I said, this was to test some things. The little demo uses 144 sprites. I wasn't about to draw them by hand. Instead, the ship was defined by 4 points, rotated to each angle and drawn. The images were then read and converted to CSub data.

Stan has pointed out something else to test - how long does it take to draw the ship as a polygon instead of as a CSub sprite, and can rotation be calculated on the fly or must it be precalculated?

Do CSub sprites work in mode 1 (640x480)? I haven't tried...

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stanleyella

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Posted: 07:04pm 09 Jan 2024

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tried the code and got rotating ship and thrust. nice.
I'll try polygons and frames for fps, see fastest way. stan

stanleyella

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Posted: 12:04am 10 Jan 2024

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Polygons need all the elements in the x,y arrays changed to move them.
using joined lines relative to x,y may be faster. testing

stanleyella

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Posted: 06:32pm 10 Jan 2024

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rotating ship?

xcentre=63
ycentre=58
radius=8
do

for d=0 to 359 step 10
cls

xp = xcentre + radius * sin (rad(d))
yp = ycentre - radius * cos (rad(d))
e=d+140:if e>359 then e=e-359
f=d+220:if f>359 then f=f-359
xe1 = xcentre + radius * sin (rad(e))
ye1 = ycentre - radius * cos (rad(e))
xe2 = xcentre + radius * sin (rad(f))
ye2 = ycentre - radius * cos (rad(f))

line xe1,ye1,xp,yp,,1
line xp,yp,xe2,ye2,,1

pause 50
next d
loop

stanleyella

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Posted: 06:57pm 10 Jan 2024

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The firing shots at different degrees will be fun to implement.
the rotating ship seems low memory and drawing the rocks could be fast enough. use frames no erase . a smaller display area to get wrap around and frames.
I'll try to chip in for the picomite asteroids if I can help. stan

stanleyella

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Posted: 08:11pm 10 Jan 2024

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bit more efficient rotating ship

xcentre=63
ycentre=58
radius=8
do

for d=0 to 359 step 10
cls
rd=rad(d)
xp = xcentre + radius * sin (rd)
yp = ycentre - radius * cos (rd)

e=d+140:if e>359 then e=e-359
rd=rad(e)
xe1 = xcentre + radius * sin (rd)
ye1 = ycentre - radius * cos (rd)

e=d+220:if e>359 then e=e-359
rd=rad(e)
xe2 = xcentre + radius * sin (rd)
ye2 = ycentre - radius * cos (rd)

line xe1,ye1,xp,yp,,1
line xp,yp,xe2,ye2,,1

pause 50
next d
loop

Footnote added 2024-01-11 07:32 by stanleyella
add
line xe2,ye2,xcentre,ycentre,,1
line xcentre,ycentre,xe1,ye1,,1
for a proper ship :)

stanleyella

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Posted: 08:31pm 10 Jan 2024

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how many angles for the ship? 16 with no trig except the ship rotate, so many x,y pixels for missiles and ship forward.? stan

vegipete

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Posted: 09:42pm 10 Jan 2024

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Ship rotation thoughts:
I started with my Rocks in Space for the CMM2. It used 96 steps for the full rotation of a 32ish pixel square ship canvas on an 800x600 screen. Scaling that ship size to the PicoMite resolution gave me a 13 pixel square canvas - convenient because that results in an actual center point. Sketched a 4-point ship, put the coordinates into a little program, plotted it, fettled a bit, sorted. Then I started rotating the resulting ship to see what number of steps looked good. 96 was unnecessarily many, 72 was aesthetically pleasing.

Here's the code I used to generate the ships:

Option DEFAULT INTEGER
option angle degrees
MODE 2
cls 0

' ship data: 4 points for ship, 5 points for flame
dim float body(8,1):for i=0 to 8:read body(i,0):read body(i,1):next
data 0,-6,-3,4,0,2,3,4,0,4,0,5,-1,5,0,6,1,5

dim float rc(8,1) ' work copy of ship
dim float sa,ca

mx = 6 : my = 56
for a = 0 to 359 step 5

' rotate a copy of the ship
sa = sin(a) : ca = cos(a) ' only do this once!
for i = 0 to 8
rc(i,0) = body(i,0) * ca - body(i,1) * sa
rc(i,1) = body(i,0) * sa + body(i,1) * ca
next

' ship body
line mx+rc(0,0),my+rc(0,1),mx+rc(1,0),my+rc(1,1),,rgb(green)
line mx+rc(1,0),my+rc(1,1),mx+rc(2,0),my+rc(2,1),,rgb(green)
line mx+rc(2,0),my+rc(2,1),mx+rc(3,0),my+rc(3,1),,rgb(green)
line mx+rc(3,0),my+rc(3,1),mx+rc(0,0),my+rc(0,1),,rgb(green)

' rocket flames
pixel mx+rc(4,0),my+rc(4,1),rgb(yellow)
pixel mx+rc(5,0),my+rc(5,1),rgb(brown)
pixel mx+rc(6,0),my+rc(6,1),rgb(rust)
pixel mx+rc(7,0),my+rc(7,1),rgb(rust)
pixel mx+rc(8,0),my+rc(8,1),rgb(rust)

' advance to next image location
mx = mx + 13
if mx >= 239 then
mx = 6
my = my + 13
endif
next a

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stanleyella

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Posted: 09:54pm 10 Jan 2024

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radius=16 is nice

mode 1
xcentre=100
ycentre=100
radius=16
do
for d=0 to 359 step 16
cls
rd=rad(d)
xp = xcentre + radius * sin (rd)'ship
yp = ycentre - radius * cos (rd)'direction
'
e=d+140:if e>359 then e=e-359
rd=rad(e)
xe1 = xcentre + radius * sin (rd)'ship
ye1 = ycentre - radius * cos (rd)'tail left
'
e=d+220:if e>359 then e=e-359
rd=rad(e)
xe2 = xcentre + radius * sin (rd)'ship
ye2 = ycentre - radius * cos (rd)'tail right
'
line xe1,ye1,xp,yp,,1' :
line xp,yp,xe2,ye2,,1' :draw
line xe2,ye2,xcentre,ycentre,,1' :ship
line xcentre,ycentre,xe1,ye1,,1' :
pause 100
next d
loop

lizby
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Joined: 17/05/2016
Location: United States
Posts: 3122

Posted: 10:19pm 10 Jan 2024

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vegipete said Ship rotation thoughts:

In MMB4W:

PicoMite, Armmite F4, SensorKits, MMBasic Hardware, Games, etc. on fruitoftheshed

stanleyella

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Posts: 1988

Posted: 12:11am 11 Jan 2024

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if drawn then 360 but how many in atari original game?
I was thinking of x,y centre to ship point ratio to get increments for movement and missile vector.
reminds me of startrek https://www.youtube.com/watch?v=CBj6AUrMVls

pwillard
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Joined: 07/06/2022
Location: United States
Posts: 287

Posted: 12:28am 11 Jan 2024

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The original atari game had one "shape" and used vector math to rotate... no sprites at all.

Mixtel90

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Location: United Kingdom
Posts: 6564

Posted: 08:21am 11 Jan 2024

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I'd suggest keeping the number of rotation steps as small as possible. The rotation won't actually be as smooth, but it will be faster - and you'll need CPU capacity to handle the drawing and movement of rocks. This is one of those cases where using a lookup table for the vertices of objects could be faster and easier than calculating them, but in order to keep the lookup table reasonable you have to keep the steps down.

Note that you can use just one or two lookup tables for rocks and simply scale them as needed.
Edited 2024-01-11 18:22 by Mixtel90

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stanleyella

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Posts: 1988

Posted: 05:23pm 11 Jan 2024

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For the classic atari asteroids look vga mode 1.
should it use sprites, line, or polygon?
I thought the sprite or blit on lcd had changed to not record black, dunno , which mmbasic version.
joined lines with 1 x,y start and the other points x,y with offset.
polygons, all points in the x,y arrays needing offset.
I got 16 16x16 sprites bouncing around very fast. a few rocks should be ok.
For the rock and ship and missile wrap around I thought copy a smaller frame than the drawing frame to the screen. just thoughts. stan

stanleyella

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Posted: 05:49pm 13 Jan 2024

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I'm trying lines for rocksfrom x,y corner as sprite to move
change rx1,ry1 and draws rock there. sprite alternative?

sub rock1
line rx1+6,ry1,rx1+14,ry1+6
line rx1+14,ry1+6,rx1+22,ry1
line rx1+22,ry1,rx1+30,ry1+6
line rx1+30,ry1+6,rx1+22,ry1+14
line rx1+22,ry1+14,rx1+30,ry1+22
line rx1+30,ry1+22,rx1+18,ry1+30
line rx1+18,ry1+30,rx1+8,ry1+30
line rx1+8,ry1+30,rx1,ry1+26
line rx1,ry1+26,rx1,ry1+6
line rx1,ry1+6,rx1+6,ry1
end sub

sub rock2
line rx1+12,ry1,rx1+28,ry1+12
line rx1+28,ry1+12,rx1+44,ry1
line rx1+44,ry1,rx1+60,ry1+12
line rx1+60,ry1+12,rx1+44,ry1+28
line rx1+44,ry1+28,rx1+60,ry1+44
line rx1+60,ry1+44,rx1+36,ry1+60
line rx1+36,ry1+60,rx1+16,ry1+60
line rx1+16,ry1+60,rx1,ry1+44
line rx1,ry1+44,rx1,ry1+16
line rx1,ry1+16,rx1+12,ry1
end sub

sub rock3
line rx1+9,ry1,rx1+21,ry1+9
line rx1+21,ry1+9,rx1+33,ry1
line rx1+33,ry1,rx1+40,ry1+9
line rx1+40,ry1+9,rx1+33,ry1+21
line rx1+33,ry1+21,rx1+40,ry1+33
line rx1+40,ry1+33,rx1+24,ry1+40
line rx1+24,ry1+40,rx1+12,ry1+40
line rx1+12,ry1+40,rx1,ry1+36
line rx1,ry1+36,rx1,ry1+12
line rx1,ry1+12,rx1+9,ry1
end sub

stanleyella

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Joined: 25/06/2022
Location: United Kingdom
Posts: 1988

Posted: 06:24pm 13 Jan 2024

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pwillard said The original atari game had one "shape" and used vector math to rotate... no sprites at all.

A 6502 board with dacs connected to x,y b/w vector monitor.
if you turned the brightness control up you saw the the lines between the graphics as it drew a rock then moved to draw the next and all graphics.
In the original asteroids only the ship rotated.
I would make the saucer a sprite.. lot to draw.
Edited 2024-01-14 04:46 by stanleyella

stanleyella

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Posts: 1988

Posted: 07:04pm 13 Jan 2024

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Mixtel90 said
Note that you can use just one or two lookup tables for rocks and simply scale them as needed.

yes,thinking that. please see rocks are multiples.
Edited 2024-01-14 05:20 by stanleyella

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