Seeking best ellipse fill function. (For everyone's sake.)

[Pete]

So what Steve is saying is that...

R + R is faster than 2 * R
R * R is faster than R ^ 2

so for example in the original code...

xx = ry * ry * (1 - rx - rx) ' Original code

is faster than changing it to...

xx = ry * ry * (1 - 2 * rx)

I see you just changed it back to the original code, which should match the last one I posted, where I changed it back as well. So we should now have the fastest way to move through the equations, plus my fix the periodic fill problem. All good to go?

Pete

[bplus]

I just ran the timed test in a 32 bit version of QB64 and saved almost 3 sec on both CircleFill and EllipseFill.

Ha! go figure.

[Pete]

And I just save hundreds by switching my car insurance to GEICO.

So 64-bit has too much memory allocated for more digits than needed, maybe, or just a fluke?

Pete

[SMcNeill]

I just ran the timed test in a 32 bit version of QB64 and saved almost 3 sec on both CircleFill and EllipseFill.

Ha! go figure.

And have fun playing with some of the math optimization flags.  They can drastically change your test times.

[STxAxTIC]

Aaaalrighty, didn't expect to be gone all day, so I'm trying to play catchup here. First thing I notice is Steve's function doesn't draw ellipses for large eccentricity (small b). There are boobs on each end - just a recent artifact or was that there all along?

100% regardless of this issue or any others, I think the situation demands a pencil-to-paper derivation of how that function works. I'll reinvent it all if I have to, but surely it's among Steve's notes somewhere?

[SMcNeill]

Aaaalrighty, didn't expect to be gone all day, so I'm trying to play catchup here. First thing I notice is Steve's function doesn't draw ellipses for large eccentricity (small b). There are boobs on each end - just a recent artifact or was that there all along?

100% regardless of this issue or any others, I think the situation demands a pencil-to-paper derivation of how that function works. I'll reinvent it all if I have to, but surely it's among Steve's notes somewhere?

Afraid not.  I found it in an old QB45 program that was on an old drive of mine from ages ago.  I have no idea where the heck I originally acquired/derived it, and I didn’t take any notes as I tweaked it to remove duplicate lines in the past. (And it seems I still missed a few, but I think Pete’s fix corrects those.)

I’ll see if I can pull the original back up later (I have to reinstall the old 40GB drive and an IDE card/cable to use it), and see if the “boob effect” is there from the original, or introduced via alterations.

[Pete]

I noticed we had an ellipse with tits, too... with some sizes... but seriously guys, you wanna change that??!

Pete :D

[STxAxTIC]

Although I'm from Massachusetts, I take a page out of the Texas playbook when it comes to certain anatomical preferences. I wish the tit effect would show up for BIG ellipses, not puny little pointy ones.

XD

I should modify my Tilted ellipse to include a Titted ellipse version as well...

[Pete]

We can still make a fortune selling this to dress designers, who outfit super-models...  So, there's a bright side!

Pete :D

[STxAxTIC]

Alright, so this function is optimized for clarity instead of speed, but has a lovely out-of-the-box feature of running about as fast as the one Steve brought in. Surely more speed can be injected into this thing, too.

Code: QB64: [Select]

1. SUB FlatEllipseFill (ox AS INTEGER, oy AS INTEGER, a AS INTEGER, b AS INTEGER, col AS _UNSIGNED LONG)
2.     DIM h2 AS LONG
3.     DIM w2 AS LONG
4.     DIM h2w2 AS LONG
5.     DIM xi AS INTEGER
6.     DIM dx AS INTEGER
7.     DIM x AS INTEGER
8.     DIM y AS INTEGER
9.     w2 = a * a
10.     h2 = b * b
11.     h2w2 = h2 * w2
12.     xi = a
13.     dx = 0
14.     LINE (ox - a, oy)-(ox + a, oy), col, BF
15.     FOR y = 1 TO b
16.         FOR x = xi - dx + 1 TO 0 STEP -1
17.             IF x * x * h2 + y * y * w2 <= h2w2 THEN EXIT FOR
18.         NEXT
19.         dx = xi - x
20.         xi = x
21.         LINE (ox - xi, oy + y)-(ox + xi, oy + y), col, BF
22.         LINE (ox - xi, oy - y)-(ox + xi, oy - y), col, BF
23.     NEXT
24. END SUB

... just have to check it for bugs, boobs, or other artifacts.

[Pete]

This one fails at various levels, too. Here is one, for example...

Code: QB64: [Select]

1. SCREEN _NEWIMAGE(1000, 700, 32)
2. _SCREENMOVE 180, 20
3.  
4. FlatEllipseFill 500, 350, 400, 200, _RGBA(255, 255, 255, 40)
5. END
6.  
7. SUB FlatEllipseFill (ox AS INTEGER, oy AS INTEGER, a AS INTEGER, b AS INTEGER, col AS _UNSIGNED LONG)
8. DIM h2 AS LONG
9. DIM w2 AS LONG
10. DIM h2w2 AS LONG
11. DIM xi AS INTEGER
12. DIM dx AS INTEGER
13. DIM x AS INTEGER
14. DIM y AS INTEGER
15. w2 = a * a
16. h2 = b * b
17. h2w2 = h2 * w2
18. xi = a
19. dx = 0
20. LINE (ox - a, oy)-(ox + a, oy), col, BF
21. FOR y = 1 TO b
22.     FOR x = xi - dx + 1 TO 0 STEP -1
23.         IF x * x * h2 + y * y * w2 <= h2w2 THEN EXIT FOR
24.     NEXT
25.     dx = xi - x
26.     xi = x
27.     LINE (ox - xi, oy + y)-(ox + xi, oy + y), col, BF
28.     LINE (ox - xi, oy - y)-(ox + xi, oy - y), col, BF
29. NEXT
30. END SUB
31.  

201 fails, too, but plug in 203 and it's fine.

Pete

[Cobalt]

So what Steve is saying is that...
...
R * R is faster than R ^ 2
...
Pete

and _SHL\_SHR are even faster if dealing with powers of 2
so _SHL(R,1) should be faster than R^2 and R*R
only draw back is it has to be power of 2.

I like 2s, 2 eyes, 2 ears, 2 hands, 2 balls.., 2 teats.... life is full of 2s unless your a cow then its 4 teats(hey power of 2!) or pigs then its 8 teats (hey another power of 2!) not versed enough in animal biology does any animal have 16 teats?

[Pete]

Siamese pigs.

[Pete]

Bill, simple variable designation problem. LONG doesn't cut it, so....

Code: QB64: [Select]

1. SCREEN _NEWIMAGE(1000, 700, 32)
2. _SCREENMOVE 180, 20
3.  
4. FlatEllipseFill 500, 350, 400, 200, _RGBA(255, 255, 255, 40)
5. END
6.  
7. SUB FlatEllipseFill (ox AS INTEGER, oy AS INTEGER, a AS INTEGER, b AS INTEGER, col AS _UNSIGNED LONG)
8. DIM h2 AS DOUBLE
9. DIM w2 AS DOUBLE
10. DIM h2w2 AS DOUBLE
11. DIM xi AS DOUBLE
12. DIM dx AS DOUBLE
13. DIM x AS DOUBLE
14. DIM y AS DOUBLE
15. w2 = a * a
16. h2 = b * b
17. h2w2 = h2 * w2
18. xi = a
19. dx = 0
20. LINE (ox - a, oy)-(ox + a, oy), col, BF
21. FOR y = 1 TO b
22.     FOR x = xi - dx + 1 TO 0 STEP -1
23.         IF x * x * h2 + y * y * w2 <= h2w2 THEN EXIT FOR
24.     NEXT
25.     dx = xi - x
26.     xi = x
27.     LINE (ox - xi, oy + y)-(ox + xi, oy + y), col, BF
28.     LINE (ox - xi, oy - y)-(ox + xi, oy - y), col, BF
29. NEXT
30. END SUB
31.  

So I tested it with this, and no glitches. It will make a circle at 300 and then start on a vertical ellipse. It's also a fun effect if you omit the CLS and sleep. Stop it at 300 and you get a full moon effect.

Anyway, maybe something less than DOUBLE can be used but that for/next loop spits out some very large figures.

Code: QB64: [Select]

1. SCREEN _NEWIMAGE(1000, 700, 32)
2. _SCREENMOVE 180, 20
3.  
4. FOR i = 1 TO 350
5.     CLS
6.     PRINT "300 x"; i
7.     FlatEllipseFill 500, 350, 300, i, _RGBA(255, 255, 255, 40)
8.     SLEEP
9. NEXT
10. END
11.  
12. SUB FlatEllipseFill (ox AS INTEGER, oy AS INTEGER, a AS INTEGER, b AS INTEGER, col AS _UNSIGNED LONG)
13. DIM h2 AS DOUBLE
14. DIM w2 AS DOUBLE
15. DIM h2w2 AS DOUBLE
16. DIM xi AS DOUBLE
17. DIM dx AS DOUBLE
18. DIM x AS DOUBLE
19. DIM y AS DOUBLE
20. w2 = a * a
21. h2 = b * b
22. h2w2 = h2 * w2
23. xi = a
24. dx = 0
25. LINE (ox - a, oy)-(ox + a, oy), col, BF
26. FOR y = 1 TO b
27.     FOR x = xi - dx + 1 TO 0 STEP -1
28.         IF x * x * h2 + y * y * w2 <= h2w2 THEN EXIT FOR
29.     NEXT
30.     dx = xi - x
31.     xi = x
32.     LINE (ox - xi, oy + y)-(ox + xi, oy + y), col, BF
33.     LINE (ox - xi, oy - y)-(ox + xi, oy - y), col, BF
34. NEXT
35. END SUB
36.  

I was about half way through making one like this, after getting the formulas together to calculate the parts of an ellipse. Oh well, spoiler. Nice find, Bill...

Pete

[STxAxTIC]

Ah, there are the finishing touches. I figured I was being lazy with respect to variable types but it was also pretty late. I blame Loki. So now I suppose we just wait for bplus to get hold of this...