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Post by johnno56 on Sept 18, 2021 6:07:48 GMT -6
Here is a snippet that I converted from QB64.
Not mine. Created by Bplus.
xmax = 1200
ymax = 600
title$ = "Plasma Text Demo by Bplus"
'
' "Borrowed" from QB64 (bplus)
'
center_x = windowpos_centered
center_y = windowpos_centered
WindowOpen(1,title$,center_x,center_y,xmax,ymax,WindowMode(1,0,0,0,0),1)
SetWindowAutoClose(1, 0)
CanvasOpen(1,xmax,ymax,0,0,xmax,ymax,0)
randomize(timer)
' Display message on a blank screen
'
mess$ = "PLASMA TEXT DEMO "
setColor(rgb(255, 255, 255))
prints(mess$)
w = 8 * length(mess$)
h = 8
Dim p[w, h]
Dim pR
Dim pG
Dim pB
Dim lc
Dim cN
black = rgb(0, 0, 0)
' SCAN the the text pixels and store in an array
'
for y = 0 to h
for x = 0 to w
if getPixel(x, y) <> black then
p[x, y] = 1
end if
next
next
cls
'======================================================================
'function range(minimum, maximum)
' return minimum + rand(maximum - minimum)
'end function
Sub resetPlasma()
pR = (rand(1000) / 1000) ^ 2
pG = (rand(1000) / 1000) ^ 2
pB = (rand(1000) / 1000) ^ 2
End Sub
Sub changePlasma()
cN = cN + 1
setColor(rgb(127 + 127 * sin(pR * 0.3 * cN), 127 + 127 * sin(pG * 0.3 * cN), 127 + 127 * sin(pB * 0.3 * cN)))
End Sub
'======================================================================
clearcanvas
' Message co-ordinates
xo = 200
yo = 235
' Image multiplier
m = 6
resetPlasma()
do
for y = 0 to h - 1
for x = 0 to w - 1
if p[x, y] then
changePlasma()
else
setColor(rgb(0, 0, 0))
end if
boxFill(xo + x * m, yo + y * m, xo + x * m + m, yo + y * m + m)
next
next
update()
wait(100)
lc = lc + 1
if lc mod (20 + rand(20)) = 0 then
resetPlasma()
end if
if Not WindowExists(1) Or WindowEvent_Close(1) Then
end
end if
update()
loop until key(27) = 1
Watch if a little while and notice the changes in the colour.
J
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Post by rosy on Sept 18, 2021 10:21:39 GMT -6
I have garbage again ... Maybe ClearCanvas is running on Canvas 0, and here we have Canvas 1 ...
And once I got a mistake, Malloc ...
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Post by johnno56 on Sept 18, 2021 15:09:48 GMT -6
Did you get an error message? I usually use Canvas(0) or Canvas(1). The Clearcanvas command 'can' clear a specific Canvas, but without the parameter, it defaults to the current Canvas. I am struggling to figure this one out... I changed it to Canvas(0) and it ran fine. Are you running with Windows or Linux? Do you have access to both systems? If so then does the issue exist for both? Just want to eliminate an Operating System cause... Are you using the RCBasic editor or another type of editor? I am "grasping at straws" when it comes to ideas... I would even go as far as suspecting a hardware issue... But, unless other programs are experiencing graphics issues, I would probably not go down that path.
No disrespect is intended... All you did was 'cut and paste' the listing? Reason: To establish that we are using the exact same program. If we are, then the program itself, can be eliminated as a source of the issue...
The fictional character, Sherlock Holmes said, "When you have eliminated the impossible, whatever remains, however improbable, must be the truth."
The truth of this problem is going to take a lot of eliminating... lol
My apologies for being so ineffective in assisting with this issue. This is so frustrating...
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Post by rosy on Sept 18, 2021 16:10:02 GMT -6
As I reported before - the garbage is on Linux. I would not rely on the default canvas, but clearly mark which one and cleaned ...
I did not rewrite the malloc error, then it did not occur anymore.
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Post by johnno56 on Sept 19, 2021 0:54:09 GMT -6
I do not know why I did not think of this earlier...
This is a quick-fix...
Change the Clearcanvas on line #63 to this...
setColor(black): RectFill(0, 0, xmax - 1, ymax - 1)
This will simulate the clearing of the screen but will not solve the 'garbage' issue...
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Post by rosy on Sept 19, 2021 5:23:49 GMT -6
I got an error again:
malloc(): invalid size (unsorted)
Aborted
------------------
(program exited with code: 134)
Press return to continue
I forgot that after ClearCanvas you have to give Update.
And as I was figuring out, it stopped working completely, there was only a black screen. After typing on line 22 Update or Waitkey - it works again. Miracles ...
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J7M
New Member
Posts: 18
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Post by J7M on Sept 19, 2021 12:20:40 GMT -6
I think in line 37 and 38 you have to write:
for y = 0 to h -----> for y = 0 to h - 1
for x = 0 to w -----> for x = 0 to w - 1
otherwise you access memory you have not allocated with dim, which might lead to the error message.
Maybe it would be nice, if rc-basic can report this kind mistake. It happens sometimes to me. When you have 1000 lines of code it is sometimes hard to find.
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J7M
New Member
Posts: 18
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Post by J7M on Sept 19, 2021 12:39:01 GMT -6
I tried the program. Really nice effect  Weird thing is, that I have to put a "wait(100)" directly after "prints(mess)" in line 22 otherwise it will not work. |
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Post by johnno56 on Sept 19, 2021 13:44:33 GMT -6
J7M,
Well spotted.
I experimented with small 'waits' to test how long my machine needed to 'scan' the text. I found that my machine could handle a 'zero' wait. Obviously, your machine, is faster than mine... But, you are correct, it would have been prudent to include the wait...
Other points for experimenting.... Line #87. Try changing the '20 + rand(20)' or perhaps the colour on line #81 or the size and location of the message in lines 66 to 69 or perhaps convert the whole listing to a Function / Subroutine to use in other programs. What if the original message did 'not' use the system default font?
If you decide to create something different, post it, show off your creativity... "If you are not having fun, you're doing something wrong..." Groucho Marx
J
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Post by johnno56 on Sept 19, 2021 14:13:08 GMT -6
Ok. Here is a modified version using a non default system font. Drawing text on a canvas and scanning will take a little longer... But, the point is, you are not restricted to a plain font... plasmaText.zip (23.9 KB) ps: Scanning area was guess work... too early in the morning to figure it out... lol... Coffee... That's what's missing... |
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Post by n00b on Sept 20, 2021 5:57:35 GMT -6
johnno56 Nice Demo. I think in line 37 and 38 you have to write: for y = 0 to h -----> for y = 0 to h - 1 for x = 0 to w -----> for x = 0 to w - 1 otherwise you access memory you have not allocated with dim, which might lead to the error message. Maybe it would be nice, if rc-basic can report this kind mistake. It happens sometimes to me. When you have 1000 lines of code it is sometimes hard to find. I want to add some debugging features in the future but my main focus right now is maintenance.
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