32-bit Screen Transient and Persistent Images

[Qwerkey]

With a Screen in 32-bit mode an image is persistent by default.  When the code executes a _PUTIMAGE statement (or other drawing command), that image will stay on the screen until the next CLS occurs.  This means that in a running loop with a _DISPLAY statement but no CLS, if the image position of a particular object moves, a trace of the object forms on on the screen.  As a matter of fact with _HARDWARE images, the opposite happens and no CLS is necessary to 'delete' previous image positions.

Is there a way in 32-bit _SOFTWARE mode to allow some images to be transient (ie only the last position on the object is displayed) whilst others are persistent (default with no CLS in the loop)?  I remember that Walter achieved something along these lines with _HARDWARE images, but I am using InForm which only allows _SOFTWARE images.  I don't believe that this is possible – either you have CLS every loop cycle (all transient images) or no CLS (all persistent), but if there is a way, I'd be glad to know.  Presently, I am creating a transient image in a persistent screen by putting an image with the background colour in the previous position before each transient image is placed.  This works, but also blanks any other image in the same region of the screen.

Richard

[FellippeHeitor]

If all your images are hardware images you can make the form surface black and draw straight to it:

The program:

Code: QB64: [Select]

1. ': This program uses
2. ': InForm - GUI library for QB64 - Beta version 7
3. ': Fellippe Heitor, 2016-2018 - fellippe@qb64.org - @fellippeheitor
4. ': https://github.com/FellippeHeitor/InForm
5. '-----------------------------------------------------------
6.  
7. ': Controls' IDs: ------------------------------------------------------------------
8. DIM SHARED hardwareImages AS LONG
9. DIM SHARED ExitBT AS LONG
10.  
11. ': External modules: ---------------------------------------------------------------
12. '$INCLUDE:'InForm\InForm.ui'
13. '$INCLUDE:'InForm\xp.uitheme'
14. '$INCLUDE:'hardwareImages.frm'
15.  
16. ': Event procedures: ---------------------------------------------------------------
17. SUB __UI_BeforeInit
18.  
19. END SUB
20.  
21. SUB __UI_OnLoad
22.  
23. END SUB
24.  
25. SUB __UI_BeforeUpdateDisplay
26.     'This event occurs at approximately 30 frames per second.
27.     'You can change the update frequency by calling SetFrameRate DesiredRate%
28.     STATIC hwImg AS LONG
29.  
30.     IF hwImg = 0 THEN
31.         tempImg = _NEWIMAGE(64, 64, 32)
32.         _DEST tempImg
33.         FOR i = 0 TO _PI(2) - .1 STEP .1
34.             PSET (_WIDTH / 2 + (COS(i) * 32), _HEIGHT / 2 + (SIN(i) * 32)), _RGB32(255 * RND, 255 * RND, 255 * RND)
35.         NEXT
36.         _DEST 0
37.         hwImg = _COPYIMAGE(tempImg, 33)
38.         _FREEIMAGE tempImg
39.     END IF
40.  
41.     _PUTIMAGE (__UI_MouseLeft - 32, __UI_MouseTop - 32), hwImg
42. END SUB
43.  
44. SUB __UI_BeforeUnload
45.     'If you set __UI_UnloadSignal = False here you can
46.     'cancel the user's request to close.
47.  
48. END SUB
49.  
50. SUB __UI_Click (id AS LONG)
51.     SELECT CASE id
52.         CASE hardwareImages
53.  
54.         CASE ExitBT
55.             SYSTEM
56.     END SELECT
57. END SUB
58.  
59. SUB __UI_MouseEnter (id AS LONG)
60.     SELECT CASE id
61.         CASE hardwareImages
62.  
63.         CASE ExitBT
64.  
65.     END SELECT
66. END SUB
67.  
68. SUB __UI_MouseLeave (id AS LONG)
69.     SELECT CASE id
70.         CASE hardwareImages
71.  
72.         CASE ExitBT
73.  
74.     END SELECT
75. END SUB
76.  
77. SUB __UI_FocusIn (id AS LONG)
78.     SELECT CASE id
79.         CASE ExitBT
80.  
81.     END SELECT
82. END SUB
83.  
84. SUB __UI_FocusOut (id AS LONG)
85.     'This event occurs right before a control loses focus.
86.     'To prevent a control from losing focus, set __UI_KeepFocus = True below.
87.     SELECT CASE id
88.         CASE ExitBT
89.  
90.     END SELECT
91. END SUB
92.  
93. SUB __UI_MouseDown (id AS LONG)
94.     SELECT CASE id
95.         CASE hardwareImages
96.  
97.         CASE ExitBT
98.  
99.     END SELECT
100. END SUB
101.  
102. SUB __UI_MouseUp (id AS LONG)
103.     SELECT CASE id
104.         CASE hardwareImages
105.  
106.         CASE ExitBT
107.  
108.     END SELECT
109. END SUB
110.  
111. SUB __UI_KeyPress (id AS LONG)
112.     'When this event is fired, __UI_KeyHit will contain the code of the key hit.
113.     'You can change it and even cancel it by making it = 0
114.     SELECT CASE id
115.         CASE ExitBT
116.  
117.     END SELECT
118. END SUB
119.  
120. SUB __UI_TextChanged (id AS LONG)
121.     SELECT CASE id
122.     END SELECT
123. END SUB
124.  
125. SUB __UI_ValueChanged (id AS LONG)
126.     SELECT CASE id
127.     END SELECT
128. END SUB
129.  
130. SUB __UI_FormResized
131.  
132. END SUB
133.  

The form (save it as hardwareImages.frm):

Code: QB64: [Select]

1. ': This form was generated by
2. ': InForm - GUI library for QB64 - Beta version 7
3. ': Fellippe Heitor, 2016-2018 - fellippe@qb64.org - @fellippeheitor
4. ': https://github.com/FellippeHeitor/InForm
5. '-----------------------------------------------------------
6. SUB __UI_LoadForm
7.  
8.     DIM __UI_NewID AS LONG
9.  
10.     __UI_NewID = __UI_NewControl(__UI_Type_Form, "hardwareImages", 300, 300, 0, 0, 0)
11.     SetCaption __UI_NewID, "hardwareImages"
12.     Control(__UI_NewID).Stretch = False
13.     Control(__UI_NewID).Font = SetFont("arial.ttf", 12)
14.     Control(__UI_NewID).BackColor = _RGB32(0, 0, 0)
15.  
16.     __UI_NewID = __UI_NewControl(__UI_Type_Button, "ExitBT", 80, 23, 210, 267, 0)
17.     SetCaption __UI_NewID, "E&xit"
18.     Control(__UI_NewID).Stretch = False
19.     Control(__UI_NewID).CanHaveFocus = True
20.  
21. END SUB
22.  
23. SUB __UI_AssignIDs
24.     hardwareImages = __UI_GetID("hardwareImages")
25.     ExitBT = __UI_GetID("ExitBT")
26. END SUB

[SMcNeill]

PCOPY is the easiest way I know to achieve the effect you're speaking of.

SCREEN _NEWIMAGE(800,600,32)
RANDOMIZE TIMER

'Create the persistent image
FOR I = 1 TO 100
    LINE (RND * 800, RND * 600)-(RND * 800, RND * 600), _RGB32(RND * 255, RND * 255, RND * 255), BF
NEXT

'Now PCOPY that background to preserve it
PCOPY 0,1

'Now create the transient image and display it:
DO
     PCOPY 1,0 'place background (no CLS needed)
     X = X + 1: IF X > 800 THEN X = 0
     LINE (X, 200)-STEP(200,200), _RGB(0,0,0), BF 'a black box for the colored background should show up nice for a transient image
    _LIMIT 30
    _DISPLAY
LOOP UNTIL _KEYHIT

[Petr]

Next method, which use is the LINE command with the BF parameter only across the area I need to overwrite. (the same can be done in the circular or elliptical area of the image, it just wants to prepare such a picture, for example, via CIRCLE and areas that have nothing to overwite just set transparent through CLEARCOLOR or SETALPHA.)

Pcopy is good, is possible saving more than 1 screens, i also use in some programs.

[Qwerkey]

Well, Shiver Me Timbers, Mateys!

If what Fellippe suggest works for both _hardware & _software images, then this has probably become another InForm topic.  The last time I discussed writing images in InForm, Fellippe told me that _hardware images wouldn't work in InForm (that's what I tried first).  I was writing to a PictureBox and using Begin/EndDraw.  But the new method puts a  _hardware image straight to the Form (I have checked it out and it works).

I've just tried Fellippe's Form & .bas and not converted the image into _hardware (,33) but left it as _software (,32), and then it doesn't display.  So, I can't do both _hardware & _software?

I'll look into Steve's & Petr's methods.  Next reply I'll attach a video of the effect I'm trying to achieve.

Richard (every day, in every way I get more & more flummoxed).

[Qwerkey]

Attached is a screen capture video of my Gravity Simulation InForm program, with the program in Demonstration mode.  The program calculates all the gravitational interactions between a number of bodies and plots their progress in a perspective view.  In theis case, we are simulating the Solar System.  In the video, we are zoomed into just the sun, mercury and venus.  Their paths are traces so you can see where they have travelled, but then I give a shrinking image (in this case of the sun) which points to a given body.

All images are software.  The normal view for the gravitational progress is a trace, so CLS is not used.  For the shrinking image, I put a blank before the actual image so it does not leave a trace.  The jittery progress of the shrinking image does not happen if screen capturing is not done.

Richard

[SMcNeill]

Another method I use is to simply get the background area I want to preserve with a temporary _PUTIMAGE, then I place the transient image and display it over it.  When finished, I simply _PUTIMAGE the background back.

I'm in town ATM, On my iPad, but when I get home, I'll grab a copy of my TextToImage library and share it for you; it has 2 simple routines in it which'll probably serve your needs:  SaveBackground and RestoreBackground.  Both work with whatever specific region which you set.

SavedHandle= SaveBackground (100,100,200,200) 'saves from (100,100)-(200,200)
'Do stuff (like a pop up)
RestoreBackground SavedHandle 'restore that background when finished

[FellippeHeitor]

I've just tried Fellippe's Form & .bas and not converted the image into _hardware (,33) but left it as _software (,32), and then it doesn't display.  So, I can't do both _hardware & _software?

Maybe BeginDraw __UI_FormID will allow software drawing to the form surface. Didn't test it though.

[SMcNeill]

I've just tried Fellippe's Form & .bas and not converted the image into _hardware (,33) but left it as _software (,32), and then it doesn't display.  So, I can't do both _hardware & _software?

Maybe BeginDraw __UI_FormID will allow software drawing to the form surface. Didn't test it though.

May need to check _DISPLAYORDER as well.  (If that's the name of the command; I'm winging it from memory here.)

[FellippeHeitor]

Can't change _DISPLAYORDER with InForm.

[FellippeHeitor]

Maybe BeginDraw __UI_FormID will allow software drawing to the form surface. Didn't test it though.

Ok, just tested it now and realized I'd made sure BeginDraw/EndDraw would only work with PictureBox controls. Here's a hack/workaround. Replace this sub in the example I gave you above:

Code: QB64: [Select]

1. SUB __UI_BeforeUpdateDisplay
2.     'This event occurs at approximately 30 frames per second.
3.     'You can change the update frequency by calling SetFrameRate DesiredRate%
4.     STATIC hwImg AS LONG, sfImg AS LONG
5.  
6.     IF hwImg = 0 THEN
7.         sfImg = _NEWIMAGE(64, 64, 32)
8.         _DEST sfImg
9.         FOR i = 0 TO _PI(2) - .1 STEP .1
10.             PSET (_WIDTH / 2 + (COS(i) * 32), _HEIGHT / 2 + (SIN(i) * 32)), _RGB32(255 * RND, 255 * RND, 255 * RND)
11.         NEXT
12.         _DEST 0
13.         hwImg = _COPYIMAGE(sfImg, 33)
14.     END IF
15.  
16.     _PUTIMAGE (__UI_MouseLeft - 32, __UI_MouseTop - 32), hwImg
17.  
18.     _DEST Control(__UI_FormID).Canvas
19.     _PUTIMAGE (0, 0), sfImg
20.     _DEST 0
21. END SUB

That'll place a software colorful circle at 0, 0 and have a hardware colorful circle following the mouse.

[Qwerkey]

If all your images are hardware images you can make the form surface black and draw straight to it:

@Fellippe:  For my next project, in which I'm using all hardware images, I've just tried the "Draw Straight to the Form" method, and it works Right Out of the Box.  Brilliant!
[If you've time, you might move this topic into the InForm Section].
Richard