Author |
Topic: DIBSection Help (Read 879 times) |
|
Ric
Full Member
member is offline
Gender: 
Posts: 136
|
 |
DIBSection Help
« Thread started on: Nov 1st, 2015, 7:50pm » |
|
I have typed the code in the following link http://bb4w.wikispaces.com/Direct+screen+memory+access
Only to get the error "couldn't create DIBSection". I don't really understand the code but the error only occurs if hbitmap% =0 so can I set the value to the last bit in the DIBSection or is it causing an error because I only have the trial version? Can anyone help?
|
|
 Logged
|
It's always possible, but not necessarily how you first thought. Chin up and try again.
|
|
|
DDRM
Administrator
member is offline
Gender:
Posts: 321
|
|
Re: DIBSection Help
« Reply #1 on: Nov 3rd, 2015, 07:32am » |
|
Hi Ric,
hbitmap% is returned by the call: you can't set it yourself. If it is 0 it means that the system failed to create the DIBSection. Either one of your parameters wasn't what was required, or potentially memory wasn't available.
Best wishes,
D
|
|
Logged
|
|
|
|
Ric
Full Member
member is offline
Gender:
Posts: 136
|
|
Re: DIBSection Help
« Reply #2 on: Nov 5th, 2015, 2:11pm » |
|
Hi DDRM
I have now corrected the code (guilty of failing to transpose properly!!!!), as you are probably aware by now I am trying to create ASM routines to produce he graphics I require. And thus, is it possible to access bits% directly from assembly?
Regards Ric
|
|
Logged
|
It's always possible, but not necessarily how you first thought. Chin up and try again.
|
|
|
David Williams
Developer
member is offline
meh
Gender:
Posts: 452
|
|
Re: DIBSection Help
« Reply #3 on: Nov 5th, 2015, 2:30pm » |
|
on Nov 5th, 2015, 2:11pm, Ric wrote:Hi DDRM
I have now corrected the code (guilty of failing to transpose properly!!!!), as you are probably aware by now I am trying to create ASM routines to produce he graphics I require. And thus, is it possible to access bits% directly from assembly?
Regards Ric |
|
Yes, for example:
Code:
or
Code:
The former assumes that bits% is (and remains) constant; the latter allows for differing/variable values of bits% from one call of the machine code routine to the next.
|
|
|
|
Ric
Full Member
member is offline
Gender:
Posts: 136
|
|
Re: DIBSection Help
« Reply #4 on: Nov 5th, 2015, 3:11pm » |
|
Thanks David,
This instruction obviously puts the value in eax into bits%, but the manual I am looking at would suggest that the instruction should put the value in bits% into eax. I am confused. can you point me in the right direction for a user guide for the assembly language.
Regards Ric
|
|
Logged
|
It's always possible, but not necessarily how you first thought. Chin up and try again.
|
|
|
Ric
Full Member
member is offline
Gender:
Posts: 136
|
|
Re: DIBSection Help
« Reply #5 on: Nov 5th, 2015, 3:27pm » |
|
David,
Thought about the instruction you posted a bit more, bits% is an array, does this matter?
the operation I would like to perform in to make bits%?(<variable> =<variable> simple in basic but when I try to perform this in asm I get a syntax or size error.
MOV bit%, ax
fails I know now because the variable is not allowed to be the destination operand, this is what I can not solve.
Do I need to transfer the memory location of bits% to a register and MOV to that location? I have tried this and it crashes bb4w!
HELP
Ric
|
|
Logged
|
It's always possible, but not necessarily how you first thought. Chin up and try again.
|
|
|
David Williams
Developer
member is offline
meh
Gender:
Posts: 452
|
|
Re: DIBSection Help
« Reply #6 on: Nov 5th, 2015, 4:17pm » |
|
Ric, I've written the following bit of example code in a huge hurry (I'm about to go out). Perhaps you'll find it of some use?
Just copy and paste it into the BB4W IDE, and run it. It just displays a coloured pattern.
Code:
ON ERROR PROCError(REPORT$ + " at line " + STR$ERL)
ScrW% = 640
ScrH% = 512
PROCFixWndSz
VDU 23,22,ScrW%;ScrH%;8,16,16,0
bits% = FNCreateDIBSection
DIM code% 127
FOR I% = 0 TO 2 STEP 2
P% = code%
[OPT I%
mov eax, [^bits%] ; base address of DIBSection
mov ecx, ScrW%*ScrH% ; no. of pixels to write
mov edx, &12345678 ; colour
.lp
mov [eax], edx ; write pixel to DIBSection
add eax, 4 ; inc. addr by 4 bytes
sub edx, &01020305
dec ecx ; dec loop counter
jg lp ; loop if > 0
ret
]
NEXT I%
CALL code%
SYS "InvalidateRect", @hwnd%, 0, 0
*REFRESH
END
DEFFNCreateDIBSection
LOCAL A%,B%,H%,O%
DIM B% 19:!B%=44:B%!4=@vdu%!208:B%!8=@vdu%!212:B%!12=&200001
SYS"CreateDIBSection",@memhdc%,B%,0,^A%,0,0TOH%
IF H%=0 PROCError("Create DIBSection failed")
SYS"SelectObject",@memhdc%,H%TOO%
SYS"DeleteObject",O%
CLS
=A%
DEF PROCFixWndSz
LOCAL W%
SYS"GetWindowLong",@hwnd%,-16 TO W%
SYS"SetWindowLong",@hwnd%,-16,W% ANDNOT&40000 ANDNOT&10000
ENDPROC
DEF PROCError(s$)
OSCLI "REFRESH ON"
CLS : ON : VDU 7
PRINT '" " + s$;
REPEAT UNTIL INKEY(1)=0
ENDPROC
David.
|
|
Logged
|
|
|
|
David Williams
Developer
member is offline
meh
Gender:
Posts: 452
|
|
Re: DIBSection Help
« Reply #7 on: Nov 6th, 2015, 07:44am » |
|
Here's a slightly neater, more efficient version of the code I put up yesterday. The program does a similar thing - just displays a colourful pattern. Copy, paste, and run:
Code:
ON ERROR PROCError(REPORT$ + " at line " + STR$ERL)
ScrW% = 512
ScrH% = 512
PROCFixWndSz
VDU 23,22,ScrW%;ScrH%;8,16,16,0
REM Create 32bpp (ARGB &AARRGGBB) DIBSection:
bits% = FNCreateDIBSection
DIM code% 127
FOR I% = 0 TO 2 STEP 2
P% = code%
[OPT I%
mov eax, [^bits%] ; base address of DIBSection colour bits (pixels)
mov ecx, ScrW%*ScrH% ; no. of pixels to write (4 bytes per pixel)
mov edx, &00654321 ; initial (&AARRGGBB) colour
.lp
mov [eax + 4*ecx -4], edx ; write pixel to DIBSection
sub edx, &00010101 ; update/modify colour
loopnz lp ; ECX is automatically decremented & checked
ret
]
NEXT I%
CALL code%
SYS "InvalidateRect", @hwnd%, 0, 0
*REFRESH
END
DEFFNCreateDIBSection
LOCAL A%,B%,H%,O%
DIM B% 19:!B%=44:B%!4=@vdu%!208:B%!8=@vdu%!212:B%!12=&200001
SYS"CreateDIBSection",@memhdc%,B%,0,^A%,0,0TOH%
IF H%=0 PROCError("Create DIBSection failed")
SYS"SelectObject",@memhdc%,H%TOO%
SYS"DeleteObject",O%
CLS
=A%
DEF PROCFixWndSz
LOCAL W%
SYS"GetWindowLong",@hwnd%,-16 TO W%
SYS"SetWindowLong",@hwnd%,-16,W% ANDNOT&40000 ANDNOT&10000
ENDPROC
DEF PROCError(s$)
OSCLI "REFRESH ON"
CLS : ON : VDU 7
PRINT '" " + s$;
REPEAT UNTIL INKEY(1)=0
ENDPROC
|
|
Logged
|
|
|
|
Ric
Full Member
member is offline
Gender:
Posts: 136
|
|
Re: DIBSection Help
« Reply #8 on: Nov 6th, 2015, 08:42am » |
|
Thanks once again David, hope your night out was OK. I went on a step learning curve last night, the code you sent to create the DIBSection was different to the one I was using which caused me a headache at first but once I realised it needed to be 32bpp suddenly the penny dropped. Another penny dropped in understanding that ie. eax was a 32bit register and that effects 4 double byte locations. So &00FFFFFF is white and not &FF &FF &FF which was the way I was doing it in basic. In the early nineties I did a degree in computer engineering would you believe, I don't recall any of this being on it , maybe I've just forgotten! Age! I am now set to create the sprite routines, so many thanks again to yourself and DDRM for your input, (I may need it again ).
PS. Is there a sensible manual I can download?
|
|
Logged
|
It's always possible, but not necessarily how you first thought. Chin up and try again.
|
|
|
ady
Junior Member
member is offline
Posts: 55
|
|
Re: DIBSection Help
« Reply #9 on: Nov 6th, 2015, 09:01am » |
|
PS. Is there a sensible manual I can download?
That's where ketman comes in, you can SEE what is happening instead of imagining or guessing, especially when it gets confusing
http://www.addogodfrey.clara.net/learn-32bit-X86-assembly-language.html
|
| « Last Edit: Nov 6th, 2015, 09:02am by ady » |
Logged
|
|
|
|
Ric
Full Member
member is offline
Gender:
Posts: 136
|
|
Re: DIBSection Help
« Reply #10 on: Nov 19th, 2015, 10:34am » |
|
Thanks Ady,
I have tried to download Ketman Maximaster, but it will not run because of issues about 64 bit machine, have you come across this before and is there a solution?
Regards Ric
|
|
Logged
|
It's always possible, but not necessarily how you first thought. Chin up and try again.
|
|
|
ady
Junior Member
member is offline
Posts: 55
|
|
Re: DIBSection Help
« Reply #11 on: Nov 20th, 2015, 10:19am » |
|
It's quite a sophisticated program and unique as far as I am aware
I would reckon that you will need a 32 bit system to run it
XP32 is fine (alt-ENTER) lets you cycle to the full screen
|
|
Logged
|
|
|
|
|
