why does this give me an error ?

[hfheatherfox07]

This fails ->

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   .if x >= 0 && x < ScreenWidth && y >= 0 && y < ScreenHeight

I found this: see next post
dibEngine(converted to assembly)


I can not post the link here , but one of the posters there ( that I know uses this a lot )posted this :

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In the PutPixel procedure you'll need to put a check when the pixel is outside the canvas to not plot it. This can make the application crash because you're writting to memory outside the screen buffer:

SPixel PROC x:DWORD, y:DWORD, colour:DWORD
   pushad
   mov   edi, [canvas_buffer]
   .if x >= 0 && x < ScreenWidth && y >= 0 && y < ScreenHeight
      mov eax,y
      imul eax,ScreenWidth
      add eax,x
      shl eax,2
      add edi,eax
      mov eax,colour
      mov dword ptr [edi],eax
   .endif
   popad
   ret
SPixel endp

[hfheatherfox07]

Here is a copy of the Original Post ( rather than linking that site )

Original Post:

Based off Wiccaan's dibEngine written for C++, just converted into assembly.

Still in beta.

Usage:

In a new project, with your other includes:

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include dibEngine.inc

After creating your window:

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invoke CreateWindowEx,0,addr lpclassname,addr lpwindowname,80000000h,100,100,400,300,0,0,esi,0      ;sample window
            mov hwnd,eax
            invoke dib_SetHwnd,hwnd
            invoke dib_InitCanvas,400,300

Your lovely pallette is now all set for dib'ing. Now in either your main program loop(message processing), a WM_TIMER case, or, if the image is static, before the main game loop, you can make a series of calls to drawing functions - the current build includes dib_PutPixel, and dib_DrawButton:

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            invoke dib_PutPixel,100,100,0,0,255              ;x,y,r,g,b
            invoke dib_DrawButton,200,200,offset lpclassname,0   ;x,y,text,bHover

Now in WM_PAINT:

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invoke dib_UpdateCanvas

That's it! All you need to draw static pixels and buttons.;p

Just kidding, more support is on the way, but just wanted to release working code to show that I'm still alive.

A special thanks to Wiccaan, STN, and KSBunker, aswell as shoutouts to pandas and DeltronZero.

Attached is an example program, and the main dibEngine.inc file.

Demonstration of button-drawing:

[dedndave]

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.if x >= 0 && x < ScreenWidth && y >= 0 && y < ScreenHeight

you are trying to compare one memory operand with another memory operand
the simplest way to fix this is to get "x" and "y" into registers

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    mov eax,y
    mov ecx,x
    .if (ecx>=0) && (ecx<ScreenWidth) && (eax>=0) && (eax<ScreenHeight)
        imul eax,ScreenWidth
        add eax,ecx
;
;
you could probably put ScreenWidth in EDX prior to the ".if" to create more efficient code

[hfheatherfox07]

Thanks dedndave !

[hfheatherfox07]

Well the original atachment works well
I have no idea why that poster recommended changing the set pixel proc to include a check
Now it does not draw pixels lol

[dedndave]

this can be simplified

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    mov eax,y
    mov ecx,x
    mov edx,ScreenWidth
    .if (ecx<edx) && (eax<ScreenHeight)
        imul eax,edx
        add eax,ecx
;
;

but i doubt that would stop it from drawing pixels
verify that ScreenWidth and ScreenHeight are set to valid values

[hfheatherfox07]

I made those changes , but it won't draw ?
lol that one pixel is gone , and so is the button colour
Did you get it to work?
When I invoked the proc I invoked with 2 less variables and used a hex value for the colour instead of 3
The (r,b,g)

:(

[dedndave]

this seems to work

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dib_PutPixel proc x:DWORD, y:DWORD, r:BYTE, g:BYTE, b:BYTE
                mov   ecx,x
                mov   ebx,ScreenWidth
mov   eax,y
                .if (ecx<ebx)&&(eax<ScreenHeight)
    imul  eax,ebx
    movzx ebx,byte ptr g
                    add   eax,ecx
    mov   bh,r
    shl   ebx,8
                    mov   ecx,lpCanvasBuffer
    mov   bl,b
    mov   [ecx+eax*4],ebx
                .endif
ret
dib_PutPixel endp
EDX has to be preserved for some reason and EBX doesn't (i guess)

[hfheatherfox07]

So you need to have r,b,g ......
Maybe that guy was messing with people ? ( I have seen some of the example he does no source)
I thought the change would be good if you can eliminate those and use hex colour

P.S
Is there an app that gives you an image's pixel coordinates + r,b,g for each pixel?

This guy does multi colour letters all plotted ????

[dedndave]

no - you can use RGB
you will have to change the PROTO
and - you will have to change everyplace this function is used to pass an RGB

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dib_PutPixel proc x:DWORD, y:DWORD, crRGB:COLORREF
                mov   ecx,x
                mov   ebx,ScreenWidth
mov   eax,y
                .if (ecx<ebx)&&(eax<ScreenHeight)
    imul  eax,ebx
                    add   eax,ecx
                    mov   ebx,crRGB
                    mov   ecx,lpCanvasBuffer
    mov   [ecx+eax*4],ebx
                .endif
ret
dib_PutPixel endp

if you have the colors as individual bytes in memory, you can use the RGB macro
otherwise, you can assign them as EQUates or something
COLORREF = 65536*Red + 256*Green + Blue
where Red, Green, and Blue are 0 to 255

[MichaelW]

COLORREF = 65536*Red + 256*Green + Blue

That reverses the order of the color components relative to the GDI RGB macro:

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#define RGB(r,g,b)          ((COLORREF)(((BYTE)(r)|((WORD)((BYTE)(g))<<8))|(((DWORD)(BYTE)(b))<<16)))


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#include <conio.h>
#include <stdio.h>
#include <stdlib.h>
#include <windows.h>
void main()
{
  BYTE r=1,g=2,b=3;
  COLORREF rgb1, rgb2;
  rgb1 = RGB(r,g,b);
  rgb2 = 65536*r + 256*g + b;
  printf("%Xh\n%Xh\n", rgb1, rgb2);
  getch();
}


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30201h
10203h


But duplicates the RGB component order for GDI+:

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enum
    {
        AlphaShift  = 24,
        RedShift    = 16,
        GreenShift  = 8,
        BlueShift   = 0
    };

    // Assemble A, R, G, B values into a 32-bit integer
   
    static ARGB MakeARGB(IN BYTE a,
                         IN BYTE r,
                         IN BYTE g,
                         IN BYTE b)
    {
        return (((ARGB) (b) <<  BlueShift) |
                ((ARGB) (g) << GreenShift) |
                ((ARGB) (r) <<   RedShift) |
                ((ARGB) (a) << AlphaShift));
    }


[dedndave]

right, Michael - my mistake
those are RGBQUAD's, not COLORREF's
(well - modified versions of RGBQUAD's - lol)

[hfheatherfox07]

no - you can use RGB
you will have to change the PROTO
and - you will have to change everyplace this function is used to pass an RGB

I meant the poster does not use r,g,b
His proto has colour : DWORD
So I assume he invokes set pixel with colour hex

What I said was that we can not use that, or can we?
That is what I tried with your first proc and it did not work....

This example is neat but I do not anticipate using it much
Unless there is an app that converts images to pixel coordinates
It would take for ever to plot image

There is a C example were I downloaded this but I don't get how they made it work

[hfheatherfox07]

@MichaelW
I was actually looking on the net Today for a batch file to compile C

Do you know how? If so and you have time can you attach the above code with batch file to compile ?

I use batch files for masm all the time with notepad2 to edit and compile ,
Never found a C example

Thank you!


And sorry for asking

[dedndave]

i would imagine you can use a command-line exe to compile with most C compilers
for microsoft, i think it's CL.EXE - you should be able to get the switches with /?
or look for it on MSDN