Some help with pointer...

[cyborg]

Hi!
Im using a pointer to plot pixels to a picturebox but i've got 2 problems with this...

1. ifi add + 1 to the colors, it adds more with pointers than with setpixel....(it gets brighter)

2. if i use setpixel, then i cant use the pointer anymore...

[cyborg]

hmm....wait.....
somethings wrong with this code but i cant figure out what!

For Angle = 0 To 180
        TempY = Round(y + Cos(Angle * PiDiv180) * Height)
        HighX = Round(x + Sin(Angle * PiDiv180) * Width)
        LowX = x - (HighX - x)
        If TempY > 0 And TempY < UBound(pic, 2) Then
            For TempX = LowX To HighX Step 3
                If TempX > 0 And TempX < UBound(pic, 1) - 3 Then
                    r = pic(TempX + 2, TempY) + 1
                    g = pic(TempX + 1, TempY) + 1
                    b = pic(TempX, TempY) + 1
                    If r > 255 Then r = 255
                    If r < 0 Then r = 0
                    If g > 255 Then g = 255
                    If g < 0 Then g = 0
                    If b > 255 Then b = 255
                    If b < 0 Then b = 0
                    pic(TempX, TempY) = b
                    pic(TempX + 1, TempY) = g
                    pic(TempX + 2, TempY) = r
                End If
            Next
        End If
    Next

[cyborg]

fixed the first error (+ some more i just discovered)
i still have the second problem!

heres the new code:

For Angle = 0 To 180  
        TempY = Round(y + Cos(Angle * PiDiv180) * Height)
        HighX = Round(x + Sin(Angle * PiDiv180) * Width)
        TempY = UBound(pic, 2) - TempY
        LowX = x - (HighX - x)
        HighX = HighX * 3
        LowX = LowX * 3
        If TempY > 0 And TempY < UBound(pic, 2) Then
            For TempX = LowX To HighX Step 3
                If TempX > 0 And TempX < UBound(pic, 1) - 3 Then
                    r = pic(TempX + 2, TempY) + 100
                    g = pic(TempX + 1, TempY) + 1
                    b = pic(TempX, TempY) + 1
                    If r > 255 Then r = 255
                    If r < 0 Then r = 0
                    If g > 255 Then g = 255
                    If g < 0 Then g = 0
                    If b > 255 Then b = 255
                    If b < 0 Then b = 0
                    pic(TempX, TempY) = b
                    pic(TempX + 1, TempY) = g
                    pic(TempX + 2, TempY) = r
                End If
            Next
        End If
    Next

[cyborg]

i've experienced some crazy things here! i need alot of help i think...
I'll attach the whole code here!

One of the major problems is that i cant paint on any other picture than the one in my program...if i do, it paints wierd!

One other problem is that i cant paint outside the picture but still in the picturebox as i can with setpixel!

Please help me with this!

[dafhi]

I see what you mean by anti-inter-operability between the two methods.

I got one thing working though

[dafhi]

the problem you mentioned where it paints weird is due to this:

in order to update a window as quickly as it does, windows likes scanlines to have widthbytes fit 'neatly' with a multiple of 4.

since the picturebox you are working with is using 3 bytes per pixel, not all widths work properly if you're working with a 2d array.

a 1d array loop works like this

WBytes = bmp.bmwidthbytes

TopLeftByte = (bmp.bmheight - 1) * WBytes

BytesPixel = bmp.bmbitspixel / 8
AddWBytes = (bmp.bmwidth - 1) * BytesPixel

For Y = 0 to TopLeft step WBYtes
DrawRight = Y + AddWBytes
For X = Y to Drawright Step BytesPixel
XP2 = x+2
XP1 = x+1
r = buf(xp2)
g = buf(xp1)
b = buf(x)

[cyborg]

thanks alot for the help!

was the code in the text file only for speeding up?

i dont really get the last code....
could you post what i should change in my code please!

thanks again!

[dafhi]

that and more critical thinking

this will enhance speed further

dim XP1&
dim XP2&

..

For TempX = LowX To HighX Step 3 'do all x poses in circle (step 3=do one of the colors)
xp1 = tempx+1
xp2 = tempx+2
r = pic(xp2, TempY) ..
g = pic(xp1, TempY) ..
b = pic(TempX, TempY) ..
..
pic(TempX, TempY) = b
pic(Xp1, TempY) = g
pic(Xp2, TempY) = r

[dafhi]

I converted what you have to 1d. 1d processing is slightly faster and will work properly with your other true-color bmps

[cyborg]

it still doesnt work with other pictures!

thanks alot for the help!

[dafhi]

"well that sucks." post one that is messed up if you have the time

[cyborg]

try with this pic:

[dafhi]

it works for me. i have a friend who was having image problems with a 'pointer' anim thing I sent. Different windows versions could be a factor. I did an experiment a while back. Thanks to a fine sub that a great man wrote, I am able to create a picturebox picture in 24 or 32-bit format. I have an older system with a 24 bit graphics card, and the 32 bit formatting works fine. Kudos to the windows team. You may find it worth researching: load a picture into and maintain 32-bit picturebox bit depth

[cyborg]

ok...hmmmmm....
im pretty new to gfx so i dont know exactly how all there things work...all i wanted with the program that i've had some problems with was to learn how to use pointer....

[dafhi]

if you're working with 24-bit array, widthbytes is the first thing to get a grip on.

if 32-bit, image handling is a snap, except for the fact that PSet and SetPixel, as well as mouse y say that y increases as you move down the form.

[cyborg]

i know how to work with 32-bit pictures in vb using setpixel/getpixel or point/pset...