Grid?

[kinjalgp]

I am using Pset to draw grid on my picture box every time my App. loads. But this take a lot of time to execute. Can anyone suggest me an alternate method of drawing grid on picture box?

[YoungBuck]

Use the SetPixel API call rather than the PSet function and you will see a significant increase in speed, the declare goes like this:

Declare Function SetPixel Lib "gdi32" Alias "SetPixel" (ByVal hdc As Long, ByVal x As Long, ByVal y As Long, ByVal crColor As Long) As Long

and implement it something like this:

Private Sub Form_Paint()
 dim x as Integer, y as Integer, color as Long
 dim returnvalue as Long

   x = 15 ' 15th pixel across
   y = 15 ' 15th pixel down
   color = RGB(0, 0, 255) ' blue
   returnvalue = SetPixel(x, y, color) ' color pixel at x=15 y=15 the color blue

End Sub

Good Luck

[Paul282]

Even Quicker !!!

Use API SetBitmapBits.

You can dump graphics straight out of a byte array...

I used it for a graphics program when the setpixel API was still too slow

Even, getbitmapbits, modify the array then setbitmap bits really flies

[kinjalgp]

Hello YoungBuck.

I tried your code but It shows an error "Argument Not Optional". Itried to find out where the error was but could not get it. Please give me the proper code.

Thanks a lot.

Kinjal

[LG]

Hi.

Private Declare Function SetPixel Lib "gdi32" _
(ByVal hdc As Long, ByVal x As Long, ByVal y As Long, ByVal crColor As Long) As Long
Private Type RECT
        Left As Long
        Top As Long
        Right As Long
        Bottom As Long
End Type
Private Declare Function GetWindowRect Lib "user32" (ByVal hwnd As Long, lpRect As RECT) As Long



Private Sub Form_Paint()

Dim winrect As RECT  ' rectangle of window Form1
Dim rgbval As Long  ' RGB value of the randomly selected color
Dim x As Long, y As Long  ' counters for x and y coordinates
Dim retval As Long  ' return value

' Get the rectangle of window Form1.
retval = GetWindowRect(Form1.hwnd, winrect)

' Loop through each pixel within Form1.
For y = 0 To winrect.Bottom - winrect.Top Step 15
  For x = 0 To winrect.Right - winrect.Left Step 15
    
    rgbval = RGB(0, 0, 255)
    ' Set the pixel to the color above.
   
    retval = SetPixel(Form1.hdc, x, y, rgbval)
  Next x
Next y

End Sub

[YoungBuck]

Sorry Kinjal replace

returnvalue = SetPixel(x, y, color)

with this

returnvalue = SetPixel(Form1.hdc, x, y, color)

sorry for the typo, also if you are going to be drawing to a picturebox you may want to use the Picturebox's paint event (Picture1_Paint) and the Picturebox's handle (Picture1.hdc).

Sorry :P