Comments on: VB Graphics Programming: Part 3 (Advanced API)

By: Agustinus Cao

Agustinus Cao — Fri, 27 Jan 2012 09:28:57 +0000

This is a very good technique. I am using this Advanced API for my program, and it works really fast. I am only using an old laptop with Pentium 4 2.40 GHZ, a very standard graphic card, and only 500 MB RAM with Windows XP Operating System, so I consider my computer is quite slow compared to computers today.

I am developing a program for textile design which involved calculations on how many yarns used, how each colors of the yarns are configured in the finished fabric, what type of weaving pattern to use, etc. In short, there are a lot of calculations involved just to put a single pixel in a picture box, but I can display a complete 575 x 487 pixels image in less then 20 milliseconds using the Advanced API.

Thank you Tanner.

By: avi

avi — Sat, 12 Mar 2011 13:07:57 +0000

Hi Tenner.
Very good and very helpful turorial.
A few comments

in this part you wrote “rotate the data 180 degrees” it doesn’t rotate it. It is reflected on the X axis. So the picture point(i,j) in the memory is
point(i,picture1.scaleheight-j).

About the color if you want to update the RGB of pixel you to do it BRG.

Because if i have 32 bit computer the array of array 3D di in DIB is a little bit chaotic. So you change one pixel easily because you don’t know it’s RGB.

Good tip about the 2D array.

Thank you.

By: Joaquim

Joaquim — Sun, 15 Nov 2009 22:35:23 +0000

can i use the GetBitmapBits and SetBitmapBits in array with 2 dimensions?
Instead work with RGBA, can we work with color value?
(has we know: in a picturebox ColorValue = Picture1.Point(X,Y))

By: Steven Stillen

Steven Stillen — Fri, 24 Jul 2009 14:23:59 +0000

I wish someone could help me. I have been porting my windows application to Linux native program that will run as a stand alone not within Wine programs. Part of my program is supposed to print Forms or windows. It fails and fews procedures or functions are not supported but are under Microsoft – GetDIBitSizes, GetDIBits…I am frustrated. I have been looking for some other ways of prints the forms programmatically, but I have been coming empty handed. They are all
located in winapih.inc. Delphi to Lazarus.

By: Tanner

Tanner — Thu, 26 Feb 2009 16:51:07 +0000

Yikes! You’re right! When I transferred this tutorial from plain HTML to WordPress, WordPress must have considered the backslash an escape character. It’s now fixed.

Glad the tutorial has been useful, and thanks again for the tip!

By: Ian Eldred

Ian Eldred — Thu, 26 Feb 2009 14:18:18 +0000

This tutorial is really helping me. Thanks very much!

My only comment is that there is a big red warning about the ReDim statement being where you can screw your computer up, but in the code snippet, the ReDim statement is wrong.

ReDim ImageData(0 To (bm.bmBitsPixel 8) – 1, 0 To bm.bmWidth – 1, 0 To bm.bmHeight – 1)

Should be:

ReDim ImageData(0 To (bm.bmBitsPixel / 8) – 1, 0 To bm.bmWidth – 1, 0 To bm.bmHeight – 1)