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Alternative to using BitmapI'm a VB.NET newbie. I've created a program that plots pixels at random on
the form. I have a 19" LCD monitor with a resolution set to 1280 by 1024. If you do the math, that means that there are over 1.3 million pixels. In one version of the program, the pixels start plotting at the upper-left & go down the form from top to bottom & left to right. In another version, the pixels are plotted at random. I have a 2.4 GHZ Athlon 64 with 1 gigabyte of RAM. If DrawImage is inside the For-Next loop, I can see the pixels being plotted. It's sooo slooow! If DrawImage is outside of the For-Next loop, I sit & stare at a blank form until the image is drawn. Unfortunately, there is no Pset or its .NET equivalent. Microsoft in its infinite wisdom chose to not include it. I want to be able to create a program that can draw fractals. I know that fractal calculations are time-consuming. I don't want to have to wait for hours to see a fractal. Is there a faster way to plot individual pixels without having to resort to using Bitmap? Remember, I'm a newbie. I don't want a complicated convoluted way to draw pixels. Can I create an object that will plot pixels faster than Bitmap or am I out of luck? What is the Path object? Can I use that to plot individual pixels? Thank you. David Can you preconstruct your fractal in a rectangular array first, then
draw it as one image? Pretend a 2D array is your form that you are drawing to. Only draw it at the end. Interesting idea. I haven't considered that. It would be a pretty big array.
If it works, it would probably be faster than going thru the hassle of creating the bitmap & then setting each pixel & then drawing the bitmap. Pset would make it a whole lot simpler & easier. My LCD monitor has a resolution of 1280 by 1024. My PC has 1 gigabyte of RAM. Wouldn't a 1280 by 1024 size array take up a lot of system resources? How would I draw the array? What is the source code? Wouldn't I have to use nested For-Next loops to access each element in the array? Show quoteHide quote "Steven Nagy" wrote: > Can you preconstruct your fractal in a rectangular array first, then > draw it as one image? > Pretend a 2D array is your form that you are drawing to. Only draw it > at the end. > > The array would take up the same amount of memory that a BitMap object
of the same size would. To draw the array you would create a bitmap, and set the color of each pixel in the bitmap from the array. Yes, to reach each element in the array using nested loops is the easiest way. pcnerd wrote: Show quoteHide quote > Interesting idea. I haven't considered that. It would be a pretty big array. > If it works, it would probably be faster than going thru the hassle of > creating the bitmap & then setting each pixel & then drawing the bitmap. Pset > would make it a whole lot simpler & easier. My LCD monitor has a resolution > of 1280 by 1024. My PC has 1 gigabyte of RAM. Wouldn't a 1280 by 1024 size > array take up a lot of system resources? How would I draw the array? What is > the source code? Wouldn't I have to use nested For-Next loops to access each > element in the array? > > "Steven Nagy" wrote: > >> Can you preconstruct your fractal in a rectangular array first, then >> draw it as one image? >> Pretend a 2D array is your form that you are drawing to. Only draw it >> at the end. >> >> So, you are telling me that I still have to use the Bitmap object? Creating
an array is an extra step. I don't want it to be complicated. I want it to be simple. Won't both the array & the Bitmap object exist in memory at the same time? I was hoping to avoid using the Bitmap. I was hoping that there was a simpler way to do it. Apparently, there isn't. Show quoteHide quote "Göran Andersson" wrote: > The array would take up the same amount of memory that a BitMap object > of the same size would. > > To draw the array you would create a bitmap, and set the color of each > pixel in the bitmap from the array. > > Yes, to reach each element in the array using nested loops is the > easiest way. > > pcnerd wrote: > > Interesting idea. I haven't considered that. It would be a pretty big array. > > If it works, it would probably be faster than going thru the hassle of > > creating the bitmap & then setting each pixel & then drawing the bitmap. Pset > > would make it a whole lot simpler & easier. My LCD monitor has a resolution > > of 1280 by 1024. My PC has 1 gigabyte of RAM. Wouldn't a 1280 by 1024 size > > array take up a lot of system resources? How would I draw the array? What is > > the source code? Wouldn't I have to use nested For-Next loops to access each > > element in the array? > > > > "Steven Nagy" wrote: > > > >> Can you preconstruct your fractal in a rectangular array first, then > >> draw it as one image? > >> Pretend a 2D array is your form that you are drawing to. Only draw it > >> at the end. > >> > >> > Typically, you could assume that if your screen size is 1200 x 1024,
just muliply the 2 to get how many elements in your array (in this case, around 1.2 million) and then assume each element is an integer (32 bit to represent your 32bit color) which is 4 bytes. So that means you have an array with 4 million bytes, or 4mb. You'll find that the Visual Studio will take at least 30mb ram straight off the bat anyway so your 4mb array is not so bad. So then assume you use a bit map to draw it to the screen, the bitmap only needs to exist during the drawing process. However you could just draw each pixel manually without using a Bitmap. The Bitmap just makes it easier to manage, particularly if you want to save the image as a file later. Bitmap objects can be converted to other types as well so that your fractal can save as GIF or whatever. So use an array to create the fractal, then stick it in a bitmap, and then cleanup the array from memory if you are overly concerned. Discussion point: Did you say you have a 64 bit processor? Then perhaps the calculation will occur faster if you use LONGs instead of INTs. It will take more RAM, but the calc should be faster because your processer will not need to do any fancy work to turn your integer calculations into long calculations. Can anyone provide advice on this? Am I just rambling? It might be 1 million pixels, but it might be way more than 1 mil calculations, particularly if fractal math requires multiple recursive operations. You state "However you could just draw each pixel manually without using a
Bitmap." Finally! This is what I've been trying to do. Microsoft in its infinite wisdom chose to not include "Pset" in VB.NET. So, how do I draw each pixel manually? Can you include example source code? Thank you. David Show quoteHide quote "Steven Nagy" wrote: > Typically, you could assume that if your screen size is 1200 x 1024, > just muliply the 2 to get how many elements in your array (in this > case, around 1.2 million) and then assume each element is an integer > (32 bit to represent your 32bit color) which is 4 bytes. So that means > you have an array with 4 million bytes, or 4mb. You'll find that the > Visual Studio will take at least 30mb ram straight off the bat anyway > so your 4mb array is not so bad. > > So then assume you use a bit map to draw it to the screen, the bitmap > only needs to exist during the drawing process. However you could just > draw each pixel manually without using a Bitmap. The Bitmap just makes > it easier to manage, particularly if you want to save the image as a > file later. Bitmap objects can be converted to other types as well so > that your fractal can save as GIF or whatever. > > So use an array to create the fractal, then stick it in a bitmap, and > then cleanup the array from memory if you are overly concerned. > > Discussion point: > Did you say you have a 64 bit processor? Then perhaps the calculation > will occur faster if you use LONGs instead of INTs. It will take more > RAM, but the calc should be faster because your processer will not need > to do any fancy work to turn your integer calculations into long > calculations. Can anyone provide advice on this? Am I just rambling? It > might be 1 million pixels, but it might be way more than 1 mil > calculations, particularly if fractal math requires multiple recursive > operations. > > Sorry I'm not currently in a position to open a windows app.
What you need will be found in the System.Drawing and System.Drawing.Drawing2D namespaces. Its all called GDI+ . There will be methods that are part of the Graphics class that enable you to draw rectangles, arcs, circles, lines, etc. There should be one to draw a dot as well. You will need to realise though that once you paint it, it isn't a permanent fixture on the form. If the form refreshes, or something paints over it (ie another form, alert or whatever) then your drawn pixels are gone. To get around this, you put your painting instructions in the OnPaint event of your form/panel/wherever you want to paint to. Let me know how you get on. I wanted at one stage to write a fractal generater in .NET but never got around to it. And of course I found a million of them on the net and decided there was no merit to it. Not sure if this has been done before, but a newer idea might be to create 3D fractals in DIRECTX... now that would be mind blowing! pcnerd wrote:
> I'm a VB.NET newbie. I've created a program that plots pixels at random on Show us your code. My own not-particularly-optimised Mandelbrot program> the form. I have a 19" LCD monitor with a resolution set to 1280 by 1024. If > you do the math, that means that there are over 1.3 million pixels. In one > version of the program, the pixels start plotting at the upper-left & go down > the form from top to bottom & left to right. In another version, the pixels > are plotted at random. I have a 2.4 GHZ Athlon 64 with 1 gigabyte of RAM. If > DrawImage is inside the For-Next loop, I can see the pixels being plotted. > It's sooo slooow! does a full screen of a part of the Mandelbrot set that is half in, half out, in about 7 seconds on a 3 GHz P4. Note that programs like this are often much (order of magnitude) quicker when run without the debuger attached - once there are no known bugs, run with Ctrl+F5 rather than F5 to try this. > If DrawImage is outside of the For-Next loop, I sit & stare What's Bitmap.SetPixel then?> at a blank form until the image is drawn. Unfortunately, there is no Pset or > its .NET equivalent. Microsoft in its infinite wisdom chose to not include > it. -- Larry Lard Replies to group please When starting a new topic, please mention which version of VB/C# you are using I haven't done the fractal program yet. I'm still learning VB. So, I can't
show you the code because it doesn't exist. I don't completely understand fractal math, but I know that the math is time-consuming. I'm still learning how to plot pixels. Does the managed code & the .NET Framework overhead slow every thing down? I think that I have a pretty fast PC ( 2.4 GHZ Athlon 64 with 1 gigabyte of RAM). I didn't know about the debugger being attached. I've been pressing F5. I'll have tp press CTRL + F5 & see if the program runs faster. Thank you. David Show quoteHide quote "Larry Lard" wrote: > > pcnerd wrote: > > I'm a VB.NET newbie. I've created a program that plots pixels at random on > > the form. I have a 19" LCD monitor with a resolution set to 1280 by 1024. If > > you do the math, that means that there are over 1.3 million pixels. In one > > version of the program, the pixels start plotting at the upper-left & go down > > the form from top to bottom & left to right. In another version, the pixels > > are plotted at random. I have a 2.4 GHZ Athlon 64 with 1 gigabyte of RAM. If > > DrawImage is inside the For-Next loop, I can see the pixels being plotted. > > It's sooo slooow! > > Show us your code. My own not-particularly-optimised Mandelbrot program > does a full screen of a part of the Mandelbrot set that is half in, > half out, in about 7 seconds on a 3 GHz P4. Note that programs like > this are often much (order of magnitude) quicker when run without the > debuger attached - once there are no known bugs, run with Ctrl+F5 > rather than F5 to try this. > > > If DrawImage is outside of the For-Next loop, I sit & stare > > at a blank form until the image is drawn. Unfortunately, there is no Pset or > > its .NET equivalent. Microsoft in its infinite wisdom chose to not include > > it. > > What's Bitmap.SetPixel then? > > -- > Larry Lard > Replies to group please > When starting a new topic, please mention which version of VB/C# you > are using > > Don't draw the bitmap for every single pixel that you draw. Use a
counter and draw the bitmap for every thousand pixel or something. pcnerd wrote: Show quoteHide quote > I'm a VB.NET newbie. I've created a program that plots pixels at random on > the form. I have a 19" LCD monitor with a resolution set to 1280 by 1024. If > you do the math, that means that there are over 1.3 million pixels. In one > version of the program, the pixels start plotting at the upper-left & go down > the form from top to bottom & left to right. In another version, the pixels > are plotted at random. I have a 2.4 GHZ Athlon 64 with 1 gigabyte of RAM. If > DrawImage is inside the For-Next loop, I can see the pixels being plotted. > It's sooo slooow! If DrawImage is outside of the For-Next loop, I sit & stare > at a blank form until the image is drawn. Unfortunately, there is no Pset or > its .NET equivalent. Microsoft in its infinite wisdom chose to not include > it. I want to be able to create a program that can draw fractals. I know that > fractal calculations are time-consuming. I don't want to have to wait for > hours to see a fractal. Is there a faster way to plot individual pixels > without having to resort to using Bitmap? Remember, I'm a newbie. I don't > want a complicated convoluted way to draw pixels. Can I create an object > that will plot pixels faster than Bitmap or am I out of luck? What is the > Path object? Can I use that to plot individual pixels? Thank you. David |
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