Graphics

PandemoniumPasha10-May-07 1:28

PandemoniumPasha

10-May-07 1:28

hi,
i would recommend that you create a separate class to hold all the fields that you need such as points and colors etc. and every time you draw any shape, you would need to save the things you need in memory. then when you click save(or whatever) you can write the contents of the array to the file.
you can use an arraylist to store the objects that you create, or any array structure that you are comfortable with.

hope this helps.
regards

mr jets10-May-07 2:01

mr jets

10-May-07 2:01

yah thats cool my bro..i have already used an arraylist and thats was my best :
// save the file

string str_Line;
System.IO.FileStream fs = new System.IO.FileStream("c:\\graphics.txt", System.IO.FileMode.OpenOrCreate, System.IO.FileAccess.Write, System.IO.FileShare.ReadWrite);
StreamWriter streamWriter=new StreamWriter(fs);

if(drawwhat==1)
{
for(int j=0;j

PandemoniumPasha10-May-07 21:52

PandemoniumPasha

10-May-07 21:52

hi,
from the code above i see that you are storing the points in the array list, but this is not a good way to store data because you don't know that kind of shape it is i.e. is it a line, a circle, a rectangle... what?
therefore, i recommmend you to store objects of the shape class that you can create for each shape you draw and store that object in the arraylist.
if you do this, you can set the type of shape that it represents just by setting a simple flag - some enum value. so, when you save the data, you will be saving the class objects and not points. when you retrieve the data, you will retrieve the class objects.
this will enable you to distinguish what type of shape it is and enable you to draw accordingly.

hope this helps.

regards

Christian Graus13-May-07 12:44

Christian Graus

13-May-07 12:44

You have been asking the same questions for some time now. Realistically, the best way to do this is to create a class for each shape you want to draw, with a common base class, and make a list of that base class. Then you can make the class know how to build itself from the string you store in your file, and to generate a string which identifies the shape type and the details of that shape.

I'd go for something less verbose, you really only need to store numbers, just assign each shape type a number.

Christian Graus - Microsoft MVP - C++
Metal Musings - Rex and my new metal blog
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )

drawing algorithms

sarah_malik6-May-07 10:06

6-May-07 10:06

Hi,
where can I find algorithms for drawing different shapes, I found some to draw spiral and circle, but I need to have more shapes.
Can you please recommend any website(s) that helps?

thanks,

El Corazon6-May-07 10:43

6-May-07 10:43

just more? nothing specific?

http://www.acm.org/tog/GraphicsGems/[^]

_________________________
Asu no koto o ieba, tenjo de nezumi ga warau.
Talk about things of tomorrow and the mice in the ceiling laugh. (Japanese Proverb)

sarah_malik6-May-07 11:11

6-May-07 11:11

thanks El Corazon,
I don't need any specific shape,
for example:

<br />
for( int i=0 ; i<200 ; ++i)<br />
{<br />
theta = 2+Math::PI*float(i)/10;<br />
r = Math::Sqrt(theta);<br />
x=r*Math::Cos(theta)+400;<br />
y=r*Math::Sin(theta)+400;<br />
}<br />

this algorithm will give me a very beautiful shape. I need more algorithms that would to the same.

El Corazon6-May-07 11:47

6-May-07 11:47

sarah_malik wrote:
I need more algorithms that would to the same.

there are many. It is called a polar graph, or polar equation. That particular one is one of the more simple ones.

x=r*cos(theta);
y=r*sin(theta);

is the translation from polar (radius=r, angle=theta) coordinates to Cartesian coordinates.

You can make your own and experiment with others from here:
http://www.analyzemath.com/polarcoordinates/polarcoordinates.html[^]
http://www.analyzemath.com/polarcoordinates/graphing_polar_equations.html[^]

I did many polar coordinates on my first computer, including a spider's web. Smile | :)

_________________________
Asu no koto o ieba, tenjo de nezumi ga warau.
Talk about things of tomorrow and the mice in the ceiling laugh. (Japanese Proverb)

[Message Deleted]

#1236-May-07 15:19

#123

6-May-07 15:19

[Message Deleted]

El Corazon7-May-07 2:16

7-May-07 2:16

The Grand Negus wrote:
the number of things you can draw with formulas is seriously limited.

Actually, the number of things you can draw with formulas are infinite, but not all of them attractive. In many cases, one formula provides infinite variations, though subtle, and given multiple formulas and methods (like fractals?), the list goes on....

however... that was why I pointed to the graphics gems first, which covers algorithmic drawing in detail.

_________________________
Asu no koto o ieba, tenjo de nezumi ga warau.
Talk about things of tomorrow and the mice in the ceiling laugh. (Japanese Proverb)

sarah_malik7-May-07 2:42

7-May-07 2:42

Thanks for your help, it was very useful.

I was wondering if there are more available algorithms that would draw shapes other than polar.
like these beautiful ones:
http://www.flickr.com/photos/fire_brace/48702455/in/set-72057594133787168/[^]

http://www.flickr.com/photos/fire_brace/48723545/in/set-72057594133787168/[^]

I know these are mosaics, but I just need algorithms that would draw such things.

El Corazon7-May-07 5:31

7-May-07 5:31

sarah_malik wrote:
but I just need algorithms that would draw such things.

check out the formulas behind fractals. There are many self-similar iterative design systems. http://en.wikipedia.org/wiki/Fractal[^] also L-Systems: http://en.wikipedia.org/wiki/L-system[^]

_________________________
Asu no koto o ieba, tenjo de nezumi ga warau.
Talk about things of tomorrow and the mice in the ceiling laugh. (Japanese Proverb)

sarah_malik7-May-07 6:52

7-May-07 6:52

THANK YOU. Rose | [Rose]

El Corazon7-May-07 7:22

7-May-07 7:22

You are welcome. The hardest part is trying to figure out what you are looking for. There are as many shapes as the imagination, and as many methods of getting them. Smile | :)

_________________________
Asu no koto o ieba, tenjo de nezumi ga warau.
Talk about things of tomorrow and the mice in the ceiling laugh. (Japanese Proverb)

sarah_malik7-May-07 10:56

7-May-07 10:56

The Grand Negus wrote:
do you want to (1) write a program to produce art of a particular kind, or do you want to (2) use someone else's program to produce these works?

I'm trying to write a program that produces art Smile | :)

The Grand Negus wrote:
I need to know what language(s) you know, your level of expertise, and how much time you're willing to spend on the thing.

I know C, C++, managed C++ and VB. I'm a beginner in the graphics field, actually this is my firt graphics program and I would spend maybe 1 to 2 weeks.

thanks,

El Corazon7-May-07 11:25

7-May-07 11:25

sarah_malik wrote:
I'm trying to write a program that produces art

Take a look at FractInt in the link that GN gave you. I haven't used fractint in years, but the idea was you could zoom in and out of fractals getting the core numbers to reproduce it. So you can find the art within the math, and get the numbers back out to reproduce it. I used to play around with it a lot. Fractals make for interesting art as you saw in the mosaic images. Fractals are a good tool, mathematically and visually interesting.

_________________________
Asu no koto o ieba, tenjo de nezumi ga warau.
Talk about things of tomorrow and the mice in the ceiling laugh. (Japanese Proverb)

El Corazon7-May-07 15:34

7-May-07 15:34

The Grand Negus wrote:
The source code (in Plain English) is also on the site.

You should try Ultimate C++, you could reduce the verbiage of that source by a factor of 3 or 4.

_________________________
Asu no koto o ieba, tenjo de nezumi ga warau.
Talk about things of tomorrow and the mice in the ceiling laugh. (Japanese Proverb)

El Corazon7-May-07 16:20

7-May-07 16:20

The Grand Negus wrote:
How 'bout them Mandelbrots?

Alive and well, and producing images through infinity. Smile | :)

http://users.erols.com/ziring/mandel.html[^]
http://www.codeproject.com/cpp/mandelbrot_obfuscation.asp[^]

or

void mandel(int xpt, int ypt)<br />
{<br />
	long double x=0;<br />
	long double y=0;		//converting from pixels to points<br />
	long double xnew=0;<br />
	long double ynew=0;<br />
<br />
	for(int k=0;k<=initer;k++)  // Each pixel loop<br />
	{<br />
	//The Mandelbrot Function Z=Z*Z+c into x and y parts<br />
<br />
	xnew=x*x-y*y + xpt*pixcorx+Minx;<br />
	ynew=2*x*y   + Maxy-ypt*pixcory;<br />
	x=xnew;<br />
	y=ynew;<br />
	if ( (x*x+y*y)>4 ) break;  // Break condition<br />
	}                      // End each pixel loop<br />
<br />
	int color = k;<br />
	if (color>15) color=color%15;<br />
	if (k>=initer)<br />
	putpixel(xpt,ypt,0);<br />
	else<br />
	putpixel(xpt,ypt,color);<br />
<br />
	newcolor=color;<br />
}

_________________________
Asu no koto o ieba, tenjo de nezumi ga warau.
Talk about things of tomorrow and the mice in the ceiling laugh. (Japanese Proverb)

sarah_malik8-May-07 0:55