Alternate way to draw Circle - Lesson 11

[Radix]

Hi

I used an alternate method to draw the circle. I think it's simpler. You draw two segments instead of four. It is based on Chili's method. See the attached picture for further explanation.

Code: Select all

	
        float radSqr = rad * rad;
	float temp = 2; 
	float what = rad / sqrt(temp);

                for( int x = -what; x <= what; x++ )
		{
			int y = sqrt( radSqr - x*x ) + 0.5f;
			PutPixel( x0 + x, y0 + y,r,g,bl);
			PutPixel( x0 + x, y0 - y,r,g,bl);
		}
		
                for( int y = -what; y <= what; y++ )
		{
			int x = sqrt( radSqr - y*y ) + 0.5f;
			PutPixel( x0 + x, y0 + y,r,g,bl);
			PutPixel( x0 - x, y0 + y,r,g,bl);
		}

[Radix]

Or maybe not lol

[LuX]

Your equations made no sense at all.
If you are referring to Bresenham's Midpoint circle algorithm I think it's exactly the one chili uses. You can't get much faster than that.

[Radix]

D3DGraphics::DrawCircle(int x0, int y0, int rad, int r, int g, int b)

[Radix]

This method splits the circle with an "X" shape vs. the "+" shape used in the tutorial. It's based on the technique used in Lesson 10. See picture attached.

[Radix]

This is meant to share an alternative way I stumbled upon... I am not implying it is better.
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On a side note these lessons rock!!! If I was a school teacher I would make every kid in my class (and petition the whole school) to take it as a requirement. Even if one doesn't have aspirations for a career in gaming/programming, it's so essential to build the type of thinking used in programming (problem solving with the tools available) and to demistify computers. This lessons are awesome for the very reason that they make learning not only extremely accessible (by assuming no prior knowledge - and being free lol) but also that it makes learning fun (and easy to share with friends).
So yah - a big shout out to Chilli and everyone else who makes this possible.

[albinopapa]

Of course you would have to censor Chili.

Fuck censorship poop that corn.