[cl-gd-devel] just to share
I just want to share a problem with cl-gd or maybe gd itself i don't know... Has anybody tried to draw an ellipse which starts and ends at a precise angle? Well, I have and it turns out that the angles that i have specified are not drawn exact , they are either bigger or smaller and SOMETIMES theyy are correct! is this a problem with gd or cl-gd? example I draw an ellipse that passes through two points then I want this ellipse to start from exactly one of the two point aand end at the other one. I calculate the angles with tthe help of the function (atan) or (asin) using the coordinates of the center of the ellipse and the two given points... and the angles drawn don't match with the given points That's funny!!! ridiculous!!! There's always 1 or 2 maybe more degrees discrapency between the angles drawn and the given points Anybody encountered the same thing? __________________________________ Yahoo! FareChase: Search multiple travel sites in one click. http://farechase.yahoo.com
On Tue, 22 Nov 2005 03:54:35 -0800 (PST), arry <frinkofox@yahoo.com> wrote:
I just want to share a problem with cl-gd or maybe gd itself i don't know...
Has anybody tried to draw an ellipse which starts and ends at a precise angle? Well, I have and it turns out that the angles that i have specified are not drawn exact , they are either bigger or smaller and SOMETIMES theyy are correct!
is this a problem with gd or cl-gd?
example I draw an ellipse that passes through two points then I want this ellipse to start from exactly one of the two point aand end at the other one. I calculate the angles with tthe help of the function (atan) or (asin) using the coordinates of the center of the ellipse and the two given points...
and the angles drawn don't match with the given points That's funny!!! ridiculous!!! There's always 1 or 2 maybe more degrees discrapency between the angles drawn and the given points
I don't have time to investigate this at the moment but if in doubt I'd first try with a similar C program to see if the problems are in GD. You also might want to check if any rounding errors occur within CL-GD. Good luck, Edi.
never mind my post I figured myself whats wrong The angles that the function "draw-arc" accepts are actually the angles that the line that draws the ellipse forms with the x-axes, which is not the angle between the radius of the ellipse and the x-axes. Hope that is clear bye --- Edi Weitz <edi@agharta.de> wrote:
On Tue, 22 Nov 2005 03:54:35 -0800 (PST), arry <frinkofox@yahoo.com> wrote:
I just want to share a problem with cl-gd or maybe gd itself i don't know...
Has anybody tried to draw an ellipse which starts and ends at a precise angle? Well, I have and it turns out that the angles that i have specified are not drawn exact , they are either bigger or smaller and SOMETIMES theyy are correct!
is this a problem with gd or cl-gd?
example I draw an ellipse that passes through two points then I want this ellipse to start from exactly one of the two point aand end at the other one. I calculate the angles with tthe help of the function (atan) or (asin) using the coordinates of the center of the ellipse and the two given points...
and the angles drawn don't match with the given points That's funny!!! ridiculous!!! There's always 1 or 2 maybe more degrees discrapency between the angles drawn and the given points
I don't have time to investigate this at the moment but if in doubt I'd first try with a similar C program to see if the problems are in GD. You also might want to check if any rounding errors occur within CL-GD.
Good luck, Edi.
__________________________________ Yahoo! FareChase: Search multiple travel sites in one click. http://farechase.yahoo.com
participants (2)
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arry -
Edi Weitz