How to connect PC and Mac directly via Wi-fi?

windows-7 wireless-networking osx-lion

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Setup an Ad-Hoc network, one system, join it from the other.

First system setup:

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Brieg

Updated on September 18, 2022

Comments

Brieg almost 2 years
How to draw circle or semi circle or arc from start(B) to end(C) point giving(without using any external library) in pure C# and OpenGL :
- A(Ax,Ay) - polyline
- B(Bx,By) - start point
- C(Cx,Cy) - end point
- M(Mx,My) - center of circle or semi circle or arc
- r - radius
- startAngle = atan2(B.y - M.y, B.x - M.x) - in radians
- endAngle = atan2f(C.y - M.y, C.x - M.x) - in radians
- segments = 80
Unknow values:
- clockwise or anticlockwise direction
Requirements
- Arc must be drawing from point B to C
Can someone please provide me equation for drawing an arc in OpenGL?

Hint:

Will it be a circle, a semicircle or arc it depends on the position of the center of the circle and the start and end points.

Please give me a some light to solve this.

-- EDIT --

Below i present the solution. But it draw sometimes in wrong direction (should clockwise but it draw anticlockwise).:
```
float startAngle = atan2(B.y - centerArc.y, B.x - centerArc.x);
float endAngle = atan2(C.y - centerArc.y, C.x - centerArc.x);

if (endAngle < startAngle)
{
    endAngle += 2.0f * PI;
}

glBegin(GL_LINE_STRIP);
for (float angle = startAngle; angle <= endAngle; angle = angle + 0.01f)
{
    float x = centerArc.x + cos(angle) * r;
    float y = centerArc.y + sin(angle) * r;
    glVertex2f(x, windowHeight - y);
}
glEnd();
```
It gives:
- BDL almost 8 years
  
  Haven't you asked the same question several times?
- Brieg almost 8 years
  
  In Java or Android with ready libraries, yes.
- Unick almost 8 years
  
  Try to call glDisable(GL_CULL_FACE) before render. Maybe it is turned on by default.
- Nicol Bolas almost 8 years
  
  "Semi circle have to be bottom of the line and not on the top." Bottom relative to what? Lines do not have a "bottom" or a "top". So how do you determine which side of the line you want the arc drawn on?
- Martijn Pieters almost 8 years
  
  Please don't vandalise your post please.
BDL almost 8 years

I do not exactly understand what you mean.
BDL almost 8 years

I see. The problem is, that the angles are in range from -pi to pi and you are not taking that into account. The easiest thing is to move add 2*pi to the angle when it is negative.
BDL almost 8 years

Exchanging B and C should do the trick. When B->C is the counter-clockwise part, then C->B will be the other direction.
BDL almost 8 years

how do you even know which orientation you want? Your problem is under-determined when not fixing the orientation. Unless you have any other constraint to determine the direction, I don't see any way how to do this. And it would make the world for both of us easier when you start with the full set of information on first place.
BDL almost 8 years

As already said: From the data you have, you will not be able to conclude which orientation is the right one. You could decide it depending on the line segment before the arc starts, but this would require at least on additional point.
Brieg almost 8 years

Please remove this topic. Thx.