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Continued the line clamping. Seems to work perfectly for all 16 directions, but I discovered an older problem in the input handler when you release a key that participates in cursor emulation. Not completely fixed.

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git-svn-id: svn://pulkomandy.tk/GrafX2/trunk@895 416bcca6-2ee7-4201-b75f-2eb2f807beb1
This commit is contained in:
Yves Rizoud
2009-07-02 21:38:11 +00:00
parent 19a2892e88
commit 9e9fd506b6
4 changed files with 79 additions and 81 deletions
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96
graph.c
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@@ -1358,66 +1358,58 @@ void Draw_filled_ellipse(short center_x,short center_y,short horizontal_radius,s
/// Alters bx and by so the (AX,AY)-(BX,BY) segment becomes either horizontal,
/// vertical, 45degrees, or isometrical for pixelart (ie 2:1 ratio)
void Clamp_coordinates_45_degrees(short ax, short ay, short* bx, short* by)
void Clamp_coordinates_regular_angle(short ax, short ay, short* bx, short* by)
{
int dx, dy;
float tan;
float angle;
float length;
dx = (*bx)-ax;
dy = ay- *by;
// On prend l'opposée car à l'écran les Y sont positifs en bas, et en
// maths, positifs en haut
dx = *bx-ax;
dy = *by-ay;
if (dx==0) return;
if (dx==0 || dy == 0) return;
// On est en lockx et de toutes façons le X n'a pas bougé, on sort tout
// de suite pour éviter une méchante division par 0
tan = (float)dy/(float)dx;
// These equation look a bit more complex than they should, but that's
// because we have to balance the line length to make it end near the
// cursor
if (tan <= 0.25 && tan >= -0.25)
{
// horizontal (OK)
*by = ay;
}
else if ( tan > 0.25 && tan < 0.75)
{
// dx=2dy, iso (ok)
*bx = (2* *bx + ax + 2*dy)/3;
*by = ay - (*bx-ax)/2;
}
else if ( tan >=0.75 && tan <= 1.5 )
{
// dy=-dx, diagonal upright (ok)
*by = (*by + ay - dx)/2;
*bx = ax + ay - *by;
}
else if ( tan > 1.5 && tan <= 3 )
{
// "vertical iso"
}
else if (tan < -0.25 && tan >= -0.75)
{
// iso to bottom
}
else if ( tan <-0.75 && tan > -1.5 )
{
// dy=dx, downright diagonal (ok)
*by = (*by + ay + dx)/2;
*bx = ax - ay + *by;
}
else if ( tan < -1.5 && tan >= -3 )
{
// vertical iso to bottom
}
else
{
// vertical (ok)
*bx = ax;
}
angle = atan2(dx, dy);
if (angle < M_PI*(-15.0/16.0) || angle > M_PI*(15.0/16.0))
angle = M_PI*(16.0/16.0);
else if (angle < M_PI*(-13.0/16.0))
angle = -2.677945045;
else if (angle < M_PI*(-11.0/16.0))
angle = M_PI*(-12.0/16.0);
else if (angle < M_PI*(-9.0/16.0))
angle = -2.034443936;
else if (angle < M_PI*(-7.0/16.0))
angle = M_PI*(-8.0/16.0);
else if (angle < M_PI*(-5.0/16.0))
angle = -1.107148718;
else if (angle < M_PI*(-3.0/16.0))
angle = M_PI*(-4.0/16.0);
else if (angle < M_PI*(-1.0/16.0))
angle = -0.463647609;
else if (angle < M_PI*(1.0/16.0))
angle = M_PI*(0.0/16.0);
else if (angle < M_PI*(3.0/16.0))
angle = 0.463647609;
else if (angle < M_PI*(5.0/16.0))
angle = M_PI*(4.0/16.0);
else if (angle < M_PI*(7.0/16.0))
angle = 1.107148718;
else if (angle < M_PI*(9.0/16.0))
angle = M_PI*(8.0/16.0);
else if (angle < M_PI*(11.0/16.0))
angle = 2.034443936;
else if (angle < M_PI*(13.0/16.0))
angle = M_PI*(12.0/16.0);
else //if (angle < M_PI*(15.0/16.0))
angle = 2.677945045;
length = sqrt((float)(dx)*(float)(dx)+(float)(dy)*(float)(dy));
*bx=ax + lrintf(sin(angle)*length);
*by=ay + lrintf(cos(angle)*length);
return;
}