/**
* @brief Draw a line
*
* Draws a straight line between the two points.
*
* @param x1 the x coordinate of the first point
* @param y2 the y coordinate of the first point
* @param x1 the x coordinate of the second point
* @param y2 the y coordinate of the second point
* @param color the Color to of the line
*/
void CatPictureApp::drawLine(int x1, int y1, int x2, int y2, Color8u* color)
// changed the names of the parametets, thought x1 would make more sense
// to the user than xF, fairly arbitrary though.. might just be personal preference
{
//Implementation of Bresenham's line algorithm, derived from pseudocode
//from Wikipedia.
int dx = intMath->abs(x2 - x1);
int dy = intMath->abs(y2 - y1);
int sx = intMath->signum(x2 - x1);
int sy = intMath->signum(y2 - y1);
int err = dx - dy;
int x = x1;
int y = y1;
while(true)
{
modify(color,x,y);
if(x == x2 && y == y2)
break;
int e2 = 2 * err;
if(e2 > -dy)
{
err -= dy;
x += sx;
}
if(e2 < dx)
{
err += dx;
y += sy;
}
}
}
/**
* Draws a straight line between the two points.
* Params:
xI = Initial X
yI = Initial Y
xF = Final X
yF = Final Y
color = Color to draw.
*/
void CatPictureApp::drawLine(int xI, int yI, int xF, int yF, Color8u* color)
{
//Implementation of Bresenham's line algorithm, derived from pseudocode
//from Wikipedia.
int dx = intMath->abs(xF - xI);
int dy = intMath->abs(yF - yI);
int sx = intMath->signum(xF - xI);
int sy = intMath->signum(yF - yI);
int err = dx - dy;
int x = xI;
int y = yI;
while(true)
{
modify(color,x,y);
if(x == xF && y == yF)
break;
int e2 = 2 * err;
if(e2 > -dy)
{
err -= dy;
x += sx;
}
if(e2 < dx)
{
err += dx;
y += sy;
}
}
}
