Method drawLine

ij/src/main/java/ij/gui/Line.java:115–150

(int sx, int sy)

	}

	protected void drawLine(int sx, int sy) {
		double xend = offScreenXD(sx);
		double yend = offScreenYD(sy);
		if (xend<0.0) xend=0.0; if (yend<0.0) yend=0.0;
		if (xend>xMax-1) xend=xMax-1; if (yend>yMax-1) yend=yMax-1;
		double xstart=getXBase()+x1R, ystart=getYBase()+y1R;
		if (constrain) {
		    int i=0;
	        double dy = Math.abs(yend-ystart);
	        double dx = Math.abs(xend-xstart);
	        double comp = dy / dx;
	        for (;i<PI_SEARCH.length; i++) {
	            if(comp < PI_SEARCH[i]) {
	                break;
	            }
	        }
	        if (i < PI_SEARCH.length) {
	            if(yend > ystart) {
	                yend = ystart + dx*PI_MULT[i];
	            } else {
	                yend = ystart - dx*PI_MULT[i];
	            }
	        } else {
	            xend = xstart;
	        }
		}
		if (!magnificationForSubPixel() || IJ.controlKeyDown()) {  //during creation, CTRL enforces integer coordinates
			xstart=Math.round(xstart); ystart=Math.round(ystart);
			xend=Math.round(xend);     yend=Math.round(yend);
		}
		updateCoordinates(xstart, ystart, xend, yend);
		updateClipRect();
		imp.draw(clipX, clipY, clipWidth, clipHeight);
		oldX=x; oldY=y;
		oldWidth=width; oldHeight=height;
	}

	/** Used for angle searches in line ROI creation: tan = y/x for angle limits 1/2*45 degrees, and 3/2*45 deg */
	private static final double[] PI_SEARCH = {Math.tan(Math.PI/8), Math.tan((3*Math.PI)/8)};