gistfile1.pde

// dashed and dotted lines in Processing
// by Josh Nimoy, Based on Bresenham
 
void dashedLine ( float x0, float y0, float x1, float y1 )
{
    dashedLine( (int)x0, (int)y0, (int)x1, (int)y1 );
}
 
void dashedLine ( int x0, int y0, int x1, int y1 )
{
    int refX = x0; int refY = y0;
    int dy = y1 - y0; 
    int dx = x1 - x0; 
    int stepx, stepy; 
    if (dy < 0) { 
        dy = -dy;  
        stepy = -1; 
    } 
    else {
        stepy = 1;
    } 
    if (dx < 0) { 
        dx = -dx;  
        stepx = -1; 
    } 
    else {
        stepx = 1;
    } 
    dy <<= 1; 
    dx <<= 1; 
    point(x0,y0); 
 
    if (dx>dy) { 
        int fraction=dy-(dx>>1); 
        //int ogx0 = x0; 
        //int ogy0 = y0; 
        double d; 
        while (x0!=x1){ 
            if(fraction>=0){ 
                y0 += stepy; 
                fraction -= dx; 
            } 
            x0 += stepx; 
            fraction += dy; 
            d = dist(refX,refY,x0,y0); 
            if(d%12 > 4)point(x0,y0); 
        } 
    }
    else { 
        int fraction = dx - (dy>>1); 
        //int ogx0 = x0; 
        //int ogy0 = y0; 
        double d; 
        while (y0 != y1) { 
            if (fraction >= 0) { 
                x0 += stepx; 
                fraction -= dy; 
            } 
            y0 += stepy; 
            fraction += dx; 
            d = dist(refX,refY,x0,y0); 
            if(d%12 > 4)point(x0,y0); 
 
        } 
    } 
}
 
 
void dotDashedLine ( float x0, float y0, float x1, float y1 )
{
    dotDashedLine( (int)x0, (int)y0, (int)x1, (int)y1 );
}
 
void dotDashedLine ( int x0, int y0, int x1, int y1 )
{
    int refX = x0; int refY = y0;
    int dy = y1 - y0; 
    int dx = x1 - x0; 
    int stepx, stepy; 
    if (dy < 0) { 
        dy = -dy;  
        stepy = -1; 
    } 
    else {
        stepy = 1;
    } 
    if (dx < 0) { 
        dx = -dx;  
        stepx = -1; 
    } 
    else {
        stepx = 1;
    } 
    dy <<= 1; 
    dx <<= 1; 
    point(x0,y0); 
 
    if (dx>dy) { 
        int fraction=dy-(dx>>1); 
        //int ogx0 = x0; 
        //int ogy0 = y0; 
        double d; 
        while (x0!=x1){ 
            if(fraction>=0){ 
                y0 += stepy; 
                fraction -= dx; 
            } 
            x0 += stepx; 
            fraction += dy; 
            d = dist(refX,refY,x0,y0)%17; 
            if(d>9 || (d>3 && d<5))point(x0,y0); 
        } 
    }
    else { 
        int fraction = dx - (dy>>1); 
        //int ogx0 = x0; 
        //int ogy0 = y0; 
        double d; 
        while (y0 != y1) { 
            if (fraction >= 0) { 
                x0 += stepx; 
                fraction -= dy; 
            } 
            y0 += stepy; 
            fraction += dx; 
            d = dist(refX,refY,x0,y0)%17; 
            if(d>9 || (d>3 && d<5))point(x0,y0); 
 
        } 
    } 
}