/*
draw the polyline using color c
*/
void polyline_draw(Polyline *p, Image *src, Color colr){
Line l;
int i;
for (i=0; i< p->numVertex-1; i++){
line_set2D(&l,p->vertex[i].val[0], p->vertex[i].val[1], p->vertex[i+1].val[0], p->vertex[i+1].val[1]);
line_draw(&l, src, colr);
}
}
void ellipse_draw(Ellipse *e, Image *src, Color p){
/* draw an ellipse into src using color p*/
double x, y, px, py, pz;
double xCenter, yCenter;
double Rx, Ry;
/*set center values */
xCenter = e->c.val[0];
yCenter = e->c.val[1];
/*Major axis: Rx*/
Rx = e->ra;
/*Minor axis: Ry*/
Ry = e->rb;
/*when you are not trying to rotate the ellipse you will be using Bresenhan's
Algorithm. It considers the cartesian equation for an ellipse and uses an
updated error term to decide on which pixel to draw up or to the side. We
will start drawing in the third quadrant to help account for pixel error*/
/*This algorithm, for when a = 0 comes from: ellipseMidpoint, Chapter 3, pg 109-110*/
if(e->a == 0){
/*set initial x and y values*/
x= -1;
y= -Ry;
/*initial starting error terms!*/
px = 2*Rx*Ry;
py = 2*Rx*Rx*-y;
printf("x: %f y: %f \n", x,y);
printf("px: %f py: %f\n", px, py);
printf("Major Axis: %f Minor Axis: %f\n", Rx, Ry);
/*set up p, this is necessray because we have to draw an entire
quadrant of the ellipse. The symmetry here is not as nice as in a
circle*/
pz = (Ry*Ry-(Rx*Rx*Ry)+(Rx*Rx*0.25)+Ry*Ry+py);
/*this sets the color of the initial points*/
image_setColor(src, xCenter+x, yCenter+y, p);
image_setColor(src, xCenter-x-1, yCenter-y-1, p);
image_setColor(src, xCenter+x, yCenter+y, p);
image_setColor(src, xCenter-x-1, yCenter+y, p);
image_setColor(src, xCenter+x, yCenter-y-1, p);
image_setColor(src, xCenter-x-1, yCenter-y-1, p);
image_setColor(src, xCenter+x, yCenter+y, p);
image_setColor(src, xCenter-x-1, yCenter+y, p);
image_setColor(src, xCenter+x, yCenter-y-1, p);
image_setColor(src, xCenter-x-1, yCenter-y-1, p);
/*wile the points are still below the tangent line with a -1 slope value
decrement over x*/
printf("Starting the first half of the ellipse\n");
while (px<py){
x--; // decrement x
px = px+ 2*Ry*Ry;
if (pz<0){
pz += Ry*Ry+px;
}else{
y++;// increment y
py = py- 2*Rx*Rx;
pz += Ry*Ry +px-py;
}
/*set the pixel color in the 4 quadrants*/
image_setColor(src, xCenter+x, yCenter+y, p);
image_setColor(src, xCenter-x-1, yCenter+y, p);
image_setColor(src, xCenter+x, yCenter-y-1, p);
image_setColor(src, xCenter-x-1, yCenter-y-1, p);
}
/* when the points pass the tangent line with slope of -1 now incrementing
over y*/
pz = Ry*Ry *(x*x +x) +Rx*Rx* (y*y-2*y +1) -Rx*Rx *Ry*Ry +Rx*Rx -py;
printf("Starting the second half of the ellipse\n");
while (y<0){
y++;//increment y
py = py - 2*Rx*Rx;
if (pz>0){
pz += Rx*Rx-py;
}else{
x--;//decrement x
px += 2*Ry *Ry;
pz += Rx*Rx-py+px;
}
/*set the pixel color in the 4 quadrants*/
image_setColor(src, xCenter+x, yCenter+y, p);
image_setColor(src, xCenter-x-1, yCenter+y, p);
image_setColor(src, xCenter+x, yCenter-y-1, p);
image_setColor(src, xCenter-x-1, yCenter-y-1, p);
}
printf("YAY you have drawn an ellipse at angle 0\n");
}else{
printf("You are rotating the ellipse\n");
/*We are going to use a different method to rotate the ellipse*/
/*First: we will build a list of points on the boundary of the ellipse
where at the further regions there are more points and we will ultimately
connect the lines together to make an ellipse.*/
Point *holdPoints;
Point pt;
double rmax, numPoints, stepSize;
double x1, y1, x2, y2;
double xR1, yR1, xR2, yR2, step;
double angle;
Line l1;
int k, m;
/*pick which is bigger the Major axis or the Minor axis*/
if (Rx >Ry){
rmax = Rx;
}else{
rmax = Ry;
}
/*convert the angle to polar coordinates*/
angle = (e->a)*(PI/180);
printf("angle: %f\n", angle);
/*determine the step size based on the fact that we will have Rmax number
of points*/
stepSize = 1/(rmax);
numPoints = rmax*0.5;
/*malloc space for an array of Points*/
holdPoints = malloc(sizeof(Point)*(numPoints));
printf("number of points %f\n", numPoints);
printf("size of a step %f\n:", stepSize);
/*get the initial point*/
x1 = Rx*cos(0);
y1 = Ry*sin(0);
point_set2D(&pt, x1,y1);
/*add that point to the list*/
holdPoints[0] = pt;
printf("x1: %f y1: %f\n", x1, y1);
/*loop through the number of points and deterine the point value for
the incremented step size*/
for(k = 1; k<numPoints; k++){
step = stepSize*(double)k;
x2 = (holdPoints[k-1].val[0] * cos(step))-((Rx/Ry)*holdPoints[k-1].val[1]*sin(step));
y2 = ((Ry/Rx)*holdPoints[k-1].val[0]*sin(step))+(holdPoints[k-1].val[1]*cos(step));
point_set2D(&pt, x2, y2);
holdPoints[k]=pt;
}
/*breaking down matrix math into two equations apply a rotation and translation to the list of points
and draw the points at there new location connecting the lines between them*/
for(m=0; m+1<numPoints; m++){
xR1 = holdPoints[m].val[0]*cos(angle)+holdPoints[m].val[1]*sin(angle)*-1 +xCenter;
yR1 = holdPoints[m].val[0]*sin(angle)+holdPoints[m].val[1]*cos(angle)+yCenter;
xR2 = holdPoints[m+1].val[0]*cos(angle)+holdPoints[m+1].val[1]*sin(angle)*-1 +xCenter;
yR2 = holdPoints[m+1].val[0]*sin(angle)+holdPoints[m+1].val[1]*cos(angle)+yCenter;
line_set2D(&l1, xR1, yR1, xR2, yR2);
line_draw(&l1, src, p);
}
/*free malloced space for the holdPoints array*/
free(holdPoints);
}
}
int main(int argc, char *argv[]){
Image *src;
Ellipse elip;
Circle circ;
Color color, red, pink, yellow;
Color blue;
Line l;
Point p;
Point pt[5];
Polygon *poly;
int i;
/*set the colors*/
color_set(&color, 1.0, 1.0, 1.0);
color_set(&red, 1.0, 0.0,0.0);
color_set(&blue, 0.4,1.0,1.0);
color_set(&pink, 1.0, 0.6, 0.8);
color_set(&yellow, 1.0, 1.0, 0.4);
/*build an image*/
src = image_create( 700,700);
/*build the cupcake like I was using turtle graphics*/
line_set2D(&l, 100,300,200,600);
line_draw( &l, src, pink );
line_set2D(&l, 600,300,500,600);
line_draw( &l, src, pink );
point_set2D( &p, 600, 350 );
ellipse_set(&elip, p, 40, 150,0);
ellipse_draw(&elip, src, pink);
point_set2D( &p, 300,350 );
ellipse_set(&elip, p, 80, 250,0);
ellipse_draw(&elip, src, pink);
point_set2D( &p, 275,350 );
ellipse_set(&elip, p, 75, 225,0);
ellipse_draw(&elip, src, blue);
point_set2D( &p, 250,350 );
ellipse_set(&elip, p, 50, 200,0);
ellipse_draw(&elip, src, blue);
point_set2D( &p, 225,350 );
ellipse_set(&elip, p, 25, 175,0);
ellipse_draw(&elip, src, blue);
point_set2D( &p, 200,350 );
ellipse_set(&elip, p, 20, 150,0);
ellipse_draw(&elip, src, blue);
point_set2D( &p, 175,350 );
ellipse_set(&elip, p, 15, 125,0);
ellipse_draw(&elip, src, blue);
point_set2D( &p, 150,350 );
ellipse_set(&elip, p, 5, 75,0);
ellipse_draw(&elip, src, blue);
point_set2D( &p, 350, 100 );
circle_set( &circ, p, 25 );
circle_draw( &circ, src, red);
/*write image*/
image_write( src, "3Dimage.ppm" );
/*free image*/
image_free( src );
/*this time fill the cupcake*/
src = image_create( 700,700);
color_set(&pink, 1.0, 0.6, 0.8);
point_set2D( &p, 600, 350 );
ellipse_set(&elip, p, 40, 150,0);
ellipse_drawFill(&elip, src, pink);
point_set2D(&(pt[0]),100 ,300);
point_set2D(&(pt[1]),600 ,300);
point_set2D(&(pt[2]),505 ,600);
point_set2D(&(pt[3]),198, 600);
poly = polygon_createp(4, pt);
polygon_drawFill(poly,src, pink);
color_set(&pink, 1.0, 0.4, 0.8);
point_set2D( &p, 300,350 );
ellipse_set(&elip, p, 80, 250,0);
ellipse_drawFill(&elip, src, pink);
color_set(&pink, 1.0, 0., 0.8);
for(i=0; i<10; i++){
line_set2D(&l, 100-i,300-i,200,600);
line_draw( &l, src, pink );
line_set2D(&l, 600-i,300-i,500,600);
line_draw( &l, src, pink );
line_set2D(&l, 175-i, 300-i, 225, 623);
line_draw(&l, src, pink);
line_set2D(&l, 275-i, 280-i, 305, 636);
line_draw(&l, src, pink);
line_set2D(&l, 385-i, 280-i, 385, 640);
line_draw(&l, src, pink);
line_set2D(&l, 510-i, 300-i, 450, 630);
line_draw(&l, src, pink);
}
point_set2D( &p, 295,350 );
ellipse_set(&elip, p, 70, 230,0);
ellipse_drawFill(&elip, src, yellow);
color_set(&blue, 0.0,0.8,0.8);
point_set2D( &p, 275,350 );
ellipse_set(&elip, p, 75, 220,0);
ellipse_drawFill(&elip, src, blue);
color_set(&blue, 0.0,1.0,1.0);
point_set2D( &p, 250,350 );
ellipse_set(&elip, p, 50, 200,0);
ellipse_drawFill(&elip, src, blue);
color_set(&blue, 0.4,1.0,1.0);
point_set2D( &p, 225,350 );
ellipse_set(&elip, p, 25, 175,0);
ellipse_drawFill(&elip, src, blue);
color_set(&blue, 0.6,1.0,1.0);
point_set2D( &p, 200,350 );
ellipse_set(&elip, p, 20, 150,0);
ellipse_drawFill(&elip, src, blue);
color_set(&blue, 0.7,1.0,1.0);
point_set2D( &p, 175,350 );
ellipse_set(&elip, p, 15, 125,0);
ellipse_drawFill(&elip, src, blue);
color_set(&blue, 0.8,1.0,1.0);
point_set2D( &p, 150,350 );
ellipse_set(&elip, p, 5, 75,0);
ellipse_drawFill(&elip, src, blue);
point_set2D( &p, 350, 100 );
circle_set( &circ, p, 25 );
circle_drawFill( &circ, src, red);
image_write( src, "3DimageFill.ppm" );
polygon_free(poly);
image_free( src );
return(0);
}