我基本上试图将左下方的正方形平分为零，然后将递归平分左上方，右上方和右下方的剩余方块，直到所有方格都被填满。但是，我的代码执行底部正方形二分，但只是在我添加新行时尝试使右下角二等分停止。任何想法为什么抽奖停止？在左下角的第一次二分之后，我似乎无法实现简单的“+”形状的绘制。
package recursivepatterns;
import java.awt.Color;
import sedgewick.*;
public class PersianRug {
public static void subDiv(double S, Color C, double x, double y) {
//
StdDraw.line(x+S/2, y, x+S/2, y+S);
StdDraw.line(x, y+S/2, x+S, y+S/2);
}
/**
*
* @param palette an array of Colors to choose from
* @param llx lower left x coordinate of this rug square
* @param lly lower left y coordinate of this rug square
* @param size width (and therefore also height) of this rug square
* @param north color index of the north side of this rug square
* @param east color index of the east side of this rug square
* @param south color index of the south side of this rug square
* @param west color index of the west side of this rug square
*/
private static void persianRug(
Color[] palette,
double llx, double lly,
double size,
int north, int east, int south, int west){
//
int c = 0;
Color C = palette[c];
subDiv(size,C,llx,lly);
if (size>0){
// ll
persianRug(palette,llx,lly,size/2, c, c, south, west); // north and east are fixed
// lr
StdDraw.setPenColor(StdDraw.RED);
StdDraw.circle(0.5,0.5,size/2); // this tests that circles do in fact recursively get bigger
persianRug(palette,llx+size/2,lly,size/2, c, c, south, west); // this line does not work at all
}
else return;
}
public static void main(String args[]) {
//
// Leave the following line commented out, but once you
// have things working, uncomment it, and also uncomment
// the similar line at the end of this method.
// Uncommenting those lines will run the graphics code
// in double-buffering mode, so that your image will appear
// almost instantaneously, instead of being drawn one line
// at a time.
//
// Here is the line to uncomment:
//
//StdDraw.show(10); // don't forget to uncomment the other line at the end
//
//
// Generate a palette of colors
//
Color[] palette = { StdDraw.BLUE, StdDraw.CYAN, StdDraw.DARK_GRAY,
StdDraw.GRAY, StdDraw.GREEN, StdDraw.LIGHT_GRAY,
StdDraw.MAGENTA, StdDraw.ORANGE, StdDraw.PINK, StdDraw.RED,
StdDraw.WHITE, StdDraw.YELLOW };
//
// Draw the outermost square as a special case
// Use color 0 for that
//
StdDraw.setPenColor(palette[0]);
StdDraw.line(0, 0, 1, 0);
StdDraw.line(1, 0, 1, 1);
StdDraw.line(1, 1, 0, 1);
StdDraw.line(0, 1, 0, 0);
//
// Kick off the recursion
// Lower left is point (0,0)
// Size of the square is 1
// The color index of each surrounding side is 0
//
persianRug(palette, 0, 0, 1, 0, 0, 0, 0);
//
// Also uncomment this line when you have things working
// to speed up the drawing:
//
//StdDraw.show(10);
//
}
}
答案 0 :(得分：0)
Result of fixing the tolerance to 0.005
package recursivepatterns;
import java.awt.Color; import sedgewick。*;
公共类PersianRug {
public static int pickColor(Color[] palette, int n, int e, int s, int w) {
// USES MODULAR ARITHMETIC AND BOUNDS OF THE PALETTE RING TO ASSIGN A COLOR
if ((n+s+w+e+2)%palette.length<palette.length/2-1)
return (n+e+s+w+8)%palette.length; // VARYING MODULAR COLOR
else if ((n+s+w+e+2)%palette.length>=palette.length/2-1 && (n+s+w+e)%palette.length<palette.length-5){
return palette.length-8;} // FIXED COLOR OF PALETTE
else
return 0; // "BACKGROUND" COLOR
}
public static void subDiv(double S, double x, double y) {
// DRAWS A CROSS GIVEN THE LOWER LEFT CORNER COORDINATES
StdDraw.line(x+S/2, y, x+S/2, y+S); // vertical
StdDraw.line(x, y+S/2, x+S, y+S/2); // horizontal
}
/**
*
* @param palette an array of Colors to choose from
* @param llx lower left x coordinate of this rug square
* @param lly lower left y coordinate of this rug square
* @param size width (and therefore also height) of this rug square
* @param n color index of the north side of this rug square
* @param e color index of the east side of this rug square
* @param s color index of the south side of this rug square
* @param w color index of the west side of this rug square
*/
private static void persianRug(
Color[] palette,
double llx, double lly,
double size,
int n, int e, int s, int w){
//
int c = pickColor(palette,n,e,s,w);
StdDraw.setPenColor(palette[c]);
subDiv(size,llx,lly);
n = (n+1)%palette.length; // ITERATE THE PALETTE FOR DIFFERENT COLOR NEXT ITER
s = (s+1)%palette.length; //
e = (e+1)%palette.length; //
w = (w+1)%palette.length; //
if (size>.0025){ // THIS BOUND DICTATES HOW DETAILED AND HOW QUICKLY THE RUG IS DRAWN
lly = lly+size/2; // TOP LEFT
persianRug(palette,llx,lly,size/2, n, c, c, w);
llx = llx+size/2; // TOP RIGHT
persianRug(palette,llx,lly,size/2, n, e, c, c);
llx=llx-size/2; // BOTTOM LEFT
lly = lly-size/2;
persianRug(palette,llx,lly,size/2, c, c, s, w);
llx = llx+(size/2); // BOTTOM RIGHT
persianRug(palette,llx,lly,size/2, c, e, s, c);
}
else return;
}
public static void main(String args[]) {
//
// Leave the following line commented out, but once you
// have things working, uncomment it, and also uncomment
// the similar line at the end of this method.
// Uncommenting those lines will run the graphics code
// in double-buffering mode, so that your image will appear
// almost instantaneously, instead of being drawn one line
// at a time.
//
// Here is the line to uncomment:
//
StdDraw.show(10); // don't forget to uncomment the other line at the end
//
//
// Generate a palette of colors
Color[] palette = { StdDraw.BLACK, StdDraw.RED, StdDraw.ORANGE,
StdDraw.PINK, StdDraw.BLUE, StdDraw.YELLOW,
StdDraw.RED, StdDraw.ORANGE, StdDraw.ORANGE, StdDraw.RED,
StdDraw.PINK, StdDraw.RED};
//
// Draw the outermost square as a special case
// Use color 0 for that
//
StdDraw.setPenColor(palette[0]);
StdDraw.line(0, 0, 1, 0);
StdDraw.line(1, 0, 1, 1);
StdDraw.line(1, 1, 0, 1);
StdDraw.line(0, 1, 0, 0);
//
// Kick off the recursion
// Lower left is point (0,0)
// Size of the square is 1
// The color index of each surrounding side is 0
//
persianRug(palette, 0, 0, 1, 0, 0, 0, 0);
//
// Also uncomment this line when you have things working
// to speed up the drawing:
//
StdDraw.show(10);
//
}
