本文介绍了如何改进Bresenham算法来绘制具有任意斜率的直线,详细讲解了算法原理及其优化方法。
```c
void Bresenham(int x0, int y0, int x1, int y1) {
int dx, dy, d, up, down, x, y;
if (x0 > x1) {
x = x1;
x1 = x0;
x0 = x;
y = y1;
y1 = y0;
y0 = y;
}
dx = abs(x1 - x0);
dy = abs(y1 - y0);
d = 2 * (dx - dy);
up = 2 * (dx + dy);
down = 2 * (-dy);
if(dy > 0 && abs(dy) - abs(dx) > 0){
x = x0;
x0 = y0;
y0 = x;
y = x1;
y1 = y1;
x1 = y;
}
if (dy < 0 && abs(dy) - abs(dx) > 0){
x = x0;
x0 = -y0;
y0 = x;
y = x1;
y1 = -y1;
x1 = y;
}
if (dy < 0 && abs(dy) - abs(dx) < 0){
x0 = -x0;
x1 = -x1;
}
while(x0 <= x1){
putpixel(x0, y0);
x0++;
if(d < 0){
y0++;
d += up;
} else {
d += down;
}
}
}
```