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Length: 904 (0x388)
Types: TextFile
Notes: UNIX file
Names: »linef.c«
└─⟦f27320a65⟧ Bits:30001972 Commodore 900 hard disk image with partial source code
└─⟦0a3c255ba⟧ UNIX V7 Filesystem
└─ ⟦this⟧ »graphics/linef.c«
#define TRUE -1
#define FALSE 0
#define max(x,y) (((x) > (y)) ? (x) : (y))
#define abs(x) (((x) < 0) ? -(x) : (x))
#define sign(x) ((x) > 0 ? 1 : ((x) == 0 ? 0 : (-1)))
linef(x1, y1, x2, y2, color, style, orxor, first_on)
unsigned style;
int x1, y1, x2, y2, color, orxor, first_on;
{
int ix, iy, i, inc, x, y, dx, dy, plot, plotx, ploty;
unsigned style_mask;
style = (style == 0) ? 0xFFFF : style;
style_mask = style;
dx = x2 - x1;
dy = y2 - y1;
ix = abs(dx);
iy = abs(dy);
inc = max(ix, iy);
plotx = x1;
ploty = y1;
x = y = 0;
if (first_on)
point(plotx, ploty);
for (i = 0; i <= inc; ++i)
{
if (style_mask == 0) style_mask = style;
x += ix;
y += iy;
plot = FALSE;
if (x > inc)
{
plot = TRUE;
x -= inc;
plotx += sign(dx);
}
if (y > inc)
{
plot = TRUE;
y -= inc;
ploty += sign(dy);
}
if (plot && style_mask & 0x0001)
point(plotx, ploty);
style_mask >>= 1;
}
}