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try it with 8-bit precision

This commit is contained in:
Amy Bowersox 2019-12-10 14:55:26 -07:00
parent cfc7519727
commit d711df60bd
1 changed files with 5 additions and 9 deletions
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14
src/devctxt.c
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@ -19,7 +19,7 @@ inline static BYTE line_clip_outcode(INT32 x, INT32 y, INT32 xmin, INT32 ymin, I
return rc;
}
#define CPX 4 /* clipping precision in bits */
#define CPX 8 /* clipping precision in bits */
#define ONE (1 << CPX) /* constant for mathematics */
@ -69,29 +69,25 @@ static BOOL line_clip(PINT32 output, INT32 x1, INT32 y1, INT32 x2, INT32 y2, INT
}
if (outcode1 & 0x8)
{
tmp = M(x2 - x1, D(ymin - y1, y2 - y1));
x1 += tmp;
x1 += M(x2 - x1, D(ymin - y1, y2 - y1));
y1 = ymin;
Log(LDEBUG, "clipped against top to point (%d, %d), dx=%d/%d", x1 >> CPX, y1 >> CPX, tmp >> CPX, tmp);
}
else if (outcode1 & 0x4)
{
tmp = M(x2 - x1, D(ymax - ONE - y1, y2 - y1));
x1 += tmp;
x1 += M(x2 - x1, D(ymax - ONE - y1, y2 - y1));
y1 = ymax - ONE;
Log(LDEBUG, "clipped against bottom to point (%d, %d), dx=%d/%d", x1 >> CPX, y1 >> CPX, tmp >> CPX, tmp);
}
else if (outcode1 & 0x2)
{
tmp = M(y2 - y1, D(xmax - ONE - x1, x2 - x1));
y1 += tmp;
y1 += M(y2 - y1, D(xmax - ONE - x1, x2 - x1));
x1 = xmax - ONE;
Log(LDEBUG, "clipped against right to point (%d, %d), dy=%d/%d", x1 >> CPX, y1 >> CPX, tmp >> CPX, tmp);
}
else if (outcode1 & 0x1)
{
tmp = M(y2 - y1, D(xmin - x1, x2 - x1));
y1 += tmp;
y1 += M(y2 - y1, D(xmin - x1, x2 - x1));
x1 = xmin;
Log(LDEBUG, "clipped against left to point (%d, %d), dy=%d/%d", x1 >> CPX, y1 >> CPX, tmp >> CPX, tmp);
}