/*
Calculates |^ a/b ^| with mathamatically correct floor
*/
static int CeilDiv(int a,int b)
{
if (b>0)
return FloorDiv(a-1,b)+1;
else
return FloorDiv(-a-1,-b)+1;
}
/*----------------------------------------------------------------------------------------------
Set the value of this SilTime according to the information in psti.
----------------------------------------------------------------------------------------------*/
void SilTime::SetTimeInfo(const SilTimeInfo & sti, bool fUtc)
{
int dyear = sti.year + FloorDiv(sti.ymon - 1, kmonPerYear) - kyearBase;
int mon = ModPos(sti.ymon - 1, kmonPerYear);
// Calculate the day number.
int64 day = (int64)365 * dyear +
FloorDiv(dyear, 4) - FloorDiv(dyear, 100) + FloorDiv(dyear, 400) +
g_rgyday[IsLeapYear(dyear + kyearBase)][mon] + sti.mday - 1;
m_msec = day * kmsecPerDay +
sti.hour * (int64)kmsecPerHour + sti.min * (int64)kmsecPerMin +
sti.sec * (int64)kmsecPerSec + sti.msec;
if (!fUtc)
m_msec = g_tmm.ToUtc(m_msec);
}
/*----------------------------------------------------------------------------------------------
Fill in the SilTimeInfo structure from this time.
----------------------------------------------------------------------------------------------*/
void SilTime::GetTimeInfo(SilTimeInfo * psti, bool fUtc) const
{
AssertPtr(psti);
int dyear;
int day;
int msecDay;
int yday;
int64 msec = m_msec;
if (!fUtc)
msec = g_tmm.ToLcl(msec);
// Decompose m_msec into which 400 year period it is in (relative to T0) and
// the millisecond within the 400 year period.
psti->year = (int)FloorDiv(msec, kmsecPerPeriod) * kyearPerPeriod + kyearBase;
msec = ModPos(msec, kmsecPerPeriod);
Assert(0 <= 0 && msec < kmsecPerPeriod);
// Find the day within the 400 year period.
day = (int)(msec / kmsecPerDay);
Assert(0 <= day && day < kdayPerPeriod);
// Get the time within the day.
msecDay = (int)(msec - day * (int64)kmsecPerDay);
Assert(0 <= msecDay && msecDay < kmsecPerDay);
// Find the year within the 400 year period (dyear) and the day within that year (yday).
Assert(0 <= day && day < 146097);
dyear = YearFromDayInPeriod(day, &yday);
Assert(0 <= dyear && dyear < 400);
Assert(0 <= yday && (yday < 365 || yday == 365 && SilTime::IsLeapYear(dyear + kyearBase)));
// Add dyear into the year.
psti->year += dyear;
// Find the month and day in the month.
const int * prgday = g_rgyday[IsLeapYear(psti->year)];
for (psti->ymon = 1; yday >= prgday[psti->ymon]; psti->ymon++)
;
psti->mday = yday - prgday[psti->ymon - 1] + 1;
// Calculate the week day.
// kdayMonday is used because T0 is a Monday. Note that kdayPerPeriod is divisible by 7
// so we don't have to adjust the day of the week.
psti->wday = ModPos(day + kwdayMonday, kdayPerWeek);
// Fill in the time.
psti->hour = msecDay / kmsecPerHour;
psti->min = (msecDay % kmsecPerHour) / kmsecPerMin;
psti->sec = (msecDay % kmsecPerMin) / kmsecPerSec;
psti->msec = msecDay % kmsecPerSec;
}
/*----------------------------------------------------------------------------------------------
Set the value of this SilTime according to the information in psti.
----------------------------------------------------------------------------------------------*/
void SilTime::SetTimeInfo(const SilTimeInfo & sti, bool fUtc)
{
int dyear = sti.year + FloorDiv(sti.ymon - 1, kmonPerYear) - kyearBase;
int mon = ModPos(sti.ymon - 1, kmonPerYear);
// Calculate the day number.
int64 day = (int64)365 * dyear +
FloorDiv(dyear, 4) - FloorDiv(dyear, 100) + FloorDiv(dyear, 400) +
g_rgyday[IsLeapYear(dyear + kyearBase)][mon] + sti.mday - 1;
m_msec = day * kmsecPerDay +
sti.hour * (int64)kmsecPerHour + sti.min * (int64)kmsecPerMin +
sti.sec * (int64)kmsecPerSec + sti.msec;
#if WIN32
if (!fUtc)
m_msec = g_tmm.ToUtc(m_msec);
#else // WIN32
if (!fUtc && (sti.year > 1970))
{
m_msec *= kfttPerMsec;
m_msec /= kfttPerSec;
m_msec -= SECS_1601_TO_1970;
time_t t = m_msec;
struct tm *tm_lcl;
tm_lcl = localtime(&t);
int64 bias = tm_lcl->tm_gmtoff;
m_msec += bias;
m_msec += SECS_1601_TO_1970;
m_msec *= kfttPerSec;
m_msec /= kfttPerMsec;
}
#endif // WIN32
}
int cs_clipline(PSD psd,int *_x0, int *_y0, int *_x1, int *_y1,
int *clip_first, int *clip_last)
{
int first,last, code;
int x0,y0,x1,y1;
int x,y;
int dx,dy;
int xmajor;
int slope;
int tempclipminx,tempclipminy,tempclipmaxx,tempclipmaxy;
if (psd->doclip) {
tempclipminx = psd->clipminx;
tempclipminy = psd->clipminy;
tempclipmaxx = psd->clipmaxx;
tempclipmaxy = psd->clipmaxy;
} else {
tempclipminx = 0;
tempclipminy = 0;
tempclipmaxx = psd->xres - 1;
tempclipmaxy = psd->yres - 1;
}
first = 0;
last = 0;
outcode(first,*_x0,*_y0);
outcode(last,*_x1,*_y1);
if ((first | last) == 0) {
return CLIP_VISIBLE; /* Trivially accepted! */
}
if ((first & last) != 0) {
return CLIP_INVISIBLE; /* Trivially rejected! */
}
x0=*_x0;
y0=*_y0;
x1=*_x1;
y1=*_y1;
dx = x1 - x0;
dy = y1 - y0;
xmajor = (abs(dx) > abs(dy));
slope = ((dx>=0) && (dy>=0)) || ((dx<0) && (dy<0));
for (;;) {
code = first;
if (first==0)
code = last;
if (code&OC_LEFT) {
x = tempclipminx;
if (xmajor) {
y = *_y0 + FloorDiv(dy*(x - *_x0)*2 + dx,
2*dx);
} else {
if (slope) {
y = *_y0 + CeilDiv(dy*((x - *_x0)*2
- 1), 2*dx);
} else {
y = *_y0 + FloorDiv(dy*((x - *_x0)*2
- 1), 2*dx);
}
}
} else if (code&OC_RIGHT) {
x = tempclipmaxx;
if (xmajor) {
y = *_y0 + FloorDiv(dy*(x - *_x0)*2 + dx, 2*dx);
} else {
if (slope) {
y = *_y0 + CeilDiv(dy*((x - *_x0)*2
+ 1), 2*dx)-1;
} else {
y = *_y0 + FloorDiv(dy*((x - *_x0)*2
+ 1), 2*dx)+1;
}
}
} else if (code&OC_TOP) {
y = tempclipminy;
if (xmajor) {
if (slope) {
x = *_x0 + CeilDiv(dx*((y - *_y0)*2
- 1), 2*dy);
} else {
x = *_x0 + FloorDiv(dx*((y - *_y0)*2
- 1), 2*dy);
}
} else {
x = *_x0 + FloorDiv( dx*(y - *_y0)*2 + dy,
2*dy);
}
} else { /* OC_BOTTOM */
y = tempclipmaxy;
if (xmajor) {
if (slope) {
x = *_x0 + CeilDiv(dx*((y - *_y0)*2
+ 1), 2*dy)-1;
} else {
x = *_x0 + FloorDiv(dx*((y - *_y0)*2
+ 1), 2*dy)+1;
}
} else {
x = *_x0 + FloorDiv(dx*(y - *_y0)*2 + dy,
2*dy);
}
}
if (first!=0) {
x0 = x;
y0 = y;
outcode(first,x0,y0);
*clip_first = 1;
} else {
x1 = x;
y1 = y;
last = code;
outcode(last,x1,y1);
*clip_last = 1;
}
if ((first & last) != 0) {
return CLIP_INVISIBLE; /* Trivially rejected! */
}
if ((first | last) == 0) {
*_x0=x0;
*_y0=y0;
*_x1=x1;
*_y1=y1;
return CLIP_PARTIAL; /* Trivially accepted! */
}
}
}
static int _ggi_clip2d(ggi_visual *vis,int *_x0, int *_y0, int *_x1, int *_y1,
int *clip_first, int *clip_last)
{
int first,last, code;
int x0,y0,x1,y1;
int x,y;
int dx,dy;
unsigned int absdx, absdy;
int xmajor;
int slope;
int i;
*clip_first = first = 0;
*clip_last = last = 0;
outcode(first,*_x0,*_y0);
outcode(last,*_x1,*_y1);
if ((first | last) == 0) {
return 1; /* Trivially accepted! */
}
if ((first & last) != 0) {
return 0; /* Trivially rejected! */
}
x0=*_x0; y0=*_y0;
x1=*_x1; y1=*_y1;
dx = x1 - x0;
dy = y1 - y0;
absdx = x0 < x1 ? x1 - x0 : x0 - x1;
absdy = y0 < y1 ? y1 - y0 : y0 - y1;
xmajor = absdx > absdy;
slope = ((x1>=x0) && (y1>=y0)) || ((x1<x0) && (y1<y0));
if ((absdx > MAX_DIFF) || (absdy > MAX_DIFF)) {
return _ggi_clip2d_3(vis, _x0, _y0, _x1, _y1,
clip_first, clip_last);
}
for (i = 0; i < 4; i++) {
code = first;
if (first==0)
code = last;
if (code&OC_LEFT) {
x = LIBGGI_GC(vis)->cliptl.x;
if (xmajor) {
y = *_y0 + FloorDiv(dy*(x - *_x0)*2 + dx,
2*dx);
} else {
if (slope) {
y = *_y0 + CeilDiv(dy*((x - *_x0)*2
- 1), 2*dx);
} else {
y = *_y0 + FloorDiv(dy*((x - *_x0)*2
- 1), 2*dx);
}
}
} else if (code&OC_RIGHT) {
x = LIBGGI_GC(vis)->clipbr.x - 1;
if (xmajor) {
y = *_y0 + FloorDiv(dy*(x - *_x0)*2 + dx, 2*dx);
} else {
if (slope) {
y = *_y0 + CeilDiv(dy*((x - *_x0)*2
+ 1), 2*dx)-1;
} else {
y = *_y0 + FloorDiv(dy*((x - *_x0)*2
+ 1), 2*dx)+1;
}
}
} else if (code&OC_TOP) {
y = LIBGGI_GC(vis)->cliptl.y;
if (xmajor) {
if (slope) {
x = *_x0 + CeilDiv(dx*((y - *_y0)*2
- 1), 2*dy);
} else {
x = *_x0 + FloorDiv(dx*((y - *_y0)*2
- 1), 2*dy);
}
} else {
x = *_x0 + FloorDiv( dx*(y - *_y0)*2 + dy,
2*dy);
}
} else { /* OC_BOTTOM */
LIB_ASSERT((code & OC_BOTTOM), "unknown outcode\n");
y = LIBGGI_GC(vis)->clipbr.y - 1;
if (xmajor) {
if (slope) {
x = *_x0 + CeilDiv(dx*((y - *_y0)*2
+ 1), 2*dy)-1;
} else {
x = *_x0 + FloorDiv(dx*((y - *_y0)*2
+ 1), 2*dy)+1;
}
} else {
x = *_x0 + FloorDiv(dx*(y - *_y0)*2 + dy,
2*dy);
}
}
if (first!=0) {
x0 = x;
y0 = y;
outcode(first,x0,y0);
*clip_first = 1;
} else {
x1 = x;
y1 = y;
last = code;
outcode(last,x1,y1);
*clip_last = 1;
}
if ((first & last) != 0) {
return 0; /* Trivially rejected! */
}
if ((first | last) == 0) {
*_x0=x0; *_y0=y0;
*_x1=x1; *_y1=y1;
return 1; /* Trivially accepted! */
}
}
return 0; /* Aieee! Failed to clip, clip whole line... */
}
