jehanne/sys/src/lib/memlayer/line.c

132 lines
2.9 KiB
C

/*
* This file is part of the UCB release of Plan 9. It is subject to the license
* terms in the LICENSE file found in the top-level directory of this
* distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No
* part of the UCB release of Plan 9, including this file, may be copied,
* modified, propagated, or distributed except according to the terms contained
* in the LICENSE file.
*/
#include <u.h>
#include <lib9.h>
#include <draw.h>
#include <memdraw.h>
#include <memlayer.h>
struct Lline
{
Point p0;
Point p1;
Point delta;
int end0;
int end1;
int radius;
Point sp;
Memlayer *dstlayer;
Memimage *src;
int op;
};
static void llineop(Memimage*, Rectangle, Rectangle, void*, int);
static
void
_memline(Memimage *dst, Point p0, Point p1, int end0, int end1, int radius, Memimage *src, Point sp, Rectangle clipr, int op)
{
Rectangle r;
struct Lline ll;
Point d;
int srcclipped;
Memlayer *dl;
if(radius < 0)
return;
if(src->layer) /* can't draw line with layered source */
return;
srcclipped = 0;
Top:
dl = dst->layer;
if(dl == nil){
_memimageline(dst, p0, p1, end0, end1, radius, src, sp, clipr, op);
return;
}
if(!srcclipped){
d = subpt(sp, p0);
if(rectclip(&clipr, rectsubpt(src->clipr, d)) == 0)
return;
if((src->flags&Frepl)==0 && rectclip(&clipr, rectsubpt(src->r, d))==0)
return;
srcclipped = 1;
}
/* dst is known to be a layer */
p0.x += dl->delta.x;
p0.y += dl->delta.y;
p1.x += dl->delta.x;
p1.y += dl->delta.y;
clipr.min.x += dl->delta.x;
clipr.min.y += dl->delta.y;
clipr.max.x += dl->delta.x;
clipr.max.y += dl->delta.y;
if(dl->clear){
dst = dst->layer->screen->image;
goto Top;
}
/* XXX */
/* this is not the correct set of tests */
// if(log2[dst->depth] != log2[src->depth] || log2[dst->depth]!=3)
// return;
/* can't use sutherland-cohen clipping because lines are wide */
r = memlinebbox(p0, p1, end0, end1, radius);
/*
* r is now a bounding box for the line;
* use it as a clipping rectangle for subdivision
*/
if(rectclip(&r, clipr) == 0)
return;
ll.p0 = p0;
ll.p1 = p1;
ll.end0 = end0;
ll.end1 = end1;
ll.sp = sp;
ll.dstlayer = dst->layer;
ll.src = src;
ll.radius = radius;
ll.delta = dl->delta;
ll.op = op;
_memlayerop(llineop, dst, r, r, &ll);
}
static
void
llineop(Memimage *dst, Rectangle screenr, Rectangle clipr, void *etc, int insave)
{
struct Lline *ll;
Point p0, p1;
USED(screenr.min.x);
ll = etc;
if(insave && ll->dstlayer->save==nil)
return;
if(!rectclip(&clipr, screenr))
return;
if(insave){
p0 = subpt(ll->p0, ll->delta);
p1 = subpt(ll->p1, ll->delta);
clipr = rectsubpt(clipr, ll->delta);
}else{
p0 = ll->p0;
p1 = ll->p1;
}
_memline(dst, p0, p1, ll->end0, ll->end1, ll->radius, ll->src, ll->sp, clipr, ll->op);
}
void
memline(Memimage *dst, Point p0, Point p1, int end0, int end1, int radius, Memimage *src, Point sp, int op)
{
_memline(dst, p0, p1, end0, end1, radius, src, sp, dst->clipr, op);
}