From 76193d7cb0457807b2f0b95f909ab5de19480cd7 Mon Sep 17 00:00:00 2001
From: rsc <devnull@localhost>
Date: Tue, 30 Sep 2003 17:47:42 +0000
Subject: Initial revision

---
 src/libdraw/ml-line.c | 122 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 122 insertions(+)
 create mode 100644 src/libdraw/ml-line.c

(limited to 'src/libdraw/ml-line.c')

diff --git a/src/libdraw/ml-line.c b/src/libdraw/ml-line.c
new file mode 100644
index 00000000..8c09a535
--- /dev/null
+++ b/src/libdraw/ml-line.c
@@ -0,0 +1,122 @@
+#include <u.h>
+#include <libc.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);
+}
-- 
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