ref: 71dbddef166f855e28dfae1989ddbd663d38176a
parent: 193e55b88cec346a4c3f301057aef692a859b642
author: cinap_lenrek <[email protected]>
date: Sun Dec 8 22:35:01 EST 2013
draw: fix drawing of replicated source image on memlayer with a clip rectangle
when a replicated source image with a clipr with clipr.min > Pt(0, 0),
drawclip() would properly translate the src->clipr on the dstr
but then clamp the source rectangle back on src->r.
while traversing down multiple layers, this would cause the translation to
be applied multiple times to the dst rectangle giving the wrong image result.
this change adds a new drawclipnorepl() function that avoids the clamping
of source and mask rectangles to src->r and mask->r. this is then used in
libmemlayer.
the final memimagedraw() call will call drawclip() which will do the final
claming.
a testcase is provided:
#include <u.h>
#include <libc.h>
#include <draw.h>
Image *blue;
Image *red;
void
main(int, char *argv[])
{
Image *i;
if(initdraw(nil, nil, argv[0]) < 0)
sysfatal("initdraw: %r");
i = allocimage(display, screen->r, screen->chan, 1, DWhite);
red = allocimage(display, Rect(0,0,1,1), screen->chan, 1, DRed);
blue = allocimage(display, Rect(0,0,1,1), screen->chan, 1, DPaleblue);
replclipr(red, 1, Rect(10, 10, 110, 110));
replclipr(blue, 1, Rect(11, 11, 111, 111));
/* draw on non-layer, works correctly */
draw(i, i->r, red, nil, ZP);
draw(i, i->r, blue, nil, ZP);
draw(screen, screen->r, i, nil, i->r.min);
flushimage(display, 1);
/* draw on (screen) layer is too far to the right */
draw(screen, screen->r, red, nil, ZP);
draw(screen, screen->r, blue, nil, ZP);
flushimage(display, 1);
for(;;){
sleep(1000);
}
}
--- a/sys/include/memdraw.h
+++ b/sys/include/memdraw.h
@@ -127,6 +127,7 @@
extern int unloadmemimage(Memimage*, Rectangle, uchar*, int);
extern ulong* wordaddr(Memimage*, Point);
extern uchar* byteaddr(Memimage*, Point);
+extern int drawclipnorepl(Memimage*, Rectangle*, Memimage*, Point*, Memimage*, Point*, Rectangle*, Rectangle*);
extern int drawclip(Memimage*, Rectangle*, Memimage*, Point*, Memimage*, Point*, Rectangle*, Rectangle*);
extern void memfillcolor(Memimage*, ulong);
extern int memsetchan(Memimage*, ulong);
--- a/sys/man/2/memdraw
+++ b/sys/man/2/memdraw
@@ -25,6 +25,7 @@
memimageline,
memimagedraw,
drawclip,
+drawclipnorepl,
memlinebbox,
memlineendsize,
allocmemsubfont,
@@ -139,6 +140,9 @@
int drawclip(Memimage *dst, Rectangle *dr, Memimage *src,
Point *sp, Memimage *mask, Point *mp,
Rectangle *sr, Rectangle *mr)
+int drawclipnorepl(Memimage *dst, Rectangle *dr, Memimage *src,
+ Point *sp, Memimage *mask, Point *mp,
+ Rectangle *sr, Rectangle *mr)
Rectangle memlinebbox(Point p0, Point p1, int end0, int end1,
int radius)
int memlineendsize(int end)
@@ -396,8 +400,18 @@
.B sp
and
.BR mp .
+.I Drawclipnorepl
+does the same as
+.B drawclip
+but avoids clamping
+.B sp
+and
+.B mr
+within the image rectangle of source and mask when replicated.
.I Drawclip
-returns zero when the clipped rectangle is empty.
+and
+.I drawclipnorepl
+return zero when the clipped rectangle is empty.
.I Memlinebbox
returns a conservative bounding box containing a line between
two points
--- a/sys/src/libmemdraw/draw.c
+++ b/sys/src/libmemdraw/draw.c
@@ -213,17 +213,16 @@
}
#undef DBG
+
/*
* Clip the destination rectangle further based on the properties of the
* source and mask rectangles. Once the destination rectangle is properly
* clipped, adjust the source and mask rectangles to be the same size.
- * Then if source or mask is replicated, move its clipped rectangle
- * so that its minimum point falls within the repl rectangle.
*
* Return zero if the final rectangle is null.
*/
int
-drawclip(Memimage *dst, Rectangle *r, Memimage *src, Point *p0, Memimage *mask, Point *p1, Rectangle *sr, Rectangle *mr)
+drawclipnorepl(Memimage *dst, Rectangle *r, Memimage *src, Point *p0, Memimage *mask, Point *p1, Rectangle *sr, Rectangle *mr)
{Point rmin, delta;
int splitcoords;
@@ -270,15 +269,13 @@
sr->min.y += mr->min.y-omr.min.y;
sr->max.x += mr->max.x-omr.max.x;
sr->max.y += mr->max.y-omr.max.y;
- *p1 = mr->min;
}else{if(!(mask->flags&Frepl) && !rectclip(sr, mask->r))
return 0;
if(!rectclip(sr, mask->clipr))
return 0;
- *p1 = sr->min;
+ *mr = *sr;
}
-
/* move source clipping back to destination */
delta.x = r->min.x - p0->x;
delta.y = r->min.y - p0->y;
@@ -286,7 +283,31 @@
r->min.y = sr->min.y + delta.y;
r->max.x = sr->max.x + delta.x;
r->max.y = sr->max.y + delta.y;
+ *p0 = sr->min;
+ *p1 = mr->min;
+ assert(Dx(*sr) == Dx(*mr) && Dx(*mr) == Dx(*r));
+ assert(Dy(*sr) == Dy(*mr) && Dy(*mr) == Dy(*r));
+ assert(ptinrect(r->min, dst->r));
+
+ return 1;
+}
+
+/*
+ * like drawclipnorepl() above, but if source or mask is replicated,
+ * move its clipped rectangle so that its minimum point falls within
+ * the repl rectangle.
+ *
+ * Return zero if the final rectangle is null.
+ */
+int
+drawclip(Memimage *dst, Rectangle *r, Memimage *src, Point *p0, Memimage *mask, Point *p1, Rectangle *sr, Rectangle *mr)
+{+ Point delta;
+
+ if(!drawclipnorepl(dst, r, src, p0, mask, p1, sr, mr))
+ return 0;
+
/* move source rectangle so sr->min is in src->r */
if(src->flags&Frepl) {delta.x = drawreplxy(src->r.min.x, src->r.max.x, sr->min.x) - sr->min.x;
@@ -295,8 +316,8 @@
sr->min.y += delta.y;
sr->max.x += delta.x;
sr->max.y += delta.y;
+ *p0 = sr->min;
}
- *p0 = sr->min;
/* move mask point so it is in mask->r */
*p1 = drawrepl(mask->r, *p1);
@@ -304,11 +325,8 @@
mr->max.x = p1->x+Dx(*sr);
mr->max.y = p1->y+Dy(*sr);
- assert(Dx(*sr) == Dx(*mr) && Dx(*mr) == Dx(*r));
- assert(Dy(*sr) == Dy(*mr) && Dy(*mr) == Dy(*r));
assert(ptinrect(*p0, src->r));
assert(ptinrect(*p1, mask->r));
- assert(ptinrect(r->min, dst->r));
return 1;
}
--- a/sys/src/libmemlayer/draw.c
+++ b/sys/src/libmemlayer/draw.c
@@ -42,7 +42,7 @@
if(!rectinrect(r, clipr)){oclipr = dst->clipr;
dst->clipr = clipr;
- ok = drawclip(dst, &r, d->src, &p0, d->mask, &p1, &srcr, &mr);
+ ok = drawclipnorepl(dst, &r, d->src, &p0, d->mask, &p1, &srcr, &mr);
dst->clipr = oclipr;
if(!ok)
return;
@@ -74,7 +74,7 @@
return;
}
- if(drawclip(dst, &r, src, &p0, mask, &p1, &srcr, &mr) == 0){+ if(drawclipnorepl(dst, &r, src, &p0, mask, &p1, &srcr, &mr) == 0){ if(drawdebug) iprint("drawclip dstcr %R srccr %R maskcr %R\n", dst->clipr, src->clipr, mask->clipr);return;
}