From e5888a1ffdae813d7575f5fb02275c6bb07e5199 Mon Sep 17 00:00:00 2001
From: Taru Karttunen <taruti@taruti.net>
Date: Wed, 30 Mar 2011 15:46:40 +0300
Subject: Import sources from 2011-03-30 iso image

---
 sys/src/libmemdraw/drawtest.c | 1004 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 1004 insertions(+)
 create mode 100755 sys/src/libmemdraw/drawtest.c

(limited to 'sys/src/libmemdraw/drawtest.c')

diff --git a/sys/src/libmemdraw/drawtest.c b/sys/src/libmemdraw/drawtest.c
new file mode 100755
index 000000000..df9dd0123
--- /dev/null
+++ b/sys/src/libmemdraw/drawtest.c
@@ -0,0 +1,1004 @@
+#include <u.h>
+#include <libc.h>
+#include <bio.h>
+#include <draw.h>
+#include <memdraw.h>
+
+#define DBG if(0)
+#define RGB2K(r,g,b)	((299*((ulong)(r))+587*((ulong)(g))+114*((ulong)(b)))/1000)
+
+/*
+ * This program tests the 'memimagedraw' primitive stochastically.
+ * It tests the combination aspects of it thoroughly, but since the
+ * three images it uses are disjoint, it makes no check of the
+ * correct behavior when images overlap.  That is, however, much
+ * easier to get right and to test.
+ */
+
+void	drawonepixel(Memimage*, Point, Memimage*, Point, Memimage*, Point);
+void	verifyone(void);
+void	verifyline(void);
+void	verifyrect(void);
+void	verifyrectrepl(int, int);
+void putpixel(Memimage *img, Point pt, ulong nv);
+ulong rgbatopix(uchar, uchar, uchar, uchar);
+
+char *dchan, *schan, *mchan;
+int dbpp, sbpp, mbpp;
+
+int drawdebug=0;
+int	seed;
+int	niters = 100;
+int	dbpp;	/* bits per pixel in destination */
+int	sbpp;	/* bits per pixel in src */
+int	mbpp;	/* bits per pixel in mask */
+int	dpm;	/* pixel mask at high part of byte, in destination */
+int	nbytes;	/* in destination */
+
+int	Xrange	= 64;
+int	Yrange	= 8;
+
+Memimage	*dst;
+Memimage	*src;
+Memimage	*mask;
+Memimage	*stmp;
+Memimage	*mtmp;
+Memimage	*ones;
+uchar	*dstbits;
+uchar	*srcbits;
+uchar	*maskbits;
+ulong	*savedstbits;
+
+void
+rdb(void)
+{
+}
+
+int
+iprint(char *fmt, ...)
+{
+	int n;	
+	va_list va;
+	char buf[1024];
+
+	va_start(va, fmt);
+	n = vseprint(buf, buf+sizeof buf, fmt, va) - buf;
+	va_end(va);
+
+	write(1,buf,n);
+	return 1;
+}
+
+void
+main(int argc, char *argv[])
+{
+	memimageinit();
+	seed = time(0);
+
+	ARGBEGIN{
+	case 'x':
+		Xrange = atoi(ARGF());
+		break;
+	case 'y':
+		Yrange = atoi(ARGF());
+		break;
+	case 'n':
+		niters = atoi(ARGF());
+		break;
+	case 's':
+		seed = atoi(ARGF());
+		break;
+	}ARGEND
+
+	dchan = "r8g8b8";
+	schan = "r8g8b8";
+	mchan = "r8g8b8";
+	switch(argc){
+	case 3:	mchan = argv[2];
+	case 2:	schan = argv[1];
+	case 1:	dchan = argv[0];
+	case 0:	break;
+	default:	goto Usage;
+	Usage:
+		fprint(2, "usage: dtest [dchan [schan [mchan]]]\n");
+		exits("usage");
+	}
+
+//	fmtinstall('b', numbconv);	/* binary! */
+
+	fprint(2, "%s -x %d -y %d -s 0x%x %s %s %s\n", argv0, Xrange, Yrange, seed, dchan, schan, mchan);
+	srand(seed);
+
+	dst = allocmemimage(Rect(0, 0, Xrange, Yrange), strtochan(dchan));
+	src = allocmemimage(Rect(0, 0, Xrange, Yrange), strtochan(schan));
+	mask = allocmemimage(Rect(0, 0, Xrange, Yrange), strtochan(mchan));
+	stmp = allocmemimage(Rect(0, 0, Xrange, Yrange), strtochan(schan));
+	mtmp = allocmemimage(Rect(0, 0, Xrange, Yrange), strtochan(mchan));
+	ones = allocmemimage(Rect(0, 0, Xrange, Yrange), strtochan(mchan));
+//	print("chan %lux %lux %lux %lux %lux %lux\n", dst->chan, src->chan, mask->chan, stmp->chan, mtmp->chan, ones->chan);
+	if(dst==0 || src==0 || mask==0 || mtmp==0 || ones==0) {
+	Alloc:
+		fprint(2, "dtest: allocation failed: %r\n");
+		exits("alloc");
+	}
+	nbytes = (4*Xrange+4)*Yrange;
+	srcbits = malloc(nbytes);
+	dstbits = malloc(nbytes);
+	maskbits = malloc(nbytes);
+	savedstbits = malloc(nbytes);
+	if(dstbits==0 || srcbits==0 || maskbits==0 || savedstbits==0)
+		goto Alloc;
+	dbpp = dst->depth;
+	sbpp = src->depth;
+	mbpp = mask->depth;
+	dpm = 0xFF ^ (0xFF>>dbpp);
+	memset(ones->data->bdata, 0xFF, ones->width*sizeof(ulong)*Yrange);
+
+
+	fprint(2, "dtest: verify single pixel operation\n");
+	verifyone();
+
+	fprint(2, "dtest: verify full line non-replicated\n");
+	verifyline();
+
+	fprint(2, "dtest: verify full rectangle non-replicated\n");
+	verifyrect();
+
+	fprint(2, "dtest: verify full rectangle source replicated\n");
+	verifyrectrepl(1, 0);
+
+	fprint(2, "dtest: verify full rectangle mask replicated\n");
+	verifyrectrepl(0, 1);
+
+	fprint(2, "dtest: verify full rectangle source and mask replicated\n");
+	verifyrectrepl(1, 1);
+
+	exits(0);
+}
+
+/*
+ * Dump out an ASCII representation of an image.  The label specifies
+ * a list of characters to put at various points in the picture.
+ */
+static void
+Bprintr5g6b5(Biobuf *bio, char*, ulong v)
+{
+	int r,g,b;
+	r = (v>>11)&31;
+	g = (v>>5)&63;
+	b = v&31;
+	Bprint(bio, "%.2x%.2x%.2x", r,g,b);
+}
+
+static void
+Bprintr5g5b5a1(Biobuf *bio, char*, ulong v)
+{
+	int r,g,b,a;
+	r = (v>>11)&31;
+	g = (v>>6)&31;
+	b = (v>>1)&31;
+	a = v&1;
+	Bprint(bio, "%.2x%.2x%.2x%.2x", r,g,b,a);
+}
+
+void
+dumpimage(char *name, Memimage *img, void *vdata, Point labelpt)
+{
+	Biobuf b;
+	uchar *data;
+	uchar *p;
+	char *arg;
+	void (*fmt)(Biobuf*, char*, ulong);
+	int npr, x, y, nb, bpp;
+	ulong v, mask;
+	Rectangle r;
+
+	fmt = nil;
+	arg = nil;
+	switch(img->depth){
+	case 1:
+	case 2:
+	case 4:
+		fmt = (void(*)(Biobuf*,char*,ulong))Bprint;
+		arg = "%.1ux";
+		break;
+	case 8:
+		fmt = (void(*)(Biobuf*,char*,ulong))Bprint;
+		arg = "%.2ux";
+		break;
+	case 16:
+		arg = nil;
+		if(img->chan == RGB16)
+			fmt = Bprintr5g6b5;
+		else{
+			fmt = (void(*)(Biobuf*,char*,ulong))Bprint;
+			arg = "%.4ux";
+		}
+		break;
+	case 24:
+		fmt = (void(*)(Biobuf*,char*,ulong))Bprint;
+		arg = "%.6lux";
+		break;
+	case 32:
+		fmt = (void(*)(Biobuf*,char*,ulong))Bprint;
+		arg = "%.8lux";
+		break;
+	}
+	if(fmt == nil){
+		fprint(2, "bad format\n");
+		abort();
+	}
+
+	r  = img->r;
+	Binit(&b, 2, OWRITE);
+	data = vdata;
+	bpp = img->depth;
+	Bprint(&b, "%s\t%d\tr %R clipr %R repl %d data %p *%P\n", name, r.min.x, r, img->clipr, (img->flags&Frepl) ? 1 : 0, vdata, labelpt);
+	mask = (1ULL<<bpp)-1;
+//	for(y=r.min.y; y<r.max.y; y++){
+	for(y=0; y<Yrange; y++){
+		nb = 0;
+		v = 0;
+		p = data+(byteaddr(img, Pt(0,y))-(uchar*)img->data->bdata);
+		Bprint(&b, "%-4d\t", y);
+//		for(x=r.min.x; x<r.max.x; x++){
+		for(x=0; x<Xrange; x++){
+			if(x==0)
+				Bprint(&b, "\t");
+
+			if(x != 0 && (x%8)==0)
+				Bprint(&b, " ");
+
+			npr = 0;
+			if(x==labelpt.x && y==labelpt.y){
+				Bprint(&b, "*");
+				npr++;
+			}
+			if(npr == 0)
+				Bprint(&b, " ");
+
+			while(nb < bpp){
+				v &= (1<<nb)-1;
+				v |= (ulong)(*p++) << nb;
+				nb += 8;
+			}
+			nb -= bpp;
+//			print("bpp %d v %.8lux mask %.8lux nb %d\n", bpp, v, mask, nb);
+			fmt(&b, arg, (v>>nb)&mask);
+		}
+		Bprint(&b, "\n");
+	}
+	Bterm(&b);
+}
+
+/*
+ * Verify that the destination pixel has the specified value.
+ * The value is in the high bits of v, suitably masked, but must
+ * be extracted from the destination Memimage.
+ */
+void
+checkone(Point p, Point sp, Point mp)
+{
+	int delta;
+	uchar *dp, *sdp;
+
+	delta = (uchar*)byteaddr(dst, p)-(uchar*)dst->data->bdata;
+	dp = (uchar*)dst->data->bdata+delta;
+	sdp = (uchar*)savedstbits+delta;
+
+	if(memcmp(dp, sdp, (dst->depth+7)/8) != 0) {
+		fprint(2, "dtest: one bad pixel drawing at dst %P from source %P mask %P\n", p, sp, mp);
+		fprint(2, " %.2ux %.2ux %.2ux %.2ux should be %.2ux %.2ux %.2ux %.2ux\n",
+			dp[0], dp[1], dp[2], dp[3], sdp[0], sdp[1], sdp[2], sdp[3]);
+		fprint(2, "addresses dst %p src %p mask %p\n", dp, byteaddr(src, sp), byteaddr(mask, mp));
+		dumpimage("src", src, src->data->bdata, sp);
+		dumpimage("mask", mask, mask->data->bdata, mp);
+		dumpimage("origdst", dst, dstbits, p);
+		dumpimage("dst", dst, dst->data->bdata, p);
+		dumpimage("gooddst", dst, savedstbits, p);
+		abort();
+	}
+}
+
+/*
+ * Verify that the destination line has the same value as the saved line.
+ */
+#define RECTPTS(r) (r).min.x, (r).min.y, (r).max.x, (r).max.y
+void
+checkline(Rectangle r, Point sp, Point mp, int y, Memimage *stmp, Memimage *mtmp)
+{
+	ulong *dp;
+	int nb;
+	ulong *saved;
+
+	dp = wordaddr(dst, Pt(0, y));
+	saved = savedstbits + y*dst->width;
+	if(dst->depth < 8)
+		nb = Xrange/(8/dst->depth);
+	else
+		nb = Xrange*(dst->depth/8);
+	if(memcmp(dp, saved, nb) != 0){
+		fprint(2, "dtest: bad line at y=%d; saved %p dp %p\n", y, saved, dp);
+		fprint(2, "draw dst %R src %P mask %P\n", r, sp, mp);
+		dumpimage("src", src, src->data->bdata, sp);
+		if(stmp) dumpimage("stmp", stmp, stmp->data->bdata, sp);
+		dumpimage("mask", mask, mask->data->bdata, mp);
+		if(mtmp) dumpimage("mtmp", mtmp, mtmp->data->bdata, mp);
+		dumpimage("origdst", dst, dstbits, r.min);
+		dumpimage("dst", dst, dst->data->bdata, r.min);
+		dumpimage("gooddst", dst, savedstbits, r.min);
+		abort();
+	}
+}
+
+/*
+ * Fill the bits of an image with random data.
+ * The Memimage parameter is used only to make sure
+ * the data is well formatted: only ucbits is written.
+ */
+void
+fill(Memimage *img, uchar *ucbits)
+{
+	int i, x, y;
+	ushort *up;
+	uchar alpha, r, g, b;
+	void *data;
+
+	if((img->flags&Falpha) == 0){
+		up = (ushort*)ucbits;
+		for(i=0; i<nbytes/2; i++)
+			*up++ = lrand() >> 7;
+		if(i+i != nbytes)
+			*(uchar*)up = lrand() >> 7;
+	}else{
+		data = img->data->bdata;
+		img->data->bdata = ucbits;
+
+		for(x=img->r.min.x; x<img->r.max.x; x++)
+		for(y=img->r.min.y; y<img->r.max.y; y++){
+			alpha = rand() >> 4;
+			r = rand()%(alpha+1);
+			g = rand()%(alpha+1);
+			b = rand()%(alpha+1);
+			putpixel(img, Pt(x,y), rgbatopix(r,g,b,alpha));
+		}
+		img->data->bdata = data;
+	}
+		
+}
+
+/*
+ * Mask is preset; do the rest
+ */
+void
+verifyonemask(void)
+{
+	Point dp, sp, mp;
+
+	fill(dst, dstbits);
+	fill(src, srcbits);
+	memmove(dst->data->bdata, dstbits, dst->width*sizeof(ulong)*Yrange);
+	memmove(src->data->bdata, srcbits, src->width*sizeof(ulong)*Yrange);
+	memmove(mask->data->bdata, maskbits, mask->width*sizeof(ulong)*Yrange);
+
+	dp.x = nrand(Xrange);
+	dp.y = nrand(Yrange);
+
+	sp.x = nrand(Xrange);
+	sp.y = nrand(Yrange);
+
+	mp.x = nrand(Xrange);
+	mp.y = nrand(Yrange);
+
+	drawonepixel(dst, dp, src, sp, mask, mp);
+	memmove(mask->data->bdata, maskbits, mask->width*sizeof(ulong)*Yrange);
+	memmove(savedstbits, dst->data->bdata, dst->width*sizeof(ulong)*Yrange);
+	
+	memmove(dst->data->bdata, dstbits, dst->width*sizeof(ulong)*Yrange);
+	memimagedraw(dst, Rect(dp.x, dp.y, dp.x+1, dp.y+1), src, sp, mask, mp, SoverD);
+	memmove(mask->data->bdata, maskbits, mask->width*sizeof(ulong)*Yrange);
+
+	checkone(dp, sp, mp);
+}
+
+void
+verifyone(void)
+{
+	int i;
+
+	/* mask all zeros */
+	memset(maskbits, 0, nbytes);
+	for(i=0; i<niters; i++)
+		verifyonemask();
+
+	/* mask all ones */
+	memset(maskbits, 0xFF, nbytes);
+	for(i=0; i<niters; i++)
+		verifyonemask();
+
+	/* random mask */
+	for(i=0; i<niters; i++){
+		fill(mask, maskbits);
+		verifyonemask();
+	}
+}
+
+/*
+ * Mask is preset; do the rest
+ */
+void
+verifylinemask(void)
+{
+	Point sp, mp, tp, up;
+	Rectangle dr;
+	int x;
+
+	fill(dst, dstbits);
+	fill(src, srcbits);
+	memmove(dst->data->bdata, dstbits, dst->width*sizeof(ulong)*Yrange);
+	memmove(src->data->bdata, srcbits, src->width*sizeof(ulong)*Yrange);
+	memmove(mask->data->bdata, maskbits, mask->width*sizeof(ulong)*Yrange);
+
+	dr.min.x = nrand(Xrange-1);
+	dr.min.y = nrand(Yrange-1);
+	dr.max.x = dr.min.x + 1 + nrand(Xrange-1-dr.min.x);
+	dr.max.y = dr.min.y + 1;
+
+	sp.x = nrand(Xrange);
+	sp.y = nrand(Yrange);
+
+	mp.x = nrand(Xrange);
+	mp.y = nrand(Yrange);
+
+	tp = sp;
+	up = mp;
+	for(x=dr.min.x; x<dr.max.x && tp.x<Xrange && up.x<Xrange; x++,tp.x++,up.x++)
+		memimagedraw(dst, Rect(x, dr.min.y, x+1, dr.min.y+1), src, tp, mask, up, SoverD);
+	memmove(savedstbits, dst->data->bdata, dst->width*sizeof(ulong)*Yrange);
+
+	memmove(dst->data->bdata, dstbits, dst->width*sizeof(ulong)*Yrange);
+
+	memimagedraw(dst, dr, src, sp, mask, mp, SoverD);
+	checkline(dr, drawrepl(src->r, sp), drawrepl(mask->r, mp), dr.min.y, nil, nil);
+}
+
+void
+verifyline(void)
+{
+	int i;
+
+	/* mask all ones */
+	memset(maskbits, 0xFF, nbytes);
+	for(i=0; i<niters; i++)
+		verifylinemask();
+
+	/* mask all zeros */
+	memset(maskbits, 0, nbytes);
+	for(i=0; i<niters; i++)
+		verifylinemask();
+
+	/* random mask */
+	for(i=0; i<niters; i++){
+		fill(mask, maskbits);
+		verifylinemask();
+	}
+}
+
+/*
+ * Mask is preset; do the rest
+ */
+void
+verifyrectmask(void)
+{
+	Point sp, mp, tp, up;
+	Rectangle dr;
+	int x, y;
+
+	fill(dst, dstbits);
+	fill(src, srcbits);
+	memmove(dst->data->bdata, dstbits, dst->width*sizeof(ulong)*Yrange);
+	memmove(src->data->bdata, srcbits, src->width*sizeof(ulong)*Yrange);
+	memmove(mask->data->bdata, maskbits, mask->width*sizeof(ulong)*Yrange);
+
+	dr.min.x = nrand(Xrange-1);
+	dr.min.y = nrand(Yrange-1);
+	dr.max.x = dr.min.x + 1 + nrand(Xrange-1-dr.min.x);
+	dr.max.y = dr.min.y + 1 + nrand(Yrange-1-dr.min.y);
+
+	sp.x = nrand(Xrange);
+	sp.y = nrand(Yrange);
+
+	mp.x = nrand(Xrange);
+	mp.y = nrand(Yrange);
+
+	tp = sp;
+	up = mp;
+	for(y=dr.min.y; y<dr.max.y && tp.y<Yrange && up.y<Yrange; y++,tp.y++,up.y++){
+		for(x=dr.min.x; x<dr.max.x && tp.x<Xrange && up.x<Xrange; x++,tp.x++,up.x++)
+			memimagedraw(dst, Rect(x, y, x+1, y+1), src, tp, mask, up, SoverD);
+		tp.x = sp.x;
+		up.x = mp.x;
+	}
+	memmove(savedstbits, dst->data->bdata, dst->width*sizeof(ulong)*Yrange);
+
+	memmove(dst->data->bdata, dstbits, dst->width*sizeof(ulong)*Yrange);
+
+	memimagedraw(dst, dr, src, sp, mask, mp, SoverD);
+	for(y=0; y<Yrange; y++)
+		checkline(dr, drawrepl(src->r, sp), drawrepl(mask->r, mp), y, nil, nil);
+}
+
+void
+verifyrect(void)
+{
+	int i;
+
+	/* mask all zeros */
+	memset(maskbits, 0, nbytes);
+	for(i=0; i<niters; i++)
+		verifyrectmask();
+
+	/* mask all ones */
+	memset(maskbits, 0xFF, nbytes);
+	for(i=0; i<niters; i++)
+		verifyrectmask();
+
+	/* random mask */
+	for(i=0; i<niters; i++){
+		fill(mask, maskbits);
+		verifyrectmask();
+	}
+}
+
+Rectangle
+randrect(void)
+{
+	Rectangle r;
+
+	r.min.x = nrand(Xrange-1);
+	r.min.y = nrand(Yrange-1);
+	r.max.x = r.min.x + 1 + nrand(Xrange-1-r.min.x);
+	r.max.y = r.min.y + 1 + nrand(Yrange-1-r.min.y);
+	return r;
+}
+
+/*
+ * Return coordinate corresponding to x withing range [minx, maxx)
+ */
+int
+tilexy(int minx, int maxx, int x)
+{
+	int sx;
+
+	sx = (x-minx) % (maxx-minx);
+	if(sx < 0)
+		sx += maxx-minx;
+	return sx+minx;
+}
+
+void
+replicate(Memimage *i, Memimage *tmp)
+{
+	Rectangle r, r1;
+	int x, y, nb;
+
+	/* choose the replication window (i->r) */
+	r.min.x = nrand(Xrange-1);
+	r.min.y = nrand(Yrange-1);
+	/* make it trivial more often than pure chance allows */
+	switch(lrand()&0){
+	case 1:
+		r.max.x = r.min.x + 2;
+		r.max.y = r.min.y + 2;
+		if(r.max.x < Xrange && r.max.y < Yrange)
+			break;
+		/* fall through */
+	case 0:
+		r.max.x = r.min.x + 1;
+		r.max.y = r.min.y + 1;
+		break;
+	default:
+		if(r.min.x+3 >= Xrange)
+			r.max.x = Xrange;
+		else
+			r.max.x = r.min.x+3 + nrand(Xrange-(r.min.x+3));
+
+		if(r.min.y+3 >= Yrange)
+			r.max.y = Yrange;
+		else
+			r.max.y = r.min.y+3 + nrand(Yrange-(r.min.y+3));
+	}
+	assert(r.min.x >= 0);	
+	assert(r.max.x <= Xrange);
+	assert(r.min.y >= 0);
+	assert(r.max.y <= Yrange);
+	/* copy from i to tmp so we have just the replicated bits */
+	nb = tmp->width*sizeof(ulong)*Yrange;
+	memset(tmp->data->bdata, 0, nb);
+	memimagedraw(tmp, r, i, r.min, ones, r.min, SoverD);
+	memmove(i->data->bdata, tmp->data->bdata, nb);
+	/* i is now a non-replicated instance of the replication */
+	/* replicate it by hand through tmp */
+	memset(tmp->data->bdata, 0, nb);
+	x = -(tilexy(r.min.x, r.max.x, 0)-r.min.x);
+	for(; x<Xrange; x+=Dx(r)){
+		y = -(tilexy(r.min.y, r.max.y, 0)-r.min.y);
+		for(; y<Yrange; y+=Dy(r)){
+			/* set r1 to instance of tile by translation */
+			r1.min.x = x;
+			r1.min.y = y;
+			r1.max.x = r1.min.x+Dx(r);
+			r1.max.y = r1.min.y+Dy(r);
+			memimagedraw(tmp, r1, i, r.min, ones, r.min, SoverD);
+		}
+	}
+	i->flags |= Frepl;
+	i->r = r;
+	i->clipr = randrect();
+//	fprint(2, "replicate [[%d %d] [%d %d]] [[%d %d][%d %d]]\n", r.min.x, r.min.y, r.max.x, r.max.y,
+//		i->clipr.min.x, i->clipr.min.y, i->clipr.max.x, i->clipr.max.y);
+	tmp->clipr = i->clipr;
+}
+
+/*
+ * Mask is preset; do the rest
+ */
+void
+verifyrectmaskrepl(int srcrepl, int maskrepl)
+{
+	Point sp, mp, tp, up;
+	Rectangle dr;
+	int x, y;
+	Memimage *s, *m;
+
+//	print("verfrect %d %d\n", srcrepl, maskrepl);
+	src->flags &= ~Frepl;
+	src->r = Rect(0, 0, Xrange, Yrange);
+	src->clipr = src->r;
+	stmp->flags &= ~Frepl;
+	stmp->r = Rect(0, 0, Xrange, Yrange);
+	stmp->clipr = src->r;
+	mask->flags &= ~Frepl;
+	mask->r = Rect(0, 0, Xrange, Yrange);
+	mask->clipr = mask->r;
+	mtmp->flags &= ~Frepl;
+	mtmp->r = Rect(0, 0, Xrange, Yrange);
+	mtmp->clipr = mask->r;
+
+	fill(dst, dstbits);
+	fill(src, srcbits);
+
+	memmove(dst->data->bdata, dstbits, dst->width*sizeof(ulong)*Yrange);
+	memmove(src->data->bdata, srcbits, src->width*sizeof(ulong)*Yrange);
+	memmove(mask->data->bdata, maskbits, mask->width*sizeof(ulong)*Yrange);
+
+	if(srcrepl){
+		replicate(src, stmp);
+		s = stmp;
+	}else
+		s = src;
+	if(maskrepl){
+		replicate(mask, mtmp);
+		m = mtmp;
+	}else
+		m = mask;
+
+	dr = randrect();
+
+	sp.x = nrand(Xrange);
+	sp.y = nrand(Yrange);
+
+	mp.x = nrand(Xrange);
+	mp.y = nrand(Yrange);
+
+DBG	print("smalldraws\n");
+	for(tp.y=sp.y,up.y=mp.y,y=dr.min.y; y<dr.max.y && tp.y<Yrange && up.y<Yrange; y++,tp.y++,up.y++)
+		for(tp.x=sp.x,up.x=mp.x,x=dr.min.x; x<dr.max.x && tp.x<Xrange && up.x<Xrange; x++,tp.x++,up.x++)
+			memimagedraw(dst, Rect(x, y, x+1, y+1), s, tp, m, up, SoverD);
+	memmove(savedstbits, dst->data->bdata, dst->width*sizeof(ulong)*Yrange);
+
+	memmove(dst->data->bdata, dstbits, dst->width*sizeof(ulong)*Yrange);
+
+DBG	print("bigdraw\n");
+	memimagedraw(dst, dr, src, sp, mask, mp, SoverD);
+	for(y=0; y<Yrange; y++)
+		checkline(dr, drawrepl(src->r, sp), drawrepl(mask->r, mp), y, srcrepl?stmp:nil, maskrepl?mtmp:nil);
+}
+
+void
+verifyrectrepl(int srcrepl, int maskrepl)
+{
+	int i;
+
+	/* mask all ones */
+	memset(maskbits, 0xFF, nbytes);
+	for(i=0; i<niters; i++)
+		verifyrectmaskrepl(srcrepl, maskrepl);
+
+	/* mask all zeros */
+	memset(maskbits, 0, nbytes);
+	for(i=0; i<niters; i++)
+		verifyrectmaskrepl(srcrepl, maskrepl);
+
+	/* random mask */
+	for(i=0; i<niters; i++){
+		fill(mask, maskbits);
+		verifyrectmaskrepl(srcrepl, maskrepl);
+	}
+}
+
+/*
+ * Trivial draw implementation.
+ * Color values are passed around as ulongs containing ααRRGGBB
+ */
+
+/*
+ * Convert v, which is nhave bits wide, into its nwant bits wide equivalent.
+ * Replicates to widen the value, truncates to narrow it.
+ */
+ulong
+replbits(ulong v, int nhave, int nwant)
+{
+	v &= (1<<nhave)-1;
+	for(; nhave<nwant; nhave*=2)
+		v |= v<<nhave;
+	v >>= (nhave-nwant);
+	return v & ((1<<nwant)-1);
+}
+
+/*
+ * Decode a pixel into the uchar* values.
+ */
+void
+pixtorgba(ulong v, uchar *r, uchar *g, uchar *b, uchar *a)
+{
+	*a = v>>24;
+	*r = v>>16;
+	*g = v>>8;
+	*b = v;
+}
+
+/*
+ * Convert uchar channels into ulong pixel.
+ */
+ulong
+rgbatopix(uchar r, uchar g, uchar b, uchar a)
+{
+	return (a<<24)|(r<<16)|(g<<8)|b;
+}
+
+/*
+ * Retrieve the pixel value at pt in the image.
+ */
+ulong
+getpixel(Memimage *img, Point pt)
+{
+	uchar r, g, b, a, *p;
+	int nbits, npack, bpp;
+	ulong v, c, rbits, bits;
+
+	r = g = b = 0;
+	a = ~0;	/* default alpha is full */
+
+	p = byteaddr(img, pt);
+	v = p[0]|(p[1]<<8)|(p[2]<<16)|(p[3]<<24);
+	bpp = img->depth;
+	if(bpp<8){
+		/*
+		 * Sub-byte greyscale pixels.
+		 *
+		 * We want to throw away the top pt.x%npack pixels and then use the next bpp bits
+		 * in the bottom byte of v.  This madness is due to having big endian bits
+		 * but little endian bytes.
+		 */
+		npack = 8/bpp;
+		v >>= 8 - bpp*(pt.x%npack+1);
+		v &= (1<<bpp)-1;
+		r = g = b = replbits(v, bpp, 8);
+	}else{
+		/*
+		 * General case.  We need to parse the channel descriptor and do what it says.
+		 * In all channels but the color map, we replicate to 8 bits because that's the
+		 * precision that all calculations are done at.
+		 *
+		 * In the case of the color map, we leave the bits alone, in case a color map
+		 * with less than 8 bits of index is used.  This is currently disallowed, so it's
+		 * sort of silly.
+		 */
+
+		for(c=img->chan; c; c>>=8){
+			nbits = NBITS(c);
+			bits = v & ((1<<nbits)-1);
+			rbits = replbits(bits, nbits, 8);
+			v >>= nbits;
+			switch(TYPE(c)){
+			case CRed:
+				r = rbits;
+				break;
+			case CGreen:
+				g = rbits;
+				break;
+			case CBlue:
+				b = rbits;
+				break;
+			case CGrey:
+				r = g = b = rbits;
+				break;
+			case CAlpha:
+				a = rbits;
+				break;
+			case CMap:
+				p = img->cmap->cmap2rgb + 3*bits;
+				r = p[0];
+				g = p[1];
+				b = p[2];
+				break;
+			case CIgnore:
+				break;
+			default:
+				fprint(2, "unknown channel type %lud\n", TYPE(c));
+				abort();
+			}
+		}
+	}
+	return rgbatopix(r, g, b, a);
+}
+
+/*
+ * Return the greyscale equivalent of a pixel.
+ */
+uchar
+getgrey(Memimage *img, Point pt)
+{
+	uchar r, g, b, a;
+	pixtorgba(getpixel(img, pt), &r, &g, &b, &a);
+	return RGB2K(r, g, b);
+}
+
+/*
+ * Return the value at pt in image, if image is interpreted
+ * as a mask.  This means the alpha channel if present, else
+ * the greyscale or its computed equivalent.
+ */
+uchar
+getmask(Memimage *img, Point pt)
+{
+	if(img->flags&Falpha)
+		return getpixel(img, pt)>>24;
+	else
+		return getgrey(img, pt);
+}
+#undef DBG
+
+#define DBG if(0)
+/*
+ * Write a pixel to img at point pt.
+ * 
+ * We do this by reading a 32-bit little endian
+ * value from p and then writing it back
+ * after tweaking the appropriate bits.  Because
+ * the data is little endian, we don't have to worry
+ * about what the actual depth is, as long as it is
+ * less than 32 bits.
+ */
+void
+putpixel(Memimage *img, Point pt, ulong nv)
+{
+	uchar r, g, b, a, *p, *q;
+	ulong c, mask, bits, v;
+	int bpp, sh, npack, nbits;
+
+	pixtorgba(nv, &r, &g, &b, &a);
+
+	p = byteaddr(img, pt);
+	v = p[0]|(p[1]<<8)|(p[2]<<16)|(p[3]<<24);
+	bpp = img->depth;
+DBG print("v %.8lux...", v);
+	if(bpp < 8){
+		/*
+		 * Sub-byte greyscale pixels.  We need to skip the leftmost pt.x%npack pixels,
+		 * which is equivalent to skipping the rightmost npack - pt.x%npack - 1 pixels.
+		 */	
+		npack = 8/bpp;
+		sh = bpp*(npack - pt.x%npack - 1);
+		bits = RGB2K(r,g,b);
+DBG print("repl %lux 8 %d = %lux...", bits, bpp, replbits(bits, 8, bpp));
+		bits = replbits(bits, 8, bpp);
+		mask = (1<<bpp)-1;
+DBG print("bits %lux mask %lux sh %d...", bits, mask, sh);
+		mask <<= sh;
+		bits <<= sh;
+DBG print("(%lux & %lux) | (%lux & %lux)", v, ~mask, bits, mask);
+		v = (v & ~mask) | (bits & mask);
+	} else {
+		/*
+		 * General case.  We need to parse the channel descriptor again.
+		 */
+		sh = 0;
+		for(c=img->chan; c; c>>=8){
+			nbits = NBITS(c);
+			switch(TYPE(c)){
+			case CRed:
+				bits = r;
+				break;
+			case CGreen:
+				bits = g;
+				break;
+			case CBlue:
+				bits = b;
+				break;
+			case CGrey:
+				bits = RGB2K(r, g, b);
+				break;
+			case CAlpha:
+				bits = a;
+				break;
+			case CIgnore:
+				bits = 0;
+				break;
+			case CMap:
+				q = img->cmap->rgb2cmap;
+				bits = q[(r>>4)*16*16+(g>>4)*16+(b>>4)];
+				break;
+			default:
+				SET(bits);
+				fprint(2, "unknown channel type %lud\n", TYPE(c));
+				abort();
+			}
+
+DBG print("repl %lux 8 %d = %lux...", bits, nbits, replbits(bits, 8, nbits));
+			if(TYPE(c) != CMap)
+				bits = replbits(bits, 8, nbits);
+			mask = (1<<nbits)-1;
+DBG print("bits %lux mask %lux sh %d...", bits, mask, sh);
+			bits <<= sh;
+			mask <<= sh;
+			v = (v & ~mask) | (bits & mask);
+			sh += nbits;
+		}
+	}
+DBG print("v %.8lux\n", v);
+	p[0] = v;
+	p[1] = v>>8;
+	p[2] = v>>16;
+	p[3] = v>>24;	
+}
+#undef DBG
+
+#define DBG if(0)
+void
+drawonepixel(Memimage *dst, Point dp, Memimage *src, Point sp, Memimage *mask, Point mp)
+{
+	uchar m, M, sr, sg, sb, sa, sk, dr, dg, db, da, dk;
+
+	pixtorgba(getpixel(dst, dp), &dr, &dg, &db, &da);
+	pixtorgba(getpixel(src, sp), &sr, &sg, &sb, &sa);
+	m = getmask(mask, mp);
+	M = 255-(sa*m)/255;
+
+DBG print("dst %x %x %x %x src %x %x %x %x m %x = ", dr,dg,db,da, sr,sg,sb,sa, m);
+	if(dst->flags&Fgrey){
+		/*
+		 * We need to do the conversion to grey before the alpha calculation
+		 * because the draw operator does this, and we need to be operating
+		 * at the same precision so we get exactly the same answers.
+		 */
+		sk = RGB2K(sr, sg, sb);
+		dk = RGB2K(dr, dg, db);
+		dk = (sk*m + dk*M)/255;
+		dr = dg = db = dk;
+		da = (sa*m + da*M)/255;
+	}else{
+		/*
+		 * True color alpha calculation treats all channels (including alpha)
+		 * the same.  It might have been nice to use an array, but oh well.
+		 */
+		dr = (sr*m + dr*M)/255;
+		dg = (sg*m + dg*M)/255;
+		db = (sb*m + db*M)/255;
+		da = (sa*m + da*M)/255;
+	}
+
+DBG print("%x %x %x %x\n", dr,dg,db,da);
+	putpixel(dst, dp, rgbatopix(dr, dg, db, da));
+}
-- 
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