From 99b75f2943cf265564a970eefe474bdcb6b49605 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sigrid=20Solveig=20Hafl=C3=ADnud=C3=B3ttir?=
 <ftrvxmtrx@gmail.com>
Date: Wed, 23 Jun 2021 13:45:02 +0000
Subject: [PATCH] add chr2img for Plan 9

---
 mkfile        |   7 +++-
 src/chr2img.c | 108 ++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 113 insertions(+), 2 deletions(-)
 create mode 100644 src/chr2img.c

diff --git a/mkfile b/mkfile
index 06a19c0..0461450 100644
--- a/mkfile
+++ b/mkfile
@@ -1,6 +1,6 @@
 </$objtype/mkfile
 
-TARG=bin/uxncli bin/uxnasm bin/uxnemu
+TARG=bin/uxncli bin/uxnasm bin/uxnemu bin/chr2img
 USM=`{walk -f projects/ | grep '\.tal$' | grep -v blank.tal}
 ROM=${USM:%.tal=%.rom}
 CFLAGS=$CFLAGS -I/sys/include/npe -I/sys/include/npe/SDL2
@@ -38,7 +38,10 @@ bin/uxnasm: uxnasm.$O
 bin/uxnemu: uxnemu.$O apu.$O mpu.$O ppu.$O uxn.$O
 	$LD $LDFLAGS -o $target $prereq
 
-(uxnasm|uxncli|uxnemu|uxn)\.$O:R: src/\1.c
+bin/chr2img: chr2img.$O
+	$LD $LDFLAGS -o $target $prereq
+
+(uxnasm|uxncli|uxnemu|uxn|chr2img)\.$O:R: src/\1.c
 	$CC $CFLAGS -Isrc -o $target src/$stem1.c
 
 (apu|mpu|ppu)\.$O:R: src/devices/\1.c
diff --git a/src/chr2img.c b/src/chr2img.c
new file mode 100644
index 0000000..b06b1c8
--- /dev/null
+++ b/src/chr2img.c
@@ -0,0 +1,108 @@
+/* note: this is for Plan 9 only */
+#include <u.h>
+#include <libc.h>
+#include <draw.h>
+#include <memdraw.h>
+
+static int hor = 44, ver = 26, bpp = 1;
+static int SZ;
+
+#define xy2n(x, y) ((y & 7) + (x/8 + y/8 * hor)*bpp*8)
+
+static u8int *
+readall(int f, int *isz)
+{
+	int bufsz, sz, n;
+	u8int *s;
+
+	bufsz = 1023;
+	s = nil;
+	for(sz = 0;; sz += n){
+		if(bufsz-sz < 1024){
+			bufsz *= 2;
+			s = realloc(s, bufsz);
+		}
+		if((n = readn(f, s+sz, bufsz-sz)) < 1)
+			break;
+	}
+	if(n < 0 || sz < 1){
+		free(s);
+		return nil;
+	}
+	*isz = sz;
+
+	return s;
+}
+
+static int
+getcoli(int x, int y, u8int *p)
+{
+	int ch1, ch2, r;
+
+	r = xy2n(x, y);
+	ch1 = (p[r+0] >> (7 - x & 7)) & 1;
+	ch2 = bpp < 2 ? 0 : (p[r+8] >> (7 - x & 7)) & 1;
+
+	return ch2<<1 | ch1;
+}
+
+static void
+usage(void)
+{
+	fprint(2, "usage: %s [-1] [-2] [-w WIDTH]\n", argv0);
+	exits("usage");
+}
+
+void
+main(int argc, char **argv)
+{
+	int sz, esz, h, w, x, y;
+	Memimage *m;
+	Memdata d;
+	u8int *p;
+	ulong col[2][4] = {
+		{DWhite, DBlack, 0, 0},
+		{DTransparent, DWhite, 0x72dec2ff, 0x666666ff},
+	};
+
+	ARGBEGIN{
+	case '1':
+		bpp = 1;
+		break;
+	case '2':
+		bpp = 2;
+		break;
+	case 'w':
+		hor = atoi(EARGF(usage()));
+		break;
+	}ARGEND
+
+	memimageinit();
+
+	if((p = readall(0, &sz)) == nil)
+		sysfatal("%r");
+
+	ver = sz / (bpp*8) / hor;
+	esz = (hor * ver * (bpp*8));
+	w = hor*8;
+	h = ver*8;
+	if(sz != esz)
+		fprint(2, "warning: size differs (%d vs %d), dimensions must be wrong\n", sz, esz);
+
+	memset(&d, 0, sizeof(d));
+	if((d.base = malloc(4*w*h)) == nil)
+		sysfatal("memory");
+	d.bdata = (uchar*)d.base;
+
+	for(y = 0; y < h; y++){
+		for(x = 0; x < w; x++)
+			d.base[y*w + x] = col[bpp-1][getcoli(x, y, p)];
+	}
+
+	if((m = allocmemimaged(Rect(0, 0, w, h), RGBA32, &d)) == nil)
+		sysfatal("%r");
+	if(writememimage(1, m) != 0)
+		sysfatal("%r");
+
+	exits(nil);
+}