sch2fig/: implement "diff" driver (WIP)

sch2fig/Makefile

@@ -13,9 +13,9 @@
 NAME = sch2fig
 OBJS = main.o sch-parse.o sch-render.o lib-parse.o lib-render.o \
        file.o \
-       style.o fig.o record.o cairo.o gfx.o dwg.o text.o misc.o
+       style.o fig.o record.o cairo.o diff.o gfx.o dwg.o text.o misc.o
 
-CFLAGS = -g -O -Wall -Wextra -Wno-unused-parameter -Wshadow \
+CFLAGS = -g  -Wall -Wextra -Wno-unused-parameter -Wshadow \
 	 -Wmissing-prototypes -Wmissing-declarations \
 	 `pkg-config --cflags cairo`
 LIBS = -lm `pkg-config --libs cairo`

sch2fig/TODO

@@ -19,3 +19,8 @@
 - on parse error, politely complain, don't terminate
 - implement destructors
 - check for memory leaks
+- record.c (bb_rot): implement bounding boxes for text
+- nesting gfx in diff is a huge kludge, caused by global vars in gfx.c
+- move path name guessing into file.c
+- return indication of whether diff found any differences
+- in diff, pass only options understood by cairo_png

sch2fig/cairo.c

@@ -13,6 +13,7 @@
 
 #include <stddef.h>
 #include <stdbool.h>
+#include <stdint.h>
 #include <stdlib.h>
 #include <stdint.h>
 #include <unistd.h>
@@ -395,6 +396,42 @@ static void cr_pdf_end(void *ctx)
 }
 
 
+uint32_t *cairo_img_end(void *ctx, int *w, int *h, int *stride)
+{
+	struct cairo_ctx *cc = ctx;
+	uint32_t *data;
+
+	end_common(cc, w, h);
+
+	*stride = cairo_format_stride_for_width(CAIRO_FORMAT_RGB24, *w);
+	data = alloc_size(*stride * *h);
+
+	cc->s = cairo_image_surface_create_for_data((unsigned char  *) data,
+	    CAIRO_FORMAT_RGB24, *w, *h, *stride);
+	cc->cr = cairo_create(cc->s);
+
+	set_color(cc->cr, COLOR_WHITE);
+	cairo_paint(cc->cr);
+
+	cairo_select_font_face(cc->cr, "Helvetica", CAIRO_FONT_SLANT_NORMAL,
+	    CAIRO_FONT_WEIGHT_BOLD);
+	cairo_set_line_width(cc->cr, 2);
+
+	record_replay(&cc->record);
+	record_destroy(&cc->record);
+
+	return data;
+}
+
+
+void cairo_img_write(void *ctx, const char *name)
+{
+	struct cairo_ctx *cc = ctx;
+
+	cairo_surface_write_to_png(cc->s, name);
+}
+
+
 /* ----- Operations -------------------------------------------------------- */
 
 

sch2fig/cairo.h

@@ -11,8 +11,10 @@
  */
 
 
-#ifndef CAIRO_H
+#ifndef MY_CAIRO_H
-#define	CAIRO_H
+#define	MY_CAIRO_H
+
+#include <stdint.h>
 
 #include "gfx.h"
 
@@ -20,4 +22,10 @@
 extern const struct gfx_ops cairo_png_ops;
 extern const struct gfx_ops cairo_pdf_ops;
 
-#endif /* !CAIRO_H */
+#define	cairo_img_ops	cairo_png_ops	/* just don't call cairo_img_ops.end */
+
+
+uint32_t *cairo_img_end(void *ctx, int *w, int *h, int *stride);
+void cairo_img_write(void *ctx, const char *name);
+
+#endif /* !MY_CAIRO_H */

sch2fig/diff.c

@@ -0,0 +1,280 @@
+/*
+ * diff.c - Schematics difference
+ *
+ * Written 2016 by Werner Almesberger
+ * Copyright 2016 by Werner Almesberger
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include "util.h"
+#include "main.h"
+#include "cairo.h"
+#include "sch.h"
+#include "lib.h"
+#include "diff.h"
+
+
+#define	DEFAULT_FRAME_RADIUS	30
+
+
+struct area {
+	int xa, ya, xb, yb;
+	struct area *next;
+};
+
+struct diff {
+	void *cr_ctx;
+	uint32_t *new_img;
+	int w, h, stride;
+	const char *output_name;
+	int frame_radius;
+	struct area *areas;
+};
+
+
+/* ----- Wrappers ---------------------------------------------------------- */
+
+
+static void diff_line(void *ctx, int sx, int sy, int ex, int ey,
+    int color, unsigned layer)
+{
+	const struct diff *diff = ctx;
+
+	cairo_img_ops.line(diff->cr_ctx, sx, sy, ex, ey, color, layer);
+}
+
+
+static void diff_poly(void *ctx,
+    int points, const int x[points], const int y[points],
+    int color, int fill_color, unsigned layer)
+{
+	const struct diff *diff = ctx;
+
+	cairo_img_ops.poly(diff->cr_ctx, points, x, y,
+	    color, fill_color, layer);
+}
+
+
+static void diff_circ(void *ctx, int x, int y, int r,
+    int color, int fill_color, unsigned layer)
+{
+	const struct diff *diff = ctx;
+
+	cairo_img_ops.circ(diff->cr_ctx, x, y, r, color, fill_color, layer);
+}
+
+
+static void diff_arc(void *ctx, int x, int y, int r, int sa, int ea,
+    int color, int fill_color, unsigned layer)
+{
+	const struct diff *diff = ctx;
+
+	cairo_img_ops.arc(diff->cr_ctx, x, y, r, sa, ea,
+	    color, fill_color, layer);
+}
+
+
+static void diff_text(void *ctx, int x, int y, const char *s, unsigned size,
+    enum text_align align, int rot, unsigned color, unsigned layer)
+{
+	const struct diff *diff = ctx;
+
+	cairo_img_ops.text(diff->cr_ctx, x, y, s, size, align, rot,
+	    color, layer);
+}
+
+
+static unsigned diff_text_width(void *ctx, const char *s, unsigned size)
+{
+	const struct diff *diff = ctx;
+
+	return cairo_img_ops.text_width(diff->cr_ctx, s, size);
+}
+
+
+/* ----- Initialization and termination ------------------------------------ */
+
+
+static void *diff_init(int argc, char *const *argv)
+{
+	struct diff *diff;
+	char c;
+	int arg;
+	struct sch_ctx new_sch;
+	struct lib new_lib;
+
+	diff = alloc_type(struct diff);
+	diff->areas = NULL;
+
+	sch_init(&new_sch, 0);
+	lib_init(&new_lib);
+
+	diff->output_name = NULL;
+	diff->frame_radius = DEFAULT_FRAME_RADIUS;
+	while ((c = getopt(argc, argv, "o:s:")) != EOF)
+		switch (c) {
+		case 'o':
+			diff->output_name = optarg;
+			break;
+		case 's':
+			/* for cairo_png */
+			break;
+		default:
+			usage(*argv);
+		}
+
+	if (argc - optind < 1)
+		usage(*argv);
+
+	for (arg = optind; arg != argc - 1; arg++)
+		lib_parse(&new_lib, argv[arg]);
+	sch_parse(&new_sch, argv[argc - 1], &new_lib);
+
+	optind = 0;
+	gfx_init(&cairo_img_ops, argc, argv);
+	diff->cr_ctx = gfx_ctx;
+	sch_render(new_sch.sheets);
+	diff->new_img = cairo_img_end(gfx_ctx,
+	    &diff->w, &diff->h, &diff->stride);
+
+	optind = 0;
+	diff->cr_ctx = cairo_img_ops.init(argc, argv);
+
+	return diff;
+}
+
+
+/* steal from schhist/ppmdiff.c */
+
+#define	ONLY_OLD	0xff0000
+#define	ONLY_NEW	0x00d000
+#define	BOTH		0x707070
+
+#define	AREA_FILL	0xffffc8
+
+
+static void mark_area(struct diff *diff, int x, int y)
+{
+	struct area *area;
+
+	for (area = diff->areas; area; area = area->next)
+		if (x >= area->xa && x <= area->xb &&
+		    y >= area->ya && y <= area->yb) {
+			if (area->xa > x - diff->frame_radius)
+				area->xa = x - diff->frame_radius;
+			if (area->xb < x + diff->frame_radius)
+				area->xb = x + diff->frame_radius;
+			if (area->ya > y - diff->frame_radius)
+				area->ya = y - diff->frame_radius;
+			if (area->yb < y + diff->frame_radius)
+				area->yb = y + diff->frame_radius;
+			return;
+		}
+
+	area = alloc_type(struct area);
+
+	area->xa = x - diff->frame_radius;
+	area->xb = x + diff->frame_radius;
+	area->ya = y - diff->frame_radius;
+	area->yb = y + diff->frame_radius;
+
+	area->next = diff->areas;
+	diff->areas = area;
+}
+
+
+#define	MASK 0xffffff
+
+
+static void differences(struct diff *diff, uint32_t *a, const uint32_t *b)
+{
+	int x, y;
+	unsigned skip = diff->w * 4 - diff->stride;
+
+	for (y = 0; y != diff->h; y++) {
+		for (x = 0; x != diff->w; x++) {
+			if (!((*a ^ *b) & MASK)) {
+				*a = ((*a >> 3) & 0x1f1f1f) | 0xe0e0e0;
+//				*a = ((*a >> 2) & 0x3f3f3f) | 0xc0c0c0;
+			} else {
+				mark_area(diff, x, y);
+//fprintf(stderr, "0x%06x 0x%06x", *a, *b);
+				*a = (*a & MASK) == MASK ? ONLY_NEW :
+				    (*b & MASK) == MASK ? ONLY_OLD : BOTH;
+//fprintf(stderr, "-> 0x%06x\n", *a);
+			}
+			a++;
+			b++;
+		}
+		a += skip;
+		b += skip;
+	}
+}
+
+
+static void show_areas(struct diff *diff, uint32_t *a)
+{
+	const struct area *area;
+	uint32_t *p;
+	int x, y;
+
+	for (area = diff->areas; area; area = area->next)
+		for (y = area->ya; y != area->yb; y++) {
+			if (y < 0 || y >= diff->h)
+				continue;
+			p = a + y * (diff->stride >> 2);
+			for (x = area->xa; x != area->xb; x++) {
+				if (x >= 0 && x < diff->w &&
+				    (p[x] & MASK) == MASK)
+					p[x] = AREA_FILL;
+			}
+		}
+}
+
+
+static void diff_end(void *ctx)
+{
+	struct diff *diff = ctx;
+	uint32_t *old_img;
+	int w, h, stride;
+
+	old_img = cairo_img_end(diff->cr_ctx, &w, &h, &stride);
+	if (diff->w != w || diff->h != h) {
+		fprintf(stderr, "%d x %d vs. %d x %d image\n",
+		    w, h, diff->w, diff->h);
+		exit(1);
+	}
+
+	differences(diff, old_img, diff->new_img);
+	show_areas(diff, old_img);
+
+	if (diff->output_name)
+		cairo_img_write(diff->cr_ctx, diff->output_name);
+}
+
+
+/* ----- Operations -------------------------------------------------------- */
+
+
+const struct gfx_ops diff_ops = {
+	.name		= "diff",
+	.line		= diff_line,
+	.poly		= diff_poly,
+	.circ		= diff_circ,
+	.arc		= diff_arc,
+	.text		= diff_text,
+	.text_width	= diff_text_width,
+	.init		= diff_init,
+	.end		= diff_end,
+};

sch2fig/diff.h

@@ -0,0 +1,22 @@
+/*
+ * diff.h - Schematics difference
+ *
+ * Written 2016 by Werner Almesberger
+ * Copyright 2016 by Werner Almesberger
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+
+#ifndef DIFF_H
+#define	DIFF_H
+
+#include "gfx.h"
+
+
+extern const struct gfx_ops diff_ops;
+
+#endif /* !DIFF_H */

sch2fig/gfx.c

@@ -18,8 +18,9 @@
 #include "gfx.h"
 
 
+void *gfx_ctx;
+
 static const struct gfx_ops *gfx_ops;
-static void *gfx_ctx;
 
 
 void gfx_line(int sx, int sy, int ex, int ey, int color, unsigned layer)
@@ -95,8 +96,8 @@ unsigned gfx_text_width(const char *s, unsigned size)
 
 void gfx_init(const struct gfx_ops *ops, int argc, char *const *argv)
 {
-	gfx_ops = ops;
 	gfx_ctx = ops->init(argc, argv);
+	gfx_ops = ops;
 }
 
 

sch2fig/gfx.h

@@ -43,6 +43,9 @@ struct gfx_ops {
 };
 
 
+extern void *gfx_ctx;
+
+
 /* wrappers */
 
 void gfx_line(int sx, int sy, int ex, int ey, int color, unsigned layer);

sch2fig/main.c

@@ -20,6 +20,7 @@
 #include "util.h"
 #include "fig.h"
 #include "cairo.h"
+#include "diff.h"
 #include "gfx.h"
 #include "lib.h"
 #include "sch.h"
@@ -30,6 +31,7 @@ static struct gfx_ops const *ops_list[] = {
 	&fig_ops,
 	&cairo_png_ops,
 	&cairo_pdf_ops,
+	&diff_ops,
 };
 
 
@@ -43,6 +45,8 @@ void usage(const char *name)
 "    png [-o output.png] [-s scale]\n"
 "  Cairo PDF driver spec:\n"
 "    pdf [-o output.pdf] [-s scale]\n"
+"  Diff driver spec:\n"
+"    diff [-o output.pdf] [-s scale] [file.lib ...] file.sch\n"
     , name);
 	exit(1);
 }