sch2fig/: add Cairo (PNG) back-end (WIP)

sch2fig/Makefile

@@ -11,10 +11,11 @@
 #
 
 NAME = sch2fig
-OBJS = main.o sch.o lib.o style.o fig.o gfx.o dwg.o text.o misc.o
+OBJS = main.o sch.o lib.o style.o fig.o cairo.o gfx.o dwg.o text.o misc.o
 
-CFLAGS = -g -O -Wall -Wextra -Wno-unused-parameter -Wshadow
+CFLAGS = -g -O -Wall -Wextra -Wno-unused-parameter -Wshadow \
-LIBS = -lm
+	 `pkg-config --cflags cairo`
+LIBS = -lm `pkg-config --libs cairo`
 
 include ../common/Makefile.c-common
 

sch2fig/cairo.c

@@ -0,0 +1,190 @@
+/*
+ * cairo.c - Cairo graphics back-end
+ *
+ * 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 <stdbool.h>
+#include <stdint.h>
+#include <math.h>
+
+#include <cairo/cairo.h>
+
+#include "util.h"
+#include "style.h"
+#include "gfx.h"
+#include "cairo.h"
+
+#if 0
+#include <stdlib.h>
+#include <stdio.h>
+#include <assert.h>
+
+#include "util.h"
+#include "style.h"
+#include "text.h"
+#include "fig.h"
+#endif
+
+
+struct cairo_ctx {
+	cairo_t *cr;
+	cairo_surface_t *s;
+};
+
+/*
+ * FIG works with 1/1200 in
+ * KiCad works with mil
+ * 1 point = 1/72 in
+ */
+
+
+static inline int cx(int x)
+{
+	return x / 5;
+}
+
+
+static inline int cy(int y)
+{
+	return y / 5;
+}
+
+
+static inline float pt(int x)
+{
+	return cx(x) * 72 * 1.5 / 1200.0;
+}
+
+
+static void set_color(cairo_t *cr, int color)
+{
+	uint32_t c;
+
+	if (color < 0)
+		return;
+	c = color_rgb[color];
+	cairo_set_source_rgb(cr, (c >> 16) / 255.0, ((c >> 8) & 255) / 255.0,
+	    (c & 255) / 255.0);
+}
+
+
+static void paint(cairo_t *cr, int color, int fill_color)
+{
+	if (fill_color != COLOR_NONE) {
+		set_color(cr, fill_color);
+		if (color == COLOR_NONE)
+			cairo_fill(cr);
+		else
+			cairo_fill_preserve(cr);
+	}
+	if (color != COLOR_NONE) {
+		set_color(cr, color);
+		cairo_stroke(cr);
+	}
+}
+
+
+/* ----- General items ----------------------------------------------------- */
+
+
+void cr_poly(void *ctx, int points, int x[points], int y[points],
+    int color, int fill_color, unsigned layer)
+{
+	struct cairo_ctx *cc = ctx;
+	bool closed;
+	int i;
+
+	if (points < 2)
+		return;
+	closed = x[0] == x[points - 1] && y[0] == y[points - 1];
+
+	cairo_new_path(cc->cr);
+	cairo_move_to(cc->cr, cx(x[0]), cy(y[0]));
+
+	for (i = 1; i != points - closed; i++)
+		cairo_line_to(cc->cr, cx(x[i]), cy(y[i]));
+	if (closed)
+		cairo_close_path(cc->cr);
+
+	paint(cc->cr, color, fill_color);
+}
+
+
+void cr_circ(void *ctx, int x, int y, int r,
+    int color, int fill_color, unsigned layer)
+{
+	struct cairo_ctx *cc = ctx;
+
+	cairo_new_path(cc->cr);
+	cairo_arc(cc->cr, cx(x), cy(y), cx(r), 0, 2 * M_PI);
+	paint(cc->cr, color, fill_color);
+}
+
+
+void cr_arc(void *ctx, int x, int y, int r, int sa, int ea,
+    int color, int fill_color, unsigned layer)
+{
+	struct cairo_ctx *cc = ctx;
+
+	cairo_new_path(cc->cr);
+	cairo_arc(cc->cr, cx(x), cy(y), cx(r),
+	    -ea / 180.0 * M_PI, -sa / 180.0 * M_PI);
+	paint(cc->cr, color, fill_color);
+}
+
+
+void cr_text(void *ctx, int x, int y, const char *s, unsigned size,
+    enum text_align align, int rot, unsigned color, unsigned layer)
+{
+//	struct cairo_ctx *cc = ctx;
+}
+
+
+/* ----- Initializatio and termination ------------------------------------- */
+
+
+void *cr_init(const char *template, int n_vars, const char **vars)
+{
+	struct cairo_ctx *cc;
+
+	cc = alloc_type(struct cairo_ctx);
+	cc->s = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, 2000, 1414);
+	cc->cr = cairo_create(cc->s);
+	set_color(cc->cr, COLOR_WHITE);
+	cairo_paint(cc->cr);
+
+	cairo_set_line_width(cc->cr, 3);
+
+	return cc;
+}
+
+
+void cr_end(void *ctx)
+{
+	struct cairo_ctx *cc = ctx;
+
+	cairo_surface_write_to_png(cc->s, "test.png");
+	cairo_surface_destroy(cc->s);
+}
+
+
+/* ----- Operations -------------------------------------------------------- */
+
+
+const struct gfx_ops cairo_ops = {
+	// .line	= cr_line,	@@@ later
+	.poly	= cr_poly,
+	.circ	= cr_circ,
+	.arc	= cr_arc,
+	.text	= cr_text,
+	.init	= cr_init,
+	.end	= cr_end,
+};

sch2fig/cairo.h

@@ -0,0 +1,22 @@
+/*
+ * cairo.h - Cairo graphics back-end
+ *
+ * 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 CAIRO_H
+#define	CAIRO_H
+
+#include "gfx.h"
+
+
+extern const struct gfx_ops cairo_ops;
+
+#endif /* !CAIRO_H */

sch2fig/main.c

@@ -17,6 +17,7 @@
 #include <string.h>
 
 #include "fig.h"
+#include "cairo.h"
 #include "gfx.h"
 #include "lib.h"
 #include "sch.h"
@@ -93,7 +94,8 @@ int main(int argc, char **argv)
 	if (argc - optind < 1)
 		usage(*argv);
 
-	gfx_init(&fig_ops, template, n_vars, vars);
+	//gfx_init(&fig_ops, template, n_vars, vars);
+	gfx_init(&cairo_ops, template, n_vars, vars);
 	for (arg = optind; arg != argc; arg++) {
 		if (arg == argc - 1) {
 			struct sch_ctx ctx;