sch2fig/: record drawing operations (for Cairo) and sort by layer

sch2fig/Makefile

@@ -13,7 +13,7 @@
 NAME = sch2fig
 OBJS = main.o sch-parse.o sch-render.o lib-parse.o lib-render.o \
        file.o \
-       style.o fig.o cairo.o gfx.o dwg.o text.o misc.o
+       style.o fig.o layer.o cairo.o gfx.o dwg.o text.o misc.o
 
 CFLAGS = -g -O -Wall -Wextra -Wno-unused-parameter -Wshadow \
 	 -Wmissing-prototypes -Wmissing-declarations \

sch2fig/TODO

@@ -12,8 +12,6 @@
 - optionally display pin shapes
 - find libraries (e.g., from .pro)
 - PDF TOC
-- generic layering for cairo (and others ?), where primitives are first
-  recorded in per layer lists, then replayed. Can also calculate BB.
 - let user set PNG size or zoom level
 - implement dashed lines in cairo.c
 - implement PDF output in cairo.o

sch2fig/cairo.c

@@ -21,6 +21,7 @@
 #include "style.h"
 #include "text.h"
 #include "gfx.h"
+#include "layer.h"
 #include "cairo.h"
 
 #if 0
@@ -36,6 +37,7 @@
 
 
 struct cairo_ctx {
+	struct layer layer;	/* must be first */
 	cairo_t *cr;
 	cairo_surface_t *s;
 };
@@ -200,11 +202,24 @@ static unsigned cr_text_width(void *ctx, const char *s, unsigned size)
 /* ----- Initializatio and termination ------------------------------------- */
 
 
+static const struct gfx_ops real_cairo_ops = {
+	.name		= "cairo",
+	// .line	= cr_line,	@@@ later
+	.poly		= cr_poly,
+	.circ		= cr_circ,
+	.arc		= cr_arc,
+	.text		= cr_text,
+	.text_width	= cr_text_width,
+};
+
+
 static void *cr_init(int argc, char *const *argv)
 {
 	struct cairo_ctx *cc;
 
 	cc = alloc_type(struct cairo_ctx);
+	layer_init(&cc->layer, &real_cairo_ops, cc);
+
 	cc->s = cairo_image_surface_create(CAIRO_FORMAT_RGB24, 2000, 1414);
 	cc->cr = cairo_create(cc->s);
 
@@ -223,6 +238,9 @@ static void cr_end(void *ctx)
 {
 	struct cairo_ctx *cc = ctx;
 
+	layer_replay(&cc->layer);
+	layer_destroy(&cc->layer);
+
 	cairo_surface_write_to_png(cc->s, "test.png");
 	cairo_surface_destroy(cc->s);
 }
@@ -234,10 +252,10 @@ static void cr_end(void *ctx)
 const struct gfx_ops cairo_ops = {
 	.name		= "cairo",
 	// .line	= cr_line,	@@@ later
-	.poly		= cr_poly,
-	.circ		= cr_circ,
-	.arc		= cr_arc,
-	.text		= cr_text,
+	.poly		= layer_poly,
+	.circ		= layer_circ,
+	.arc		= layer_arc,
+	.text		= layer_text,
 	.text_width	= cr_text_width,
 	.init		= cr_init,
 	.end		= cr_end,

sch2fig/layer.c

@@ -0,0 +1,327 @@
+/*
+ * layer.h - Separate graphics operations by layers and replay
+ *
+ * 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 <stdlib.h>
+#include <limits.h>
+#include <math.h>
+
+#include "util.h"
+#include "style.h"
+#include "gfx.h"
+#include "text.h"
+#include "layer.h"
+
+
+struct layer_obj {
+	enum lo_type {
+		lo_line,
+		lo_rect,
+		lo_poly,
+		lo_circ,
+		lo_arc,
+		lo_text,
+	} type;
+
+	int x, y;
+	int color, fill_color;
+	union {
+		struct {
+			int ex, ey;
+		} line;
+		struct {
+			int ex, ey;
+		} rect;
+		struct {
+			unsigned n;
+			int *vx, *vy;
+		} poly;
+		struct {
+			int r;
+		} circ;
+		struct {
+			int r;
+			int sa, ea;
+		} arc;
+		struct {
+			char *s;
+			unsigned size;
+			enum text_align align;
+			int rot;
+		} text;
+	} u;
+	struct layer_obj *next;
+};
+
+
+static void bb(struct layer *layer, int x, int y)
+{
+	if (layer->xmin > x)
+		layer->xmin = x;
+	if (layer->ymin > y)
+		layer->ymin = y;
+	if (layer->xmax < x)
+		layer->xmax = x;
+	if (layer->ymax < y)
+		layer->ymax = y;
+}
+
+
+static void bb_rot(struct layer *layer, int x, int y, int rot)
+{
+	double a = rot / 180.0 * M_PI;
+
+	bb(layer, cos(a) * x + sin(a) * y, cos(a) * y - sin(a) * y);
+}
+
+
+static struct layer_obj *new_obj(struct layer *lc, enum lo_type type,
+    int color, int fill_color, unsigned layer)
+{
+	struct layer_objs **objs;
+	struct layer_objs *new_objs;
+	struct layer_obj *new_obj;
+
+	for (objs = &lc->objs; *objs; objs = &(*objs)->next) {
+		if ((*objs)->layer == layer)
+			goto this_layer;
+		if ((*objs)->layer < layer)
+			break;
+	}
+
+	new_objs = alloc_type(struct layer_objs);
+	new_objs->layer = layer;
+	new_objs->obj = NULL;
+	new_objs->next_obj = &new_objs->obj;
+	new_objs->next = *objs;
+	*objs = new_objs;
+
+this_layer:
+	new_obj = alloc_type(struct layer_obj);
+	new_obj->type = type;
+	new_obj->color = color;
+	new_obj->fill_color = fill_color;
+	new_obj->next = NULL;
+
+	*(*objs)->next_obj = new_obj;
+	(*objs)->next_obj = &new_obj->next;
+
+	return new_obj;
+}
+
+
+void layer_line(void *ctx, int sx, int sy, int ex, int ey,
+    int color, unsigned layer)
+{
+	struct layer *lc = ctx;
+	struct layer_obj *obj = new_obj(ctx, lo_line, color, COLOR_NONE, layer);
+
+	bb(lc, sx, sy);
+	bb(lc, ex, ey);
+
+	obj->x = sx;
+	obj->y = sy;
+	obj->u.line.ex = ex;
+	obj->u.line.ey = ey;
+}
+
+
+void layer_rect(void *ctx, int sx, int sy, int ex, int ey,
+    int color, int fill_color, unsigned layer)
+{
+	struct layer *lc = ctx;
+	struct layer_obj *obj = new_obj(ctx, lo_rect, color, fill_color, layer);
+
+	bb(lc, sx, sy);
+	bb(lc, ex, ey);
+
+	obj->x = sx;
+	obj->y = sy;
+	obj->u.rect.ex = ex;
+	obj->u.rect.ey = ey;
+}
+
+
+void layer_poly(void *ctx, int points, int x[points], int y[points],
+    int color, int fill_color, unsigned layer)
+{
+	struct layer *lc = ctx;
+	struct layer_obj *obj = new_obj(ctx, lo_poly, color, fill_color, layer);
+	int i;
+	unsigned  size;
+
+	for (i = 0; i != points; i++)
+		bb(lc, x[i], y[i]);
+
+	obj->u.poly.n = points;
+	size = sizeof(int) * points;
+	obj->u.poly.vx = alloc_size(size);
+	obj->u.poly.vy = alloc_size(size);
+	memcpy(obj->u.poly.vx, x, size);
+	memcpy(obj->u.poly.vy, y, size);
+}
+
+
+void layer_circ(void *ctx, int x, int y, int r,
+    int color, int fill_color, unsigned layer)
+{
+	struct layer *lc = ctx;
+	struct layer_obj *obj = new_obj(ctx, lo_circ, color, fill_color, layer);
+
+	bb(lc, x - r, y - r);
+	bb(lc, x + r, y + r);
+
+	obj->x = x;
+	obj->y = y;
+	obj->u.circ.r = r;
+}
+
+
+void layer_arc(void *ctx, int x, int y, int r, int sa, int ea,
+    int color, int fill_color, unsigned layer)
+{
+	struct layer *lc = ctx;
+	struct layer_obj *obj = new_obj(ctx, lo_arc, color, fill_color, layer);
+
+	bb(lc, x - r, y - r);
+	bb(lc, x + r, y + r);
+
+	obj->x = x;
+	obj->y = y;
+	obj->u.arc.r = r;
+	obj->u.arc.sa = sa;
+	obj->u.arc.ea = ea;
+}
+
+
+void layer_text(void *ctx, int x, int y, const char *s, unsigned size,
+    enum text_align align, int rot, unsigned color, unsigned layer)
+{
+	struct layer *lc = ctx;
+	struct layer_obj *obj = new_obj(ctx, lo_text, color, COLOR_NONE, layer);
+	unsigned width = lc->ops->text_width(lc->user, s, size);
+
+	bb_rot(lc, x, y - size, rot);
+	bb_rot(lc, x + width, y, rot);
+
+	obj->x = x;
+	obj->y = y;
+	obj->u.text.s = stralloc(s);
+	obj->u.text.size = size;
+	obj->u.text.align = align;
+	obj->u.text.rot = rot;
+}
+
+
+void layer_init(struct layer *layer, const struct gfx_ops *ops, void *user)
+{
+	layer->ops = ops;
+	layer->user = user;
+	layer->xmin = layer->ymin = INT_MAX;
+	layer->xmax = layer->ymax = INT_MIN;
+	layer->objs = NULL;
+}
+
+
+void layer_replay(const struct layer *layer)
+{
+	const struct gfx_ops *ops = layer->ops;
+	void *ctx = layer->user;
+	const struct layer_objs *objs;
+	const struct layer_obj *obj;
+
+	for (objs = layer->objs; objs; objs = objs->next)
+		for (obj = objs->obj; obj; obj = obj->next)
+			switch (obj->type) {
+			case lo_line:
+				ops->line(ctx, obj->x, obj->y,
+				    obj->u.line.ex, obj->u.line.ey,
+				    obj->color, objs->layer);
+				break;
+			case lo_rect:
+				ops->rect(ctx, obj->x, obj->y,
+				    obj->u.rect.ex, obj->u.rect.ey,
+				    obj->color, obj->fill_color, objs->layer);
+				break;
+			case lo_poly:
+				ops->poly(ctx, obj->u.poly.n,
+				    obj->u.poly.vx, obj->u.poly.vy,
+				    obj->color, obj->fill_color, objs->layer);
+				break;
+			case lo_circ:
+				ops->circ(ctx, obj->x, obj->y,
+				    obj->u.circ.r,
+				    obj->color, obj->fill_color, objs->layer);
+				break;
+			case lo_arc:
+				ops->arc(ctx, obj->x, obj->y, obj->u.arc.r,
+				    obj->u.arc.sa, obj->u.arc.ea,
+				    obj->color, obj->fill_color, objs->layer);
+				break;
+			case lo_text:
+				ops->text(ctx, obj->x, obj->y, obj->u.text.s,
+				    obj->u.text.size, obj->u.text.align,
+				    obj->u.text.rot,
+				    obj->color, objs->layer);
+				break;
+			default:
+				abort();
+			}
+}
+
+
+void layer_bbox(const struct layer *layer, int *x, int *y, int *w, int *h)
+{
+	if (x)
+		*x = layer->xmin;
+	if (y)
+		*y = layer->ymin;
+	if (w)
+		*w = layer->xmax - layer->xmin + 1;
+	if (h)
+		*h = layer->ymax - layer->ymin + 1;
+}
+
+
+static void layer_obj_destroy(struct layer_obj *obj)
+{
+	switch (obj->type) {
+	case lo_poly:
+		free(obj->u.poly.vx);
+		free(obj->u.poly.vy);
+		break;
+	case lo_text:
+		free(obj->u.text.s);
+		break;
+	default:
+		break;
+	}
+	free(obj);
+}
+
+
+void layer_destroy(struct layer *layer)
+{
+	struct layer_objs *next_objs;
+	struct layer_obj *next_obj;
+
+	while (layer->objs) {
+		next_objs = layer->objs->next;
+		while (layer->objs->obj) {
+			next_obj = layer->objs->obj->next;
+			layer_obj_destroy(layer->objs->obj);
+			layer->objs->obj = next_obj;
+		}
+		free(layer->objs);
+		layer->objs = next_objs;
+	}
+}

sch2fig/layer.h

@@ -0,0 +1,56 @@
+/*
+ * layer.h - Separate graphics operations by layers and replay
+ *
+ * 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 LAYER_H
+#define	LAYER_H
+
+#include "gfx.h"
+
+
+struct layer_obj;
+
+struct layer_objs {
+	unsigned layer;
+	struct layer_obj *obj;
+	struct layer_obj **next_obj;
+	struct layer_objs *next;
+};
+
+struct layer {
+	const struct gfx_ops *ops;
+	void *user;
+	int xmin, xmax;
+	int ymin, ymax;
+	struct layer_objs *objs;
+};
+
+
+void layer_line(void *ctx, int sx, int sy, int ex, int ey,
+    int color, unsigned layer);
+void layer_rect(void *ctx, int sx, int sy, int ex, int ey,
+    int color, int fill_color, unsigned layer);
+void layer_poly(void *ctx, int points, int x[points], int y[points],
+    int color, int fill_color, unsigned layer);
+void layer_circ(void *ctx, int x, int y, int r,
+    int color, int fill_color, unsigned layer);
+void layer_arc(void *ctx, int x, int y, int r, int sa, int ea,
+    int color, int fill_color, unsigned layer);
+void layer_text(void *ctx, int x, int y, const char *s, unsigned size,
+    enum text_align align, int rot, unsigned color, unsigned layer);
+
+void layer_init(struct layer *layer, const struct gfx_ops *ops, void *user);
+void layer_replay(const struct layer *layer);
+void layer_bbox(const struct layer *layer, int *x, int *y, int *w, int *h);
+void layer_destroy(struct layer *layer);
+
+#endif /* !LAYER_H */