Add fz_begin_layer/fz_end_layer.

Call these from the PDF interpreter. Make the DisplayList and
Trace devices cope.

Use these in the SVG output device.

6 files changed, 143 insertions, 3 deletions

diff --git a/include/mupdf/fitz/device.h b/include/mupdf/fitz/device.h
index 549ae9be..132668c1 100644
--- a/include/mupdf/fitz/device.h
+++ b/include/mupdf/fitz/device.h
@@ -115,6 +115,9 @@ struct fz_device_s
 	void (*render_flags)(fz_context *, fz_device *, int set, int clear);
 	void (*set_default_colorspaces)(fz_context *, fz_device *, fz_default_colorspaces *);
 
+	void (*begin_layer)(fz_context *, fz_device *, const char *layer_name);
+	void (*end_layer)(fz_context *, fz_device *);
+
 	fz_rect d1_rect;
 
 	int error_depth;
@@ -148,6 +151,8 @@ int fz_begin_tile_id(fz_context *ctx, fz_device *dev, const fz_rect *area, const
 void fz_end_tile(fz_context *ctx, fz_device *dev);
 void fz_render_flags(fz_context *ctx, fz_device *dev, int set, int clear);
 void fz_set_default_colorspaces(fz_context *ctx, fz_device *dev, fz_default_colorspaces *default_cs);
+void fz_begin_layer(fz_context *ctx, fz_device *dev, const char *layer_name);
+void fz_end_layer(fz_context *ctx, fz_device *dev);
 fz_device *fz_new_device_of_size(fz_context *ctx, int size);
 
 #define fz_new_derived_device(CTX, TYPE) \
diff --git a/source/fitz/device.c b/source/fitz/device.c
index 8a4e3394..42377030 100644
--- a/source/fitz/device.c
+++ b/source/fitz/device.c
@@ -528,6 +528,18 @@ fz_set_default_colorspaces(fz_context *ctx, fz_device *dev, fz_default_colorspac
 		dev->set_default_colorspaces(ctx, dev, default_cs);
 }
 
+void fz_begin_layer(fz_context *ctx, fz_device *dev, const char *layer_name)
+{
+	if (dev->begin_layer)
+		dev->begin_layer(ctx, dev, layer_name);
+}
+
+void fz_end_layer(fz_context *ctx, fz_device *dev)
+{
+	if (dev->end_layer)
+		dev->end_layer(ctx, dev);
+}
+
 const fz_rect *
 fz_device_current_scissor(fz_context *ctx, fz_device *dev)
 {
diff --git a/source/fitz/list-device.c b/source/fitz/list-device.c
index 7a1f67ee..39314b54 100644
--- a/source/fitz/list-device.c
+++ b/source/fitz/list-device.c
@@ -31,7 +31,9 @@ typedef enum fz_display_command_e
 	FZ_CMD_BEGIN_TILE,
 	FZ_CMD_END_TILE,
 	FZ_CMD_RENDER_FLAGS,
-	FZ_CMD_DEFAULT_COLORSPACES
+	FZ_CMD_DEFAULT_COLORSPACES,
+	FZ_CMD_BEGIN_LAYER,
+	FZ_CMD_END_LAYER
 } fz_display_command;
 
 /* The display list is a list of nodes.
@@ -165,7 +167,7 @@ fz_append_display_node(
 	const float *alpha,
 	const fz_matrix *ctm,
 	const fz_stroke_state *stroke,
-	void *private_data,
+	const void *private_data,
 	int private_data_len)
 {
 	fz_display_node node = { 0 };
@@ -1262,6 +1264,44 @@ fz_list_set_default_colorspaces(fz_context *ctx, fz_device *dev, fz_default_colo
 }
 
 static void
+fz_list_begin_layer(fz_context *ctx, fz_device *dev, const char *layer_name)
+{
+	fz_append_display_node(
+		ctx,
+		dev,
+		FZ_CMD_BEGIN_LAYER,
+		0, /* flags */
+		NULL,
+		NULL, /* path */
+		NULL, /* color */
+		NULL, /* colorspace */
+		NULL, /* alpha */
+		NULL,
+		NULL, /* stroke */
+		layer_name, /* private_data */
+		1+strlen(layer_name)); /* private_data_len */
+}
+
+static void
+fz_list_end_layer(fz_context *ctx, fz_device *dev)
+{
+	fz_append_display_node(
+		ctx,
+		dev,
+		FZ_CMD_END_LAYER,
+		0, /* flags */
+		NULL,
+		NULL, /* path */
+		NULL, /* color */
+		NULL, /* colorspace */
+		NULL, /* alpha */
+		NULL, /* ctm */
+		NULL, /* stroke */
+		NULL, /* private_data */
+		0); /* private_data_len */
+}
+
+static void
 fz_list_drop_device(fz_context *ctx, fz_device *dev)
 {
 	fz_list_device *writer = (fz_list_device *)dev;
@@ -1307,6 +1347,9 @@ fz_new_list_device(fz_context *ctx, fz_display_list *list)
 	dev->super.render_flags = fz_list_render_flags;
 	dev->super.set_default_colorspaces = fz_list_set_default_colorspaces;
 
+	dev->super.begin_layer = fz_list_begin_layer;
+	dev->super.end_layer = fz_list_end_layer;
+
 	dev->super.drop_device = fz_list_drop_device;
 
 	dev->list = list;
@@ -1645,7 +1688,8 @@ fz_run_display_list(fz_context *ctx, fz_display_list *list, fz_device *dev, cons
 
 		if (tiled ||
 			n.cmd == FZ_CMD_BEGIN_TILE || n.cmd == FZ_CMD_END_TILE ||
-			n.cmd == FZ_CMD_RENDER_FLAGS || n.cmd == FZ_CMD_DEFAULT_COLORSPACES)
+			n.cmd == FZ_CMD_RENDER_FLAGS || n.cmd == FZ_CMD_DEFAULT_COLORSPACES ||
+			n.cmd == FZ_CMD_BEGIN_LAYER || n.cmd == FZ_CMD_END_LAYER)
 		{
 			empty = 0;
 		}
@@ -1778,6 +1822,12 @@ visible:
 			case FZ_CMD_DEFAULT_COLORSPACES:
 				fz_set_default_colorspaces(ctx, dev, *(fz_default_colorspaces **)node);
 				break;
+			case FZ_CMD_BEGIN_LAYER:
+				fz_begin_layer(ctx, dev, (const char *)node);
+				break;
+			case FZ_CMD_END_LAYER:
+				fz_end_layer(ctx, dev);
+				break;
 			}
 		}
 		fz_catch(ctx)
diff --git a/source/fitz/svg-device.c b/source/fitz/svg-device.c
index 7c8dfd50..c5905938 100644
--- a/source/fitz/svg-device.c
+++ b/source/fitz/svg-device.c
@@ -66,6 +66,8 @@ struct svg_device_s
 	int num_images;
 	int max_images;
 	image *images;
+
+	int layers;
 };
 
 /* SVG is awkward about letting us define things within symbol definitions
@@ -1163,10 +1165,40 @@ svg_dev_end_tile(fz_context *ctx, fz_device *dev)
 }
 
 static void
+svg_dev_begin_layer(fz_context *ctx, fz_device *dev, const char *name)
+{
+	svg_device *sdev = (svg_device*)dev;
+	fz_output *out = sdev->out;
+
+	sdev->layers++;
+	fz_write_printf(ctx, out, "<g id=\"Layer-%d\" data-name=\"%s\">\n", sdev->layers, name);
+}
+
+static void
+svg_dev_end_layer(fz_context *ctx, fz_device *dev)
+{
+	svg_device *sdev = (svg_device*)dev;
+	fz_output *out = sdev->out;
+
+	if (sdev->layers == 0)
+		return;
+
+	sdev->layers--;
+	fz_write_printf(ctx, out, "</g>\n");
+}
+
+static void
 svg_dev_close_device(fz_context *ctx, fz_device *dev)
 {
 	svg_device *sdev = (svg_device*)dev;
 	fz_output *out = sdev->out;
+
+	while (sdev->layers > 0)
+	{
+		fz_write_printf(ctx, out, "</g>\n");
+		sdev->layers--;
+	}
+
 	fz_write_printf(ctx, out, "</svg>\n");
 }
 
@@ -1225,11 +1257,15 @@ fz_device *fz_new_svg_device(fz_context *ctx, fz_output *out, float page_width,
 	dev->super.begin_tile = svg_dev_begin_tile;
 	dev->super.end_tile = svg_dev_end_tile;
 
+	dev->super.begin_layer = svg_dev_begin_layer;
+	dev->super.end_layer = svg_dev_end_layer;
+
 	dev->super.hints |= FZ_MAINTAIN_CONTAINER_STACK;
 
 	dev->out = out;
 	dev->out_store = out;
 	dev->id = 0;
+	dev->layers = 0;
 	dev->text_as_text = (text_format == FZ_SVG_TEXT_AS_TEXT);
 	dev->reuse_images = reuse_images;
 
diff --git a/source/fitz/trace-device.c b/source/fitz/trace-device.c
index 65c91924..59d625c7 100644
--- a/source/fitz/trace-device.c
+++ b/source/fitz/trace-device.c
@@ -348,6 +348,20 @@ fz_trace_end_tile(fz_context *ctx, fz_device *dev)
 	fz_write_printf(ctx, out, "</tile>\n");
 }
 
+static void
+fz_trace_begin_layer(fz_context *ctx, fz_device *dev, const char *name)
+{
+	fz_output *out = ((fz_trace_device*)dev)->out;
+	fz_write_printf(ctx, out, "<layer name=\"%s\">\n", name);
+}
+
+static void
+fz_trace_end_layer(fz_context *ctx, fz_device *dev)
+{
+	fz_output *out = ((fz_trace_device*)dev)->out;
+	fz_write_printf(ctx, out, "</layer>\n");
+}
+
 fz_device *fz_new_trace_device(fz_context *ctx, fz_output *out)
 {
 	fz_trace_device *dev = fz_new_derived_device(ctx, fz_trace_device);
@@ -378,6 +392,9 @@ fz_device *fz_new_trace_device(fz_context *ctx, fz_output *out)
 	dev->super.begin_tile = fz_trace_begin_tile;
 	dev->super.end_tile = fz_trace_end_tile;
 
+	dev->super.begin_layer = fz_trace_begin_layer;
+	dev->super.end_layer = fz_trace_end_layer;
+
 	dev->out = out;
 
 	return (fz_device*)dev;
diff --git a/source/pdf/pdf-op-run.c b/source/pdf/pdf-op-run.c
index c51bb535..355e94d2 100644
--- a/source/pdf/pdf-op-run.c
+++ b/source/pdf/pdf-op-run.c
@@ -1987,14 +1987,34 @@ static void pdf_run_DP(fz_context *ctx, pdf_processor *proc, const char *tag, pd
 
 static void pdf_run_BMC(fz_context *ctx, pdf_processor *proc, const char *tag)
 {
+	pdf_run_processor *pr = (pdf_run_processor *)proc;
+
+	if (!tag)
+		tag = "UnnamedLayer";
+
+	fz_begin_layer(ctx, pr->dev, tag);
 }
 
 static void pdf_run_BDC(fz_context *ctx, pdf_processor *proc, const char *tag, pdf_obj *raw, pdf_obj *cooked)
 {
+	pdf_run_processor *pr = (pdf_run_processor *)proc;
+	const char *str;
+
+	if (!tag || strcmp(tag, "OC"))
+		return;
+
+	str = pdf_to_str_buf(ctx, pdf_dict_get(ctx, cooked, PDF_NAME_Name));
+	if (str == NULL)
+		str = "UnnamedLayer";
+
+	fz_begin_layer(ctx, pr->dev, str);
 }
 
 static void pdf_run_EMC(fz_context *ctx, pdf_processor *proc)
 {
+	pdf_run_processor *pr = (pdf_run_processor *)proc;
+
+	fz_end_layer(ctx, pr->dev);
 }
 
 /* compatibility */