Issue #19:

Create a base class GdsOutputRenderer with a virtual function render_output,
which can be derived by the different output renderers.

include/gds-render/output-renderers/gds-output-renderer.h

@@ -0,0 +1,92 @@
+/*
+ * GDSII-Converter
+ * Copyright (C) 2018  Mario Hüttel <mario.huettel@gmx.net>
+ *
+ * This file is part of GDSII-Converter.
+ *
+ * GDSII-Converter is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * GDSII-Converter is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GDSII-Converter.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * @file gds-output-renderer.h
+ * @brief Header for output renderer base class
+ * @author Mario Hüttel <mario.huettel@gmx.net>
+ */
+
+/**
+ * @addtogroup GdsOutputRenderer
+ * @{
+ */
+
+#ifndef _GDS_OUTPUT_RENDERER_H_
+#define _GDS_OUTPUT_RENDERER_H_
+
+#include <gds-render/gds-utils/gds-types.h>
+#include <glib-object.h>
+#include <glib.h>
+
+G_BEGIN_DECLS
+
+#define GDS_RENDER_TYPE_OUTPUT_RENDERER (gds_output_renderer_get_type())
+
+G_DECLARE_DERIVABLE_TYPE(GdsOutputRenderer, gds_output_renderer, GDS_RENDER, OUTPUT_RENDERER, GObject);
+
+/**
+ * @brief Base output renderer class structure.
+ * @note This structure is only used for internal inheritance of GObjects. Do not use in code outside of these classes.
+ */
+struct _GdsOutputRendererClass {
+	GObjectClass parent_class;
+
+	/**
+	 * @brief Virtual render output function. Overwritten by final class implementation
+	 */
+	int (*render_output)(GdsOutputRenderer *renderer,
+	                        struct gds_cell *cell,
+	                        GList *layer_infos,
+	                        const char *output_file,
+	                        double scale);
+	gpointer padding[4];
+};
+
+enum {
+	GDS_OUTPUT_RENDERER_GEN_ERR = -100, /**< @brief Error set by the _GdsOutputRendererClass::render_output virtual function, if renderer is invalid. */
+	GDS_OUTPUT_RENDERER_PARAM_ERR = -200 /**< @brief Error set by the _GdsOutputRendererClass::render_output virtual function, if parameters are faulty. */
+};
+
+/**
+ * @brief Create a new GdsOutputRenderer GObject.
+ * @return New object
+ */
+GdsOutputRenderer *gds_output_renderer_new();
+
+/**
+ * @brief gds_output_renderer_render_output
+ * @param renderer Renderer object
+ * @param cell Cell to render
+ * @param layer_infos List of Layer information (@ref layer_info)
+ * @param output_file Output file name
+ * @param scale scale value. The output is scaled *down* by this value
+ * @return 0 if successful
+ */
+int gds_output_renderer_render_output(GdsOutputRenderer *renderer,
+                                        struct gds_cell *cell,
+                                        GList *layer_infos,
+                                        const char *output_file,
+                                        double scale);
+
+G_END_DECLS
+
+#endif /* _GDS_OUTPUT_RENDERER_H_ */
+
+/** @} */

output-renderers/gds-output-renderer.c

@@ -0,0 +1,98 @@
+/*
+ * GDSII-Converter
+ * Copyright (C) 2019  Mario Hüttel <mario.huettel@gmx.net>
+ *
+ * This file is part of GDSII-Converter.
+ *
+ * GDSII-Converter is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * GDSII-Converter is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GDSII-Converter.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+  * @file gds-output-renderer.c
+  * @brief Base GObject class for output renderers
+  *
+  * All output renderers are derived from this class
+  *
+  * @author Mario Hüttel <mario.huettel@gmx.net>
+  */
+
+/** @addtogroup GdsOutputRenderer
+ *  @{
+ */
+
+#include <gds-render/output-renderers/gds-output-renderer.h>
+
+typedef struct {
+	gpointer padding[12];
+} GdsOutputRendererPrivate;
+
+G_DEFINE_TYPE_WITH_PRIVATE(GdsOutputRenderer, gds_output_renderer, G_TYPE_OBJECT)
+
+static int gds_output_renderer_render_dummy(GdsOutputRenderer *renderer,
+						struct gds_cell *cell,
+						GList *layer_infos,
+						const char *output_file,
+						double scale)
+{
+	(void)renderer;
+	(void)cell;
+	(void)layer_infos;
+	(void)output_file;
+	(void)scale;
+
+	g_warning("Output renderer does not define a render_output function!");
+	return 0;
+}
+
+static void gds_output_renderer_class_init(GdsOutputRendererClass *klass)
+{
+	klass->render_output = gds_output_renderer_render_dummy;
+}
+
+void gds_output_renderer_init(GdsOutputRenderer *self)
+{
+	(void)self;
+
+	return;
+}
+
+GdsOutputRenderer *gds_output_renderer_new()
+{
+	return GDS_RENDER_OUTPUT_RENDERER(g_object_new(GDS_RENDER_TYPE_OUTPUT_RENDERER, NULL));
+}
+
+int gds_output_renderer_render_output(GdsOutputRenderer *renderer, struct gds_cell *cell, GList *layer_infos, const char *output_file, double scale)
+{
+	GdsOutputRendererClass *klass;
+
+	if (GDS_RENDER_IS_OUTPUT_RENDERER(renderer) == FALSE) {
+		g_error("Output Renderer not valid.");
+		return GDS_OUTPUT_RENDERER_GEN_ERR;
+	}
+
+	if (!cell || !layer_infos || !output_file) {
+		g_error("Output renderer called with insufficient parameters.");
+		return GDS_OUTPUT_RENDERER_PARAM_ERR;
+	}
+
+	klass = GDS_RENDER_OUTPUT_RENDERER_GET_CLASS(renderer);
+	if (klass->render_output == NULL) {
+		g_critical("Output Renderer: Rendering function broken. This is a bug.");
+		return GDS_OUTPUT_RENDERER_GEN_ERR;
+	}
+
+	return klass->render_output(renderer, cell, layer_infos, output_file, scale);
+}
+
+
+/** @} */