GPencil: New modules for Import and Export

This patch adds support to export and import grease pencil in several formats.

Inlude:

* Export SVG
* Export PDF (always from camera view)

* Import SVG

The import and export only support solid colors and not gradients or textures.

Requires libharu and pugixml.

For importing SVG, the NanoSVG lib is used, but this does not require installation (just a .h file embedded in the project  folder)

Example of PDF export: https://youtu.be/BMm0KeMJsI4

Reviewed By: #grease_pencil, HooglyBoogly

Maniphest Tasks: T83190, T79875, T83191, T83192

Differential Revision: https://developer.blender.org/D10482

1 files changed, 92 insertions, 0 deletions

diff --git a/source/blender/io/gpencil/gpencil_io.h b/source/blender/io/gpencil/gpencil_io.h
new file mode 100644
index 00000000000..f4b2e59f8c5
--- /dev/null
+++ b/source/blender/io/gpencil/gpencil_io.h
@@ -0,0 +1,92 @@
+/*
+ * 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.
+ *
+ * This program 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 this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2020 Blender Foundation
+ * All rights reserved.
+ */
+#pragma once
+
+/** \file
+ * \ingroup bgpencil
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct ARegion;
+struct bContext;
+struct Object;
+struct View3D;
+
+typedef struct GpencilIOParams {
+  bContext *C;
+  ARegion *region;
+  View3D *v3d;
+  /** Grease pencil object. */
+  Object *ob;
+  /** Mode (see eGpencilIO_Modes). */
+  uint16_t mode;
+  int32_t frame_start;
+  int32_t frame_end;
+  int32_t frame_cur;
+  uint32_t flag;
+  float scale;
+  /** Select mode (see eGpencilExportSelect). */
+  uint16_t select_mode;
+  /** Frame mode (see eGpencilExportFrame). */
+  uint16_t frame_mode;
+  /** Stroke sampling factor. */
+  float stroke_sample;
+  int32_t resolution;
+} GpencilIOParams;
+
+/* GpencilIOParams->flag. */
+typedef enum eGpencilIOParams_Flag {
+  /* Export Filled strokes. */
+  GP_EXPORT_FILL = (1 << 0),
+  /* Export normalized thickness. */
+  GP_EXPORT_NORM_THICKNESS = (1 << 1),
+  /* Clip camera area. */
+  GP_EXPORT_CLIP_CAMERA = (1 << 2),
+} eGpencilIOParams_Flag;
+
+typedef enum eGpencilIO_Modes {
+  GP_EXPORT_TO_SVG = 0,
+  GP_EXPORT_TO_PDF = 1,
+
+  GP_IMPORT_FROM_SVG = 2,
+  /* Add new formats here. */
+} eGpencilIO_Modes;
+
+/* Object to be exported. */
+typedef enum eGpencilExportSelect {
+  GP_EXPORT_ACTIVE = 0,
+  GP_EXPORT_SELECTED = 1,
+  GP_EXPORT_VISIBLE = 2,
+} eGpencilExportSelect;
+
+/* Framerange to be exported. */
+typedef enum eGpencilExportFrame {
+  GP_EXPORT_FRAME_ACTIVE = 0,
+  GP_EXPORT_FRAME_SELECTED = 1,
+} eGpencilExportFrame;
+
+bool gpencil_io_export(const char *filename, struct GpencilIOParams *iparams);
+bool gpencil_io_import(const char *filename, struct GpencilIOParams *iparams);
+
+#ifdef __cplusplus
+}
+#endif