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, 430 insertions, 0 deletions

diff --git a/source/blender/editors/io/io_gpencil_export.c b/source/blender/editors/io/io_gpencil_export.c
new file mode 100644
index 00000000000..6f1e503403b
--- /dev/null
+++ b/source/blender/editors/io/io_gpencil_export.c
@@ -0,0 +1,430 @@
+/*
+ * 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.
+ */
+
+/** \file
+ * \ingroup editor/io
+ */
+
+#include "BLI_path_util.h"
+#include "BLI_string.h"
+
+#include "DNA_gpencil_types.h"
+#include "DNA_space_types.h"
+
+#include "BKE_gpencil.h"
+#include "BKE_main.h"
+#include "BKE_report.h"
+#include "BKE_screen.h"
+
+#include "BLT_translation.h"
+
+#include "RNA_access.h"
+#include "RNA_define.h"
+
+#include "UI_interface.h"
+#include "UI_resources.h"
+
+#include "WM_api.h"
+#include "WM_types.h"
+
+#include "DEG_depsgraph.h"
+#include "DEG_depsgraph_query.h"
+
+#include "io_gpencil.h"
+
+#include "gpencil_io.h"
+
+/* Definition of enum elements to export. */
+/* Common props for exporting. */
+static void gpencil_export_common_props_definition(wmOperatorType *ot)
+{
+  static const EnumPropertyItem select_items[] = {
+      {GP_EXPORT_ACTIVE, "ACTIVE", 0, "Active", "Include only the active object"},
+      {GP_EXPORT_SELECTED, "SELECTED", 0, "Selected", "Include selected objects"},
+      {GP_EXPORT_VISIBLE, "VISIBLE", 0, "Visible", "Include all visible objects"},
+      {0, NULL, 0, NULL, NULL},
+  };
+
+  RNA_def_boolean(ot->srna, "use_fill", true, "Fill", "Export strokes with fill enabled");
+  RNA_def_enum(ot->srna,
+               "selected_object_type",
+               select_items,
+               GP_EXPORT_SELECTED,
+               "Object",
+               "Which objects to include in the export");
+  RNA_def_float(ot->srna,
+                "stroke_sample",
+                0.0f,
+                0.0f,
+                100.0f,
+                "Sampling",
+                "Precision of stroke sampling. Low values mean a more precise result, and zero "
+                "disables sampling",
+                0.0f,
+                100.0f);
+  RNA_def_boolean(ot->srna,
+                  "use_normalized_thickness",
+                  false,
+                  "Normalize",
+                  "Export strokes with constant thickness");
+}
+
+static void set_export_filepath(bContext *C, wmOperator *op)
+{
+  if (!RNA_struct_property_is_set(op->ptr, "filepath")) {
+    Main *bmain = CTX_data_main(C);
+    char filepath[FILE_MAX];
+
+    if (BKE_main_blendfile_path(bmain)[0] == '\0') {
+      BLI_strncpy(filepath, "untitled", sizeof(filepath));
+    }
+    else {
+      BLI_strncpy(filepath, BKE_main_blendfile_path(bmain), sizeof(filepath));
+    }
+
+    BLI_path_extension_replace(filepath, sizeof(filepath), ".pdf");
+    RNA_string_set(op->ptr, "filepath", filepath);
+  }
+}
+
+/* <-------- SVG single frame export. --------> */
+#ifdef WITH_PUGIXML
+static bool wm_gpencil_export_svg_common_check(bContext *UNUSED(C), wmOperator *op)
+{
+  char filepath[FILE_MAX];
+  RNA_string_get(op->ptr, "filepath", filepath);
+
+  if (!BLI_path_extension_check(filepath, ".svg")) {
+    BLI_path_extension_ensure(filepath, FILE_MAX, ".svg");
+    RNA_string_set(op->ptr, "filepath", filepath);
+    return true;
+  }
+
+  return false;
+}
+
+static int wm_gpencil_export_svg_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
+{
+  set_export_filepath(C, op);
+
+  WM_event_add_fileselect(C, op);
+
+  return OPERATOR_RUNNING_MODAL;
+}
+
+static int wm_gpencil_export_svg_exec(bContext *C, wmOperator *op)
+{
+  Scene *scene = CTX_data_scene(C);
+  Object *ob = CTX_data_active_object(C);
+
+  if (!RNA_struct_property_is_set(op->ptr, "filepath")) {
+    BKE_report(op->reports, RPT_ERROR, "No filename given");
+    return OPERATOR_CANCELLED;
+  }
+
+  ARegion *region = get_invoke_region(C);
+  if (region == NULL) {
+    BKE_report(op->reports, RPT_ERROR, "Unable to find valid 3D View area");
+    return OPERATOR_CANCELLED;
+  }
+  View3D *v3d = get_invoke_view3d(C);
+
+  char filename[FILE_MAX];
+  RNA_string_get(op->ptr, "filepath", filename);
+
+  const bool use_fill = RNA_boolean_get(op->ptr, "use_fill");
+  const bool use_norm_thickness = RNA_boolean_get(op->ptr, "use_normalized_thickness");
+  const eGpencilExportSelect select_mode = RNA_enum_get(op->ptr, "selected_object_type");
+
+  const bool use_clip_camera = RNA_boolean_get(op->ptr, "use_clip_camera");
+
+  /* Set flags. */
+  int flag = 0;
+  SET_FLAG_FROM_TEST(flag, use_fill, GP_EXPORT_FILL);
+  SET_FLAG_FROM_TEST(flag, use_norm_thickness, GP_EXPORT_NORM_THICKNESS);
+  SET_FLAG_FROM_TEST(flag, use_clip_camera, GP_EXPORT_CLIP_CAMERA);
+
+  GpencilIOParams params = {.C = C,
+                            .region = region,
+                            .v3d = v3d,
+                            .ob = ob,
+                            .mode = GP_EXPORT_TO_SVG,
+                            .frame_start = CFRA,
+                            .frame_end = CFRA,
+                            .frame_cur = CFRA,
+                            .flag = flag,
+                            .scale = 1.0f,
+                            .select_mode = select_mode,
+                            .frame_mode = GP_EXPORT_FRAME_ACTIVE,
+                            .stroke_sample = RNA_float_get(op->ptr, "stroke_sample"),
+                            .resolution = 1.0f};
+
+  /* Do export. */
+  WM_cursor_wait(true);
+  const bool done = gpencil_io_export(filename, &params);
+  WM_cursor_wait(false);
+
+  if (!done) {
+    BKE_report(op->reports, RPT_WARNING, "Unable to export SVG");
+  }
+
+  return OPERATOR_FINISHED;
+}
+
+static void ui_gpencil_export_svg_settings(uiLayout *layout, PointerRNA *imfptr)
+{
+  uiLayout *box, *row;
+
+  uiLayoutSetPropSep(layout, true);
+  uiLayoutSetPropDecorate(layout, false);
+
+  box = uiLayoutBox(layout);
+
+  row = uiLayoutRow(box, false);
+  uiItemL(row, IFACE_("Scene Options"), ICON_NONE);
+
+  row = uiLayoutRow(box, false);
+  uiItemR(row, imfptr, "selected_object_type", 0, NULL, ICON_NONE);
+
+  box = uiLayoutBox(layout);
+  row = uiLayoutRow(box, false);
+  uiItemL(row, IFACE_("Export Options"), ICON_NONE);
+
+  uiLayout *col = uiLayoutColumn(box, false);
+  uiItemR(col, imfptr, "stroke_sample", 0, NULL, ICON_NONE);
+  uiItemR(col, imfptr, "use_fill", 0, NULL, ICON_NONE);
+  uiItemR(col, imfptr, "use_normalized_thickness", 0, NULL, ICON_NONE);
+  uiItemR(col, imfptr, "use_clip_camera", 0, NULL, ICON_NONE);
+}
+
+static void wm_gpencil_export_svg_draw(bContext *UNUSED(C), wmOperator *op)
+{
+  PointerRNA ptr;
+
+  RNA_pointer_create(NULL, op->type->srna, op->properties, &ptr);
+
+  ui_gpencil_export_svg_settings(op->layout, &ptr);
+}
+
+static bool wm_gpencil_export_svg_poll(bContext *C)
+{
+  if ((CTX_wm_window(C) == NULL) || (CTX_data_mode_enum(C) != CTX_MODE_OBJECT)) {
+    return false;
+  }
+
+  return true;
+}
+
+void WM_OT_gpencil_export_svg(wmOperatorType *ot)
+{
+  ot->name = "Export to SVG";
+  ot->description = "Export grease pencil to SVG";
+  ot->idname = "WM_OT_gpencil_export_svg";
+
+  ot->invoke = wm_gpencil_export_svg_invoke;
+  ot->exec = wm_gpencil_export_svg_exec;
+  ot->poll = wm_gpencil_export_svg_poll;
+  ot->ui = wm_gpencil_export_svg_draw;
+  ot->check = wm_gpencil_export_svg_common_check;
+
+  WM_operator_properties_filesel(ot,
+                                 FILE_TYPE_OBJECT_IO,
+                                 FILE_BLENDER,
+                                 FILE_SAVE,
+                                 WM_FILESEL_FILEPATH | WM_FILESEL_SHOW_PROPS,
+                                 FILE_DEFAULTDISPLAY,
+                                 FILE_SORT_ALPHA);
+
+  gpencil_export_common_props_definition(ot);
+
+  RNA_def_boolean(ot->srna,
+                  "use_clip_camera",
+                  false,
+                  "Clip Camera",
+                  "Clip drawings to camera size when export in camera view");
+}
+#endif
+
+/* <-------- PDF single frame export. --------> */
+#ifdef WITH_HARU
+static bool wm_gpencil_export_pdf_common_check(bContext *UNUSED(C), wmOperator *op)
+{
+
+  char filepath[FILE_MAX];
+  RNA_string_get(op->ptr, "filepath", filepath);
+
+  if (!BLI_path_extension_check(filepath, ".pdf")) {
+    BLI_path_extension_ensure(filepath, FILE_MAX, ".pdf");
+    RNA_string_set(op->ptr, "filepath", filepath);
+    return true;
+  }
+
+  return false;
+}
+
+static int wm_gpencil_export_pdf_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
+{
+  set_export_filepath(C, op);
+
+  WM_event_add_fileselect(C, op);
+
+  return OPERATOR_RUNNING_MODAL;
+}
+
+static int wm_gpencil_export_pdf_exec(bContext *C, wmOperator *op)
+{
+  Scene *scene = CTX_data_scene(C);
+  Object *ob = CTX_data_active_object(C);
+
+  if (!RNA_struct_property_is_set(op->ptr, "filepath")) {
+    BKE_report(op->reports, RPT_ERROR, "No filename given");
+    return OPERATOR_CANCELLED;
+  }
+
+  ARegion *region = get_invoke_region(C);
+  if (region == NULL) {
+    BKE_report(op->reports, RPT_ERROR, "Unable to find valid 3D View area");
+    return OPERATOR_CANCELLED;
+  }
+  View3D *v3d = get_invoke_view3d(C);
+
+  char filename[FILE_MAX];
+  RNA_string_get(op->ptr, "filepath", filename);
+
+  const bool use_fill = RNA_boolean_get(op->ptr, "use_fill");
+  const bool use_norm_thickness = RNA_boolean_get(op->ptr, "use_normalized_thickness");
+  const short select_mode = RNA_enum_get(op->ptr, "selected_object_type");
+  const short frame_mode = RNA_enum_get(op->ptr, "frame_mode");
+
+  /* Set flags. */
+  int flag = 0;
+  SET_FLAG_FROM_TEST(flag, use_fill, GP_EXPORT_FILL);
+  SET_FLAG_FROM_TEST(flag, use_norm_thickness, GP_EXPORT_NORM_THICKNESS);
+
+  GpencilIOParams params = {.C = C,
+                            .region = region,
+                            .v3d = v3d,
+                            .ob = ob,
+                            .mode = GP_EXPORT_TO_PDF,
+                            .frame_start = SFRA,
+                            .frame_end = EFRA,
+                            .frame_cur = CFRA,
+                            .flag = flag,
+                            .scale = 1.0f,
+                            .select_mode = select_mode,
+                            .frame_mode = frame_mode,
+                            .stroke_sample = RNA_float_get(op->ptr, "stroke_sample"),
+                            .resolution = 1.0f};
+
+  /* Do export. */
+  WM_cursor_wait(true);
+  const bool done = gpencil_io_export(filename, &params);
+  WM_cursor_wait(false);
+
+  if (!done) {
+    BKE_report(op->reports, RPT_WARNING, "Unable to export PDF");
+  }
+
+  return OPERATOR_FINISHED;
+}
+
+static void ui_gpencil_export_pdf_settings(uiLayout *layout, PointerRNA *imfptr)
+{
+  uiLayout *box, *row, *col, *sub;
+
+  uiLayoutSetPropSep(layout, true);
+  uiLayoutSetPropDecorate(layout, false);
+
+  box = uiLayoutBox(layout);
+
+  row = uiLayoutRow(box, false);
+  uiItemL(row, IFACE_("Scene Options"), ICON_NONE);
+
+  row = uiLayoutRow(box, false);
+  uiItemR(row, imfptr, "selected_object_type", 0, NULL, ICON_NONE);
+
+  box = uiLayoutBox(layout);
+  row = uiLayoutRow(box, false);
+  uiItemL(row, IFACE_("Export Options"), ICON_NONE);
+
+  col = uiLayoutColumn(box, false);
+  sub = uiLayoutColumn(col, true);
+  uiItemR(sub, imfptr, "frame_mode", 0, IFACE_("Frame"), ICON_NONE);
+
+  uiLayoutSetPropSep(box, true);
+
+  sub = uiLayoutColumn(col, true);
+  uiItemR(sub, imfptr, "stroke_sample", 0, NULL, ICON_NONE);
+  uiItemR(sub, imfptr, "use_fill", 0, NULL, ICON_NONE);
+  uiItemR(sub, imfptr, "use_normalized_thickness", 0, NULL, ICON_NONE);
+}
+
+static void wm_gpencil_export_pdf_draw(bContext *UNUSED(C), wmOperator *op)
+{
+  PointerRNA ptr;
+
+  RNA_pointer_create(NULL, op->type->srna, op->properties, &ptr);
+
+  ui_gpencil_export_pdf_settings(op->layout, &ptr);
+}
+
+static bool wm_gpencil_export_pdf_poll(bContext *C)
+{
+  if ((CTX_wm_window(C) == NULL) || (CTX_data_mode_enum(C) != CTX_MODE_OBJECT)) {
+    return false;
+  }
+
+  return true;
+}
+
+void WM_OT_gpencil_export_pdf(wmOperatorType *ot)
+{
+  ot->name = "Export to PDF";
+  ot->description = "Export grease pencil to PDF";
+  ot->idname = "WM_OT_gpencil_export_pdf";
+
+  ot->invoke = wm_gpencil_export_pdf_invoke;
+  ot->exec = wm_gpencil_export_pdf_exec;
+  ot->poll = wm_gpencil_export_pdf_poll;
+  ot->ui = wm_gpencil_export_pdf_draw;
+  ot->check = wm_gpencil_export_pdf_common_check;
+
+  WM_operator_properties_filesel(ot,
+                                 FILE_TYPE_OBJECT_IO,
+                                 FILE_BLENDER,
+                                 FILE_SAVE,
+                                 WM_FILESEL_FILEPATH | WM_FILESEL_SHOW_PROPS,
+                                 FILE_DEFAULTDISPLAY,
+                                 FILE_SORT_ALPHA);
+
+  static const EnumPropertyItem gpencil_export_frame_items[] = {
+      {GP_EXPORT_FRAME_ACTIVE, "ACTIVE", 0, "Active", "Include only active frame"},
+      {GP_EXPORT_FRAME_SELECTED, "SELECTED", 0, "Selected", "Include selected frames"},
+      {0, NULL, 0, NULL, NULL},
+  };
+
+  gpencil_export_common_props_definition(ot);
+  ot->prop = RNA_def_enum(ot->srna,
+                          "frame_mode",
+                          gpencil_export_frame_items,
+                          GP_EXPORT_ACTIVE,
+                          "Frames",
+                          "Which frames to include in the export");
+}
+#endif