Refactor: move preview image .blend I/O to blenkernel

Ref T76372

2 files changed, 49 insertions, 0 deletions

diff --git a/source/blender/blenkernel/BKE_icons.h b/source/blender/blenkernel/BKE_icons.h
index 8a4fc78eb97..e40489a80da 100644
--- a/source/blender/blenkernel/BKE_icons.h
+++ b/source/blender/blenkernel/BKE_icons.h
@@ -78,6 +78,8 @@ struct ImBuf;
 struct PreviewImage;
 struct StudioLight;
 struct bGPDlayer;
+struct BlendWriter;
+struct BlendDataReader;
 
 enum eIconSizes;
 
@@ -156,6 +158,9 @@ struct PreviewImage *BKE_previewimg_cached_thumbnail_read(const char *name,
 void BKE_previewimg_cached_release(const char *name);
 void BKE_previewimg_cached_release_pointer(struct PreviewImage *prv);
 
+void BKE_previewimg_blend_write(struct BlendWriter *writer, const struct PreviewImage *prv);
+void BKE_previewimg_blend_read(struct BlendDataReader *reader, struct PreviewImage *prv);
+
 int BKE_icon_geom_ensure(struct Icon_Geom *geom);
 struct Icon_Geom *BKE_icon_geom_from_memory(const uchar *data, size_t data_len);
 struct Icon_Geom *BKE_icon_geom_from_file(const char *filename);
diff --git a/source/blender/blenkernel/intern/icons.c b/source/blender/blenkernel/intern/icons.c
index 6f181cc74d5..01e3eef4e19 100644
--- a/source/blender/blenkernel/intern/icons.c
+++ b/source/blender/blenkernel/intern/icons.c
@@ -59,6 +59,8 @@
 #include "IMB_imbuf_types.h"
 #include "IMB_thumbs.h"
 
+#include "BLO_read_write.h"
+
 /**
  * Only allow non-managed icons to be removed (by Python for eg).
  * Previews & ID's have their own functions to remove icons.
@@ -515,6 +517,48 @@ void BKE_previewimg_ensure(PreviewImage *prv, const int size)
   }
 }
 
+void BKE_previewimg_blend_write(BlendWriter *writer, const PreviewImage *prv)
+{
+  /* Note we write previews also for undo steps. It takes up some memory,
+   * but not doing so would causes all previews to be re-rendered after
+   * undo which is too expensive. */
+
+  if (prv == NULL) {
+    return;
+  }
+
+  PreviewImage prv_copy = *prv;
+  /* don't write out large previews if not requested */
+  if (!(U.flag & USER_SAVE_PREVIEWS)) {
+    prv_copy.w[1] = 0;
+    prv_copy.h[1] = 0;
+    prv_copy.rect[1] = NULL;
+  }
+  BLO_write_struct_at_address(writer, PreviewImage, prv, &prv_copy);
+  if (prv_copy.rect[0]) {
+    BLO_write_uint32_array(writer, prv_copy.w[0] * prv_copy.h[0], prv_copy.rect[0]);
+  }
+  if (prv_copy.rect[1]) {
+    BLO_write_uint32_array(writer, prv_copy.w[1] * prv_copy.h[1], prv_copy.rect[1]);
+  }
+}
+
+void BKE_previewimg_blend_read(BlendDataReader *reader, PreviewImage *prv)
+{
+  if (prv == NULL) {
+    return;
+  }
+
+  for (int i = 0; i < NUM_ICON_SIZES; i++) {
+    if (prv->rect[i]) {
+      BLO_read_data_address(reader, &prv->rect[i]);
+    }
+    prv->gputexture[i] = NULL;
+  }
+  prv->icon_id = 0;
+  prv->tag = 0;
+}
+
 void BKE_icon_changed(const int icon_id)
 {
   BLI_assert(BLI_thread_is_main());