GPU: Add Image property to allow high bitdepth support on a per image basis

This adds the `Half Float Precision` option in the image property panel.
This option is only available on float textures and is enabled by default.

Adding a flag inside the imbuf (IB_halffloat) on load is done for EXR and PSD formats that can store half floating point (16bits/channels).
The option is then not displayed in this case and forced.

Related task T73086

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D6891

1 files changed, 18 insertions, 0 deletions

diff --git a/source/blender/makesrna/intern/rna_image.c b/source/blender/makesrna/intern/rna_image.c
index 9f5f1635536..94b5786665c 100644
--- a/source/blender/makesrna/intern/rna_image.c
+++ b/source/blender/makesrna/intern/rna_image.c
@@ -193,6 +193,17 @@ static char *rna_ImageUser_path(PointerRNA *ptr)
   return BLI_strdup("");
 }
 
+static void rna_Image_gpu_texture_update(Main *bmain, Scene *scene, PointerRNA *ptr)
+{
+  Image *ima = (Image *)ptr->owner_id;
+
+  if (!G.background) {
+    GPU_free_image(ima);
+  }
+
+  WM_main_add_notifier(NC_IMAGE | ND_DISPLAY, &ima->id);
+}
+
 static const EnumPropertyItem *rna_Image_source_itemf(bContext *UNUSED(C),
                                                       PointerRNA *ptr,
                                                       PropertyRNA *UNUSED(prop),
@@ -1119,6 +1130,13 @@ static void rna_def_image(BlenderRNA *brna)
                            "when saving and loading the image");
   RNA_def_property_update(prop, NC_IMAGE | ND_DISPLAY, "rna_Image_colormanage_update");
 
+  prop = RNA_def_property(srna, "use_half_precision", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_negative_sdna(prop, NULL, "flag", IMA_HIGH_BITDEPTH);
+  RNA_def_property_ui_text(prop,
+                           "Half Float Precision",
+                           "Use 16bits per channel to lower the memory usage during rendering");
+  RNA_def_property_update(prop, NC_IMAGE | ND_DISPLAY, "rna_Image_gpu_texture_update");
+
   /* multiview */
   prop = RNA_def_property(srna, "views_format", PROP_ENUM, PROP_NONE);
   RNA_def_property_override_flag(prop, PROPOVERRIDE_OVERRIDABLE_LIBRARY);