Paint refactoring commit, non-disruptive (in theory :p)

* Fix precision overflow issue with overlay previews,
* Expose alpha mask mapping to UI (still not functional but coming soon).
* More overlay refactoring:

Overlay now does minimal checking for texture refresh.
Instead, we now have invalidation flags to set an aspect of the brush
overlay as invalid. This is necessary because this way we will be able to
separate and preview different brush attributes on the overlays, using
different textures:

These attributes/aspects are:

Primary texture (main texture for sculpt, vertex, imapaint)
Secondary texture (mask/alpha texture for imapaint)
Cursor texture (cursor texture. It involves brush strength and curves)

Modified the relevant RNA property update functions and C update callback
functions to call the relevant cursor invalidation functions instead
of checking every frame for multiple properties.

Properties that affect this are:

Image changes, if image is used by current brush,
Texture slot changes, similarly
Curve changes,
Object mode change invalidates the cursor
Paint tool change invalidates the cursor.

These changes give slightly more invalidation cases than simply
comparing the relevant properties each frame, but these do not occur in
performance critical moments and it's a much more elegant system than
adding more variables to check per frame each time we add something on
the system.

1 files changed, 18 insertions, 6 deletions

diff --git a/source/blender/blenkernel/BKE_paint.h b/source/blender/blenkernel/BKE_paint.h
index 35941d0a05a..810ff2faabc 100644
--- a/source/blender/blenkernel/BKE_paint.h
+++ b/source/blender/blenkernel/BKE_paint.h
@@ -36,6 +36,7 @@ struct bContext;
 struct BMesh;
 struct BMFace;
 struct Brush;
+struct CurveMapping;
 struct MDisps;
 struct MeshElemMap;
 struct GridPaintMask;
@@ -47,6 +48,7 @@ struct Paint;
 struct PBVH;
 struct Scene;
 struct StrokeCache;
+struct Tex;
 struct ImagePool;
 struct UnifiedPaintSettings;
 
@@ -65,16 +67,26 @@ typedef enum PaintMode {
 	PAINT_INVALID = 6
 } PaintMode;
 
+/* overlay invalidation */
+#define PAINT_INVALID_OVERLAY_TEXTURE_PRIMARY 1
+#define PAINT_INVALID_OVERLAY_TEXTURE_SECONDARY 2
+#define PAINT_INVALID_OVERLAY_CURVE 4
+
+void BKE_paint_invalidate_overlay_tex (struct Scene *scene,const struct Tex *tex);
+void BKE_paint_invalidate_cursor_overlay (struct Scene *scene, struct CurveMapping *curve);
+void BKE_paint_invalidate_overlay_all(void);
+int BKE_paint_get_overlay_flags (void);
+void BKE_paint_reset_overlay_invalid (void);
+
 void BKE_paint_init(struct Paint *p, const char col[3]);
 void BKE_paint_free(struct Paint *p);
 void BKE_paint_copy(struct Paint *src, struct Paint *tar);
 
-/* TODO, give these BKE_ prefix too */
-struct Paint *paint_get_active(struct Scene *sce);
-struct Paint *paint_get_active_from_context(const struct bContext *C);
-PaintMode paintmode_get_active_from_context(const struct bContext *C);
-struct Brush *paint_brush(struct Paint *paint);
-void paint_brush_set(struct Paint *paint, struct Brush *br);
+struct Paint *BKE_paint_get_active(struct Scene *sce);
+struct Paint *BKE_paint_get_active_from_context(const struct bContext *C);
+PaintMode BKE_paintmode_get_active_from_context(const struct bContext *C);
+struct Brush *BKE_paint_brush(struct Paint *paint);
+void BKE_paint_brush_set(struct Paint *paint, struct Brush *br);
 
 /* testing face select mode
  * Texture paint could be removed since selected faces are not used