GPU: Simplify select shaders.

The shaders are: `GPU_SHADER_3D_FLAT_SELECT_ID` and `GPU_SHADER_3D_UNIFORM_SELECT_ID`.
This commit allows the drawing of the mesh select ids to be done on a 32UI format texture.
This simplifies the shader that previously acted on the backbuffer and had to do an uint to rgba conversion.

Differential Revision: https://developer.blender.org/D4350

2 files changed, 23 insertions, 15 deletions

diff --git a/source/blender/editors/include/ED_mesh.h b/source/blender/editors/include/ED_mesh.h
index 7318df8adab..e8c5e0dd789 100644
--- a/source/blender/editors/include/ED_mesh.h
+++ b/source/blender/editors/include/ED_mesh.h
@@ -237,7 +237,7 @@ void EDBM_project_snap_verts(struct bContext *C, struct ARegion *ar, struct BMEd
 /* editface.c */
 void paintface_flush_flags(struct bContext *C, struct Object *ob, short flag);
 bool paintface_mouse_select(struct bContext *C, struct Object *ob, const int mval[2], bool extend, bool deselect, bool toggle);
-int  do_paintface_box_select(struct ViewContext *vc, struct rcti *rect, int sel_op);
+int  do_paintface_box_select(struct ViewContext *vc, const struct rcti *rect, int sel_op);
 void paintface_deselect_all_visible(struct bContext *C, struct Object *ob, int action, bool flush_flags);
 void paintface_select_linked(struct bContext *C, struct Object *ob, const int mval[2], const bool select);
 bool paintface_minmax(struct Object *ob, float r_min[3], float r_max[3]);
@@ -365,9 +365,9 @@ int *mesh_get_x_mirror_faces(struct Object *ob, struct BMEditMesh *em, struct Me
 
 int ED_mesh_mirror_get_vert(struct Object *ob, int index);
 
-bool ED_mesh_pick_vert(struct bContext *C,      struct Object *ob, const int mval[2], unsigned int *index, int size, bool use_zbuf);
-bool ED_mesh_pick_face(struct bContext *C,      struct Object *ob, const int mval[2], unsigned int *index, int size);
-bool ED_mesh_pick_face_vert(struct bContext *C, struct Object *ob, const int mval[2], unsigned int *index, int size);
+bool ED_mesh_pick_vert(struct bContext *C,      struct Object *ob, const int mval[2], unsigned int *index, int dist_px, bool use_zbuf);
+bool ED_mesh_pick_face(struct bContext *C,      struct Object *ob, const int mval[2], unsigned int *index, int dist_px);
+bool ED_mesh_pick_face_vert(struct bContext *C, struct Object *ob, const int mval[2], unsigned int *index, int dist_px);
 
 
 struct MDeformVert *ED_mesh_active_dvert_get_em(struct Object *ob, struct BMVert **r_eve);
@@ -377,8 +377,8 @@ struct MDeformVert *ED_mesh_active_dvert_get_only(struct Object *ob);
 void EDBM_mesh_stats_multi(struct Object **objects, const uint objects_len, int totelem[3], int totelem_sel[3]);
 void EDBM_mesh_elem_index_ensure_multi(struct Object **objects, const uint objects_len, const char htype);
 
-#define ED_MESH_PICK_DEFAULT_VERT_SIZE 50
-#define ED_MESH_PICK_DEFAULT_FACE_SIZE 3
+#define ED_MESH_PICK_DEFAULT_VERT_DIST 25
+#define ED_MESH_PICK_DEFAULT_FACE_DIST 1
 
 #define USE_LOOPSLIDE_HACK
 
diff --git a/source/blender/editors/include/ED_view3d.h b/source/blender/editors/include/ED_view3d.h
index 131069bfb5f..e8cd6ebf5f3 100644
--- a/source/blender/editors/include/ED_view3d.h
+++ b/source/blender/editors/include/ED_view3d.h
@@ -348,16 +348,24 @@ float ED_view3d_radius_to_dist(
 void imm_drawcircball(const float cent[3], float rad, const float tmat[4][4], unsigned pos);
 
 /* backbuffer select and draw support */
-void          ED_view3d_backbuf_validate_with_select_mode(struct ViewContext *vc, short select_mode);
-void          ED_view3d_backbuf_validate(struct ViewContext *vc);
-struct ImBuf *ED_view3d_backbuf_read(
-        struct ViewContext *vc, int xmin, int ymin, int xmax, int ymax);
-unsigned int  ED_view3d_backbuf_sample_rect(
-        struct ViewContext *vc, const int mval[2], int size,
-        unsigned int min, unsigned int max, float *r_dist);
-int          ED_view3d_backbuf_sample_size_clamp(struct ARegion *ar, const float dist);
-unsigned int ED_view3d_backbuf_sample(
+void  ED_view3d_backbuf_depth_validate(struct ViewContext *vc);
+int   ED_view3d_backbuf_sample_size_clamp(struct ARegion *ar, const float dist);
+
+void  ED_view3d_select_id_validate(struct ViewContext *vc);
+void  ED_view3d_select_id_validate_with_select_mode(
+        struct ViewContext *vc, short select_mode);
+
+uint ED_view3d_select_id_sample(
         struct ViewContext *vc, int x, int y);
+uint *ED_view3d_select_id_read(
+        struct ViewContext *vc,
+        int xmin, int ymin, int xmax, int ymax,
+        uint *r_buf_len);
+uint *ED_view3d_select_id_read_rect(
+        struct ViewContext *vc, const struct rcti *rect, uint *r_buf_len);
+uint ED_view3d_select_id_read_nearest(
+        struct ViewContext *vc, const int mval[2],
+        const uint min, const uint max, uint *r_dist);
 
 bool ED_view3d_autodist(
         struct Depsgraph *depsgraph, struct ARegion *ar, struct View3D *v3d,