Cleanup: use struct for GPU the select buffer

GPU_select originally used GL_SELECT which defined the format for
storing the selection result.

Now this is no longer the case, define our own struct - making the code
easier to follow:

- Avoid having to deal with arrays in both `uint*` and `uint(*)[4]`
  multiplying offsets by 4 in some cases & not others.

- No magic numbers for the offsets of depth & selection-ID.

- No need to allocate unused members to match GL_SELECT
  (halving the buffer size).

1 files changed, 44 insertions, 37 deletions

diff --git a/source/blender/editors/armature/armature_select.c b/source/blender/editors/armature/armature_select.c
index 5e4cb813064..f9b52eb53ed 100644
--- a/source/blender/editors/armature/armature_select.c
+++ b/source/blender/editors/armature/armature_select.c
@@ -55,6 +55,8 @@
 
 #include "DEG_depsgraph.h"
 
+#include "GPU_select.h"
+
 #include "armature_intern.h"
 
 /* utility macros for storing a temp int in the bone (selection flag) */
@@ -67,10 +69,10 @@
 
 Base *ED_armature_base_and_ebone_from_select_buffer(Base **bases,
                                                     uint bases_len,
-                                                    int hit,
+                                                    const uint select_id,
                                                     EditBone **r_ebone)
 {
-  const uint hit_object = hit & 0xFFFF;
+  const uint hit_object = select_id & 0xFFFF;
   Base *base = NULL;
   EditBone *ebone = NULL;
   /* TODO(campbell): optimize, eg: sort & binary search. */
@@ -81,7 +83,7 @@ Base *ED_armature_base_and_ebone_from_select_buffer(Base **bases,
     }
   }
   if (base != NULL) {
-    const uint hit_bone = (hit & ~BONESEL_ANY) >> 16;
+    const uint hit_bone = (select_id & ~BONESEL_ANY) >> 16;
     bArmature *arm = base->object->data;
     ebone = BLI_findlink(arm->edbo, hit_bone);
   }
@@ -91,10 +93,10 @@ Base *ED_armature_base_and_ebone_from_select_buffer(Base **bases,
 
 Object *ED_armature_object_and_ebone_from_select_buffer(Object **objects,
                                                         uint objects_len,
-                                                        int hit,
+                                                        const uint select_id,
                                                         EditBone **r_ebone)
 {
-  const uint hit_object = hit & 0xFFFF;
+  const uint hit_object = select_id & 0xFFFF;
   Object *ob = NULL;
   EditBone *ebone = NULL;
   /* TODO(campbell): optimize, eg: sort & binary search. */
@@ -105,7 +107,7 @@ Object *ED_armature_object_and_ebone_from_select_buffer(Object **objects,
     }
   }
   if (ob != NULL) {
-    const uint hit_bone = (hit & ~BONESEL_ANY) >> 16;
+    const uint hit_bone = (select_id & ~BONESEL_ANY) >> 16;
     bArmature *arm = ob->data;
     ebone = BLI_findlink(arm->edbo, hit_bone);
   }
@@ -115,10 +117,10 @@ Object *ED_armature_object_and_ebone_from_select_buffer(Object **objects,
 
 Base *ED_armature_base_and_pchan_from_select_buffer(Base **bases,
                                                     uint bases_len,
-                                                    int hit,
+                                                    const uint select_id,
                                                     bPoseChannel **r_pchan)
 {
-  const uint hit_object = hit & 0xFFFF;
+  const uint hit_object = select_id & 0xFFFF;
   Base *base = NULL;
   bPoseChannel *pchan = NULL;
   /* TODO(campbell): optimize, eg: sort & binary search. */
@@ -130,7 +132,7 @@ Base *ED_armature_base_and_pchan_from_select_buffer(Base **bases,
   }
   if (base != NULL) {
     if (base->object->pose != NULL) {
-      const uint hit_bone = (hit & ~BONESEL_ANY) >> 16;
+      const uint hit_bone = (select_id & ~BONESEL_ANY) >> 16;
       /* pchan may be NULL. */
       pchan = BLI_findlink(&base->object->pose->chanbase, hit_bone);
     }
@@ -141,11 +143,11 @@ Base *ED_armature_base_and_pchan_from_select_buffer(Base **bases,
 
 Base *ED_armature_base_and_bone_from_select_buffer(Base **bases,
                                                    uint bases_len,
-                                                   int hit,
+                                                   const uint select_id,
                                                    Bone **r_bone)
 {
   bPoseChannel *pchan = NULL;
-  Base *base = ED_armature_base_and_pchan_from_select_buffer(bases, bases_len, hit, &pchan);
+  Base *base = ED_armature_base_and_pchan_from_select_buffer(bases, bases_len, select_id, &pchan);
   *r_bone = pchan ? pchan->bone : NULL;
   return base;
 }
@@ -166,8 +168,8 @@ Base *ED_armature_base_and_bone_from_select_buffer(Base **bases,
 static void *ed_armature_pick_bone_from_selectbuffer_impl(const bool is_editmode,
                                                           Base **bases,
                                                           uint bases_len,
-                                                          const uint *buffer,
-                                                          short hits,
+                                                          const GPUSelectResult *buffer,
+                                                          const short hits,
                                                           bool findunsel,
                                                           bool do_nearest,
                                                           Base **r_base)
@@ -181,7 +183,7 @@ static void *ed_armature_pick_bone_from_selectbuffer_impl(const bool is_editmode
   int minsel = 0xffffffff, minunsel = 0xffffffff;
 
   for (short i = 0; i < hits; i++) {
-    hitresult = buffer[3 + (i * 4)];
+    hitresult = buffer[i].id;
 
     if (hitresult & BONESEL_ANY) { /* to avoid including objects in selection */
       Base *base = NULL;
@@ -221,10 +223,10 @@ static void *ed_armature_pick_bone_from_selectbuffer_impl(const bool is_editmode
       if (data) {
         if (sel) {
           if (do_nearest) {
-            if (minsel > buffer[4 * i + 1]) {
+            if (minsel > buffer[i].depth) {
               firstSel = data;
               firstSel_base = base;
-              minsel = buffer[4 * i + 1];
+              minsel = buffer[i].depth;
             }
           }
           else {
@@ -237,10 +239,10 @@ static void *ed_armature_pick_bone_from_selectbuffer_impl(const bool is_editmode
         }
         else {
           if (do_nearest) {
-            if (minunsel > buffer[4 * i + 1]) {
+            if (minunsel > buffer[i].depth) {
               firstunSel = data;
               firstunSel_base = base;
-              minunsel = buffer[4 * i + 1];
+              minunsel = buffer[i].depth;
             }
           }
           else {
@@ -268,8 +270,8 @@ static void *ed_armature_pick_bone_from_selectbuffer_impl(const bool is_editmode
 
 EditBone *ED_armature_pick_ebone_from_selectbuffer(Base **bases,
                                                    uint bases_len,
-                                                   const uint *buffer,
-                                                   short hits,
+                                                   const GPUSelectResult *buffer,
+                                                   const short hits,
                                                    bool findunsel,
                                                    bool do_nearest,
                                                    Base **r_base)
@@ -281,8 +283,8 @@ EditBone *ED_armature_pick_ebone_from_selectbuffer(Base **bases,
 
 bPoseChannel *ED_armature_pick_pchan_from_selectbuffer(Base **bases,
                                                        uint bases_len,
-                                                       const uint *buffer,
-                                                       short hits,
+                                                       const GPUSelectResult *buffer,
+                                                       const short hits,
                                                        bool findunsel,
                                                        bool do_nearest,
                                                        Base **r_base)
@@ -294,8 +296,8 @@ bPoseChannel *ED_armature_pick_pchan_from_selectbuffer(Base **bases,
 
 Bone *ED_armature_pick_bone_from_selectbuffer(Base **bases,
                                               uint bases_len,
-                                              const uint *buffer,
-                                              short hits,
+                                              const GPUSelectResult *buffer,
+                                              const short hits,
                                               bool findunsel,
                                               bool do_nearest,
                                               Base **r_base)
@@ -327,7 +329,7 @@ static void *ed_armature_pick_bone_impl(
   Depsgraph *depsgraph = CTX_data_ensure_evaluated_depsgraph(C);
   ViewContext vc;
   rcti rect;
-  uint buffer[MAXPICKBUF];
+  GPUSelectResult buffer[MAXPICKELEMS];
   short hits;
 
   ED_view3d_viewcontext_init(C, &vc, depsgraph);
@@ -340,7 +342,7 @@ static void *ed_armature_pick_bone_impl(
 
   hits = view3d_opengl_select_with_id_filter(&vc,
                                              buffer,
-                                             MAXPICKBUF,
+                                             ARRAY_SIZE(buffer),
                                              &rect,
                                              VIEW3D_SELECT_PICK_NEAREST,
                                              VIEW3D_SELECT_FILTER_NOP,
@@ -636,15 +638,15 @@ void ARMATURE_OT_select_linked_pick(wmOperatorType *ot)
  * \{ */
 
 /* utility function for get_nearest_editbonepoint */
-static int selectbuffer_ret_hits_12(uint *UNUSED(buffer), const int hits12)
+static int selectbuffer_ret_hits_12(GPUSelectResult *UNUSED(buffer), const int hits12)
 {
   return hits12;
 }
 
-static int selectbuffer_ret_hits_5(uint *buffer, const int hits12, const int hits5)
+static int selectbuffer_ret_hits_5(GPUSelectResult *buffer, const int hits12, const int hits5)
 {
-  const int ofs = 4 * hits12;
-  memcpy(buffer, buffer + ofs, 4 * hits5 * sizeof(uint));
+  const int ofs = hits12;
+  memcpy(buffer, buffer + ofs, hits5 * sizeof(*buffer));
   return hits5;
 }
 
@@ -653,7 +655,7 @@ static int selectbuffer_ret_hits_5(uint *buffer, const int hits12, const int hit
 static EditBone *get_nearest_editbonepoint(
     ViewContext *vc, bool findunsel, bool use_cycle, Base **r_base, int *r_selmask)
 {
-  uint buffer[MAXPICKBUF];
+  GPUSelectResult buffer[MAXPICKELEMS];
   struct {
     uint hitresult;
     Base *base;
@@ -692,7 +694,7 @@ static EditBone *get_nearest_editbonepoint(
     rcti rect;
     BLI_rcti_init_pt_radius(&rect, vc->mval, 12);
     const int hits12 = view3d_opengl_select_with_id_filter(
-        vc, buffer, MAXPICKBUF, &rect, select_mode, select_filter, select_id_ignore);
+        vc, buffer, ARRAY_SIZE(buffer), &rect, select_mode, select_filter, select_id_ignore);
 
     if (hits12 == 1) {
       hits = selectbuffer_ret_hits_12(buffer, hits12);
@@ -701,10 +703,15 @@ static EditBone *get_nearest_editbonepoint(
     else if (hits12 > 0) {
       int ofs;
 
-      ofs = 4 * hits12;
+      ofs = hits12;
       BLI_rcti_init_pt_radius(&rect, vc->mval, 5);
-      const int hits5 = view3d_opengl_select_with_id_filter(
-          vc, buffer + ofs, MAXPICKBUF - ofs, &rect, select_mode, select_filter, select_id_ignore);
+      const int hits5 = view3d_opengl_select_with_id_filter(vc,
+                                                            buffer + ofs,
+                                                            ARRAY_SIZE(buffer) - ofs,
+                                                            &rect,
+                                                            select_mode,
+                                                            select_filter,
+                                                            select_id_ignore);
 
       if (hits5 == 1) {
         hits = selectbuffer_ret_hits_5(buffer, hits12, hits5);
@@ -732,7 +739,7 @@ cache_end:
   /* See if there are any selected bones in this group */
   if (hits > 0) {
     if (hits == 1) {
-      result_bias.hitresult = buffer[3];
+      result_bias.hitresult = buffer->id;
       result_bias.base = ED_armature_base_and_ebone_from_select_buffer(
           bases, bases_len, result_bias.hitresult, &result_bias.ebone);
     }
@@ -771,7 +778,7 @@ cache_end:
       }
 
       for (int i = 0; i < hits; i++) {
-        const uint hitresult = buffer[3 + (i * 4)];
+        const uint hitresult = buffer[i].id;
 
         Base *base = NULL;
         EditBone *ebone;