DRW: Fix issues with multiview

Resource ids buf must be allocated for the worst case scenario.
Also fix issue with non procedural data overriding procedural view.

source/blender/draw/intern/draw_command.cc

@@ -597,7 +597,7 @@ void DrawMultiBuf::bind(RecordingState &state,
   for (DrawGroup &group : MutableSpan<DrawGroup>(group_buf_.data(), group_count_)) {
     /* Compute prefix sum of all instance of previous group. */
     group.start = resource_id_count_;
-    resource_id_count_ += group.len;
+    resource_id_count_ += group.len * view_len;
 
     int batch_inst_len;
     /* Now that GPUBatches are guaranteed to be finished, extract their parameters. */

source/blender/draw/intern/draw_view.cc

@@ -205,7 +205,7 @@ void View::frustum_culling_sphere_calc(const BoundBox &bbox, BoundSphere &bspher
 
 void View::bind()
 {
-  if (dirty_) {
+  if (dirty_ && !procedural_) {
     dirty_ = false;
     data_.push_update();
     culling_.push_update();

source/blender/draw/intern/draw_view.hh

@@ -51,10 +51,11 @@ class View {
   bool do_visibility_ = true;
   bool dirty_ = true;
   bool frozen_ = false;
+  bool procedural_ = false;
 
  public:
-  View(const char *name, int view_len = 1)
-      : visibility_buf_(name), debug_name_(name), view_len_(view_len)
+  View(const char *name, int view_len = 1, bool procedural = false)
+      : visibility_buf_(name), debug_name_(name), view_len_(view_len), procedural_(procedural)
   {
     BLI_assert(view_len < DRW_VIEW_MAX);
   }

source/blender/draw/intern/shaders/draw_command_generate_comp.glsl

@@ -51,6 +51,8 @@ void main()
   if (visibility_word_per_draw > 0) {
     uint visibility_word = resource_index * visibility_word_per_draw;
     for (uint i = 0; i < visibility_word_per_draw; i++, visibility_word++) {
+      /* \note: This assumes proto.instance_len is 1. */
+      /* TODO: Assert. */
       visible_instance_len += bitCount(visibility_buf[visibility_word]);
     }
   }
@@ -89,7 +91,7 @@ void main()
     }
   }
 
-  /* Fill resource_id buffer for each instance of this draw */
+  /* Fill resource_id buffer for each instance of this draw. */
   if (visibility_word_per_draw > 0) {
     uint visibility_word = resource_index * visibility_word_per_draw;
     for (uint i = 0; i < visibility_word_per_draw; i++, visibility_word++) {