Fix T72504 EEVEE: Crash when rendering Instance Collection with hair

This was caused by a double free of the instance data. Remove the need
of the instance data fix the issue.

2 files changed, 12 insertions, 25 deletions

diff --git a/source/blender/draw/intern/draw_hair.c b/source/blender/draw/intern/draw_hair.c
index 58085cf08c6..08256b931ba 100644
--- a/source/blender/draw/intern/draw_hair.c
+++ b/source/blender/draw/intern/draw_hair.c
@@ -104,12 +104,6 @@ void DRW_hair_init(void)
 #endif
 }
 
-typedef struct DRWHairInstanceData {
-  DrawData dd;
-
-  float mat[4][4];
-} DRWHairInstanceData;
-
 static DRWShadingGroup *drw_shgroup_create_hair_procedural_ex(Object *object,
                                                               ParticleSystem *psys,
                                                               ModifierData *md,
@@ -120,13 +114,7 @@ static DRWShadingGroup *drw_shgroup_create_hair_procedural_ex(Object *object,
   /* TODO(fclem): Pass the scene as parameter */
   const DRWContextState *draw_ctx = DRW_context_state_get();
   Scene *scene = draw_ctx->scene;
-  static float unit_mat[4][4] = {
-      {1, 0, 0, 0},
-      {0, 1, 0, 0},
-      {0, 0, 1, 0},
-      {0, 0, 0, 1},
-  };
-  float(*dupli_mat)[4];
+  float dupli_mat[4][4];
   Object *dupli_parent = DRW_object_get_dupli_parent(object);
   DupliObject *dupli_object = DRW_object_get_dupli(object);
 
@@ -164,13 +152,6 @@ static DRWShadingGroup *drw_shgroup_create_hair_procedural_ex(Object *object,
   }
 
   if ((dupli_parent != NULL) && (dupli_object != NULL)) {
-    DRWHairInstanceData *hair_inst_data = (DRWHairInstanceData *)DRW_drawdata_ensure(
-        &object->id,
-        (DrawEngineType *)&drw_shgroup_create_hair_procedural_ex,
-        sizeof(DRWHairInstanceData),
-        NULL,
-        NULL);
-    dupli_mat = hair_inst_data->mat;
     if (dupli_object->type & OB_DUPLICOLLECTION) {
       copy_m4_m4(dupli_mat, dupli_parent->obmat);
     }
@@ -181,14 +162,17 @@ static DRWShadingGroup *drw_shgroup_create_hair_procedural_ex(Object *object,
     }
   }
   else {
-    dupli_mat = unit_mat;
+    unit_m4(dupli_mat);
   }
 
   DRW_shgroup_uniform_texture(shgrp, "hairPointBuffer", hair_cache->final[subdiv].proc_tex);
   DRW_shgroup_uniform_int(shgrp, "hairStrandsRes", &hair_cache->final[subdiv].strands_res, 1);
   DRW_shgroup_uniform_int_copy(shgrp, "hairThicknessRes", thickness_res);
   DRW_shgroup_uniform_float(shgrp, "hairRadShape", &part->shape, 1);
-  DRW_shgroup_uniform_mat4(shgrp, "hairDupliMatrix", dupli_mat);
+  DRW_shgroup_uniform_vec4_copy(shgrp, "hairDupliMatrix[0]", dupli_mat[0]);
+  DRW_shgroup_uniform_vec4_copy(shgrp, "hairDupliMatrix[1]", dupli_mat[1]);
+  DRW_shgroup_uniform_vec4_copy(shgrp, "hairDupliMatrix[2]", dupli_mat[2]);
+  DRW_shgroup_uniform_vec4_copy(shgrp, "hairDupliMatrix[3]", dupli_mat[3]);
   DRW_shgroup_uniform_float_copy(shgrp, "hairRadRoot", part->rad_root * part->rad_scale * 0.5f);
   DRW_shgroup_uniform_float_copy(shgrp, "hairRadTip", part->rad_tip * part->rad_scale * 0.5f);
   DRW_shgroup_uniform_bool_copy(
diff --git a/source/blender/draw/intern/shaders/common_hair_lib.glsl b/source/blender/draw/intern/shaders/common_hair_lib.glsl
index cbcdc947bc7..ffff631e34b 100644
--- a/source/blender/draw/intern/shaders/common_hair_lib.glsl
+++ b/source/blender/draw/intern/shaders/common_hair_lib.glsl
@@ -26,7 +26,7 @@ uniform float hairRadTip = 0.0;
 uniform float hairRadShape = 0.5;
 uniform bool hairCloseTip = true;
 
-uniform mat4 hairDupliMatrix;
+uniform vec4 hairDupliMatrix[4];
 
 /* -- Per control points -- */
 uniform samplerBuffer hairPointBuffer; /* RGBA32F */
@@ -159,8 +159,11 @@ void hair_get_pos_tan_binor_time(bool is_persp,
     wtan = wpos - texelFetch(hairPointBuffer, id - 1).point_position;
   }
 
-  wpos = (hairDupliMatrix * vec4(wpos, 1.0)).xyz;
-  wtan = -normalize(mat3(hairDupliMatrix) * wtan);
+  mat4 obmat = mat4(
+      hairDupliMatrix[0], hairDupliMatrix[1], hairDupliMatrix[2], hairDupliMatrix[3]);
+
+  wpos = (obmat * vec4(wpos, 1.0)).xyz;
+  wtan = -normalize(mat3(obmat) * wtan);
 
   vec3 camera_vec = (is_persp) ? camera_pos - wpos : camera_z;
   wbinor = normalize(cross(camera_vec, wtan));