Fix T99129: Eevee Hair Info Length not working (old particle hair).

When using the old particle hair with the hair info length it wasn't
working with AMD GPUs. The reason was that the drw_curves uniform buffer
wasn't initialized what made the shader select the incorrect length.

1 files changed, 14 insertions, 0 deletions

diff --git a/source/blender/draw/intern/draw_hair.cc b/source/blender/draw/intern/draw_hair.cc
index 0a3c16e0d71..dc791314333 100644
--- a/source/blender/draw/intern/draw_hair.cc
+++ b/source/blender/draw/intern/draw_hair.cc
@@ -27,8 +27,11 @@
 #include "GPU_texture.h"
 #include "GPU_vertex_buffer.h"
 
+#include "DRW_gpu_wrapper.hh"
+
 #include "draw_hair_private.h"
 #include "draw_shader.h"
+#include "draw_shader_shared.h"
 
 #ifndef __APPLE__
 #  define USE_TRANSFORM_FEEDBACK
@@ -65,6 +68,7 @@ static int g_tf_target_height;
 static GPUVertBuf *g_dummy_vbo = nullptr;
 static GPUTexture *g_dummy_texture = nullptr;
 static DRWPass *g_tf_pass; /* XXX can be a problem with multiple DRWManager in the future */
+static blender::draw::UniformBuffer<CurvesInfos> *g_dummy_curves_info = nullptr;
 
 static GPUShader *hair_refine_shader_get(ParticleRefineShader refinement)
 {
@@ -93,6 +97,13 @@ void DRW_hair_init(void)
     GPU_vertbuf_use(g_dummy_vbo);
 
     g_dummy_texture = GPU_texture_create_from_vertbuf("hair_dummy_attr", g_dummy_vbo);
+
+    g_dummy_curves_info = MEM_new<blender::draw::UniformBuffer<CurvesInfos>>(
+        "g_dummy_curves_info");
+    memset(g_dummy_curves_info->is_point_attribute,
+           0,
+           sizeof(g_dummy_curves_info->is_point_attribute));
+    g_dummy_curves_info->push_update();
   }
 }
 
@@ -276,6 +287,8 @@ DRWShadingGroup *DRW_shgroup_hair_create_sub(Object *object,
   if (hair_cache->length_tex) {
     DRW_shgroup_uniform_texture(shgrp, "l", hair_cache->length_tex);
   }
+
+  DRW_shgroup_uniform_block(shgrp, "drw_curves", *g_dummy_curves_info);
   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_copy(shgrp, "hairRadShape", hair_rad_shape);
@@ -374,4 +387,5 @@ void DRW_hair_free(void)
 {
   GPU_VERTBUF_DISCARD_SAFE(g_dummy_vbo);
   DRW_TEXTURE_FREE_SAFE(g_dummy_texture);
+  MEM_delete(g_dummy_curves_info);
 }