Hair UV implementation for Eevee

This implements UV support for Eevee hair, enabling the usage of
textures.

6 files changed, 245 insertions, 66 deletions

diff --git a/source/blender/draw/engines/clay/clay_engine.c b/source/blender/draw/engines/clay/clay_engine.c
index f39438e660c..00cc93a9db2 100644
--- a/source/blender/draw/engines/clay/clay_engine.c
+++ b/source/blender/draw/engines/clay/clay_engine.c
@@ -828,7 +828,7 @@ static void CLAY_cache_populate(void *vedata, Object *ob)
 					unit_m4(mat);
 
 					if (draw_as == PART_DRAW_PATH) {
-						geom = DRW_cache_particles_get_hair(psys);
+						geom = DRW_cache_particles_get_hair(psys, NULL);
 						hair_shgrp = CLAY_hair_shgrp_get(ob, stl, psl);
 						DRW_shgroup_call_add(hair_shgrp, geom, mat);
 					}
diff --git a/source/blender/draw/engines/eevee/eevee_materials.c b/source/blender/draw/engines/eevee/eevee_materials.c
index 6126aab1014..74cb6b0d7a0 100644
--- a/source/blender/draw/engines/eevee/eevee_materials.c
+++ b/source/blender/draw/engines/eevee/eevee_materials.c
@@ -26,6 +26,7 @@
 #include "DRW_render.h"
 
 #include "DNA_world_types.h"
+#include "DNA_modifier_types.h"
 
 #include "BLI_dynstr.h"
 #include "BLI_ghash.h"
@@ -624,72 +625,76 @@ void EEVEE_materials_cache_populate(EEVEE_Data *vedata, EEVEE_SceneLayerData *sl
 		if (ob != draw_ctx->scene->obedit) {
 			material_hash = stl->g_data->hair_material_hash;
 
-			for (ParticleSystem *psys = ob->particlesystem.first; psys; psys = psys->next) {
-				if (psys_check_enabled(ob, psys, false)) {
-					ParticleSettings *part = psys->part;
-					int draw_as = (part->draw_as == PART_DRAW_REND) ? part->ren_as : part->draw_as;
+			for (ModifierData *md = ob->modifiers.first; md; md = md->next) {
+				if (md->type == eModifierType_ParticleSystem) {
+					ParticleSystem *psys = ((ParticleSystemModifierData *)md)->psys;
 
-					if (draw_as == PART_DRAW_PATH && (psys->pathcache || psys->childcache)) {
-						struct Gwn_Batch *hair_geom = DRW_cache_particles_get_hair(psys);
-						DRWShadingGroup *shgrp = NULL;
-						Material *ma = give_current_material(ob, part->omat);
-						static float mat[4][4];
+					if (psys_check_enabled(ob, psys, false)) {
+						ParticleSettings *part = psys->part;
+						int draw_as = (part->draw_as == PART_DRAW_REND) ? part->ren_as : part->draw_as;
 
-						unit_m4(mat);
+						if (draw_as == PART_DRAW_PATH && (psys->pathcache || psys->childcache)) {
+							struct Gwn_Batch *hair_geom = DRW_cache_particles_get_hair(psys, md);
+							DRWShadingGroup *shgrp = NULL;
+							Material *ma = give_current_material(ob, part->omat);
+							static float mat[4][4];
 
-						if (ma == NULL) {
-							ma = &defmaterial;
-						}
+							unit_m4(mat);
+
+							if (ma == NULL) {
+								ma = &defmaterial;
+							}
 
-						float *color_p = &ma->r;
-						float *metal_p = &ma->ray_mirror;
-						float *spec_p = &ma->spec;
-						float *rough_p = &ma->gloss_mir;
+							float *color_p = &ma->r;
+							float *metal_p = &ma->ray_mirror;
+							float *spec_p = &ma->spec;
+							float *rough_p = &ma->gloss_mir;
 
-						DRW_shgroup_call_add(stl->g_data->depth_shgrp, hair_geom, mat);
-						DRW_shgroup_call_add(stl->g_data->depth_shgrp_clip, hair_geom, mat);
+							DRW_shgroup_call_add(stl->g_data->depth_shgrp, hair_geom, mat);
+							DRW_shgroup_call_add(stl->g_data->depth_shgrp_clip, hair_geom, mat);
 
-						shgrp = BLI_ghash_lookup(material_hash, (const void *)ma);
+							shgrp = BLI_ghash_lookup(material_hash, (const void *)ma);
 
-						if (shgrp) {
-							DRW_shgroup_call_add(shgrp, hair_geom, mat);
-						}
-						else {
-							if (ma->use_nodes && ma->nodetree) {
-								Scene *scene = draw_ctx->scene;
-								struct GPUMaterial *gpumat = EEVEE_material_hair_get(scene, ma,
-								        stl->effects->use_ao, stl->effects->use_bent_normals);
+							if (shgrp) {
+								DRW_shgroup_call_add(shgrp, hair_geom, mat);
+							}
+							else {
+								if (ma->use_nodes && ma->nodetree) {
+									Scene *scene = draw_ctx->scene;
+									struct GPUMaterial *gpumat = EEVEE_material_hair_get(scene, ma,
+									        stl->effects->use_ao, stl->effects->use_bent_normals);
+
+									shgrp = DRW_shgroup_material_create(gpumat, psl->material_pass);
+									if (shgrp) {
+										add_standard_uniforms(shgrp, sldata, vedata);
+
+										BLI_ghash_insert(material_hash, ma, shgrp);
+
+										DRW_shgroup_call_add(shgrp, hair_geom, mat);
+									}
+									else {
+										/* Shader failed : pink color */
+										static float col[3] = {1.0f, 0.0f, 1.0f};
+										static float half = 0.5f;
+
+										color_p = col;
+										metal_p = spec_p = rough_p = ½
+									}
+								}
 
-								shgrp = DRW_shgroup_material_create(gpumat, psl->material_pass);
-								if (shgrp) {
-									add_standard_uniforms(shgrp, sldata, vedata);
+								/* Fallback to default shader */
+								if (shgrp == NULL) {
+									shgrp = EEVEE_default_shading_group_get(sldata, vedata, true, false,
+									        stl->effects->use_ao, stl->effects->use_bent_normals);
+									DRW_shgroup_uniform_vec3(shgrp, "basecol", color_p, 1);
+									DRW_shgroup_uniform_float(shgrp, "metallic", metal_p, 1);
+									DRW_shgroup_uniform_float(shgrp, "specular", spec_p, 1);
+									DRW_shgroup_uniform_float(shgrp, "roughness", rough_p, 1);
 
 									BLI_ghash_insert(material_hash, ma, shgrp);
 
 									DRW_shgroup_call_add(shgrp, hair_geom, mat);
 								}
-								else {
-									/* Shader failed : pink color */
-									static float col[3] = {1.0f, 0.0f, 1.0f};
-									static float half = 0.5f;
-
-									color_p = col;
-									metal_p = spec_p = rough_p = ½
-								}
-							}
-
-							/* Fallback to default shader */
-							if (shgrp == NULL) {
-								shgrp = EEVEE_default_shading_group_get(sldata, vedata, true, false,
-								        stl->effects->use_ao, stl->effects->use_bent_normals);
-								DRW_shgroup_uniform_vec3(shgrp, "basecol", color_p, 1);
-								DRW_shgroup_uniform_float(shgrp, "metallic", metal_p, 1);
-								DRW_shgroup_uniform_float(shgrp, "specular", spec_p, 1);
-								DRW_shgroup_uniform_float(shgrp, "roughness", rough_p, 1);
-
-								BLI_ghash_insert(material_hash, ma, shgrp);
-
-								DRW_shgroup_call_add(shgrp, hair_geom, mat);
 							}
 						}
 					}
diff --git a/source/blender/draw/intern/draw_cache.c b/source/blender/draw/intern/draw_cache.c
index 4dfb9f960c2..5d0485b03e6 100644
--- a/source/blender/draw/intern/draw_cache.c
+++ b/source/blender/draw/intern/draw_cache.c
@@ -29,6 +29,7 @@
 #include "DNA_curve_types.h"
 #include "DNA_object_types.h"
 #include "DNA_particle_types.h"
+#include "DNA_modifier_types.h"
 
 #include "BLI_utildefines.h"
 #include "BLI_math.h"
@@ -2331,9 +2332,9 @@ Gwn_Batch *DRW_cache_lattice_vert_overlay_get(Object *ob)
 /** \name Particles
  * \{ */
 
-Gwn_Batch *DRW_cache_particles_get_hair(ParticleSystem *psys)
+Gwn_Batch *DRW_cache_particles_get_hair(ParticleSystem *psys, ModifierData *md)
 {
-	return DRW_particles_batch_cache_get_hair(psys);
+	return DRW_particles_batch_cache_get_hair(psys, md);
 }
 
 Gwn_Batch *DRW_cache_particles_get_dots(ParticleSystem *psys)
diff --git a/source/blender/draw/intern/draw_cache.h b/source/blender/draw/intern/draw_cache.h
index a4fac3fe71f..857d4c60053 100644
--- a/source/blender/draw/intern/draw_cache.h
+++ b/source/blender/draw/intern/draw_cache.h
@@ -28,6 +28,7 @@
 
 struct Gwn_Batch;
 struct Object;
+struct ModifierData;
 
 void DRW_shape_cache_free(void);
 
@@ -144,7 +145,7 @@ struct Gwn_Batch *DRW_cache_lattice_wire_get(struct Object *ob);
 struct Gwn_Batch *DRW_cache_lattice_vert_overlay_get(struct Object *ob);
 
 /* Particles */
-struct Gwn_Batch *DRW_cache_particles_get_hair(struct ParticleSystem *psys);
+struct Gwn_Batch *DRW_cache_particles_get_hair(struct ParticleSystem *psys, struct ModifierData *md);
 struct Gwn_Batch *DRW_cache_particles_get_dots(struct ParticleSystem *psys);
 struct Gwn_Batch *DRW_cache_particles_get_prim(int type);
 
diff --git a/source/blender/draw/intern/draw_cache_impl.h b/source/blender/draw/intern/draw_cache_impl.h
index 066ca9f60e0..8786dda9d51 100644
--- a/source/blender/draw/intern/draw_cache_impl.h
+++ b/source/blender/draw/intern/draw_cache_impl.h
@@ -30,6 +30,7 @@ struct Gwn_Batch;
 struct ListBase;
 struct CurveCache;
 struct ParticleSystem;
+struct ModifierData;
 
 struct Curve;
 struct Lattice;
@@ -94,7 +95,7 @@ struct Gwn_Batch *DRW_mesh_batch_cache_get_overlay_loose_verts(struct Mesh *me);
 struct Gwn_Batch *DRW_mesh_batch_cache_get_overlay_facedots(struct Mesh *me);
 
 /* Particles */
-struct Gwn_Batch *DRW_particles_batch_cache_get_hair(struct ParticleSystem *psys);
+struct Gwn_Batch *DRW_particles_batch_cache_get_hair(struct ParticleSystem *psys, struct ModifierData *md);
 struct Gwn_Batch *DRW_particles_batch_cache_get_dots(struct ParticleSystem *psys);
 
 #endif /* __DRAW_CACHE_IMPL_H__ */
diff --git a/source/blender/draw/intern/draw_cache_impl_particles.c b/source/blender/draw/intern/draw_cache_impl_particles.c
index 6b15bd673c9..f3f658dbd8d 100644
--- a/source/blender/draw/intern/draw_cache_impl_particles.c
+++ b/source/blender/draw/intern/draw_cache_impl_particles.c
@@ -33,10 +33,13 @@
 
 #include "BLI_utildefines.h"
 #include "BLI_math_vector.h"
+#include "BLI_ghash.h"
 
+#include "DNA_modifier_types.h"
 #include "DNA_particle_types.h"
 
 #include "BKE_particle.h"
+#include "BKE_DerivedMesh.h"
 
 #include "GPU_batch.h"
 
@@ -170,21 +173,46 @@ static void ensure_seg_pt_count(ParticleSystem *psys, ParticleBatchCache *cache)
 }
 
 /* Gwn_Batch cache usage. */
-static void particle_batch_cache_ensure_pos_and_seg(ParticleSystem *psys, ParticleBatchCache *cache)
+static void particle_batch_cache_ensure_pos_and_seg(ParticleSystem *psys, ModifierData *md, ParticleBatchCache *cache)
 {
 	if (cache->pos == NULL || cache->segments == NULL) {
 		int curr_point = 0;
+		ParticleSystemModifierData *psmd = (ParticleSystemModifierData *)md;
 
 		GWN_VERTBUF_DISCARD_SAFE(cache->pos);
 		GWN_INDEXBUF_DISCARD_SAFE(cache->segments);
 
 		static Gwn_VertFormat format = { 0 };
 		static struct { uint pos, tan, ind; } attr_id;
-		if (format.attrib_ct == 0) {
-			/* initialize vertex format */
-			attr_id.pos = GWN_vertformat_attr_add(&format, "pos", GWN_COMP_F32, 3, GWN_FETCH_FLOAT);
-			attr_id.tan = GWN_vertformat_attr_add(&format, "nor", GWN_COMP_F32, 3, GWN_FETCH_FLOAT);
-			attr_id.ind = GWN_vertformat_attr_add(&format, "ind", GWN_COMP_I32, 1, GWN_FETCH_INT);
+		unsigned int *uv_id;
+		int uv_layers = 0;
+		MTFace **mtfaces;
+		float (**parent_uvs)[2] = NULL;
+		bool simple = psys->part->childtype == PART_CHILD_PARTICLES;
+
+		if (psmd) {
+			if (CustomData_has_layer(&psmd->dm_final->loopData, CD_MLOOPUV)) {
+				uv_layers = CustomData_number_of_layers(&psmd->dm_final->loopData, CD_MLOOPUV);
+			}
+		}
+
+		GWN_vertformat_clear(&format);
+
+		/* initialize vertex format */
+		attr_id.pos = GWN_vertformat_attr_add(&format, "pos", GWN_COMP_F32, 3, GWN_FETCH_FLOAT);
+		attr_id.tan = GWN_vertformat_attr_add(&format, "nor", GWN_COMP_F32, 3, GWN_FETCH_FLOAT);
+		attr_id.ind = GWN_vertformat_attr_add(&format, "ind", GWN_COMP_I32, 1, GWN_FETCH_INT);
+
+		if (psmd) {
+			uv_id = MEM_mallocN(sizeof(*uv_id) * uv_layers, "UV attrib format");
+
+			for (int i = 0; i < uv_layers; i++) {
+				const char *name = CustomData_get_layer_name(&psmd->dm_final->loopData, CD_MLOOPUV, i);
+				char uuid[32];
+
+				BLI_snprintf(uuid, sizeof(uuid), "u%u", BLI_ghashutil_strhash_p(name));
+				uv_id[i] = GWN_vertformat_attr_add(&format, uuid, GWN_COMP_F32, 2, GWN_FETCH_FLOAT);
+			}
 		}
 
 		cache->pos = GWN_vertbuf_create_with_format(&format);
@@ -193,12 +221,55 @@ static void particle_batch_cache_ensure_pos_and_seg(ParticleSystem *psys, Partic
 		Gwn_IndexBufBuilder elb;
 		GWN_indexbuf_init(&elb, GWN_PRIM_LINES, cache->segment_count, cache->point_count);
 
+		if (uv_layers) {
+			DM_ensure_tessface(psmd->dm_final);
+
+			mtfaces = MEM_mallocN(sizeof(*mtfaces) * uv_layers, "Faces UV layers");
+
+			for (int i = 0; i < uv_layers; i++) {
+				mtfaces[i] = (MTFace *)CustomData_get_layer_n(&psmd->dm_final->faceData, CD_MTFACE, i);
+			}
+		}
+
 		if (psys->pathcache && (!psys->childcache || (psys->part->draw & PART_DRAW_PARENT))) {
+			if (simple) {
+				parent_uvs = MEM_callocN(sizeof(*parent_uvs) * psys->totpart, "Parent particle UVs");
+			}
+
 			for (int i = 0; i < psys->totpart; i++) {
 				ParticleCacheKey *path = psys->pathcache[i];
 
 				if (path->segments > 0) {
 					float tangent[3];
+					int from = psmd ? psmd->psys->part->from : 0;
+					float (*uv)[2];
+
+					if (psmd) {
+						uv = MEM_callocN(sizeof(*uv) * uv_layers, "Particle UVs");
+
+						if (simple) {
+							parent_uvs[i] = uv;
+						}
+					}
+
+					if (ELEM(from, PART_FROM_FACE, PART_FROM_VOLUME)) {
+						ParticleData *particle = &psys->particles[i];
+						int num = particle->num_dmcache;
+
+						if (num == DMCACHE_NOTFOUND) {
+							if (particle->num < psmd->dm_final->getNumTessFaces(psmd->dm_final)) {
+								num = particle->num;
+							}
+						}
+
+						if (num != DMCACHE_NOTFOUND) {
+							MFace *mface = psmd->dm_final->getTessFaceData(psmd->dm_final, num, CD_MFACE);
+
+							for (int j = 0; j < uv_layers; j++) {
+								psys_interpolate_uvs(mtfaces[j] + num, mface->v4, particle->fuv, uv[j]);
+							}
+						}
+					}
 
 					for (int j = 0; j < path->segments; j++) {
 						if (j == 0) {
@@ -212,6 +283,12 @@ static void particle_batch_cache_ensure_pos_and_seg(ParticleSystem *psys, Partic
 						GWN_vertbuf_attr_set(cache->pos, attr_id.tan, curr_point, tangent);
 						GWN_vertbuf_attr_set(cache->pos, attr_id.ind, curr_point, &i);
 
+						if (psmd) {
+							for (int k = 0; k < uv_layers; k++) {
+								GWN_vertbuf_attr_set(cache->pos, uv_id[k], curr_point, uv[k]);
+							}
+						}
+
 						GWN_indexbuf_add_line_verts(&elb, curr_point, curr_point + 1);
 
 						curr_point++;
@@ -223,6 +300,16 @@ static void particle_batch_cache_ensure_pos_and_seg(ParticleSystem *psys, Partic
 					GWN_vertbuf_attr_set(cache->pos, attr_id.tan, curr_point, tangent);
 					GWN_vertbuf_attr_set(cache->pos, attr_id.ind, curr_point, &i);
 
+					if (psmd) {
+						for (int k = 0; k < uv_layers; k++) {
+							GWN_vertbuf_attr_set(cache->pos, uv_id[k], curr_point, uv[k]);
+						}
+
+						if (!simple) {
+							MEM_freeN(uv);
+						}
+					}
+
 					curr_point++;
 				}
 			}
@@ -231,11 +318,61 @@ static void particle_batch_cache_ensure_pos_and_seg(ParticleSystem *psys, Partic
 		if (psys->childcache) {
 			int child_count = psys->totchild * psys->part->disp / 100;
 
+			if (simple && !parent_uvs) {
+				parent_uvs = MEM_callocN(sizeof(*parent_uvs) * psys->totpart, "Parent particle UVs");
+			}
+
 			for (int i = 0, x = psys->totpart; i < child_count; i++, x++) {
 				ParticleCacheKey *path = psys->childcache[i];
 				float tangent[3];
 
 				if (path->segments > 0) {
+					int from = psmd ? psmd->psys->part->from : 0;
+					float (*uv)[2];
+
+					if (!simple) {
+						if (psmd) {
+							uv = MEM_callocN(sizeof(*uv) * uv_layers, "Particle UVs");
+						}
+
+						if (ELEM(from, PART_FROM_FACE, PART_FROM_VOLUME)) {
+							ChildParticle *particle = &psys->child[i];
+							int num = psys->part->childtype == particle->num;
+
+							if (num != DMCACHE_NOTFOUND) {
+								MFace *mface = psmd->dm_final->getTessFaceData(psmd->dm_final, num, CD_MFACE);
+
+								for (int j = 0; j < uv_layers; j++) {
+									psys_interpolate_uvs(mtfaces[j] + num, mface->v4, particle->fuv, uv[j]);
+								}
+							}
+						}
+					}
+					else if (!parent_uvs[psys->child[i].parent]) {
+						if (psmd) {
+							parent_uvs[psys->child[i].parent] = MEM_callocN(sizeof(*uv) * uv_layers, "Particle UVs");
+						}
+
+						if (ELEM(from, PART_FROM_FACE, PART_FROM_VOLUME)) {
+							ParticleData *particle = &psys->particles[psys->child[i].parent];
+							int num = particle->num_dmcache;
+
+							if (num == DMCACHE_NOTFOUND) {
+								if (particle->num < psmd->dm_final->getNumTessFaces(psmd->dm_final)) {
+									num = particle->num;
+								}
+							}
+
+							if (num != DMCACHE_NOTFOUND) {
+								MFace *mface = psmd->dm_final->getTessFaceData(psmd->dm_final, num, CD_MFACE);
+
+								for (int j = 0; j < uv_layers; j++) {
+									psys_interpolate_uvs(mtfaces[j] + num, mface->v4, particle->fuv, parent_uvs[psys->child[i].parent][j]);
+								}
+							}
+						}
+					}
+
 					for (int j = 0; j < path->segments; j++) {
 						if (j == 0) {
 							sub_v3_v3v3(tangent, path[j + 1].co, path[j].co);
@@ -248,6 +385,13 @@ static void particle_batch_cache_ensure_pos_and_seg(ParticleSystem *psys, Partic
 						GWN_vertbuf_attr_set(cache->pos, attr_id.tan, curr_point, tangent);
 						GWN_vertbuf_attr_set(cache->pos, attr_id.ind, curr_point, &x);
 
+						if (psmd) {
+							for (int k = 0; k < uv_layers; k++) {
+								GWN_vertbuf_attr_set(cache->pos, uv_id[k], curr_point,
+								                     simple ? parent_uvs[psys->child[i].parent][k] : uv[k]);
+							}
+						}
+
 						GWN_indexbuf_add_line_verts(&elb, curr_point, curr_point + 1);
 
 						curr_point++;
@@ -259,11 +403,38 @@ static void particle_batch_cache_ensure_pos_and_seg(ParticleSystem *psys, Partic
 					GWN_vertbuf_attr_set(cache->pos, attr_id.tan, curr_point, tangent);
 					GWN_vertbuf_attr_set(cache->pos, attr_id.ind, curr_point, &x);
 
+					if (psmd) {
+						for (int k = 0; k < uv_layers; k++) {
+							GWN_vertbuf_attr_set(cache->pos, uv_id[k], curr_point,
+							                     simple ? parent_uvs[psys->child[i].parent][k] : uv[k]);
+						}
+
+						if (!simple) {
+							MEM_freeN(uv);
+						}
+					}
+
 					curr_point++;
 				}
 			}
 		}
 
+		if (parent_uvs) {
+			for (int i = 0; i < psys->totpart; i++) {
+				MEM_SAFE_FREE(parent_uvs[i]);
+			}
+
+			MEM_freeN(parent_uvs);
+		}
+
+		if (uv_layers) {
+			MEM_freeN(mtfaces);
+		}
+
+		if (psmd) {
+			MEM_freeN(uv_id);
+		}
+
 		cache->segments = GWN_indexbuf_build(&elb);
 	}
 }
@@ -322,13 +493,13 @@ static void particle_batch_cache_ensure_pos(ParticleSystem *psys, ParticleBatchC
 	}
 }
 
-Gwn_Batch *DRW_particles_batch_cache_get_hair(ParticleSystem *psys)
+Gwn_Batch *DRW_particles_batch_cache_get_hair(ParticleSystem *psys, ModifierData *md)
 {
 	ParticleBatchCache *cache = particle_batch_cache_get(psys);
 
 	if (cache->hairs == NULL) {
 		ensure_seg_pt_count(psys, cache);
-		particle_batch_cache_ensure_pos_and_seg(psys, cache);
+		particle_batch_cache_ensure_pos_and_seg(psys, md, cache);
 		cache->hairs = GWN_batch_create(GWN_PRIM_LINES, cache->pos, cache->segments);
 	}