Eevee: Ssr: Add ssr id to glossy nodes.

An id is given to each glossy node in order to determine which specular lobe is using ssr.

7 files changed, 63 insertions, 16 deletions

diff --git a/source/blender/draw/engines/eevee/shaders/lit_surface_frag.glsl b/source/blender/draw/engines/eevee/shaders/lit_surface_frag.glsl
index 1cfc00ef8d7..4241eeb8b8e 100644
--- a/source/blender/draw/engines/eevee/shaders/lit_surface_frag.glsl
+++ b/source/blender/draw/engines/eevee/shaders/lit_surface_frag.glsl
@@ -24,7 +24,7 @@ in vec3 viewNormal;
 
 /* ----------- default -----------  */
 
-vec3 eevee_surface_lit(vec3 N, vec3 albedo, vec3 f0, float roughness, float ao)
+vec3 eevee_surface_lit(vec3 N, vec3 albedo, vec3 f0, float roughness, float ao, float ssr_id)
 {
 	/* Zero length vectors cause issues, see: T51979. */
 #if 0
@@ -166,7 +166,7 @@ vec3 eevee_surface_lit(vec3 N, vec3 albedo, vec3 f0, float roughness, float ao)
 vec3 eevee_surface_clearcoat_lit(
         vec3 N, vec3 albedo, vec3 f0, float roughness,
         vec3 C_N, float C_intensity, float C_roughness, /* Clearcoat params */
-        float ao)
+        float ao, float ssr_id)
 {
 	roughness = clamp(roughness, 1e-8, 0.9999);
 	float roughnessSquared = roughness * roughness;
diff --git a/source/blender/gpu/shaders/gpu_shader_material.glsl b/source/blender/gpu/shaders/gpu_shader_material.glsl
index 81f70332876..f319cfd82c6 100644
--- a/source/blender/gpu/shaders/gpu_shader_material.glsl
+++ b/source/blender/gpu/shaders/gpu_shader_material.glsl
@@ -2824,13 +2824,13 @@ void node_bsdf_principled(vec4 base_color, float subsurface, vec3 subsurface_rad
 
 void node_bsdf_principled_simple(vec4 base_color, float subsurface, vec3 subsurface_radius, vec4 subsurface_color, float metallic, float specular,
 	float specular_tint, float roughness, float anisotropic, float anisotropic_rotation, float sheen, float sheen_tint, float clearcoat,
-	float clearcoat_roughness, float ior, float transmission, float transmission_roughness, vec3 N, vec3 CN, vec3 T, vec3 I, out Closure result)
+	float clearcoat_roughness, float ior, float transmission, float transmission_roughness, vec3 N, vec3 CN, vec3 T, vec3 I, float ssr_id, out Closure result)
 {
 #ifdef EEVEE_ENGINE
 	vec3 diffuse, f0;
 	convert_metallic_to_specular_tinted(base_color.rgb, metallic, specular, specular_tint, diffuse, f0);
 
-	result = Closure(eevee_surface_lit(N, diffuse, f0, roughness, 1.0), 1.0);
+	result = Closure(eevee_surface_lit(N, diffuse, f0, roughness, 1.0, ssr_id), 1.0);
 #else
 	node_bsdf_principled(base_color, subsurface, subsurface_radius, subsurface_color, metallic, specular,
 		specular_tint, roughness, anisotropic, anisotropic_rotation, sheen, sheen_tint, clearcoat,
@@ -2840,7 +2840,7 @@ void node_bsdf_principled_simple(vec4 base_color, float subsurface, vec3 subsurf
 
 void node_bsdf_principled_clearcoat(vec4 base_color, float subsurface, vec3 subsurface_radius, vec4 subsurface_color, float metallic, float specular,
 	float specular_tint, float roughness, float anisotropic, float anisotropic_rotation, float sheen, float sheen_tint, float clearcoat,
-	float clearcoat_roughness, float ior, float transmission, float transmission_roughness, vec3 N, vec3 CN, vec3 T, vec3 I, out Closure result)
+	float clearcoat_roughness, float ior, float transmission, float transmission_roughness, vec3 N, vec3 CN, vec3 T, vec3 I, float ssr_id, out Closure result)
 {
 #ifdef EEVEE_ENGINE
 	vec3 diffuse, f0;
@@ -2865,13 +2865,13 @@ void node_bsdf_principled_clearcoat(vec4 base_color, float subsurface, vec3 subs
 		N = tangent_to_world(Ht, N, Y, X);
 
 		if (dot(N, cameraVec) > 0) {
-			surface_color.rgb += eevee_surface_clearcoat_lit(N, diffuse, f0, sqrt(min(ax, ay)), CN, clearcoat, clearcoat_roughness, 1.0);
+			surface_color.rgb += eevee_surface_clearcoat_lit(N, diffuse, f0, sqrt(min(ax, ay)), CN, clearcoat, clearcoat_roughness, 1.0, ssr_id);
 			surface_color.a += 1.0;
 		}
 	}
 	result = Closure(surface_color.rgb / surface_color.a, 1.0);
 #else
-	result = Closure(eevee_surface_clearcoat_lit(N, diffuse, f0, roughness, CN, clearcoat, clearcoat_roughness, 1.0), 1.0);
+	result = Closure(eevee_surface_clearcoat_lit(N, diffuse, f0, roughness, CN, clearcoat, clearcoat_roughness, 1.0, ssr_id), 1.0);
 #endif
 
 #else
@@ -4013,20 +4013,20 @@ void world_normals_get(out vec3 N)
 void node_eevee_metallic(
         vec4 basecol, float metallic, float specular, float roughness, vec4 emissive, float transp, vec3 normal,
         float clearcoat, float clearcoat_roughness, vec3 clearcoat_normal,
-        float occlusion, out Closure result)
+        float occlusion, float ssr_id, out Closure result)
 {
 	vec3 diffuse, f0;
 	convert_metallic_to_specular(basecol.rgb, metallic, specular, diffuse, f0);
 
-	result = Closure(eevee_surface_lit(normal, diffuse, f0, roughness, occlusion) + emissive.rgb, 1.0 - transp);
+	result = Closure(eevee_surface_lit(normal, diffuse, f0, roughness, occlusion, ssr_id) + emissive.rgb, 1.0 - transp);
 }
 
 void node_eevee_specular(
         vec4 diffuse, vec4 specular, float roughness, vec4 emissive, float transp, vec3 normal,
         float clearcoat, float clearcoat_roughness, vec3 clearcoat_normal,
-        float occlusion, out Closure result)
+        float occlusion, float ssr_id, out Closure result)
 {
-	result = Closure(eevee_surface_lit(normal, diffuse.rgb, specular.rgb, roughness, occlusion) + emissive.rgb, 1.0 - transp);
+	result = Closure(eevee_surface_lit(normal, diffuse.rgb, specular.rgb, roughness, occlusion, ssr_id) + emissive.rgb, 1.0 - transp);
 }
 
 void node_output_eevee_material(Closure surface, out Closure result)
diff --git a/source/blender/makesdna/DNA_node_types.h b/source/blender/makesdna/DNA_node_types.h
index b922ac072b0..de1214e9b3d 100644
--- a/source/blender/makesdna/DNA_node_types.h
+++ b/source/blender/makesdna/DNA_node_types.h
@@ -214,8 +214,11 @@ typedef struct bNode {
 	 * and replacing all uses with per-instance data.
 	 */
 	short preview_xsize, preview_ysize;	/* reserved size of the preview rect */
-	int pad2;
+	short pad2[2];
 	struct uiBlock *block;	/* runtime during drawing */
+
+	float ssr_id; /* XXX: eevee only, id of screen space reflection layer, needs to be a float to feed GPU_uniform. */
+	float pad3;
 } bNode;
 
 /* node->flag */
diff --git a/source/blender/nodes/shader/node_shader_tree.c b/source/blender/nodes/shader/node_shader_tree.c
index b5d77e99328..52e9ed35a2e 100644
--- a/source/blender/nodes/shader/node_shader_tree.c
+++ b/source/blender/nodes/shader/node_shader_tree.c
@@ -475,6 +475,48 @@ static void ntree_shader_relink_displacement(bNodeTree *ntree,
 	ntreeUpdateTree(G.main, ntree);
 }
 
+static bool ntree_tag_ssr_bsdf_cb(bNode *fromnode, bNode *UNUSED(tonode), void *userdata, const bool UNUSED(reversed))
+{
+	switch (fromnode->type) {
+		case SH_NODE_BSDF_ANISOTROPIC:
+		case SH_NODE_EEVEE_METALLIC:
+		case SH_NODE_EEVEE_SPECULAR:
+		case SH_NODE_BSDF_PRINCIPLED:
+		case SH_NODE_BSDF_GLOSSY:
+			fromnode->ssr_id = (*(float *)userdata);
+			(*(float *)userdata) += 1;
+			break;
+		default:
+			/* We could return false here but since we (will)
+			 * allow the use of Closure as RGBA, we can have
+			 * Bsdf nodes linked to other Bsdf nodes. */
+			break;
+	}
+
+	return true;
+}
+
+/* EEVEE: Scan the ntree to set the Screen Space Reflection
+ * layer id of every specular node.
+ */
+static void ntree_shader_tag_ssr_node(bNodeTree *ntree, short compatibility)
+{
+	if (compatibility != NODE_NEWER_SHADING) {
+		/* We can only deal with new shading system here. */
+		return;
+	}
+
+	bNode *output_node = ntree_shader_output_node(ntree);
+	if (output_node == NULL) {
+		return;
+	}
+	/* Make sure sockets links pointers are correct. */
+	ntreeUpdateTree(G.main, ntree);
+
+	int lobe_count = 0;
+	nodeChainIter(ntree, output_node, ntree_tag_ssr_bsdf_cb, &lobe_count, true);
+}
+
 void ntreeGPUMaterialNodes(bNodeTree *ntree, GPUMaterial *mat, short compatibility)
 {
 	/* localize tree to create links for reroute and mute */
@@ -486,6 +528,8 @@ void ntreeGPUMaterialNodes(bNodeTree *ntree, GPUMaterial *mat, short compatibili
 	 */
 	ntree_shader_relink_displacement(localtree, compatibility);
 
+	ntree_shader_tag_ssr_node(localtree, compatibility);
+
 	exec = ntreeShaderBeginExecTree(localtree);
 	ntreeExecGPUNodes(exec, mat, 1, compatibility);
 	ntreeShaderEndExecTree(exec);
diff --git a/source/blender/nodes/shader/nodes/node_shader_bsdf_principled.c b/source/blender/nodes/shader/nodes/node_shader_bsdf_principled.c
index 4ae0474d685..1ec77bc9189 100644
--- a/source/blender/nodes/shader/nodes/node_shader_bsdf_principled.c
+++ b/source/blender/nodes/shader/nodes/node_shader_bsdf_principled.c
@@ -100,10 +100,10 @@ static int node_shader_gpu_bsdf_principled(GPUMaterial *mat, bNode *node, bNodeE
 
 	/* Only use complex versions when needed. */
 	if (!in[12].link && (in[12].vec[0] == 0.0f)) {
-		return GPU_stack_link(mat, node, "node_bsdf_principled_simple", in, out, GPU_builtin(GPU_VIEW_POSITION));
+		return GPU_stack_link(mat, node, "node_bsdf_principled_simple", in, out, GPU_builtin(GPU_VIEW_POSITION), GPU_uniform(&node->ssr_id));
 	}
 	else {
-		return GPU_stack_link(mat, node, "node_bsdf_principled_clearcoat", in, out, GPU_builtin(GPU_VIEW_POSITION));
+		return GPU_stack_link(mat, node, "node_bsdf_principled_clearcoat", in, out, GPU_builtin(GPU_VIEW_POSITION), GPU_uniform(&node->ssr_id));
 	}
 }
 
diff --git a/source/blender/nodes/shader/nodes/node_shader_eevee_metallic.c b/source/blender/nodes/shader/nodes/node_shader_eevee_metallic.c
index 2a8a3a44f39..071486493fa 100644
--- a/source/blender/nodes/shader/nodes/node_shader_eevee_metallic.c
+++ b/source/blender/nodes/shader/nodes/node_shader_eevee_metallic.c
@@ -68,7 +68,7 @@ static int node_shader_gpu_eevee_metallic(GPUMaterial *mat, bNode *node, bNodeEx
 		GPU_link(mat, "set_value", GPU_uniform(&one), &in[10].link);
 	}
 
-	return GPU_stack_link(mat, node, "node_eevee_metallic", in, out);
+	return GPU_stack_link(mat, node, "node_eevee_metallic", in, out, GPU_uniform(&node->ssr_id));
 }
 
 
diff --git a/source/blender/nodes/shader/nodes/node_shader_eevee_specular.c b/source/blender/nodes/shader/nodes/node_shader_eevee_specular.c
index 954f9b3ee4a..c249e77c17a 100644
--- a/source/blender/nodes/shader/nodes/node_shader_eevee_specular.c
+++ b/source/blender/nodes/shader/nodes/node_shader_eevee_specular.c
@@ -67,7 +67,7 @@ static int node_shader_gpu_eevee_specular(GPUMaterial *mat, bNode *node, bNodeEx
 		GPU_link(mat, "set_value", GPU_uniform(&one), &in[9].link);
 	}
 
-	return GPU_stack_link(mat, node, "node_eevee_specular", in, out);
+	return GPU_stack_link(mat, node, "node_eevee_specular", in, out, GPU_uniform(&node->ssr_id));
 }