From 8a2fd9800473de45ac22964489926a2175d9f5fe Mon Sep 17 00:00:00 2001
From: LuoZhihao <luo_zhihao@outlook.com>
Date: Tue, 17 Jun 2025 20:14:53 +0800
Subject: [PATCH] Forward+: Fix builtins in light shader

---
 .../scene_shader_forward_clustered.cpp        | 10 +++---
 .../scene_forward_clustered.glsl              | 32 +++++++++++++------
 2 files changed, 28 insertions(+), 14 deletions(-)

diff --git a/servers/rendering/renderer_rd/forward_clustered/scene_shader_forward_clustered.cpp b/servers/rendering/renderer_rd/forward_clustered/scene_shader_forward_clustered.cpp
index f740644a3bb..80178f3664e 100644
--- a/servers/rendering/renderer_rd/forward_clustered/scene_shader_forward_clustered.cpp
+++ b/servers/rendering/renderer_rd/forward_clustered/scene_shader_forward_clustered.cpp
@@ -692,7 +692,7 @@ void SceneShaderForwardClustered::init(const String p_defines) {
 		actions.renames["MAIN_CAM_INV_VIEW_MATRIX"] = "scene_data.main_cam_inv_view_matrix";
 
 		actions.renames["VERTEX"] = "vertex";
-		actions.renames["NORMAL"] = "normal";
+		actions.renames["NORMAL"] = "normal_highp";
 		actions.renames["TANGENT"] = "tangent";
 		actions.renames["BINORMAL"] = "binormal";
 		actions.renames["POSITION"] = "position";
@@ -726,12 +726,12 @@ void SceneShaderForwardClustered::init(const String p_defines) {
 		actions.renames["NORMAL_MAP"] = "normal_map";
 		actions.renames["NORMAL_MAP_DEPTH"] = "normal_map_depth";
 		actions.renames["BENT_NORMAL_MAP"] = "bent_normal_map";
-		actions.renames["ALBEDO"] = "albedo";
-		actions.renames["ALPHA"] = "alpha";
+		actions.renames["ALBEDO"] = "albedo_highp";
+		actions.renames["ALPHA"] = "alpha_highp";
 		actions.renames["PREMUL_ALPHA_FACTOR"] = "premul_alpha";
-		actions.renames["METALLIC"] = "metallic";
+		actions.renames["METALLIC"] = "metallic_highp";
 		actions.renames["SPECULAR"] = "specular";
-		actions.renames["ROUGHNESS"] = "roughness";
+		actions.renames["ROUGHNESS"] = "roughness_highp";
 		actions.renames["RIM"] = "rim";
 		actions.renames["RIM_TINT"] = "rim_tint";
 		actions.renames["CLEARCOAT"] = "clearcoat";
diff --git a/servers/rendering/renderer_rd/shaders/forward_clustered/scene_forward_clustered.glsl b/servers/rendering/renderer_rd/shaders/forward_clustered/scene_forward_clustered.glsl
index afe3452037a..059a409ec6a 100644
--- a/servers/rendering/renderer_rd/shaders/forward_clustered/scene_forward_clustered.glsl
+++ b/servers/rendering/renderer_rd/shaders/forward_clustered/scene_forward_clustered.glsl
@@ -339,7 +339,7 @@ void vertex_shader(vec3 vertex_input,
 
 	vec3 vertex = vertex_input;
 #ifdef NORMAL_USED
-	vec3 normal = normal_input;
+	vec3 normal_highp = normal_input;
 #endif
 
 #ifdef TANGENT_USED
@@ -387,7 +387,7 @@ void vertex_shader(vec3 vertex_input,
 	vertex = (model_matrix * vec4(vertex, 1.0)).xyz;
 
 #ifdef NORMAL_USED
-	normal = model_normal_matrix * normal;
+	normal_highp = model_normal_matrix * normal_highp;
 #endif
 
 #ifdef TANGENT_USED
@@ -402,7 +402,7 @@ void vertex_shader(vec3 vertex_input,
 	float z_clip_scale = 1.0;
 #endif
 
-	float roughness = 1.0;
+	float roughness_highp = 1.0;
 
 	mat4 modelview = scene_data.view_matrix * model_matrix;
 	mat3 modelview_normal = mat3(scene_data.view_matrix) * model_normal_matrix;
@@ -413,6 +413,11 @@ void vertex_shader(vec3 vertex_input,
 #CODE : VERTEX
 	}
 
+	float roughness = roughness_highp;
+#ifdef NORMAL_USED
+	vec3 normal = normal_highp;
+#endif
+
 // using local coordinates (default)
 #if !defined(SKIP_TRANSFORM_USED) && !defined(VERTEX_WORLD_COORDS_USED)
 
@@ -1142,15 +1147,15 @@ void fragment_shader(in SceneData scene_data) {
 	vec3 eye_offset = vec3(0.0, 0.0, 0.0);
 	vec3 view_highp = -normalize(vertex_interp);
 #endif
-	vec3 albedo = vec3(1.0);
+	vec3 albedo_highp = vec3(1.0);
 	vec3 backlight = vec3(0.0);
 	vec4 transmittance_color = vec4(0.0, 0.0, 0.0, 1.0);
 	float transmittance_depth = 0.0;
 	float transmittance_boost = 0.0;
-	float metallic = 0.0;
+	float metallic_highp = 0.0;
 	float specular = 0.5;
 	vec3 emission = vec3(0.0);
-	float roughness = 1.0;
+	float roughness_highp = 1.0;
 	float rim = 0.0;
 	float rim_tint = 0.0;
 	float clearcoat = 0.0;
@@ -1171,7 +1176,7 @@ void fragment_shader(in SceneData scene_data) {
 	float ao = 1.0;
 	float ao_light_affect = 0.0;
 
-	float alpha = float(instances.data[instance_index].flags >> INSTANCE_FLAGS_FADE_SHIFT) / float(255.0);
+	float alpha_highp = float(instances.data[instance_index].flags >> INSTANCE_FLAGS_FADE_SHIFT) / float(255.0);
 
 #ifdef TANGENT_USED
 	vec3 binormal = binormal_interp;
@@ -1182,10 +1187,10 @@ void fragment_shader(in SceneData scene_data) {
 #endif
 
 #ifdef NORMAL_USED
-	vec3 normal = normal_interp;
+	vec3 normal_highp = normal_interp;
 #if defined(DO_SIDE_CHECK)
 	if (!gl_FrontFacing) {
-		normal = -normal;
+		normal_highp = -normal_highp;
 	}
 #endif // DO_SIDE_CHECK
 #endif // NORMAL_USED
@@ -1255,10 +1260,19 @@ void fragment_shader(in SceneData scene_data) {
 
 	mat4 read_view_matrix = scene_data.view_matrix;
 	vec2 read_viewport_size = scene_data.viewport_size;
+
 	{
 #CODE : FRAGMENT
 	}
 
+	float roughness = roughness_highp;
+	float metallic = metallic_highp;
+	vec3 albedo = albedo_highp;
+	float alpha = alpha_highp;
+#ifdef NORMAL_USED
+	vec3 normal = normal_highp;
+#endif
+
 #ifdef LIGHT_TRANSMITTANCE_USED
 	transmittance_color.a *= sss_strength;
 #endif