Fix Depth-Prepass transparency mode

Add mising bits of implementation and ensure depth-prepass objects are
only rendered in the transparency pass.

10 files changed, 41 insertions, 21 deletions

diff --git a/servers/rendering/renderer_rd/forward_clustered/render_forward_clustered.cpp b/servers/rendering/renderer_rd/forward_clustered/render_forward_clustered.cpp
index 22e3bbdb00..6d85c1f4c1 100644
--- a/servers/rendering/renderer_rd/forward_clustered/render_forward_clustered.cpp
+++ b/servers/rendering/renderer_rd/forward_clustered/render_forward_clustered.cpp
@@ -334,6 +334,10 @@ void RenderForwardClustered::_render_list_template(RenderingDevice::DrawListID p
 		const GeometryInstanceSurfaceDataCache *surf = p_params->elements[i];
 		const RenderElementInfo &element_info = p_params->element_info[i];
 
+		if ((p_pass_mode == PASS_MODE_COLOR || p_pass_mode == PASS_MODE_COLOR_SPECULAR) && !(surf->flags & GeometryInstanceSurfaceDataCache::FLAG_PASS_OPAQUE)) {
+			continue; // Objects with "Depth-prepass" transparency are included in both render lists, but should only be rendered in the transparent pass
+		}
+
 		if (surf->owner->instance_count == 0) {
 			continue;
 		}
@@ -958,20 +962,20 @@ void RenderForwardClustered::_fill_render_list(RenderListType p_render_list, con
 		bool uses_gi = false;
 		float fade_alpha = 1.0;
 
-		if (p_render_list == RENDER_LIST_OPAQUE) {
-			if (inst->fade_near || inst->fade_far) {
-				float fade_dist = inst->transform.origin.distance_to(p_render_data->cam_transform.origin);
-				if (inst->fade_far && fade_dist > inst->fade_far_begin) {
-					fade_alpha = MAX(0.0, 1.0 - (fade_dist - inst->fade_far_begin) / (inst->fade_far_end - inst->fade_far_begin));
-				} else if (inst->fade_near && fade_dist < inst->fade_near_end) {
-					fade_alpha = MAX(0.0, (fade_dist - inst->fade_near_begin) / (inst->fade_near_end - inst->fade_near_begin));
-				}
+		if (inst->fade_near || inst->fade_far) {
+			float fade_dist = inst->transform.origin.distance_to(p_render_data->cam_transform.origin);
+			if (inst->fade_far && fade_dist > inst->fade_far_begin) {
+				fade_alpha = MAX(0.0, 1.0 - (fade_dist - inst->fade_far_begin) / (inst->fade_far_end - inst->fade_far_begin));
+			} else if (inst->fade_near && fade_dist < inst->fade_near_end) {
+				fade_alpha = MAX(0.0, (fade_dist - inst->fade_near_begin) / (inst->fade_near_end - inst->fade_near_begin));
 			}
+		}
 
-			fade_alpha *= inst->force_alpha * inst->parent_fade_alpha;
+		fade_alpha *= inst->force_alpha * inst->parent_fade_alpha;
 
-			flags = (flags & ~INSTANCE_DATA_FLAGS_FADE_MASK) | (uint32_t(fade_alpha * 255.0) << INSTANCE_DATA_FLAGS_FADE_SHIFT);
+		flags = (flags & ~INSTANCE_DATA_FLAGS_FADE_MASK) | (uint32_t(fade_alpha * 255.0) << INSTANCE_DATA_FLAGS_FADE_SHIFT);
 
+		if (p_render_list == RENDER_LIST_OPAQUE) {
 			// Setup GI
 			if (inst->lightmap_instance.is_valid()) {
 				int32_t lightmap_cull_index = -1;
@@ -1206,6 +1210,7 @@ void RenderForwardClustered::_render_scene(RenderDataRD *p_render_data, const Co
 	scene_state.ubo.viewport_size[0] = vp_he.x;
 	scene_state.ubo.viewport_size[1] = vp_he.y;
 	scene_state.ubo.directional_light_count = 0;
+	scene_state.ubo.opaque_prepass_threshold = 0.99f;
 
 	Size2i screen_size;
 	RID opaque_framebuffer;
@@ -1449,6 +1454,7 @@ void RenderForwardClustered::_render_scene(RenderDataRD *p_render_data, const Co
 	RD::get_singleton()->draw_command_begin_label("Render Opaque Pass");
 
 	scene_state.ubo.directional_light_count = p_render_data->directional_light_count;
+	scene_state.ubo.opaque_prepass_threshold = 0.0f;
 
 	_setup_environment(p_render_data, p_render_data->reflection_probe.is_valid(), screen_size, !p_render_data->reflection_probe.is_valid(), p_default_bg_color, p_render_data->render_buffers.is_valid());
 
@@ -1632,6 +1638,7 @@ void RenderForwardClustered::_render_shadow_append(RID p_framebuffer, const Page
 	render_data.render_info = p_render_info;
 
 	scene_state.ubo.dual_paraboloid_side = p_use_dp_flip ? -1 : 1;
+	scene_state.ubo.opaque_prepass_threshold = 0.1f;
 
 	_setup_environment(&render_data, true, Vector2(1, 1), !p_flip_y, Color(), false, p_use_pancake, shadow_pass_index);
 
@@ -1718,6 +1725,7 @@ void RenderForwardClustered::_render_particle_collider_heightfield(RID p_fb, con
 
 	_update_render_base_uniform_set();
 	scene_state.ubo.dual_paraboloid_side = 0;
+	scene_state.ubo.opaque_prepass_threshold = 0.0;
 
 	_setup_environment(&render_data, true, Vector2(1, 1), true, Color(), false, false);
 
@@ -1755,6 +1763,7 @@ void RenderForwardClustered::_render_material(const Transform3D &p_cam_transform
 
 	scene_state.ubo.dual_paraboloid_side = 0;
 	scene_state.ubo.material_uv2_mode = false;
+	scene_state.ubo.opaque_prepass_threshold = 0.0f;
 
 	_setup_environment(&render_data, true, Vector2(1, 1), false, Color());
 
@@ -1798,6 +1807,7 @@ void RenderForwardClustered::_render_uv2(const PagedArray<GeometryInstance *> &p
 
 	scene_state.ubo.dual_paraboloid_side = 0;
 	scene_state.ubo.material_uv2_mode = true;
+	scene_state.ubo.opaque_prepass_threshold = 0.0;
 
 	_setup_environment(&render_data, true, Vector2(1, 1), false, Color());
 
diff --git a/servers/rendering/renderer_rd/forward_clustered/render_forward_clustered.h b/servers/rendering/renderer_rd/forward_clustered/render_forward_clustered.h
index 2ba9558128..7707d77296 100644
--- a/servers/rendering/renderer_rd/forward_clustered/render_forward_clustered.h
+++ b/servers/rendering/renderer_rd/forward_clustered/render_forward_clustered.h
@@ -257,7 +257,8 @@ class RenderForwardClustered : public RendererSceneRenderRD {
 
 			float roughness_limiter_amount;
 			float roughness_limiter_limit;
-			uint32_t roughness_limiter_pad[2];
+			float opaque_prepass_threshold;
+			uint32_t roughness_limiter_pad;
 
 			float sdf_to_bounds[16];
 
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 61f2031a70..768bd1de9d 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
@@ -650,6 +650,7 @@ void SceneShaderForwardClustered::init(RendererStorageRD *p_storage, const Strin
 		actions.render_mode_defines["cull_front"] = "#define DO_SIDE_CHECK\n";
 		actions.render_mode_defines["cull_disabled"] = "#define DO_SIDE_CHECK\n";
 		actions.render_mode_defines["particle_trails"] = "#define USE_PARTICLE_TRAILS\n";
+		actions.render_mode_defines["depth_draw_opaque"] = "#define USE_OPAQUE_PREPASS\n";
 
 		bool force_lambert = GLOBAL_GET("rendering/shading/overrides/force_lambert_over_burley");
 
diff --git a/servers/rendering/renderer_rd/forward_mobile/render_forward_mobile.cpp b/servers/rendering/renderer_rd/forward_mobile/render_forward_mobile.cpp
index f23a386acf..445623fb86 100644
--- a/servers/rendering/renderer_rd/forward_mobile/render_forward_mobile.cpp
+++ b/servers/rendering/renderer_rd/forward_mobile/render_forward_mobile.cpp
@@ -483,6 +483,7 @@ void RenderForwardMobile::_render_scene(RenderDataRD *p_render_data, const Color
 	scene_state.ubo.viewport_size[0] = vp_he.x;
 	scene_state.ubo.viewport_size[1] = vp_he.y;
 	scene_state.ubo.directional_light_count = 0;
+	scene_state.ubo.opaque_prepass_threshold = 0.0;
 
 	// We can only use our full subpass approach if we're:
 	// - not reading from SCREEN_TEXTURE/DEPTH_TEXTURE
@@ -793,7 +794,7 @@ void RenderForwardMobile::_render_scene(RenderDataRD *p_render_data, const Color
 
 		if (using_subpass_transparent) {
 			RD::FramebufferFormatID fb_format = RD::get_singleton()->framebuffer_get_format(framebuffer);
-			RenderListParameters render_list_params(render_list[RENDER_LIST_ALPHA].elements.ptr(), render_list[RENDER_LIST_ALPHA].element_info.ptr(), render_list[RENDER_LIST_ALPHA].elements.size(), reverse_cull, PASS_MODE_COLOR, rp_uniform_set, spec_constant_base_flags, get_debug_draw_mode() == RS::VIEWPORT_DEBUG_DRAW_WIREFRAME, Vector2(), p_render_data->lod_camera_plane, p_render_data->lod_distance_multiplier, p_render_data->screen_lod_threshold, p_render_data->view_count);
+			RenderListParameters render_list_params(render_list[RENDER_LIST_ALPHA].elements.ptr(), render_list[RENDER_LIST_ALPHA].element_info.ptr(), render_list[RENDER_LIST_ALPHA].elements.size(), reverse_cull, PASS_MODE_COLOR_TRANSPARENT, rp_uniform_set, spec_constant_base_flags, get_debug_draw_mode() == RS::VIEWPORT_DEBUG_DRAW_WIREFRAME, Vector2(), p_render_data->lod_camera_plane, p_render_data->lod_distance_multiplier, p_render_data->screen_lod_threshold, p_render_data->view_count);
 			render_list_params.framebuffer_format = fb_format;
 			if ((uint32_t)render_list_params.element_count > render_list_thread_threshold && false) {
 				// secondary command buffers need more testing at this time
@@ -897,6 +898,7 @@ void RenderForwardMobile::_render_shadow_append(RID p_framebuffer, const PagedAr
 	render_data.lod_distance_multiplier = p_lod_distance_multiplier;
 
 	scene_state.ubo.dual_paraboloid_side = p_use_dp_flip ? -1 : 1;
+	scene_state.ubo.opaque_prepass_threshold = 0.1;
 
 	_setup_environment(&render_data, true, Vector2(1, 1), !p_flip_y, Color(), false, p_use_pancake, shadow_pass_index);
 
@@ -978,6 +980,7 @@ void RenderForwardMobile::_render_material(const Transform3D &p_cam_transform, c
 
 	scene_state.ubo.dual_paraboloid_side = 0;
 	scene_state.ubo.material_uv2_mode = false;
+	scene_state.ubo.opaque_prepass_threshold = 0.0f;
 
 	RenderDataRD render_data;
 	render_data.cam_projection = p_cam_projection;
@@ -1089,6 +1092,7 @@ void RenderForwardMobile::_render_particle_collider_heightfield(RID p_fb, const
 
 	_update_render_base_uniform_set();
 	scene_state.ubo.dual_paraboloid_side = 0;
+	scene_state.ubo.opaque_prepass_threshold = 0.0;
 
 	RenderDataRD render_data;
 	render_data.cam_projection = p_cam_projection;
@@ -1447,13 +1451,13 @@ void RenderForwardMobile::_fill_render_list(RenderListType p_render_list, const
 			}
 
 			// ADD Element
-			if (p_pass_mode == PASS_MODE_COLOR) {
+			if (p_pass_mode == PASS_MODE_COLOR || p_pass_mode == PASS_MODE_COLOR_TRANSPARENT) {
 #ifdef DEBUG_ENABLED
 				bool force_alpha = unlikely(get_debug_draw_mode() == RS::VIEWPORT_DEBUG_DRAW_OVERDRAW);
 #else
 				bool force_alpha = false;
 #endif
-				if (!force_alpha && (surf->flags & (GeometryInstanceSurfaceDataCache::FLAG_PASS_DEPTH | GeometryInstanceSurfaceDataCache::FLAG_PASS_OPAQUE))) {
+				if (!force_alpha && (surf->flags & GeometryInstanceSurfaceDataCache::FLAG_PASS_OPAQUE)) {
 					rl->add_element(surf);
 				}
 				if (force_alpha || (surf->flags & GeometryInstanceSurfaceDataCache::FLAG_PASS_ALPHA)) {
diff --git a/servers/rendering/renderer_rd/forward_mobile/render_forward_mobile.h b/servers/rendering/renderer_rd/forward_mobile/render_forward_mobile.h
index 74bfe16557..485d08b589 100644
--- a/servers/rendering/renderer_rd/forward_mobile/render_forward_mobile.h
+++ b/servers/rendering/renderer_rd/forward_mobile/render_forward_mobile.h
@@ -292,7 +292,8 @@ protected:
 
 			float roughness_limiter_amount;
 			float roughness_limiter_limit;
-			uint32_t roughness_limiter_pad[2];
+			float opaque_prepass_threshold;
+			uint32_t roughness_limiter_pad;
 
 			// Fog
 			uint32_t fog_enabled;
diff --git a/servers/rendering/renderer_rd/forward_mobile/scene_shader_forward_mobile.cpp b/servers/rendering/renderer_rd/forward_mobile/scene_shader_forward_mobile.cpp
index 5d5cb7a6b7..e6d9a60f94 100644
--- a/servers/rendering/renderer_rd/forward_mobile/scene_shader_forward_mobile.cpp
+++ b/servers/rendering/renderer_rd/forward_mobile/scene_shader_forward_mobile.cpp
@@ -637,6 +637,7 @@ void SceneShaderForwardMobile::init(RendererStorageRD *p_storage, const String p
 		actions.render_mode_defines["cull_front"] = "#define DO_SIDE_CHECK\n";
 		actions.render_mode_defines["cull_disabled"] = "#define DO_SIDE_CHECK\n";
 		actions.render_mode_defines["particle_trails"] = "#define USE_PARTICLE_TRAILS\n";
+		actions.render_mode_defines["depth_draw_opaque"] = "#define USE_OPAQUE_PREPASS\n";
 
 		bool force_lambert = GLOBAL_GET("rendering/shading/overrides/force_lambert_over_burley");
 		if (!force_lambert) {
diff --git a/servers/rendering/renderer_rd/shaders/scene_forward_clustered.glsl b/servers/rendering/renderer_rd/shaders/scene_forward_clustered.glsl
index 20982a466c..8e33610ae2 100644
--- a/servers/rendering/renderer_rd/shaders/scene_forward_clustered.glsl
+++ b/servers/rendering/renderer_rd/shaders/scene_forward_clustered.glsl
@@ -695,7 +695,7 @@ void main() {
 #endif // ALPHA_ANTIALIASING_EDGE_USED
 
 #ifdef USE_OPAQUE_PREPASS
-	if (alpha < opaque_prepass_threshold) {
+	if (alpha < scene_data.opaque_prepass_threshold) {
 		discard;
 	}
 #endif // USE_OPAQUE_PREPASS
@@ -1711,7 +1711,7 @@ void main() {
 
 #ifdef USE_OPAQUE_PREPASS
 
-	if (alpha < opaque_prepass_threshold) {
+	if (alpha < scene_data.opaque_prepass_threshold) {
 		discard;
 	}
 
diff --git a/servers/rendering/renderer_rd/shaders/scene_forward_clustered_inc.glsl b/servers/rendering/renderer_rd/shaders/scene_forward_clustered_inc.glsl
index c8489f2137..be29cf4f58 100644
--- a/servers/rendering/renderer_rd/shaders/scene_forward_clustered_inc.glsl
+++ b/servers/rendering/renderer_rd/shaders/scene_forward_clustered_inc.glsl
@@ -208,7 +208,8 @@ layout(set = 1, binding = 0, std140) uniform SceneData {
 
 	float roughness_limiter_amount;
 	float roughness_limiter_limit;
-	uvec2 roughness_limiter_pad;
+	float opaque_prepass_threshold;
+	uint roughness_limiter_pad;
 
 	mat4 sdf_to_bounds;
 
diff --git a/servers/rendering/renderer_rd/shaders/scene_forward_mobile.glsl b/servers/rendering/renderer_rd/shaders/scene_forward_mobile.glsl
index b6fd89d912..e92fbecfd0 100644
--- a/servers/rendering/renderer_rd/shaders/scene_forward_mobile.glsl
+++ b/servers/rendering/renderer_rd/shaders/scene_forward_mobile.glsl
@@ -705,7 +705,7 @@ void main() {
 #endif // ALPHA_ANTIALIASING_EDGE_USED
 
 #ifdef USE_OPAQUE_PREPASS
-	if (alpha < opaque_prepass_threshold) {
+	if (alpha < scene_data.opaque_prepass_threshold) {
 		discard;
 	}
 #endif // USE_OPAQUE_PREPASS
@@ -1476,7 +1476,7 @@ void main() {
 
 #ifdef USE_OPAQUE_PREPASS
 
-	if (alpha < opaque_prepass_threshold) {
+	if (alpha < scene_data.opaque_prepass_threshold) {
 		discard;
 	}
 
diff --git a/servers/rendering/renderer_rd/shaders/scene_forward_mobile_inc.glsl b/servers/rendering/renderer_rd/shaders/scene_forward_mobile_inc.glsl
index eb8fb49598..a9a4fce82a 100644
--- a/servers/rendering/renderer_rd/shaders/scene_forward_mobile_inc.glsl
+++ b/servers/rendering/renderer_rd/shaders/scene_forward_mobile_inc.glsl
@@ -168,7 +168,8 @@ layout(set = 1, binding = 0, std140) uniform SceneData {
 
 	mediump float roughness_limiter_amount;
 	mediump float roughness_limiter_limit;
-	uvec2 roughness_limiter_pad;
+	mediump float opaque_prepass_threshold;
+	uint roughness_limiter_pad;
 
 	bool fog_enabled;
 	highp float fog_density;