3D View: add back initial clipping support

Use clipping for workbench solid mode drawing.

Other modes & shading support still needs to be added.

7 files changed, 52 insertions, 5 deletions

diff --git a/source/blender/blenloader/intern/readfile.c b/source/blender/blenloader/intern/readfile.c
index b264b457396..3dfb262414b 100644
--- a/source/blender/blenloader/intern/readfile.c
+++ b/source/blender/blenloader/intern/readfile.c
@@ -6675,10 +6675,6 @@ static void direct_link_region(FileData *fd, ARegion *ar, int spacetype)
 				rv3d->render_engine = NULL;
 				rv3d->sms = NULL;
 				rv3d->smooth_timer = NULL;
-
-				/* TODO: support clipping in 2.8x,
-				 * Tools use clipping which is confusing when it isn't displayed, T59580. */
-				rv3d->rflag &= ~RV3D_CLIPPING;
 			}
 		}
 	}
diff --git a/source/blender/draw/engines/workbench/shaders/workbench_prepass_vert.glsl b/source/blender/draw/engines/workbench/shaders/workbench_prepass_vert.glsl
index 7c5b528c40d..e821581298d 100644
--- a/source/blender/draw/engines/workbench/shaders/workbench_prepass_vert.glsl
+++ b/source/blender/draw/engines/workbench/shaders/workbench_prepass_vert.glsl
@@ -1,10 +1,16 @@
 uniform mat4 ModelViewProjectionMatrix;
+uniform mat4 ModelMatrix;
 uniform mat4 ModelMatrixInverse;
 uniform mat4 ProjectionMatrix;
 uniform mat4 ViewProjectionMatrix;
 uniform mat4 ViewMatrixInverse;
 uniform mat3 NormalMatrix;
 
+#ifdef USE_WORLD_CLIP_PLANES
+uniform vec4 WorldClipPlanes[6];
+uniform int  WorldClipPlanesLen;
+#endif
+
 #ifndef HAIR_SHADER
 in vec3 pos;
 in vec3 nor;
@@ -68,4 +74,14 @@ void main()
 	normal_viewport = normalize(normal_viewport);
 #  endif
 #endif
+
+#ifdef USE_WORLD_CLIP_PLANES
+	{
+		vec3 worldPosition = (ModelMatrix * vec4(pos, 1.0)).xyz;
+		for (int i = 0; i < WorldClipPlanesLen; i++) {
+			gl_ClipDistance[i] = dot(WorldClipPlanes[i].xyz, worldPosition) + WorldClipPlanes[i].w;
+		}
+	}
+#endif
+
 }
diff --git a/source/blender/draw/engines/workbench/workbench_data.c b/source/blender/draw/engines/workbench/workbench_data.c
index 937378dabb4..427ae4063f9 100644
--- a/source/blender/draw/engines/workbench/workbench_data.c
+++ b/source/blender/draw/engines/workbench/workbench_data.c
@@ -88,6 +88,18 @@ void workbench_private_data_init(WORKBENCH_PrivateData *wpd)
 	wd->curvature_ridge = 0.5f / max_ff(SQUARE(wpd->shading.curvature_ridge_factor), 1e-4f);
 	wd->curvature_valley = 0.7f / max_ff(SQUARE(wpd->shading.curvature_valley_factor), 1e-4f);
 
+	{
+		RegionView3D *rv3d = draw_ctx->rv3d;
+		if (rv3d->rflag & RV3D_CLIPPING) {
+			memcpy(wpd->world_clip_planes, rv3d->clip, sizeof(float[6][4]));
+			wpd->world_clip_planes_len = (rv3d->viewlock & RV3D_BOXCLIP) ? 4 : 6;
+			DRW_state_clip_planes_count_set(6);
+		}
+		else {
+			wpd->world_clip_planes_len = 0;
+		}
+	}
+
 	wpd->world_ubo = DRW_uniformbuffer_create(sizeof(WORKBENCH_UBO_World), &wpd->world_data);
 
 	/* Cavity settings */
@@ -172,6 +184,13 @@ void workbench_private_data_get_light_direction(WORKBENCH_PrivateData *wpd, floa
 	DRW_uniformbuffer_update(wpd->world_ubo, wd);
 }
 
+void workbench_private_draw_finish(WORKBENCH_PrivateData *wpd)
+{
+	if (wpd->world_clip_planes_len) {
+		DRW_state_clip_planes_reset();
+	}
+}
+
 void workbench_private_data_free(WORKBENCH_PrivateData *wpd)
 {
 	BLI_ghash_free(wpd->material_hash, NULL, MEM_freeN);
diff --git a/source/blender/draw/engines/workbench/workbench_deferred.c b/source/blender/draw/engines/workbench/workbench_deferred.c
index 3f537f6c6d0..5868ad90206 100644
--- a/source/blender/draw/engines/workbench/workbench_deferred.c
+++ b/source/blender/draw/engines/workbench/workbench_deferred.c
@@ -1081,6 +1081,7 @@ void workbench_deferred_draw_finish(WORKBENCH_Data *vedata)
 	WORKBENCH_StorageList *stl = vedata->stl;
 	WORKBENCH_PrivateData *wpd = stl->g_data;
 
+	workbench_private_draw_finish(wpd);
 	workbench_private_data_free(wpd);
 	workbench_volume_smoke_textures_free(wpd);
 }
diff --git a/source/blender/draw/engines/workbench/workbench_forward.c b/source/blender/draw/engines/workbench/workbench_forward.c
index 94cbb20ef5f..0ccc95d6b94 100644
--- a/source/blender/draw/engines/workbench/workbench_forward.c
+++ b/source/blender/draw/engines/workbench/workbench_forward.c
@@ -647,6 +647,7 @@ void workbench_forward_draw_finish(WORKBENCH_Data *vedata)
 	WORKBENCH_StorageList *stl = vedata->stl;
 	WORKBENCH_PrivateData *wpd = stl->g_data;
 
+	workbench_private_draw_finish(wpd);
 	workbench_private_data_free(wpd);
 	workbench_volume_smoke_textures_free(wpd);
 }
diff --git a/source/blender/draw/engines/workbench/workbench_materials.c b/source/blender/draw/engines/workbench/workbench_materials.c
index 679f11620b4..ce71189f344 100644
--- a/source/blender/draw/engines/workbench/workbench_materials.c
+++ b/source/blender/draw/engines/workbench/workbench_materials.c
@@ -110,6 +110,9 @@ char *workbench_material_build_defines(WORKBENCH_PrivateData *wpd, bool use_text
 	if (is_hair) {
 		BLI_dynstr_appendf(ds, "#define HAIR_SHADER\n");
 	}
+	if (wpd->world_clip_planes_len) {
+		BLI_dynstr_appendf(ds, "#define USE_WORLD_CLIP_PLANES\n");
+	}
 
 	str = BLI_dynstr_get_cstring(ds);
 	BLI_dynstr_free(ds);
@@ -168,6 +171,7 @@ int workbench_material_get_prepass_shader_index(
 	SET_FLAG_FROM_TEST(index, NORMAL_VIEWPORT_PASS_ENABLED(wpd), 1 << 3);
 	SET_FLAG_FROM_TEST(index, MATCAP_ENABLED(wpd), 1 << 4);
 	SET_FLAG_FROM_TEST(index, use_textures, 1 << 5);
+	SET_FLAG_FROM_TEST(index, wpd->world_clip_planes_len != 0, 1 << 6);
 	return index;
 }
 
@@ -236,6 +240,12 @@ void workbench_material_shgroup_uniform(
 		}
 		DRW_shgroup_uniform_float(grp, "materialRoughness", &material->roughness, 1);
 	}
+
+	if (wpd->world_clip_planes_len) {
+		DRW_shgroup_uniform_vec4(grp, "WorldClipPlanes", wpd->world_clip_planes[0], wpd->world_clip_planes_len);
+		DRW_shgroup_uniform_int(grp, "WorldClipPlanesLen", &wpd->world_clip_planes_len, 1);
+		DRW_shgroup_state_enable(grp, DRW_STATE_CLIP_PLANES);
+	}
 }
 
 void workbench_material_copy(WORKBENCH_MaterialData *dest_material, const WORKBENCH_MaterialData *source_material)
diff --git a/source/blender/draw/engines/workbench/workbench_private.h b/source/blender/draw/engines/workbench/workbench_private.h
index e7712ff8f32..e38c7ae424d 100644
--- a/source/blender/draw/engines/workbench/workbench_private.h
+++ b/source/blender/draw/engines/workbench/workbench_private.h
@@ -41,7 +41,7 @@
 #define WORKBENCH_ENGINE "BLENDER_WORKBENCH"
 #define M_GOLDEN_RATION_CONJUGATE 0.618033988749895
 #define MAX_COMPOSITE_SHADERS (1 << 6)
-#define MAX_PREPASS_SHADERS (1 << 6)
+#define MAX_PREPASS_SHADERS (1 << 7)
 #define MAX_ACCUM_SHADERS (1 << 4)
 #define MAX_CAVITY_SHADERS (1 << 3)
 
@@ -200,6 +200,9 @@ typedef struct WORKBENCH_PrivateData {
 	bool shadow_changed;
 	bool is_playback;
 
+	float world_clip_planes[6][4];
+	int   world_clip_planes_len;
+
 	/* Volumes */
 	bool volumes_do;
 	ListBase smoke_domains;
@@ -318,6 +321,7 @@ bool studiolight_camera_in_object_shadow(WORKBENCH_PrivateData *wpd, Object *ob,
 /* workbench_data.c */
 void workbench_effect_info_init(WORKBENCH_EffectInfo *effect_info);
 void workbench_private_data_init(WORKBENCH_PrivateData *wpd);
+void workbench_private_draw_finish(WORKBENCH_PrivateData *wpd);
 void workbench_private_data_free(WORKBENCH_PrivateData *wpd);
 void workbench_private_data_get_light_direction(WORKBENCH_PrivateData *wpd, float r_light_direction[3]);