GP: Refactor Instance modifier and rename to Array

The old name Instance was logic when the modifier created new object instances, but now works equal to mesh Array modifier, so the old name was not logic and must be Array.

Also added a Object to use as offset similar to mesh Array modifier.

4 files changed, 156 insertions, 69 deletions

diff --git a/source/blender/gpencil_modifiers/CMakeLists.txt b/source/blender/gpencil_modifiers/CMakeLists.txt
index 00a387c58e8..b28a83372b8 100644
--- a/source/blender/gpencil_modifiers/CMakeLists.txt
+++ b/source/blender/gpencil_modifiers/CMakeLists.txt
@@ -50,7 +50,7 @@ set(SRC
 	intern/MOD_gpencilthick.c
 	intern/MOD_gpenciltint.c
 	intern/MOD_gpencilcolor.c
-	intern/MOD_gpencilinstance.c
+	intern/MOD_gpencilarray.c
 	intern/MOD_gpencilbuild.c
 	intern/MOD_gpencilopacity.c
 	intern/MOD_gpencillattice.c
diff --git a/source/blender/gpencil_modifiers/MOD_gpencil_modifiertypes.h b/source/blender/gpencil_modifiers/MOD_gpencil_modifiertypes.h
index d820bbcc7c8..07db9f15288 100644
--- a/source/blender/gpencil_modifiers/MOD_gpencil_modifiertypes.h
+++ b/source/blender/gpencil_modifiers/MOD_gpencil_modifiertypes.h
@@ -36,7 +36,7 @@ extern GpencilModifierTypeInfo modifierType_Gpencil_Simplify;
 extern GpencilModifierTypeInfo modifierType_Gpencil_Thick;
 extern GpencilModifierTypeInfo modifierType_Gpencil_Tint;
 extern GpencilModifierTypeInfo modifierType_Gpencil_Color;
-extern GpencilModifierTypeInfo modifierType_Gpencil_Instance;
+extern GpencilModifierTypeInfo modifierType_Gpencil_Array;
 extern GpencilModifierTypeInfo modifierType_Gpencil_Build;
 extern GpencilModifierTypeInfo modifierType_Gpencil_Opacity;
 extern GpencilModifierTypeInfo modifierType_Gpencil_Lattice;
diff --git a/source/blender/gpencil_modifiers/intern/MOD_gpencil_util.c b/source/blender/gpencil_modifiers/intern/MOD_gpencil_util.c
index 1a61133f3f7..2551d9a216d 100644
--- a/source/blender/gpencil_modifiers/intern/MOD_gpencil_util.c
+++ b/source/blender/gpencil_modifiers/intern/MOD_gpencil_util.c
@@ -69,7 +69,7 @@ void gpencil_modifier_type_init(GpencilModifierTypeInfo *types[])
 	INIT_GP_TYPE(Thick);
 	INIT_GP_TYPE(Tint);
 	INIT_GP_TYPE(Color);
-	INIT_GP_TYPE(Instance);
+	INIT_GP_TYPE(Array);
 	INIT_GP_TYPE(Build);
 	INIT_GP_TYPE(Opacity);
 	INIT_GP_TYPE(Lattice);
diff --git a/source/blender/gpencil_modifiers/intern/MOD_gpencilinstance.c b/source/blender/gpencil_modifiers/intern/MOD_gpencilarray.c
index 9c56a06af99..b188dd0de0b 100644
--- a/source/blender/gpencil_modifiers/intern/MOD_gpencilinstance.c
+++ b/source/blender/gpencil_modifiers/intern/MOD_gpencilarray.c
@@ -44,12 +44,14 @@
 
 #include "BKE_gpencil.h"
 #include "BKE_gpencil_modifier.h"
+#include "BKE_modifier.h"
 #include "BKE_context.h"
 #include "BKE_global.h"
 #include "BKE_object.h"
 #include "BKE_main.h"
 #include "BKE_scene.h"
 #include "BKE_layer.h"
+#include "BKE_library_query.h"
 #include "BKE_collection.h"
 
 #include "DEG_depsgraph.h"
@@ -59,15 +61,17 @@
 #include "MOD_gpencil_util.h"
 #include "MOD_gpencil_modifiertypes.h"
 
+#include "DEG_depsgraph.h"
+#include "DEG_depsgraph_build.h"
+#include "DEG_depsgraph_query.h"
+
 static void initData(GpencilModifierData *md)
 {
-	InstanceGpencilModifierData *gpmd = (InstanceGpencilModifierData *)md;
-	gpmd->count[0] = 1;
-	gpmd->count[1] = 1;
-	gpmd->count[2] = 1;
+	ArrayGpencilModifierData *gpmd = (ArrayGpencilModifierData *)md;
+	gpmd->count = 2;
 	gpmd->offset[0] = 1.0f;
-	gpmd->offset[1] = 1.0f;
-	gpmd->offset[2] = 1.0f;
+	gpmd->offset[1] = 0.0f;
+	gpmd->offset[2] = 0.0f;
 	gpmd->shift[0] = 0.0f;
 	gpmd->shift[1] = 0.0f;
 	gpmd->shift[2] = 0.0f;
@@ -76,7 +80,7 @@ static void initData(GpencilModifierData *md)
 	gpmd->scale[2] = 1.0f;
 	gpmd->rnd_rot = 0.5f;
 	gpmd->rnd_size = 0.5f;
-	gpmd->lock_axis |= GP_LOCKAXIS_X;
+	gpmd->object = NULL;
 
 	/* fill random values */
 	BLI_array_frand(gpmd->rnd, 20, 1);
@@ -89,14 +93,74 @@ static void copyData(const GpencilModifierData *md, GpencilModifierData *target)
 }
 
 /* -------------------------------- */
+/* helper function for per-instance positioning */
+static void BKE_gpencil_instance_modifier_instance_tfm(
+	Object *ob, ArrayGpencilModifierData *mmd, const int elem_idx,
+	float r_mat[4][4], float r_offset[4][4])
+{
+	float offset[3], rot[3], scale[3];
+	int ri = mmd->rnd[0];
+	float factor;
+
+	offset[0] = mmd->offset[0] * elem_idx;
+	offset[1] = mmd->offset[1] * elem_idx;
+	offset[2] = mmd->offset[2] * elem_idx;
+
+	/* rotation */
+	if (mmd->flag & GP_ARRAY_RANDOM_ROT) {
+		factor = mmd->rnd_rot * mmd->rnd[ri];
+		mul_v3_v3fl(rot, mmd->rot, factor);
+		add_v3_v3(rot, mmd->rot);
+	}
+	else {
+		copy_v3_v3(rot, mmd->rot);
+	}
+
+	/* scale */
+	if (mmd->flag & GP_ARRAY_RANDOM_SIZE) {
+		factor = mmd->rnd_size * mmd->rnd[ri];
+		mul_v3_v3fl(scale, mmd->scale, factor);
+		add_v3_v3(scale, mmd->scale);
+	}
+	else {
+		copy_v3_v3(scale, mmd->scale);
+	}
+
+	/* advance random index */
+	mmd->rnd[0]++;
+	if (mmd->rnd[0] > 19) {
+		mmd->rnd[0] = 1;
+	}
+
+	/* calculate matrix */
+	loc_eul_size_to_mat4(r_mat, offset, rot, scale);
+
+	copy_m4_m4(r_offset, r_mat);
+
+	/* offset object */
+	if (mmd->object) {
+		float mat_offset[4][4];
+		float obinv[4][4];
+
+		unit_m4(mat_offset);
+		add_v3_v3(mat_offset[3], mmd->offset);
+		invert_m4_m4(obinv, ob->obmat);
+
+		mul_m4_series(r_offset, mat_offset,
+			obinv, mmd->object->obmat);
+		copy_m4_m4(mat_offset, r_offset);
+
+		/* clear r_mat locations to avoid double transform */
+		zero_v3(r_mat[3]);
+	}
+}
 
 /* array modifier - generate geometry callback (for viewport/rendering) */
-/* TODO: How to skip this for the simplify options?   -->  !GP_SIMPLIFY_MODIF(ts, playing) */
 static void generate_geometry(
         GpencilModifierData *md, Depsgraph *UNUSED(depsgraph),
         Object *ob, bGPDlayer *gpl, bGPDframe *gpf)
 {
-	InstanceGpencilModifierData *mmd = (InstanceGpencilModifierData *)md;
+	ArrayGpencilModifierData *mmd = (ArrayGpencilModifierData *)md;
 	ListBase stroke_cache = {NULL, NULL};
 	bGPDstroke *gps;
 	int idx;
@@ -115,8 +179,8 @@ static void generate_geometry(
 		 */
 		if (is_stroke_affected_by_modifier(ob,
 		        mmd->layername, mmd->pass_index, mmd->layer_pass, 1, gpl, gps,
-		        mmd->flag & GP_INSTANCE_INVERT_LAYER, mmd->flag & GP_INSTANCE_INVERT_PASS,
-				mmd->flag & GP_INSTANCE_INVERT_LAYERPASS))
+		        mmd->flag & GP_ARRAY_INVERT_LAYER, mmd->flag & GP_ARRAY_INVERT_PASS,
+				mmd->flag & GP_ARRAY_INVERT_LAYERPASS))
 		{
 			valid_strokes[idx] = true;
 			num_valid++;
@@ -138,66 +202,69 @@ static void generate_geometry(
 	 * keeping each instance together so they maintain
 	 * the correct ordering relative to each other
 	 */
-	for (int x = 0; x < mmd->count[0]; x++) {
-		for (int y = 0; y < mmd->count[1]; y++) {
-			for (int z = 0; z < mmd->count[2]; z++) {
-				/* original strokes are at index = 0,0,0 */
-				if ((x == 0) && (y == 0) && (z == 0)) {
-					continue;
-				}
+	float current_offset[4][4];
+	unit_m4(current_offset);
 
-				/* Compute transforms for this instance */
-				const int elem_idx[3] = {x, y, z};
-				float mat[4][4];
+	for (int x = 0; x < mmd->count; x++) {
+		/* original strokes are at index = 0 */
+		if (x == 0) {
+			continue;
+		}
 
-				BKE_gpencil_instance_modifier_instance_tfm(mmd, elem_idx, mat);
+		/* Compute transforms for this instance */
+		float mat[4][4];
+		float mat_offset[4][4];
+		BKE_gpencil_instance_modifier_instance_tfm(ob, mmd, x, mat, mat_offset);
 
-				/* apply shift */
-				int sh = x;
-				if (mmd->lock_axis == GP_LOCKAXIS_Y) {
-					sh = y;
-				}
-				if (mmd->lock_axis == GP_LOCKAXIS_Z) {
-					sh = z;
+		if (mmd->object) {
+			/* recalculate cumulative offset here */
+			mul_m4_m4m4(current_offset, current_offset, mat_offset);
+		}
+		else {
+			copy_m4_m4(current_offset, mat);
+		}
+		/* apply shift */
+		madd_v3_v3fl(current_offset[3], mmd->shift, x);
+
+		/* Duplicate original strokes to create this instance */
+		for (gps = gpf->strokes.first, idx = 0; gps; gps = gps->next, idx++) {
+			/* check if stroke can be duplicated */
+			if (valid_strokes[idx]) {
+				/* Duplicate stroke */
+				bGPDstroke *gps_dst = MEM_dupallocN(gps);
+				gps_dst->points = MEM_dupallocN(gps->points);
+				if (gps->dvert) {
+					gps_dst->dvert = MEM_dupallocN(gps->dvert);
+					BKE_gpencil_stroke_weights_duplicate(gps, gps_dst);
 				}
-				madd_v3_v3fl(mat[3], mmd->shift, sh);
-
-				/* Duplicate original strokes to create this instance */
-				for (gps = gpf->strokes.first, idx = 0; gps; gps = gps->next, idx++) {
-					/* check if stroke can be duplicated */
-					if (valid_strokes[idx]) {
-						/* Duplicate stroke */
-						bGPDstroke *gps_dst = MEM_dupallocN(gps);
-						gps_dst->points = MEM_dupallocN(gps->points);
-						if (gps->dvert) {
-							gps_dst->dvert = MEM_dupallocN(gps->dvert);
-							BKE_gpencil_stroke_weights_duplicate(gps, gps_dst);
-						}
-						gps_dst->triangles = MEM_dupallocN(gps->triangles);
-
-						/* Move points */
-						for (int i = 0; i < gps->totpoints; i++) {
-							bGPDspoint *pt = &gps_dst->points[i];
-							mul_m4_v3(mat, &pt->x);
-						}
-
-						/* if replace material, use new one */
-						if ((mmd->mat_rpl > 0) && (mmd->mat_rpl <= ob->totcol)) {
-							gps_dst->mat_nr = mmd->mat_rpl - 1;
-						}
-
-						/* Add new stroke to cache, to be added to the frame once
-						 * all duplicates have been made
-						 */
-						BLI_addtail(&stroke_cache, gps_dst);
+				gps_dst->triangles = MEM_dupallocN(gps->triangles);
+
+				/* Move points */
+				for (int i = 0; i < gps->totpoints; i++) {
+					bGPDspoint *pt = &gps_dst->points[i];
+					if (mmd->object) {
+						/* apply local changes (rot/scale) */
+						mul_m4_v3(mat, &pt->x);
 					}
+					/* global changes */
+					mul_m4_v3(current_offset, &pt->x);
 				}
+
+				/* if replace material, use new one */
+				if ((mmd->mat_rpl > 0) && (mmd->mat_rpl <= ob->totcol)) {
+					gps_dst->mat_nr = mmd->mat_rpl - 1;
+				}
+
+				/* Add new stroke to cache, to be added to the frame once
+				 * all duplicates have been made
+				 */
+				BLI_addtail(&stroke_cache, gps_dst);
 			}
 		}
 	}
 
 	/* merge newly created stroke instances back into the main stroke list */
-	if (mmd->flag & GP_INSTANCE_KEEP_ONTOP) {
+	if (mmd->flag & GP_ARRAY_KEEP_ONTOP) {
 		BLI_movelisttolist_reverse(&gpf->strokes, &stroke_cache);
 	}
 	else {
@@ -232,10 +299,30 @@ static void generateStrokes(
 	generate_geometry(md, depsgraph, ob, gpl, gpf);
 }
 
-GpencilModifierTypeInfo modifierType_Gpencil_Instance = {
-	/* name */              "Instance",
-	/* structName */        "InstanceGpencilModifierData",
-	/* structSize */        sizeof(InstanceGpencilModifierData),
+static void updateDepsgraph(GpencilModifierData *md, const ModifierUpdateDepsgraphContext *ctx)
+{
+	ArrayGpencilModifierData *lmd = (ArrayGpencilModifierData *)md;
+	if (lmd->object != NULL) {
+		DEG_add_object_relation(ctx->node, lmd->object, DEG_OB_COMP_GEOMETRY, "Array Modifier");
+		DEG_add_object_relation(ctx->node, lmd->object, DEG_OB_COMP_TRANSFORM, "Array Modifier");
+	}
+	DEG_add_object_relation(ctx->node, ctx->object, DEG_OB_COMP_TRANSFORM, "Array Modifier");
+}
+
+static void foreachObjectLink(
+	GpencilModifierData *md, Object *ob,
+	ObjectWalkFunc walk, void *userData)
+{
+	ArrayGpencilModifierData *mmd = (ArrayGpencilModifierData *)md;
+
+	walk(userData, ob, &mmd->object, IDWALK_CB_NOP);
+}
+
+
+GpencilModifierTypeInfo modifierType_Gpencil_Array = {
+	/* name */              "Array",
+	/* structName */        "ArrayGpencilModifierData",
+	/* structSize */        sizeof(ArrayGpencilModifierData),
 	/* type */              eGpencilModifierTypeType_Gpencil,
 	/* flags */             0,
 
@@ -249,9 +336,9 @@ GpencilModifierTypeInfo modifierType_Gpencil_Instance = {
 	/* initData */          initData,
 	/* freeData */          NULL,
 	/* isDisabled */        NULL,
-	/* updateDepsgraph */   NULL,
+	/* updateDepsgraph */   updateDepsgraph,
 	/* dependsOnTime */     NULL,
-	/* foreachObjectLink */ NULL,
+	/* foreachObjectLink */ foreachObjectLink,
 	/* foreachIDLink */     NULL,
 	/* foreachTexLink */    NULL,
 };