Merge branch 'blender-v2.90-release'

1 files changed, 76 insertions, 20 deletions

diff --git a/source/blender/editors/uvedit/uvedit_parametrizer.c b/source/blender/editors/uvedit/uvedit_parametrizer.c
index dd422f2443a..f6485fdef5d 100644
--- a/source/blender/editors/uvedit/uvedit_parametrizer.c
+++ b/source/blender/editors/uvedit/uvedit_parametrizer.c
@@ -190,6 +190,9 @@ typedef struct PChart {
       LinearSolver *context;
       float *abf_alpha;
       PVert *pin1, *pin2;
+      PVert *single_pin;
+      float single_pin_area;
+      float single_pin_uv[2];
     } lscm;
     struct PChartPack {
       float rescale, area;
@@ -467,6 +470,17 @@ static void p_chart_uv_bbox(PChart *chart, float minv[2], float maxv[2])
   }
 }
 
+static float p_chart_uv_area(PChart *chart)
+{
+  float area = 0.0f;
+
+  for (PFace *f = chart->faces; f; f = f->nextlink) {
+    area += fabsf(p_face_uv_area_signed(f));
+  }
+
+  return area;
+}
+
 static void p_chart_uv_scale(PChart *chart, float scale)
 {
   PVert *v;
@@ -3176,7 +3190,7 @@ static void p_chart_lscm_begin(PChart *chart, PBool live, PBool abf)
     }
   }
 
-  if ((live && (!select || !deselect)) || (npins == 1)) {
+  if ((live && (!select || !deselect))) {
     chart->u.lscm.context = NULL;
   }
   else {
@@ -3185,6 +3199,16 @@ static void p_chart_lscm_begin(PChart *chart, PBool live, PBool abf)
     p_chart_topological_sanity_check(chart);
 #endif
 
+    if (npins == 1) {
+      chart->u.lscm.single_pin_area = p_chart_uv_area(chart);
+      for (v = chart->verts; v; v = v->nextlink) {
+        if (v->flag & PVERT_PIN) {
+          chart->u.lscm.single_pin = v;
+          break;
+        }
+      }
+    }
+
     if (abf) {
       if (!p_chart_abf_solve(chart)) {
         param_warning("ABF solving failed: falling back to LSCM.\n");
@@ -3192,12 +3216,12 @@ static void p_chart_lscm_begin(PChart *chart, PBool live, PBool abf)
     }
 
     if (npins <= 1) {
-      /* not enough pins, lets find some ourself */
+      /* No pins, let's find some ourself. */
       PEdge *outer;
 
       p_chart_boundaries(chart, NULL, &outer);
 
-      /* outer can be NULL with non-finite coords. */
+      /* Outer can be NULL with non-finite coords. */
       if (!(outer && p_chart_symmetry_pins(chart, outer, &pin1, &pin2))) {
         p_chart_extrema_verts(chart, &pin1, &pin2);
       }
@@ -3235,6 +3259,11 @@ static PBool p_chart_lscm_solve(PHandle *handle, PChart *chart)
     }
   }
 
+  if (chart->u.lscm.single_pin) {
+    /* If only one pin, save area and pin for transform later. */
+    copy_v2_v2(chart->u.lscm.single_pin_uv, chart->u.lscm.single_pin->uv);
+  }
+
   if (chart->u.lscm.pin1) {
     EIG_linear_solver_variable_lock(context, 2 * pin1->u.id);
     EIG_linear_solver_variable_lock(context, 2 * pin1->u.id + 1);
@@ -3358,6 +3387,25 @@ static PBool p_chart_lscm_solve(PHandle *handle, PChart *chart)
   return P_FALSE;
 }
 
+static void p_chart_lscm_transform_single_pin(PChart *chart)
+{
+  PVert *pin = chart->u.lscm.single_pin;
+
+  /* If only one pin, keep UV area the same. */
+  const float new_area = p_chart_uv_area(chart);
+  if (new_area > 0.0f) {
+    const float scale = chart->u.lscm.single_pin_area / new_area;
+    if (scale > 0.0f) {
+      p_chart_uv_scale(chart, sqrtf(scale));
+    }
+  }
+
+  /* Translate to keep the pinned vertex in place. */
+  float offset[2];
+  sub_v2_v2v2(offset, chart->u.lscm.single_pin_uv, pin->uv);
+  p_chart_uv_translate(chart, offset);
+}
+
 static void p_chart_lscm_end(PChart *chart)
 {
   if (chart->u.lscm.context) {
@@ -3372,6 +3420,8 @@ static void p_chart_lscm_end(PChart *chart)
   chart->u.lscm.context = NULL;
   chart->u.lscm.pin1 = NULL;
   chart->u.lscm.pin2 = NULL;
+  chart->u.lscm.single_pin = NULL;
+  chart->u.lscm.single_pin_area = 0.0f;
 }
 
 /* Stretch */
@@ -3781,6 +3831,23 @@ static void p_chart_rotate_minimum_area(PChart *chart)
   }
 }
 
+static void p_chart_rotate_fit_aabb(PChart *chart)
+{
+  float(*points)[2] = MEM_mallocN(sizeof(*points) * chart->nverts, __func__);
+
+  p_chart_uv_to_array(chart, points);
+
+  float angle = BLI_convexhull_aabb_fit_points_2d(points, chart->nverts);
+
+  MEM_freeN(points);
+
+  if (angle != 0.0f) {
+    float mat[2][2];
+    angle_to_mat2(mat, angle);
+    p_chart_uv_transform(chart, mat);
+  }
+}
+
 /* Area Smoothing */
 
 /* 2d bsp tree for inverse mapping - that's a bit silly */
@@ -4576,8 +4643,12 @@ void param_lscm_solve(ParamHandle *handle)
       if (result && !(chart->flag & PCHART_HAS_PINS)) {
         p_chart_rotate_minimum_area(chart);
       }
+      else if (result && chart->u.lscm.single_pin) {
+        p_chart_rotate_fit_aabb(chart);
+        p_chart_lscm_transform_single_pin(chart);
+      }
 
-      if (!result || (chart->u.lscm.pin1)) {
+      if (!result || !(chart->flag & PCHART_HAS_PINS)) {
         p_chart_lscm_end(chart);
       }
     }
@@ -4692,28 +4763,13 @@ static void param_pack_rotate(ParamHandle *handle, bool ignore_pinned)
   PHandle *phandle = (PHandle *)handle;
 
   for (i = 0; i < phandle->ncharts; i++) {
-    float(*points)[2];
-    float angle;
-
     chart = phandle->charts[i];
 
     if (ignore_pinned && (chart->flag & PCHART_HAS_PINS)) {
       continue;
     }
 
-    points = MEM_mallocN(sizeof(*points) * chart->nverts, __func__);
-
-    p_chart_uv_to_array(chart, points);
-
-    angle = BLI_convexhull_aabb_fit_points_2d(points, chart->nverts);
-
-    MEM_freeN(points);
-
-    if (angle != 0.0f) {
-      float mat[2][2];
-      angle_to_mat2(mat, angle);
-      p_chart_uv_transform(chart, mat);
-    }
+    p_chart_rotate_fit_aabb(chart);
   }
 }