Sculpt Vertex Colors: Initial implementation

Sculpt Vertex Colors is a painting system that runs inside sculpt mode, reusing all its tools and optimizations. This provides much better performance, easier to maintain code and more advanced features (new brush engine, filters, symmetry options, masks and face sets compatibility...). This is also the initial step for future features like vertex painting in Multires and brushes that can sculpt and paint at the same time.

This commit includes:
  - SCULPT_UNDO_COLOR for undo support in sculpt mode
  - SCULPT_UPDATE_COLOR and PBVH flags and rendering
  - Sculpt Color API functions
  - Sculpt capability for sculpt tools (only enabled in the Paint Brush for now)
  - Rendering support in workbench (default to Sculpt Vertex Colors except in Vertex Paint)
  - Conversion operator between MPropCol (Sculpt Vertex Colors) and MLoopCol (Vertex Paint)
  - Remesher reprojection in the Voxel Remehser
  - Paint Brush and Smear Brush with color smoothing in alt-smooth mode
  - Parameters for the new brush engine (density, opacity, flow, wet paint mixing, tip scale) implemented in Sculpt Vertex Colors
  - Color Filter
  - Color picker (uses S shortcut, replaces smooth)
  - Color selector in the top bar

Reviewed By: brecht

Maniphest Tasks: T72866

Differential Revision: https://developer.blender.org/D5975

1 files changed, 471 insertions, 0 deletions

diff --git a/source/blender/editors/sculpt_paint/sculpt_paint_color.c b/source/blender/editors/sculpt_paint/sculpt_paint_color.c
new file mode 100644
index 00000000000..1ae40837998
--- /dev/null
+++ b/source/blender/editors/sculpt_paint/sculpt_paint_color.c
@@ -0,0 +1,471 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software  Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2020 Blender Foundation.
+ * All rights reserved.
+ */
+
+/** \file
+ * \ingroup edsculpt
+ */
+
+#include "MEM_guardedalloc.h"
+
+#include "BLI_blenlib.h"
+#include "BLI_hash.h"
+#include "BLI_math.h"
+#include "BLI_math_color_blend.h"
+#include "BLI_task.h"
+
+#include "DNA_mesh_types.h"
+#include "DNA_meshdata_types.h"
+
+#include "BKE_brush.h"
+#include "BKE_colortools.h"
+#include "BKE_context.h"
+#include "BKE_mesh.h"
+#include "BKE_mesh_mapping.h"
+#include "BKE_object.h"
+#include "BKE_paint.h"
+#include "BKE_pbvh.h"
+#include "BKE_scene.h"
+
+#include "DEG_depsgraph.h"
+
+#include "WM_api.h"
+#include "WM_message.h"
+#include "WM_toolsystem.h"
+#include "WM_types.h"
+
+#include "ED_object.h"
+#include "ED_screen.h"
+#include "ED_sculpt.h"
+#include "paint_intern.h"
+#include "sculpt_intern.h"
+
+#include "RNA_access.h"
+#include "RNA_define.h"
+
+#include "UI_interface.h"
+
+#include "IMB_imbuf.h"
+
+#include "bmesh.h"
+
+#include <math.h>
+#include <stdlib.h>
+
+static void do_color_smooth_task_cb_exec(void *__restrict userdata,
+                                         const int n,
+                                         const TaskParallelTLS *__restrict tls)
+{
+  SculptThreadedTaskData *data = userdata;
+  SculptSession *ss = data->ob->sculpt;
+  const Brush *brush = data->brush;
+  const float bstrength = ss->cache->bstrength;
+
+  PBVHVertexIter vd;
+
+  SculptBrushTest test;
+  SculptBrushTestFn sculpt_brush_test_sq_fn = SCULPT_brush_test_init_with_falloff_shape(
+      ss, &test, data->brush->falloff_shape);
+  const int thread_id = BLI_task_parallel_thread_id(tls);
+
+  BKE_pbvh_vertex_iter_begin(ss->pbvh, data->nodes[n], vd, PBVH_ITER_UNIQUE)
+  {
+    if (sculpt_brush_test_sq_fn(&test, vd.co)) {
+      const float fade = bstrength * SCULPT_brush_strength_factor(ss,
+                                                                  brush,
+                                                                  vd.co,
+                                                                  sqrtf(test.dist),
+                                                                  vd.no,
+                                                                  vd.fno,
+                                                                  vd.mask ? *vd.mask : 0.0f,
+                                                                  vd.index,
+                                                                  thread_id);
+
+      float smooth_color[4];
+      SCULPT_neighbor_color_average(ss, smooth_color, vd.index);
+      blend_color_interpolate_float(vd.col, vd.col, smooth_color, fade);
+
+      if (vd.mvert) {
+        vd.mvert->flag |= ME_VERT_PBVH_UPDATE;
+      }
+    }
+  }
+  BKE_pbvh_vertex_iter_end;
+}
+
+static void do_paint_brush_task_cb_ex(void *__restrict userdata,
+                                      const int n,
+                                      const TaskParallelTLS *__restrict tls)
+{
+  SculptThreadedTaskData *data = userdata;
+  SculptSession *ss = data->ob->sculpt;
+  const Brush *brush = data->brush;
+  const float bstrength = fabsf(ss->cache->bstrength);
+
+  PBVHVertexIter vd;
+  PBVHColorBufferNode *color_buffer;
+
+  SculptOrigVertData orig_data;
+  SCULPT_orig_vert_data_init(&orig_data, data->ob, data->nodes[n]);
+
+  color_buffer = BKE_pbvh_node_color_buffer_get(data->nodes[n]);
+
+  SculptBrushTest test;
+  SculptBrushTestFn sculpt_brush_test_sq_fn = SCULPT_brush_test_init_with_falloff_shape(
+      ss, &test, data->brush->falloff_shape);
+  const int thread_id = BLI_task_parallel_thread_id(tls);
+
+  BKE_pbvh_vertex_iter_begin(ss->pbvh, data->nodes[n], vd, PBVH_ITER_UNIQUE)
+  {
+    SCULPT_orig_vert_data_update(&orig_data, &vd);
+
+    bool affect_vertex = false;
+    float distance_to_stroke_location = 0.0f;
+    if (brush->tip_roundness < 1.0f) {
+      affect_vertex = SCULPT_brush_test_cube(&test, vd.co, data->mat, brush->tip_roundness);
+      distance_to_stroke_location = ss->cache->radius * test.dist;
+    }
+    else {
+      affect_vertex = sculpt_brush_test_sq_fn(&test, vd.co);
+      distance_to_stroke_location = sqrtf(test.dist);
+    }
+
+    if (affect_vertex) {
+      float fade = bstrength * SCULPT_brush_strength_factor(ss,
+                                                            brush,
+                                                            vd.co,
+                                                            distance_to_stroke_location,
+                                                            vd.no,
+                                                            vd.fno,
+                                                            vd.mask ? *vd.mask : 0.0f,
+                                                            vd.index,
+                                                            thread_id);
+
+      /* Density. */
+      float noise = 1.0f;
+      const float density = brush->density;
+      if (density < 1.0f) {
+        const float hash_noise = BLI_hash_int_01(ss->cache->density_seed * 1000 * vd.index);
+        if (hash_noise > density) {
+          noise = density * hash_noise;
+          fade = fade * noise;
+        }
+      }
+
+      /* Brush paint color, brush test falloff and flow. */
+      float paint_color[4] = {brush->rgb[0], brush->rgb[1], brush->rgb[2], 1.0f};
+      float wet_mix_color[4];
+      float buffer_color[4];
+
+      mul_v4_fl(paint_color, fade * brush->flow);
+      mul_v4_v4fl(wet_mix_color, data->wet_mix_sampled_color, fade * brush->flow);
+
+      /* Interpolate with the wet_mix color for wet paint mixing. */
+      blend_color_interpolate_float(paint_color, paint_color, wet_mix_color, brush->wet_mix);
+      blend_color_mix_float(color_buffer->color[vd.i], color_buffer->color[vd.i], paint_color);
+
+      /* Final mix over the original color using brush alpha. */
+      mul_v4_v4fl(buffer_color, color_buffer->color[vd.i], brush->alpha);
+
+      IMB_blend_color_float(vd.col, orig_data.col, buffer_color, brush->blend);
+    }
+    CLAMP4(vd.col, 0.0f, 1.0f);
+
+    if (vd.mvert) {
+      vd.mvert->flag |= ME_VERT_PBVH_UPDATE;
+    }
+  }
+  BKE_pbvh_vertex_iter_end;
+}
+
+typedef struct SampleWetPaintTLSData {
+  int tot_samples;
+  float color[4];
+} SampleWetPaintTLSData;
+
+static void do_sample_wet_paint_task_cb(void *__restrict userdata,
+                                        const int n,
+                                        const TaskParallelTLS *__restrict tls)
+{
+  SculptThreadedTaskData *data = userdata;
+  SculptSession *ss = data->ob->sculpt;
+  SampleWetPaintTLSData *swptd = tls->userdata_chunk;
+  PBVHVertexIter vd;
+
+  SculptBrushTest test;
+  SculptBrushTestFn sculpt_brush_test_sq_fn = SCULPT_brush_test_init_with_falloff_shape(
+      ss, &test, data->brush->falloff_shape);
+
+  BKE_pbvh_vertex_iter_begin(ss->pbvh, data->nodes[n], vd, PBVH_ITER_UNIQUE)
+  {
+    if (sculpt_brush_test_sq_fn(&test, vd.co)) {
+      add_v4_v4(swptd->color, vd.col);
+      swptd->tot_samples++;
+    }
+  }
+  BKE_pbvh_vertex_iter_end;
+}
+
+static void sample_wet_paint_reduce(const void *__restrict UNUSED(userdata),
+                                    void *__restrict chunk_join,
+                                    void *__restrict chunk)
+{
+  SampleWetPaintTLSData *join = chunk_join;
+  SampleWetPaintTLSData *swptd = chunk;
+
+  join->tot_samples += swptd->tot_samples;
+  add_v4_v4(join->color, swptd->color);
+}
+
+void SCULPT_do_paint_brush(Sculpt *sd, Object *ob, PBVHNode **nodes, int totnode)
+{
+  Brush *brush = BKE_paint_brush(&sd->paint);
+  SculptSession *ss = ob->sculpt;
+
+  if (!ss->vcol) {
+    return;
+  }
+
+  if (ss->cache->first_time && ss->cache->mirror_symmetry_pass == 0) {
+    ss->cache->density_seed = BLI_hash_int_01(ss->cache->location[0] * 1000);
+    return;
+  }
+
+  BKE_curvemapping_initialize(brush->curve);
+
+  float area_no[3];
+  float mat[4][4];
+  float scale[4][4];
+  float tmat[4][4];
+
+  /* If the brush is round the tip does not need to be aligned to the surface, so this saves a
+   * whole iteration over the affected nodes. */
+  if (brush->tip_roundness < 1.0f) {
+    SCULPT_calc_area_normal(sd, ob, nodes, totnode, area_no);
+
+    cross_v3_v3v3(mat[0], area_no, ss->cache->grab_delta_symmetry);
+    mat[0][3] = 0;
+    cross_v3_v3v3(mat[1], area_no, mat[0]);
+    mat[1][3] = 0;
+    copy_v3_v3(mat[2], area_no);
+    mat[2][3] = 0;
+    copy_v3_v3(mat[3], ss->cache->location);
+    mat[3][3] = 1;
+    normalize_m4(mat);
+
+    scale_m4_fl(scale, ss->cache->radius);
+    mul_m4_m4m4(tmat, mat, scale);
+    mul_v3_fl(tmat[1], brush->tip_scale_x);
+    invert_m4_m4(mat, tmat);
+    if (is_zero_m4(mat)) {
+      return;
+    }
+  }
+
+  /* Smooth colors mode. */
+  if (ss->cache->alt_smooth) {
+    SculptThreadedTaskData data = {
+        .sd = sd,
+        .ob = ob,
+        .brush = brush,
+        .nodes = nodes,
+        .mat = mat,
+    };
+
+    TaskParallelSettings settings;
+    BKE_pbvh_parallel_range_settings(&settings, (sd->flags & SCULPT_USE_OPENMP), totnode);
+    BLI_task_parallel_range(0, totnode, &data, do_color_smooth_task_cb_exec, &settings);
+    return;
+  }
+
+  /* Regular Paint mode. */
+
+  /* Wet paint color sampling. */
+  float wet_color[4] = {0.0f};
+  if (brush->wet_mix > 0.0f) {
+    SculptThreadedTaskData task_data = {
+        .sd = sd,
+        .ob = ob,
+        .nodes = nodes,
+        .brush = brush,
+    };
+
+    SampleWetPaintTLSData swptd;
+    swptd.tot_samples = 0;
+    zero_v4(swptd.color);
+
+    TaskParallelSettings settings_sample;
+    BKE_pbvh_parallel_range_settings(&settings_sample, (sd->flags & SCULPT_USE_OPENMP), totnode);
+    settings_sample.func_reduce = sample_wet_paint_reduce;
+    settings_sample.userdata_chunk = &swptd;
+    settings_sample.userdata_chunk_size = sizeof(SampleWetPaintTLSData);
+    BLI_task_parallel_range(0, totnode, &task_data, do_sample_wet_paint_task_cb, &settings_sample);
+
+    if (swptd.tot_samples > 0 && is_finite_v4(swptd.color)) {
+      copy_v4_v4(wet_color, swptd.color);
+      mul_v4_fl(wet_color, 1.0f / (float)swptd.tot_samples);
+      CLAMP4(wet_color, 0.0f, 1.0f);
+
+      if (ss->cache->first_time) {
+        copy_v4_v4(ss->cache->wet_mix_prev_color, wet_color);
+      }
+      blend_color_interpolate_float(
+          wet_color, wet_color, ss->cache->wet_mix_prev_color, brush->wet_persistence);
+      copy_v4_v4(ss->cache->wet_mix_prev_color, wet_color);
+      CLAMP4(ss->cache->wet_mix_prev_color, 0.0f, 1.0f);
+    }
+  }
+
+  /* Threaded loop over nodes. */
+  SculptThreadedTaskData data = {
+      .sd = sd,
+      .ob = ob,
+      .brush = brush,
+      .nodes = nodes,
+      .wet_mix_sampled_color = wet_color,
+      .mat = mat,
+  };
+
+  TaskParallelSettings settings;
+  BKE_pbvh_parallel_range_settings(&settings, (sd->flags & SCULPT_USE_OPENMP), totnode);
+  BLI_task_parallel_range(0, totnode, &data, do_paint_brush_task_cb_ex, &settings);
+}
+
+static void do_smear_brush_task_cb_exec(void *__restrict userdata,
+                                        const int n,
+                                        const TaskParallelTLS *__restrict tls)
+{
+  SculptThreadedTaskData *data = userdata;
+  SculptSession *ss = data->ob->sculpt;
+  const Brush *brush = data->brush;
+  const float bstrength = ss->cache->bstrength;
+
+  PBVHVertexIter vd;
+
+  SculptBrushTest test;
+  SculptBrushTestFn sculpt_brush_test_sq_fn = SCULPT_brush_test_init_with_falloff_shape(
+      ss, &test, data->brush->falloff_shape);
+  const int thread_id = BLI_task_parallel_thread_id(tls);
+
+  BKE_pbvh_vertex_iter_begin(ss->pbvh, data->nodes[n], vd, PBVH_ITER_UNIQUE)
+  {
+    if (sculpt_brush_test_sq_fn(&test, vd.co)) {
+      const float fade = bstrength * SCULPT_brush_strength_factor(ss,
+                                                                  brush,
+                                                                  vd.co,
+                                                                  sqrtf(test.dist),
+                                                                  vd.no,
+                                                                  vd.fno,
+                                                                  vd.mask ? *vd.mask : 0.0f,
+                                                                  vd.index,
+                                                                  thread_id);
+
+      float current_disp[3];
+      float current_disp_norm[3];
+      float interp_color[4];
+      copy_v4_v4(interp_color, ss->cache->prev_colors[vd.index]);
+
+      sub_v3_v3v3(current_disp, ss->cache->location, ss->cache->last_location);
+      normalize_v3_v3(current_disp_norm, current_disp);
+      mul_v3_v3fl(current_disp, current_disp_norm, ss->cache->bstrength);
+
+      SculptVertexNeighborIter ni;
+      SCULPT_VERTEX_NEIGHBORS_ITER_BEGIN (ss, vd.index, ni) {
+        float vertex_disp[3];
+        float vertex_disp_norm[3];
+        sub_v3_v3v3(vertex_disp, SCULPT_vertex_co_get(ss, ni.index), vd.co);
+        const float *neighbor_color = ss->cache->prev_colors[ni.index];
+        normalize_v3_v3(vertex_disp_norm, vertex_disp);
+        if (dot_v3v3(current_disp_norm, vertex_disp_norm) < 0.0f) {
+          const float color_interp = clamp_f(
+              -dot_v3v3(current_disp_norm, vertex_disp_norm), 0.0f, 1.0f);
+          float color_mix[4];
+          copy_v4_v4(color_mix, neighbor_color);
+          mul_v4_fl(color_mix, color_interp * fade);
+          blend_color_mix_float(interp_color, interp_color, color_mix);
+        }
+      }
+      SCULPT_VERTEX_NEIGHBORS_ITER_END(ni);
+
+      blend_color_interpolate_float(vd.col, ss->cache->prev_colors[vd.index], interp_color, fade);
+
+      if (vd.mvert) {
+        vd.mvert->flag |= ME_VERT_PBVH_UPDATE;
+      }
+    }
+  }
+  BKE_pbvh_vertex_iter_end;
+}
+
+static void do_smear_store_prev_colors_task_cb_exec(void *__restrict userdata,
+                                                    const int n,
+                                                    const TaskParallelTLS *__restrict UNUSED(tls))
+{
+  SculptThreadedTaskData *data = userdata;
+  SculptSession *ss = data->ob->sculpt;
+
+  PBVHVertexIter vd;
+  BKE_pbvh_vertex_iter_begin(ss->pbvh, data->nodes[n], vd, PBVH_ITER_UNIQUE)
+  {
+    copy_v4_v4(ss->cache->prev_colors[vd.index], SCULPT_vertex_color_get(ss, vd.index));
+  }
+  BKE_pbvh_vertex_iter_end;
+}
+
+void SCULPT_do_smear_brush(Sculpt *sd, Object *ob, PBVHNode **nodes, int totnode)
+{
+  Brush *brush = BKE_paint_brush(&sd->paint);
+  SculptSession *ss = ob->sculpt;
+
+  if (!ss->vcol) {
+    return;
+  }
+
+  const int totvert = SCULPT_vertex_count_get(ss);
+
+  if (ss->cache->first_time && ss->cache->mirror_symmetry_pass == 0) {
+    if (!ss->cache->prev_colors) {
+      ss->cache->prev_colors = MEM_callocN(sizeof(float) * 4 * totvert, "prev colors");
+      for (int i = 0; i < totvert; i++) {
+        copy_v4_v4(ss->cache->prev_colors[i], SCULPT_vertex_color_get(ss, i));
+      }
+    }
+  }
+
+  BKE_curvemapping_initialize(brush->curve);
+
+  SculptThreadedTaskData data = {
+      .sd = sd,
+      .ob = ob,
+      .brush = brush,
+      .nodes = nodes,
+  };
+
+  TaskParallelSettings settings;
+  BKE_pbvh_parallel_range_settings(&settings, (sd->flags & SCULPT_USE_OPENMP), totnode);
+
+  /* Smooth colors mode. */
+  if (ss->cache->alt_smooth) {
+    BLI_task_parallel_range(0, totnode, &data, do_color_smooth_task_cb_exec, &settings);
+  }
+  else {
+    /* Smear mode. */
+    BLI_task_parallel_range(0, totnode, &data, do_smear_store_prev_colors_task_cb_exec, &settings);
+    BLI_task_parallel_range(0, totnode, &data, do_smear_brush_task_cb_exec, &settings);
+  }
+}