Grease Pencil: Add LineArt modifier

This adds the LineArt grease pencil modifier.

It takes objects or collections as input and generates various grease
pencil lines from these objects with the help of the active scene
camera. For example it can generate contour lines, intersection lines
and crease lines to name a few.

This is really useful as artists can then use 3D meshes to automatically
generate grease pencil lines for characters, enviroments or other
visualization purposes.

These lines can then be baked and edited as regular grease pencil lines.

Reviewed By: Sebastian Parborg, Antonio Vazquez, Matias Mendiola

Differential Revision: http://developer.blender.org/D8758

1 files changed, 233 insertions, 0 deletions

diff --git a/source/blender/gpencil_modifiers/intern/lineart/lineart_util.c b/source/blender/gpencil_modifiers/intern/lineart/lineart_util.c
new file mode 100644
index 00000000000..0d145042e08
--- /dev/null
+++ b/source/blender/gpencil_modifiers/intern/lineart/lineart_util.c
@@ -0,0 +1,233 @@
+/*
+ * 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) 2019 Blender Foundation.
+ * All rights reserved.
+ */
+
+/** \file
+ * \ingroup editors
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+/* #include <time.h> */
+#include "MEM_guardedalloc.h"
+#include "MOD_lineart.h"
+#include <math.h>
+
+#include "lineart_intern.h"
+
+/* Line art memory and list helper */
+
+void *lineart_list_append_pointer_pool(ListBase *h, LineartStaticMemPool *smp, void *data)
+{
+  LinkData *lip;
+  if (h == NULL) {
+    return 0;
+  }
+  lip = lineart_mem_aquire(smp, sizeof(LinkData));
+  lip->data = data;
+  BLI_addtail(h, lip);
+  return lip;
+}
+void *lineart_list_append_pointer_pool_sized(ListBase *h,
+                                             LineartStaticMemPool *smp,
+                                             void *data,
+                                             int size)
+{
+  LinkData *lip;
+  if (h == NULL) {
+    return 0;
+  }
+  lip = lineart_mem_aquire(smp, size);
+  lip->data = data;
+  BLI_addtail(h, lip);
+  return lip;
+}
+
+void *lineart_list_pop_pointer_no_free(ListBase *h)
+{
+  LinkData *lip;
+  void *rev = 0;
+  if (h == NULL) {
+    return 0;
+  }
+  lip = BLI_pophead(h);
+  rev = lip ? lip->data : 0;
+  return rev;
+}
+void lineart_list_remove_pointer_item_no_free(ListBase *h, LinkData *lip)
+{
+  BLI_remlink(h, (void *)lip);
+}
+
+LineartStaticMemPoolNode *lineart_mem_new_static_pool(LineartStaticMemPool *smp, size_t size)
+{
+  size_t set_size = size;
+  if (set_size < LRT_MEMORY_POOL_64MB) {
+    set_size = LRT_MEMORY_POOL_64MB; /* Prevent too many small allocations. */
+  }
+  size_t total_size = size + sizeof(LineartStaticMemPoolNode);
+  LineartStaticMemPoolNode *smpn = MEM_callocN(total_size, "mempool");
+  smpn->size = total_size;
+  smpn->used_byte = sizeof(LineartStaticMemPoolNode);
+  BLI_addhead(&smp->pools, smpn);
+  return smpn;
+}
+void *lineart_mem_aquire(LineartStaticMemPool *smp, size_t size)
+{
+  LineartStaticMemPoolNode *smpn = smp->pools.first;
+  void *ret;
+
+  if (!smpn || (smpn->used_byte + size) > smpn->size) {
+    smpn = lineart_mem_new_static_pool(smp, size);
+  }
+
+  ret = ((unsigned char *)smpn) + smpn->used_byte;
+
+  smpn->used_byte += size;
+
+  return ret;
+}
+void *lineart_mem_aquire_thread(LineartStaticMemPool *smp, size_t size)
+{
+  void *ret;
+
+  BLI_spin_lock(&smp->lock_mem);
+
+  LineartStaticMemPoolNode *smpn = smp->pools.first;
+
+  if (!smpn || (smpn->used_byte + size) > smpn->size) {
+    smpn = lineart_mem_new_static_pool(smp, size);
+  }
+
+  ret = ((unsigned char *)smpn) + smpn->used_byte;
+
+  smpn->used_byte += size;
+
+  BLI_spin_unlock(&smp->lock_mem);
+
+  return ret;
+}
+void lineart_mem_destroy(LineartStaticMemPool *smp)
+{
+  LineartStaticMemPoolNode *smpn;
+  while ((smpn = BLI_pophead(&smp->pools)) != NULL) {
+    MEM_freeN(smpn);
+  }
+}
+
+void lineart_prepend_line_direct(LineartRenderLine **first, void *node)
+{
+  LineartRenderLine *ln = (LineartRenderLine *)node;
+  ln->next = (*first);
+  (*first) = ln;
+}
+
+void lineart_prepend_pool(LinkNode **first, LineartStaticMemPool *smp, void *link)
+{
+  LinkNode *ln = lineart_mem_aquire_thread(smp, sizeof(LinkNode));
+  ln->next = (*first);
+  ln->link = link;
+  (*first) = ln;
+}
+
+/* =======================================================================[str] */
+
+void lineart_matrix_perspective_44d(
+    double (*mProjection)[4], double fFov_rad, double fAspect, double zMin, double zMax)
+{
+  double yMax;
+  double yMin;
+  double xMin;
+  double xMax;
+
+  if (fAspect < 1) {
+    yMax = zMin * tan(fFov_rad * 0.5f);
+    yMin = -yMax;
+    xMin = yMin * fAspect;
+    xMax = -xMin;
+  }
+  else {
+    xMax = zMin * tan(fFov_rad * 0.5f);
+    xMin = -xMax;
+    yMin = xMin / fAspect;
+    yMax = -yMin;
+  }
+
+  unit_m4_db(mProjection);
+
+  mProjection[0][0] = (2.0f * zMin) / (xMax - xMin);
+  mProjection[1][1] = (2.0f * zMin) / (yMax - yMin);
+  mProjection[2][0] = (xMax + xMin) / (xMax - xMin);
+  mProjection[2][1] = (yMax + yMin) / (yMax - yMin);
+  mProjection[2][2] = -((zMax + zMin) / (zMax - zMin));
+  mProjection[2][3] = -1.0f;
+  mProjection[3][2] = -((2.0f * (zMax * zMin)) / (zMax - zMin));
+  mProjection[3][3] = 0.0f;
+}
+void lineart_matrix_ortho_44d(double (*mProjection)[4],
+                              double xMin,
+                              double xMax,
+                              double yMin,
+                              double yMax,
+                              double zMin,
+                              double zMax)
+{
+  unit_m4_db(mProjection);
+
+  mProjection[0][0] = 2.0f / (xMax - xMin);
+  mProjection[1][1] = 2.0f / (yMax - yMin);
+  mProjection[2][2] = -2.0f / (zMax - zMin);
+  mProjection[3][0] = -((xMax + xMin) / (xMax - xMin));
+  mProjection[3][1] = -((yMax + yMin) / (yMax - yMin));
+  mProjection[3][2] = -((zMax + zMin) / (zMax - zMin));
+  mProjection[3][3] = 1.0f;
+}
+
+void lineart_count_and_print_render_buffer_memory(LineartRenderBuffer *rb)
+{
+  size_t total = 0;
+  size_t sum_this = 0;
+  size_t count_this = 0;
+
+  LISTBASE_FOREACH (LineartStaticMemPoolNode *, smpn, &rb->render_data_pool.pools) {
+    count_this++;
+    sum_this += LRT_MEMORY_POOL_64MB;
+  }
+  printf("LANPR Memory allocated %lu Standalone nodes, total %lu Bytes.\n", count_this, sum_this);
+  total += sum_this;
+  sum_this = 0;
+  count_this = 0;
+
+  LISTBASE_FOREACH (LineartRenderElementLinkNode *, reln, &rb->line_buffer_pointers) {
+    count_this++;
+    sum_this += reln->element_count * sizeof(LineartRenderLine);
+  }
+  printf("             allocated %lu edge blocks, total %lu Bytes.\n", count_this, sum_this);
+  total += sum_this;
+  sum_this = 0;
+  count_this = 0;
+
+  LISTBASE_FOREACH (LineartRenderElementLinkNode *, reln, &rb->triangle_buffer_pointers) {
+    count_this++;
+    sum_this += reln->element_count * rb->triangle_size;
+  }
+  printf("             allocated %lu triangle blocks, total %lu Bytes.\n", count_this, sum_this);
+  total += sum_this;
+  sum_this = 0;
+  count_this = 0;
+}