GPencil: Refactor of Draw Engine, Vertex Paint and all internal functions

This commit is a full refactor of the grease pencil modules including Draw Engine, Modifiers, VFX, depsgraph update, improvements in operators and conversion of Sculpt and Weight paint tools to real brushes.

Also, a huge code cleanup has been done at all levels.

Thanks to @fclem for his work and yo @pepeland and @mendio for the testing and help in the development.

Differential Revision: https://developer.blender.org/D6293

1 files changed, 359 insertions, 88 deletions

diff --git a/source/blender/blenloader/intern/versioning_280.c b/source/blender/blenloader/intern/versioning_280.c
index e29c4f8658f..2035ee3590f 100644
--- a/source/blender/blenloader/intern/versioning_280.c
+++ b/source/blender/blenloader/intern/versioning_280.c
@@ -52,6 +52,7 @@
 #include "DNA_rigidbody_types.h"
 #include "DNA_scene_types.h"
 #include "DNA_screen_types.h"
+#include "DNA_shader_fx_types.h"
 #include "DNA_view3d_types.h"
 #include "DNA_genfile.h"
 #include "DNA_workspace_types.h"
@@ -63,6 +64,7 @@
 #include "DNA_world_types.h"
 
 #include "BKE_animsys.h"
+#include "BKE_brush.h"
 #include "BKE_cloth.h"
 #include "BKE_collection.h"
 #include "BKE_constraint.h"
@@ -71,6 +73,8 @@
 #include "BKE_fcurve.h"
 #include "BKE_freestyle.h"
 #include "BKE_global.h"
+#include "BKE_gpencil.h"
+#include "BKE_gpencil_modifier.h"
 #include "BKE_idprop.h"
 #include "BKE_key.h"
 #include "BKE_lib_id.h"
@@ -573,7 +577,7 @@ static void do_versions_fix_annotations(bGPdata *gpd)
   for (const bGPDpalette *palette = gpd->palettes.first; palette; palette = palette->next) {
     for (bGPDpalettecolor *palcolor = palette->colors.first; palcolor; palcolor = palcolor->next) {
       /* fix layers */
-      for (bGPDlayer *gpl = gpd->layers.first; gpl; gpl = gpl->next) {
+      LISTBASE_FOREACH (bGPDlayer *, gpl, &gpd->layers) {
         /* unlock/unhide layer */
         gpl->flag &= ~GP_LAYER_LOCKED;
         gpl->flag &= ~GP_LAYER_HIDE;
@@ -582,8 +586,8 @@ static void do_versions_fix_annotations(bGPdata *gpd)
         /* disable tint */
         gpl->tintcolor[3] = 0.0f;
 
-        for (bGPDframe *gpf = gpl->frames.first; gpf; gpf = gpf->next) {
-          for (bGPDstroke *gps = gpf->strokes.first; gps; gps = gps->next) {
+        LISTBASE_FOREACH (bGPDframe *, gpf, &gpl->frames) {
+          LISTBASE_FOREACH (bGPDstroke *, gps, &gpf->strokes) {
             if ((gps->colorname[0] != '\0') && (STREQ(gps->colorname, palcolor->info))) {
               /* copy color settings */
               copy_v4_v4(gpl->color, palcolor->color);
@@ -1057,6 +1061,48 @@ static void do_version_curvemapping_walker(Main *bmain, void (*callback)(CurveMa
           callback(gpmd->curfalloff);
         }
       }
+      else if (md->type == eGpencilModifierType_Noise) {
+        NoiseGpencilModifierData *gpmd = (NoiseGpencilModifierData *)md;
+
+        if (gpmd->curve_intensity) {
+          callback(gpmd->curve_intensity);
+        }
+      }
+      else if (md->type == eGpencilModifierType_Vertexcolor) {
+        VertexcolorGpencilModifierData *gpmd = (VertexcolorGpencilModifierData *)md;
+
+        if (gpmd->curve_intensity) {
+          callback(gpmd->curve_intensity);
+        }
+      }
+      else if (md->type == eGpencilModifierType_Smooth) {
+        SmoothGpencilModifierData *gpmd = (SmoothGpencilModifierData *)md;
+
+        if (gpmd->curve_intensity) {
+          callback(gpmd->curve_intensity);
+        }
+      }
+      else if (md->type == eGpencilModifierType_Color) {
+        ColorGpencilModifierData *gpmd = (ColorGpencilModifierData *)md;
+
+        if (gpmd->curve_intensity) {
+          callback(gpmd->curve_intensity);
+        }
+      }
+      else if (md->type == eGpencilModifierType_Opacity) {
+        OpacityGpencilModifierData *gpmd = (OpacityGpencilModifierData *)md;
+
+        if (gpmd->curve_intensity) {
+          callback(gpmd->curve_intensity);
+        }
+      }
+      else if (md->type == eGpencilModifierType_Tint) {
+        TintGpencilModifierData *gpmd = (TintGpencilModifierData *)md;
+
+        if (gpmd->curve_intensity) {
+          callback(gpmd->curve_intensity);
+        }
+      }
     }
   }
 
@@ -1554,7 +1600,7 @@ void do_versions_after_linking_280(Main *bmain, ReportList *UNUSED(reports))
       if (gpd == NULL) {
         continue;
       }
-      for (bGPDlayer *gpl = gpd->layers.first; gpl; gpl = gpl->next) {
+      LISTBASE_FOREACH (bGPDlayer *, gpl, &gpd->layers) {
         if (STREQ(gpl->info, "RulerData3D")) {
           gpl->flag |= GP_LAYER_IS_RULER;
           break;
@@ -1588,6 +1634,34 @@ void do_versions_after_linking_280(Main *bmain, ReportList *UNUSED(reports))
     }
   }
 
+  if (!MAIN_VERSION_ATLEAST(bmain, 282, 2)) {
+    /* Init all Vertex/Sculpt and Weight Paint brushes. */
+    Brush *brush = BLI_findstring(&bmain->brushes, "Pencil", offsetof(ID, name) + 2);
+    for (Scene *scene = bmain->scenes.first; scene; scene = scene->id.next) {
+      ToolSettings *ts = scene->toolsettings;
+
+      BKE_brush_gpencil_vertex_presets(bmain, ts);
+      BKE_brush_gpencil_sculpt_presets(bmain, ts);
+      BKE_brush_gpencil_weight_presets(bmain, ts);
+
+      /* Ensure new Paint modes. */
+      BKE_paint_ensure_from_paintmode(scene, PAINT_MODE_GPENCIL);
+      BKE_paint_ensure_from_paintmode(scene, PAINT_MODE_VERTEX_GPENCIL);
+      BKE_paint_ensure_from_paintmode(scene, PAINT_MODE_SCULPT_GPENCIL);
+      BKE_paint_ensure_from_paintmode(scene, PAINT_MODE_WEIGHT_GPENCIL);
+
+      /* Set default Draw brush. */
+      if (brush != NULL) {
+        Paint *paint = &ts->gp_paint->paint;
+        BKE_paint_brush_set(paint, brush);
+        /* Enable cursor by default. */
+        paint->flags |= PAINT_SHOW_BRUSH;
+      }
+      /* Ensure Palette by default. */
+      BKE_gpencil_palette_ensure(bmain, scene);
+    }
+  }
+
   /**
    * Versioning code until next subversion bump goes here.
    *
@@ -1774,36 +1848,6 @@ void blo_do_versions_280(FileData *fd, Library *UNUSED(lib), Main *bmain)
 #endif
 
     {
-      /* Grease pencil sculpt and paint cursors */
-      if (!DNA_struct_elem_find(fd->filesdna, "GP_Sculpt_Settings", "int", "weighttype")) {
-        for (Scene *scene = bmain->scenes.first; scene; scene = scene->id.next) {
-          /* sculpt brushes */
-          GP_Sculpt_Settings *gset = &scene->toolsettings->gp_sculpt;
-          if (gset) {
-            gset->weighttype = GP_SCULPT_TYPE_WEIGHT;
-          }
-        }
-      }
-
-      {
-        float curcolor_add[3], curcolor_sub[3];
-        ARRAY_SET_ITEMS(curcolor_add, 1.0f, 0.6f, 0.6f);
-        ARRAY_SET_ITEMS(curcolor_sub, 0.6f, 0.6f, 1.0f);
-        GP_Sculpt_Data *gp_brush;
-
-        for (Scene *scene = bmain->scenes.first; scene; scene = scene->id.next) {
-          ToolSettings *ts = scene->toolsettings;
-          /* sculpt brushes */
-          GP_Sculpt_Settings *gset = &ts->gp_sculpt;
-          for (int i = 0; i < GP_SCULPT_TYPE_MAX; i++) {
-            gp_brush = &gset->brush[i];
-            gp_brush->flag |= GP_SCULPT_FLAG_ENABLE_CURSOR;
-            copy_v3_v3(gp_brush->curcolor_add, curcolor_add);
-            copy_v3_v3(gp_brush->curcolor_sub, curcolor_sub);
-          }
-        }
-      }
-
       /* Init grease pencil edit line color */
       if (!DNA_struct_elem_find(fd->filesdna, "bGPdata", "float", "line_color[4]")) {
         for (bGPdata *gpd = bmain->gpencils.first; gpd; gpd = gpd->id.next) {
@@ -1866,8 +1910,7 @@ void blo_do_versions_280(FileData *fd, Library *UNUSED(lib), Main *bmain)
 
   if (!MAIN_VERSION_ATLEAST(bmain, 280, 3)) {
     /* init grease pencil grids and paper */
-    if (!DNA_struct_elem_find(
-            fd->filesdna, "gp_paper_opacity", "float", "gpencil_paper_color[3]")) {
+    if (!DNA_struct_elem_find(fd->filesdna, "View3DOverlay", "float", "gpencil_paper_color[3]")) {
       for (bScreen *screen = bmain->screens.first; screen; screen = screen->id.next) {
         for (ScrArea *area = screen->areabase.first; area; area = area->next) {
           for (SpaceLink *sl = area->spacedata.first; sl; sl = sl->next) {
@@ -2621,7 +2664,7 @@ void blo_do_versions_280(FileData *fd, Library *UNUSED(lib), Main *bmain)
     }
     if (!DNA_struct_elem_find(fd->filesdna, "bGPDlayer", "short", "line_change")) {
       for (bGPdata *gpd = bmain->gpencils.first; gpd; gpd = gpd->id.next) {
-        for (bGPDlayer *gpl = gpd->layers.first; gpl; gpl = gpl->next) {
+        LISTBASE_FOREACH (bGPDlayer *, gpl, &gpd->layers) {
           gpl->line_change = gpl->thickness;
           if ((gpl->thickness < 1) || (gpl->thickness > 10)) {
             gpl->thickness = 3;
@@ -2953,34 +2996,13 @@ void blo_do_versions_280(FileData *fd, Library *UNUSED(lib), Main *bmain)
     /* grease pencil main material show switches */
     for (Material *mat = bmain->materials.first; mat; mat = mat->id.next) {
       if (mat->gp_style) {
-        mat->gp_style->flag |= GP_STYLE_STROKE_SHOW;
-        mat->gp_style->flag |= GP_STYLE_FILL_SHOW;
+        mat->gp_style->flag |= GP_MATERIAL_STROKE_SHOW;
+        mat->gp_style->flag |= GP_MATERIAL_FILL_SHOW;
       }
     }
   }
 
   if (!MAIN_VERSION_ATLEAST(bmain, 280, 33)) {
-    /* Grease pencil reset sculpt brushes after struct rename  */
-    if (!DNA_struct_elem_find(fd->filesdna, "GP_Sculpt_Settings", "int", "weighttype")) {
-      float curcolor_add[3], curcolor_sub[3];
-      ARRAY_SET_ITEMS(curcolor_add, 1.0f, 0.6f, 0.6f);
-      ARRAY_SET_ITEMS(curcolor_sub, 0.6f, 0.6f, 1.0f);
-
-      for (Scene *scene = bmain->scenes.first; scene; scene = scene->id.next) {
-        /* sculpt brushes */
-        GP_Sculpt_Settings *gset = &scene->toolsettings->gp_sculpt;
-        if (gset) {
-          for (int i = 0; i < GP_SCULPT_TYPE_MAX; i++) {
-            GP_Sculpt_Data *gp_brush = &gset->brush[i];
-            gp_brush->size = 30;
-            gp_brush->strength = 0.5f;
-            gp_brush->flag = GP_SCULPT_FLAG_USE_FALLOFF | GP_SCULPT_FLAG_ENABLE_CURSOR;
-            copy_v3_v3(gp_brush->curcolor_add, curcolor_add);
-            copy_v3_v3(gp_brush->curcolor_sub, curcolor_sub);
-          }
-        }
-      }
-    }
 
     if (!DNA_struct_elem_find(fd->filesdna, "SceneEEVEE", "float", "overscan")) {
       for (Scene *scene = bmain->scenes.first; scene; scene = scene->id.next) {
@@ -3214,7 +3236,7 @@ void blo_do_versions_280(FileData *fd, Library *UNUSED(lib), Main *bmain)
     /* init Annotations onion skin */
     if (!DNA_struct_elem_find(fd->filesdna, "bGPDlayer", "int", "gstep")) {
       for (bGPdata *gpd = bmain->gpencils.first; gpd; gpd = gpd->id.next) {
-        for (bGPDlayer *gpl = gpd->layers.first; gpl; gpl = gpl->next) {
+        LISTBASE_FOREACH (bGPDlayer *, gpl, &gpd->layers) {
           ARRAY_SET_ITEMS(gpl->gcolor_prev, 0.302f, 0.851f, 0.302f);
           ARRAY_SET_ITEMS(gpl->gcolor_next, 0.250f, 0.1f, 1.0f);
         }
@@ -3420,20 +3442,6 @@ void blo_do_versions_280(FileData *fd, Library *UNUSED(lib), Main *bmain)
       }
     }
 
-    /* Grease pencil target weight  */
-    if (!DNA_struct_elem_find(fd->filesdna, "GP_Sculpt_Settings", "float", "weight")) {
-      for (Scene *scene = bmain->scenes.first; scene; scene = scene->id.next) {
-        /* sculpt brushes */
-        GP_Sculpt_Settings *gset = &scene->toolsettings->gp_sculpt;
-        if (gset) {
-          for (int i = 0; i < GP_SCULPT_TYPE_MAX; i++) {
-            GP_Sculpt_Data *gp_brush = &gset->brush[i];
-            gp_brush->weight = 1.0f;
-          }
-        }
-      }
-    }
-
     /* Grease pencil cutter/select segment intersection threshold  */
     if (!DNA_struct_elem_find(fd->filesdna, "GP_Sculpt_Settings", "float", "isect_threshold")) {
       for (Scene *scene = bmain->scenes.first; scene; scene = scene->id.next) {
@@ -3653,7 +3661,7 @@ void blo_do_versions_280(FileData *fd, Library *UNUSED(lib), Main *bmain)
         if (gpd->flag & GP_DATA_ANNOTATIONS) {
           continue;
         }
-        for (bGPDlayer *gpl = gpd->layers.first; gpl; gpl = gpl->next) {
+        LISTBASE_FOREACH (bGPDlayer *, gpl, &gpd->layers) {
           /* default channel color */
           ARRAY_SET_ITEMS(gpl->color, 0.2f, 0.2f, 0.2f);
         }
@@ -3744,26 +3752,24 @@ void blo_do_versions_280(FileData *fd, Library *UNUSED(lib), Main *bmain)
     }
 
     /* init grease pencil brush gradients */
-    if (!DNA_struct_elem_find(fd->filesdna, "BrushGpencilSettings", "float", "gradient_f")) {
+    if (!DNA_struct_elem_find(fd->filesdna, "BrushGpencilSettings", "float", "hardeness")) {
       for (Brush *brush = bmain->brushes.first; brush; brush = brush->id.next) {
         if (brush->gpencil_settings != NULL) {
           BrushGpencilSettings *gp = brush->gpencil_settings;
-          gp->gradient_f = 1.0f;
-          gp->gradient_s[0] = 1.0f;
-          gp->gradient_s[1] = 1.0f;
+          gp->hardeness = 1.0f;
+          copy_v2_fl(gp->aspect_ratio, 1.0f);
         }
       }
     }
 
     /* init grease pencil stroke gradients */
-    if (!DNA_struct_elem_find(fd->filesdna, "bGPDstroke", "float", "gradient_f")) {
+    if (!DNA_struct_elem_find(fd->filesdna, "bGPDstroke", "float", "hardeness")) {
       for (bGPdata *gpd = bmain->gpencils.first; gpd; gpd = gpd->id.next) {
-        for (bGPDlayer *gpl = gpd->layers.first; gpl; gpl = gpl->next) {
-          for (bGPDframe *gpf = gpl->frames.first; gpf; gpf = gpf->next) {
-            for (bGPDstroke *gps = gpf->strokes.first; gps; gps = gps->next) {
-              gps->gradient_f = 1.0f;
-              gps->gradient_s[0] = 1.0f;
-              gps->gradient_s[1] = 1.0f;
+        LISTBASE_FOREACH (bGPDlayer *, gpl, &gpd->layers) {
+          LISTBASE_FOREACH (bGPDframe *, gpf, &gpl->frames) {
+            LISTBASE_FOREACH (bGPDstroke *, gps, &gpf->strokes) {
+              gps->hardeness = 1.0f;
+              copy_v2_fl(gps->aspect_ratio, 1.0f);
             }
           }
         }
@@ -4217,7 +4223,6 @@ void blo_do_versions_280(FileData *fd, Library *UNUSED(lib), Main *bmain)
       }
     }
 
-    /* Fix wrong 3D viewport copying causing corrupt pointers (T69974). */
     for (bScreen *screen = bmain->screens.first; screen; screen = screen->id.next) {
       for (ScrArea *sa = screen->areabase.first; sa; sa = sa->next) {
         for (SpaceLink *sl = sa->spacedata.first; sl; sl = sl->next) {
@@ -4507,6 +4512,272 @@ void blo_do_versions_280(FileData *fd, Library *UNUSED(lib), Main *bmain)
     }
   }
 
+  if (!MAIN_VERSION_ATLEAST(bmain, 283, 7)) {
+    /* Init default Grease Pencil Vertex paint mix factor for Viewport. */
+    if (!DNA_struct_elem_find(
+            fd->filesdna, "View3DOverlay", "float", "gpencil_vertex_paint_opacity")) {
+      LISTBASE_FOREACH (bScreen *, screen, &bmain->screens) {
+        LISTBASE_FOREACH (ScrArea *, area, &screen->areabase) {
+          LISTBASE_FOREACH (SpaceLink *, sl, &area->spacedata) {
+            if (sl->spacetype == SPACE_VIEW3D) {
+              View3D *v3d = (View3D *)sl;
+              v3d->overlay.gpencil_vertex_paint_opacity = 1.0f;
+            }
+          }
+        }
+      }
+    }
+
+    /* Update Grease Pencil after drawing engine and code refactor.
+     * It uses the seed variable of Array modifier to avoid double patching for
+     * files created with a development version. */
+    if (!DNA_struct_elem_find(fd->filesdna, "ArrayGpencilModifierData", "int", "seed")) {
+      /* Init new Grease Pencil Paint tools. */
+      {
+        LISTBASE_FOREACH (Brush *, brush, &bmain->brushes) {
+          if (brush->gpencil_settings != NULL) {
+            brush->gpencil_vertex_tool = brush->gpencil_settings->brush_type;
+            brush->gpencil_sculpt_tool = brush->gpencil_settings->brush_type;
+            brush->gpencil_weight_tool = brush->gpencil_settings->brush_type;
+          }
+        }
+
+        BKE_paint_toolslots_init_from_main(bmain);
+      }
+
+      LISTBASE_FOREACH (Material *, mat, &bmain->materials) {
+        MaterialGPencilStyle *gp_style = mat->gp_style;
+        if (gp_style == NULL) {
+          continue;
+        }
+        /* Fix Grease Pencil Material colors to Linear. */
+        srgb_to_linearrgb_v4(gp_style->stroke_rgba, gp_style->stroke_rgba);
+        srgb_to_linearrgb_v4(gp_style->fill_rgba, gp_style->fill_rgba);
+
+        /* Move old gradient variables to texture. */
+        if (gp_style->fill_style == GP_MATERIAL_FILL_STYLE_GRADIENT) {
+          gp_style->texture_angle = gp_style->gradient_angle;
+          copy_v2_v2(gp_style->texture_scale, gp_style->gradient_scale);
+          copy_v2_v2(gp_style->texture_offset, gp_style->gradient_shift);
+        }
+        /* Set Checker material as Solid. This fill mode has been removed and replaced
+         * by textures. */
+        if (gp_style->fill_style == GP_MATERIAL_FILL_STYLE_CHECKER) {
+          gp_style->fill_style = GP_MATERIAL_FILL_STYLE_SOLID;
+        }
+        /* Update Alpha channel for texture opacity. */
+        if (gp_style->fill_style == GP_MATERIAL_FILL_STYLE_TEXTURE) {
+          gp_style->fill_rgba[3] *= gp_style->texture_opacity;
+        }
+        /* Stroke stencil mask to mix = 1. */
+        if (gp_style->flag & GP_MATERIAL_STROKE_PATTERN) {
+          gp_style->mix_stroke_factor = 1.0f;
+          gp_style->flag &= ~GP_MATERIAL_STROKE_PATTERN;
+        }
+        /* Mix disabled, set mix factor to 0. */
+        else if ((gp_style->flag & GP_MATERIAL_STROKE_TEX_MIX) == 0) {
+          gp_style->mix_stroke_factor = 0.0f;
+        }
+      }
+
+      /* Fix Grease Pencil VFX and modifiers. */
+      LISTBASE_FOREACH (Object *, ob, &bmain->objects) {
+        if (ob->type != OB_GPENCIL) {
+          continue;
+        }
+
+        /* VFX. */
+        LISTBASE_FOREACH (ShaderFxData *, fx, &ob->shader_fx) {
+          switch (fx->type) {
+            case eShaderFxType_Colorize: {
+              ColorizeShaderFxData *vfx = (ColorizeShaderFxData *)fx;
+              if (ELEM(vfx->mode, eShaderFxColorizeMode_GrayScale, eShaderFxColorizeMode_Sepia)) {
+                vfx->factor = 1.0f;
+              }
+              srgb_to_linearrgb_v4(vfx->low_color, vfx->low_color);
+              srgb_to_linearrgb_v4(vfx->high_color, vfx->high_color);
+              break;
+            }
+            case eShaderFxType_Pixel: {
+              PixelShaderFxData *vfx = (PixelShaderFxData *)fx;
+              srgb_to_linearrgb_v4(vfx->rgba, vfx->rgba);
+              break;
+            }
+            case eShaderFxType_Rim: {
+              RimShaderFxData *vfx = (RimShaderFxData *)fx;
+              srgb_to_linearrgb_v3_v3(vfx->rim_rgb, vfx->rim_rgb);
+              srgb_to_linearrgb_v3_v3(vfx->mask_rgb, vfx->mask_rgb);
+              break;
+            }
+            case eShaderFxType_Shadow: {
+              ShadowShaderFxData *vfx = (ShadowShaderFxData *)fx;
+              srgb_to_linearrgb_v4(vfx->shadow_rgba, vfx->shadow_rgba);
+              break;
+            }
+            case eShaderFxType_Glow: {
+              GlowShaderFxData *vfx = (GlowShaderFxData *)fx;
+              srgb_to_linearrgb_v3_v3(vfx->glow_color, vfx->glow_color);
+              vfx->glow_color[3] = 1.0f;
+              srgb_to_linearrgb_v3_v3(vfx->select_color, vfx->select_color);
+              vfx->blur[1] = vfx->blur[0];
+              break;
+            }
+            default:
+              break;
+          }
+        }
+
+        /* Modifiers. */
+        LISTBASE_FOREACH (GpencilModifierData *, md, &ob->greasepencil_modifiers) {
+          switch ((GpencilModifierType)md->type) {
+            case eGpencilModifierType_Array: {
+              ArrayGpencilModifierData *mmd = (ArrayGpencilModifierData *)md;
+              mmd->seed = 1;
+              if ((mmd->offset[0] != 0.0f) || (mmd->offset[1] != 0.0f) ||
+                  (mmd->offset[2] != 0.0f)) {
+                mmd->flag |= GP_ARRAY_USE_OFFSET;
+              }
+              if ((mmd->shift[0] != 0.0f) || (mmd->shift[1] != 0.0f) || (mmd->shift[2] != 0.0f)) {
+                mmd->flag |= GP_ARRAY_USE_OFFSET;
+              }
+              if (mmd->object != NULL) {
+                mmd->flag |= GP_ARRAY_USE_OB_OFFSET;
+              }
+              break;
+            }
+            case eGpencilModifierType_Noise: {
+              NoiseGpencilModifierData *mmd = (NoiseGpencilModifierData *)md;
+              mmd->factor /= 25.0f;
+              mmd->factor_thickness = mmd->factor;
+              mmd->factor_strength = mmd->factor;
+              mmd->factor_uvs = mmd->factor;
+              mmd->noise_scale = (mmd->flag & GP_NOISE_FULL_STROKE) ? 0.0f : 1.0f;
+
+              if (mmd->curve_intensity == NULL) {
+                mmd->curve_intensity = BKE_curvemapping_add(1, 0.0f, 0.0f, 1.0f, 1.0f);
+                if (mmd->curve_intensity) {
+                  BKE_curvemapping_initialize(mmd->curve_intensity);
+                }
+              }
+              break;
+            }
+            case eGpencilModifierType_Tint: {
+              TintGpencilModifierData *mmd = (TintGpencilModifierData *)md;
+              srgb_to_linearrgb_v3_v3(mmd->rgb, mmd->rgb);
+              if (mmd->curve_intensity == NULL) {
+                mmd->curve_intensity = BKE_curvemapping_add(1, 0.0f, 0.0f, 1.0f, 1.0f);
+                if (mmd->curve_intensity) {
+                  BKE_curvemapping_initialize(mmd->curve_intensity);
+                }
+              }
+              break;
+            }
+            case eGpencilModifierType_Smooth: {
+              SmoothGpencilModifierData *mmd = (SmoothGpencilModifierData *)md;
+              if (mmd->curve_intensity == NULL) {
+                mmd->curve_intensity = BKE_curvemapping_add(1, 0.0f, 0.0f, 1.0f, 1.0f);
+                if (mmd->curve_intensity) {
+                  BKE_curvemapping_initialize(mmd->curve_intensity);
+                }
+              }
+              break;
+            }
+            case eGpencilModifierType_Opacity: {
+              OpacityGpencilModifierData *mmd = (OpacityGpencilModifierData *)md;
+              if (mmd->curve_intensity == NULL) {
+                mmd->curve_intensity = BKE_curvemapping_add(1, 0.0f, 0.0f, 1.0f, 1.0f);
+                if (mmd->curve_intensity) {
+                  BKE_curvemapping_initialize(mmd->curve_intensity);
+                }
+              }
+              break;
+            }
+            case eGpencilModifierType_Color: {
+              ColorGpencilModifierData *mmd = (ColorGpencilModifierData *)md;
+              if (mmd->curve_intensity == NULL) {
+                mmd->curve_intensity = BKE_curvemapping_add(1, 0.0f, 0.0f, 1.0f, 1.0f);
+                if (mmd->curve_intensity) {
+                  BKE_curvemapping_initialize(mmd->curve_intensity);
+                }
+              }
+              break;
+            }
+            case eGpencilModifierType_Thick: {
+              if (!DNA_struct_elem_find(
+                      fd->filesdna, "ThickGpencilModifierData", "float", "thickness_fac")) {
+                ThickGpencilModifierData *mmd = (ThickGpencilModifierData *)md;
+                mmd->thickness_fac = mmd->thickness;
+              }
+              break;
+            }
+            case eGpencilModifierType_Multiply: {
+              MultiplyGpencilModifierData *mmd = (MultiplyGpencilModifierData *)md;
+              mmd->fading_opacity = 1.0 - mmd->fading_opacity;
+              break;
+            }
+            case eGpencilModifierType_Subdiv: {
+              const short simple = (1 << 0);
+              SubdivGpencilModifierData *mmd = (SubdivGpencilModifierData *)md;
+              if (mmd->flag & simple) {
+                mmd->flag &= ~simple;
+                mmd->type = GP_SUBDIV_SIMPLE;
+              }
+              break;
+            }
+            case eGpencilModifierType_Vertexcolor: {
+              VertexcolorGpencilModifierData *mmd = (VertexcolorGpencilModifierData *)md;
+              if (mmd->curve_intensity == NULL) {
+                mmd->curve_intensity = BKE_curvemapping_add(1, 0.0f, 0.0f, 1.0f, 1.0f);
+                if (mmd->curve_intensity) {
+                  BKE_curvemapping_initialize(mmd->curve_intensity);
+                }
+              }
+              break;
+            }
+            default:
+              break;
+          }
+        }
+      }
+
+      /* Fix Layers Colors and Vertex Colors to Linear.
+       * Also set lights to on for layers. */
+      LISTBASE_FOREACH (bGPdata *, gpd, &bmain->gpencils) {
+        if (gpd->flag & GP_DATA_ANNOTATIONS) {
+          continue;
+        }
+        /* Onion colors. */
+        srgb_to_linearrgb_v3_v3(gpd->gcolor_prev, gpd->gcolor_prev);
+        srgb_to_linearrgb_v3_v3(gpd->gcolor_next, gpd->gcolor_next);
+        /* Z-depth Offset. */
+        gpd->zdepth_offset = 0.150f;
+
+        LISTBASE_FOREACH (bGPDlayer *, gpl, &gpd->layers) {
+          gpl->flag |= GP_LAYER_USE_LIGHTS;
+          srgb_to_linearrgb_v4(gpl->tintcolor, gpl->tintcolor);
+          gpl->vertex_paint_opacity = 1.0f;
+
+          LISTBASE_FOREACH (bGPDframe *, gpf, &gpl->frames) {
+            LISTBASE_FOREACH (bGPDstroke *, gps, &gpf->strokes) {
+              /* Set initial opacity for fill color. */
+              gps->fill_opacity_fac = 1.0f;
+
+              /* Calc geometry data because in old versions this data was not saved. */
+              BKE_gpencil_stroke_geometry_update(gps);
+
+              srgb_to_linearrgb_v4(gps->vert_color_fill, gps->vert_color_fill);
+              int i;
+              bGPDspoint *pt;
+              for (i = 0, pt = gps->points; i < gps->totpoints; i++, pt++) {
+                srgb_to_linearrgb_v4(pt->vert_color, pt->vert_color);
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+
   /**
    * Versioning code until next subversion bump goes here.
    *