GPencil: Include new Brush random curves

Now the brushes have several new random settings and use curves to define the effect. The curves have been moved below the parameter to keep UI standards and extra curve panels have been removed.

{F8505387}

The new curves are:

* Hue.
* Saturation.
* Value.

New option to random at stroke level instead to random at point level for the following values:

* Thickness.
* Strength.
* UV.
* Hue.
* Saturation.
* Value.

Curves have been moved below the corresponding parameter and only are displayed in properties panel. Display the curves in the popover made it unusable.

{F8505392}

Also, the Pressure random has been renamed to Radius because the old name was not clear enough.

Reviewed By: mendio, pablovazquez

Differential Revision: https://developer.blender.org/D7577

1 files changed, 80 insertions, 49 deletions

diff --git a/source/blender/editors/gpencil/gpencil_primitive.c b/source/blender/editors/gpencil/gpencil_primitive.c
index 11aeeba5a24..1778162c1a3 100644
--- a/source/blender/editors/gpencil/gpencil_primitive.c
+++ b/source/blender/editors/gpencil/gpencil_primitive.c
@@ -124,8 +124,13 @@ static void gp_session_validatebuffer(tGPDprimitive *p)
   gpd->runtime.sbuffer_sflag |= GP_STROKE_3DSPACE;
 
   /* Set vertex colors for buffer. */
-  ED_gpencil_sbuffer_vertex_color_set(
-      p->depsgraph, p->ob, p->scene->toolsettings, p->brush, p->material);
+  ED_gpencil_sbuffer_vertex_color_set(p->depsgraph,
+                                      p->ob,
+                                      p->scene->toolsettings,
+                                      p->brush,
+                                      p->material,
+                                      p->random_settings.hsv,
+                                      1.0f);
 
   if (ELEM(p->type, GP_STROKE_BOX, GP_STROKE_CIRCLE)) {
     gpd->runtime.sbuffer_sflag |= GP_STROKE_CYCLIC;
@@ -681,6 +686,8 @@ static void gp_primitive_update_strokes(bContext *C, tGPDprimitive *tgpi)
   ToolSettings *ts = tgpi->scene->toolsettings;
   bGPdata *gpd = tgpi->gpd;
   Brush *brush = tgpi->brush;
+  BrushGpencilSettings *brush_settings = brush->gpencil_settings;
+  GpRandomSettings random_settings = tgpi->random_settings;
   bGPDstroke *gps = tgpi->gpf->strokes.first;
   GP_Sculpt_Settings *gset = &ts->gp_sculpt;
   int depth_margin = (ts->gpencil_v3d_align & GP_PROJECT_DEPTH_STROKE) ? 4 : 0;
@@ -735,11 +742,11 @@ static void gp_primitive_update_strokes(bContext *C, tGPDprimitive *tgpi)
   if (gset->flag & GP_SCULPT_SETT_FLAG_PRIMITIVE_CURVE) {
     BKE_curvemapping_initialize(ts->gp_sculpt.cur_primitive);
   }
-  if (tgpi->brush->gpencil_settings->flag & GP_BRUSH_USE_JITTER_PRESSURE) {
-    BKE_curvemapping_initialize(tgpi->brush->gpencil_settings->curve_jitter);
+  if (brush_settings->flag & GP_BRUSH_USE_JITTER_PRESSURE) {
+    BKE_curvemapping_initialize(brush_settings->curve_jitter);
   }
-  if (tgpi->brush->gpencil_settings->flag & GP_BRUSH_USE_STENGTH_PRESSURE) {
-    BKE_curvemapping_initialize(tgpi->brush->gpencil_settings->curve_strength);
+  if (brush_settings->flag & GP_BRUSH_USE_STENGTH_PRESSURE) {
+    BKE_curvemapping_initialize(brush_settings->curve_strength);
   }
 
   /* get an array of depths, far depths are blended */
@@ -841,10 +848,9 @@ static void gp_primitive_update_strokes(bContext *C, tGPDprimitive *tgpi)
     tGPspoint *p2d = &points2D[i];
 
     /* set rnd value for reuse */
-    if ((brush->gpencil_settings->flag & GP_BRUSH_GROUP_RANDOM) && (p2d->rnd_dirty != true)) {
+    if ((brush_settings->flag & GP_BRUSH_GROUP_RANDOM) && (p2d->rnd_dirty != true)) {
       p2d->rnd[0] = BLI_rng_get_float(tgpi->rng);
       p2d->rnd[1] = BLI_rng_get_float(tgpi->rng);
-      p2d->rnd[2] = BLI_rng_get_float(tgpi->rng);
       p2d->rnd_dirty = true;
     }
 
@@ -858,7 +864,7 @@ static void gp_primitive_update_strokes(bContext *C, tGPDprimitive *tgpi)
     /* calc pressure */
     float curve_pressure = 1.0;
     float pressure = 1.0;
-    float strength = brush->gpencil_settings->draw_strength;
+    float strength = brush_settings->draw_strength;
 
     /* normalize value to evaluate curve */
     if (gset->flag & GP_SCULPT_SETT_FLAG_PRIMITIVE_CURVE) {
@@ -868,20 +874,18 @@ static void gp_primitive_update_strokes(bContext *C, tGPDprimitive *tgpi)
     }
 
     /* apply jitter to position */
-    if ((brush->gpencil_settings->flag & GP_BRUSH_GROUP_RANDOM) &&
-        (brush->gpencil_settings->draw_jitter > 0.0f)) {
+    if ((brush_settings->flag & GP_BRUSH_GROUP_RANDOM) && (brush_settings->draw_jitter > 0.0f)) {
       float jitter;
 
-      if (brush->gpencil_settings->flag & GP_BRUSH_USE_JITTER_PRESSURE) {
-        jitter = BKE_curvemapping_evaluateF(
-            brush->gpencil_settings->curve_jitter, 0, curve_pressure);
+      if (brush_settings->flag & GP_BRUSH_USE_JITTER_PRESSURE) {
+        jitter = BKE_curvemapping_evaluateF(brush_settings->curve_jitter, 0, curve_pressure);
       }
       else {
-        jitter = brush->gpencil_settings->draw_jitter;
+        jitter = brush_settings->draw_jitter;
       }
 
       /* exponential value */
-      const float exfactor = square_f(brush->gpencil_settings->draw_jitter + 2.0f);
+      const float exfactor = square_f(brush_settings->draw_jitter + 2.0f);
       const float fac = p2d->rnd[0] * exfactor * jitter;
 
       /* vector */
@@ -906,47 +910,68 @@ static void gp_primitive_update_strokes(bContext *C, tGPDprimitive *tgpi)
       add_v2_v2(&p2d->x, svec);
     }
 
-    /* apply randomness to pressure */
-    if ((brush->gpencil_settings->flag & GP_BRUSH_GROUP_RANDOM) &&
-        (brush->gpencil_settings->draw_random_press > 0.0f)) {
-      if (p2d->rnd[0] > 0.5f) {
-        pressure -= (brush->gpencil_settings->draw_random_press * 2.0f) * p2d->rnd[1];
-      }
-      else {
-        pressure += (brush->gpencil_settings->draw_random_press * 2.0f) * p2d->rnd[2];
-      }
-    }
-
     /* color strength */
-    if (brush->gpencil_settings->flag & GP_BRUSH_USE_STENGTH_PRESSURE) {
-      float curvef = BKE_curvemapping_evaluateF(
-          brush->gpencil_settings->curve_strength, 0, curve_pressure);
+    if (brush_settings->flag & GP_BRUSH_USE_STENGTH_PRESSURE) {
+      float curvef = BKE_curvemapping_evaluateF(brush_settings->curve_strength, 0, curve_pressure);
       strength *= curvef;
-      strength *= brush->gpencil_settings->draw_strength;
+      strength *= brush_settings->draw_strength;
     }
 
     CLAMP(strength, GPENCIL_STRENGTH_MIN, 1.0f);
 
-    /* apply randomness to color strength */
-    if ((brush->gpencil_settings->flag & GP_BRUSH_GROUP_RANDOM) &&
-        (brush->gpencil_settings->draw_random_strength > 0.0f)) {
-      if (p2d->rnd[2] > 0.5f) {
-        strength -= strength * brush->gpencil_settings->draw_random_strength * p2d->rnd[0];
+    if (brush_settings->flag & GP_BRUSH_GROUP_RANDOM) {
+      /* Apply randomness to pressure. */
+      if (brush_settings->draw_random_press > 0.0f) {
+        if ((brush_settings->flag2 & GP_BRUSH_USE_PRESS_AT_STROKE) == 0) {
+          float rand = BLI_rng_get_float(tgpi->rng) * 2.0f - 1.0f;
+          pressure *= 1.0 + rand * 2.0 * brush_settings->draw_random_press;
+        }
+        else {
+          pressure *= 1.0 + random_settings.pressure * brush_settings->draw_random_press;
+        }
+
+        /* Apply random curve. */
+        if (brush_settings->flag2 & GP_BRUSH_USE_PRESSURE_RAND_PRESS) {
+          pressure *= BKE_curvemapping_evaluateF(brush_settings->curve_rand_pressure, 0, pressure);
+        }
+
+        CLAMP(pressure, 0.1f, 1.0f);
       }
-      else {
-        strength += strength * brush->gpencil_settings->draw_random_strength * p2d->rnd[1];
+
+      /* Apply randomness to color strength. */
+      if (brush_settings->draw_random_strength) {
+        if ((brush_settings->flag2 & GP_BRUSH_USE_STRENGTH_AT_STROKE) == 0) {
+          float rand = BLI_rng_get_float(tgpi->rng) * 2.0f - 1.0f;
+          strength *= 1.0 + rand * brush_settings->draw_random_strength;
+        }
+        else {
+          strength *= 1.0 + random_settings.strength * brush_settings->draw_random_strength;
+        }
+
+        /* Apply random curve. */
+        if (brush_settings->flag2 & GP_BRUSH_USE_STRENGTH_RAND_PRESS) {
+          strength *= BKE_curvemapping_evaluateF(brush_settings->curve_rand_strength, 0, pressure);
+        }
+
+        CLAMP(strength, GPENCIL_STRENGTH_MIN, 1.0f);
       }
-      CLAMP(strength, GPENCIL_STRENGTH_MIN, 1.0f);
     }
 
     copy_v2_v2(&tpt->x, &p2d->x);
 
-    CLAMP_MIN(pressure, 0.1f);
-
     tpt->pressure = pressure;
     tpt->strength = strength;
     tpt->time = p2d->time;
 
+    /* Set vertex colors for buffer. */
+    ED_gpencil_sbuffer_vertex_color_set(tgpi->depsgraph,
+                                        tgpi->ob,
+                                        tgpi->scene->toolsettings,
+                                        tgpi->brush,
+                                        tgpi->material,
+                                        tgpi->random_settings.hsv,
+                                        strength);
+
     /* point uv */
     if (gpd->runtime.sbuffer_used > 0) {
       tGPspoint *tptb = (tGPspoint *)gpd->runtime.sbuffer + gpd->runtime.sbuffer_used - 1;
@@ -994,8 +1019,7 @@ static void gp_primitive_update_strokes(bContext *C, tGPDprimitive *tgpi)
     pt->time = 0.0f;
     pt->flag = 0;
     pt->uv_fac = tpt->uv_fac;
-    /* Apply the vertex color to point. */
-    ED_gpencil_point_vertex_color_set(ts, brush, pt);
+    copy_v4_v4(pt->vert_color, tpt->vert_color);
 
     if (gps->dvert != NULL) {
       MDeformVert *dvert = &gps->dvert[i];
@@ -1159,6 +1183,7 @@ static void gpencil_primitive_init(bContext *C, wmOperator *op)
 
   /* Set Draw brush. */
   Brush *brush = BKE_paint_toolslots_brush_get(paint, 0);
+
   BKE_brush_tool_set(brush, paint, 0);
   BKE_paint_brush_set(paint, brush);
   tgpi->brush = brush;
@@ -1226,6 +1251,9 @@ static int gpencil_primitive_invoke(bContext *C, wmOperator *op, const wmEvent *
   gpencil_primitive_init(C, op);
   tgpi = op->customdata;
 
+  /* Init random settings. */
+  ED_gpencil_init_random_settings(tgpi->brush, event->mval, &tgpi->random_settings);
+
   const bool is_modal = RNA_boolean_get(op->ptr, "wait_for_input");
   if (!is_modal) {
     tgpi->flag = IN_PROGRESS;
@@ -1262,6 +1290,7 @@ static void gpencil_primitive_interaction_end(bContext *C,
 
   ToolSettings *ts = tgpi->scene->toolsettings;
   Brush *brush = tgpi->brush;
+  BrushGpencilSettings *brush_settings = brush->gpencil_settings;
 
   const int def_nr = tgpi->ob->actdef - 1;
   const bool have_weight = (bool)BLI_findlink(&tgpi->ob->defbase, def_nr);
@@ -1285,8 +1314,8 @@ static void gpencil_primitive_interaction_end(bContext *C,
   gps = tgpi->gpf->strokes.first;
   if (gps) {
     gps->thickness = brush->size;
-    gps->hardeness = brush->gpencil_settings->hardeness;
-    copy_v2_v2(gps->aspect_ratio, brush->gpencil_settings->aspect_ratio);
+    gps->hardeness = brush_settings->hardeness;
+    copy_v2_v2(gps->aspect_ratio, brush_settings->aspect_ratio);
 
     /* Calc geometry data. */
     BKE_gpencil_stroke_geometry_update(gps);
@@ -1449,23 +1478,25 @@ static void gpencil_primitive_edit_event_handling(
 static void gpencil_primitive_strength(tGPDprimitive *tgpi, bool reset)
 {
   Brush *brush = tgpi->brush;
+  BrushGpencilSettings *brush_settings = brush->gpencil_settings;
+
   if (brush) {
     if (reset) {
-      brush->gpencil_settings->draw_strength = tgpi->brush_strength;
+      brush_settings->draw_strength = tgpi->brush_strength;
       tgpi->brush_strength = 0.0f;
     }
     else {
       if (tgpi->brush_strength == 0.0f) {
-        tgpi->brush_strength = brush->gpencil_settings->draw_strength;
+        tgpi->brush_strength = brush_settings->draw_strength;
       }
       float move[2];
       sub_v2_v2v2(move, tgpi->mval, tgpi->mvalo);
       float adjust = (move[1] > 0.0f) ? 0.01f : -0.01f;
-      brush->gpencil_settings->draw_strength += adjust * fabsf(len_manhattan_v2(move));
+      brush_settings->draw_strength += adjust * fabsf(len_manhattan_v2(move));
     }
 
     /* limit low limit because below 0.2f the stroke is invisible */
-    CLAMP(brush->gpencil_settings->draw_strength, 0.2f, 1.0f);
+    CLAMP(brush_settings->draw_strength, 0.2f, 1.0f);
   }
 }