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, 161 insertions, 10 deletions

diff --git a/source/blender/editors/gpencil/gpencil_utils.c b/source/blender/editors/gpencil/gpencil_utils.c
index 6a7bb2012a7..6b18117cf8a 100644
--- a/source/blender/editors/gpencil/gpencil_utils.c
+++ b/source/blender/editors/gpencil/gpencil_utils.c
@@ -30,11 +30,14 @@
 
 #include "BLI_blenlib.h"
 #include "BLI_ghash.h"
+#include "BLI_hash.h"
 #include "BLI_math.h"
 #include "BLI_rand.h"
 #include "BLI_utildefines.h"
 #include "BLT_translation.h"
 
+#include "PIL_time.h"
+
 #include "DNA_brush_types.h"
 #include "DNA_gpencil_types.h"
 #include "DNA_meshdata_types.h"
@@ -74,6 +77,7 @@
 #include "ED_object.h"
 #include "ED_screen.h"
 #include "ED_select_utils.h"
+#include "ED_transform_snap_object_context.h"
 #include "ED_view3d.h"
 
 #include "GPU_immediate.h"
@@ -2559,26 +2563,170 @@ void ED_gpencil_fill_vertex_color_set(ToolSettings *ts, Brush *brush, bGPDstroke
   }
 }
 
-void ED_gpencil_point_vertex_color_set(ToolSettings *ts, Brush *brush, bGPDspoint *pt)
+void ED_gpencil_point_vertex_color_set(ToolSettings *ts,
+                                       Brush *brush,
+                                       bGPDspoint *pt,
+                                       tGPspoint *tpt)
 {
   if (GPENCIL_USE_VERTEX_COLOR_STROKE(ts, brush)) {
-    copy_v3_v3(pt->vert_color, brush->rgb);
-    pt->vert_color[3] = brush->gpencil_settings->vertex_factor;
-    srgb_to_linearrgb_v4(pt->vert_color, pt->vert_color);
+    if (tpt == NULL) {
+      copy_v3_v3(pt->vert_color, brush->rgb);
+      pt->vert_color[3] = brush->gpencil_settings->vertex_factor;
+      srgb_to_linearrgb_v4(pt->vert_color, pt->vert_color);
+    }
+    else {
+      copy_v3_v3(pt->vert_color, tpt->vert_color);
+      pt->vert_color[3] = brush->gpencil_settings->vertex_factor;
+    }
   }
   else {
     zero_v4(pt->vert_color);
   }
 }
 
-void ED_gpencil_sbuffer_vertex_color_set(
-    Depsgraph *depsgraph, Object *ob, ToolSettings *ts, Brush *brush, Material *material)
+void ED_gpencil_init_random_settings(Brush *brush,
+                                     const int mval[2],
+                                     GpRandomSettings *random_settings)
+{
+  int seed = ((uint)(ceil(PIL_check_seconds_timer())) + 1) % 128;
+  /* Use mouse position to get randomness. */
+  int ix = mval[0] * seed;
+  int iy = mval[1] * seed;
+  int iz = ix + iy * seed;
+  zero_v3(random_settings->hsv);
+
+  BrushGpencilSettings *brush_settings = brush->gpencil_settings;
+  /* Random to Hue. */
+  if (brush_settings->random_hue > 0.0f) {
+    float rand = BLI_hash_int_01(BLI_hash_int_2d(ix, iy)) * 2.0f - 1.0f;
+    random_settings->hsv[0] = rand * brush_settings->random_hue * 0.5f;
+  }
+  /* Random to Saturation. */
+  if (brush_settings->random_saturation > 0.0f) {
+    float rand = BLI_hash_int_01(BLI_hash_int_2d(iy, ix)) * 2.0f - 1.0f;
+    random_settings->hsv[1] = rand * brush_settings->random_saturation;
+  }
+  /* Random to Value. */
+  if (brush_settings->random_value > 0.0f) {
+    float rand = BLI_hash_int_01(BLI_hash_int_2d(ix * iz, iy * iz)) * 2.0f - 1.0f;
+    random_settings->hsv[2] = rand * brush_settings->random_value;
+  }
+
+  /* Random to pressure. */
+  if (brush_settings->draw_random_press > 0.0f) {
+    random_settings->pressure = BLI_hash_int_01(BLI_hash_int_2d(ix + iz, iy + iz)) * 2.0f - 1.0f;
+  }
+
+  /* Randomn to color strength. */
+  if (brush_settings->draw_random_strength) {
+    random_settings->strength = BLI_hash_int_01(BLI_hash_int_2d(ix + iy, iy + iz + ix)) * 2.0f -
+                                1.0f;
+  }
+
+  /* Random to uv texture rotation. */
+  if (brush_settings->uv_random > 0.0f) {
+    random_settings->uv = BLI_hash_int_01(BLI_hash_int_2d(iy + iz, ix * iz)) * 2.0f - 1.0f;
+  }
+}
+
+static void gpencil_sbuffer_vertex_color_random(
+    bGPdata *gpd, Brush *brush, tGPspoint *tpt, float random_color[3], float pen_pressure)
+{
+  BrushGpencilSettings *brush_settings = brush->gpencil_settings;
+  if (brush_settings->flag & GP_BRUSH_GROUP_RANDOM) {
+    int seed = ((uint)(ceil(PIL_check_seconds_timer())) + 1) % 128;
+
+    int ix = (int)(tpt->x * seed);
+    int iy = (int)(tpt->y * seed);
+    int iz = ix + iy * seed;
+    float hsv[3];
+    float factor_value[3];
+    zero_v3(factor_value);
+
+    /* Apply randomness to Hue. */
+    if (brush_settings->random_hue > 0.0f) {
+      if ((brush_settings->flag2 & GP_BRUSH_USE_HUE_AT_STROKE) == 0) {
+
+        float rand = BLI_hash_int_01(BLI_hash_int_2d(ix, gpd->runtime.sbuffer_used)) * 2.0f - 1.0f;
+        factor_value[0] = rand * brush_settings->random_hue * 0.5f;
+      }
+      else {
+        factor_value[0] = random_color[0];
+      }
+
+      /* Apply random curve. */
+      if (brush_settings->flag2 & GP_BRUSH_USE_HUE_RAND_PRESS) {
+        factor_value[0] *= BKE_curvemapping_evaluateF(
+            brush_settings->curve_rand_hue, 0, pen_pressure);
+      }
+    }
+
+    /* Apply randomness to Saturation. */
+    if (brush_settings->random_saturation > 0.0f) {
+      if ((brush_settings->flag2 & GP_BRUSH_USE_SAT_AT_STROKE) == 0) {
+        float rand = BLI_hash_int_01(BLI_hash_int_2d(iy, gpd->runtime.sbuffer_used)) * 2.0f - 1.0f;
+        factor_value[1] = rand * brush_settings->random_saturation;
+      }
+      else {
+        factor_value[1] = random_color[1];
+      }
+
+      /* Apply random curve. */
+      if (brush_settings->flag2 & GP_BRUSH_USE_SAT_RAND_PRESS) {
+        factor_value[1] *= BKE_curvemapping_evaluateF(
+            brush_settings->curve_rand_saturation, 0, pen_pressure);
+      }
+    }
+
+    /* Apply randomness to Value. */
+    if (brush_settings->random_value > 0.0f) {
+      if ((brush_settings->flag2 & GP_BRUSH_USE_VAL_AT_STROKE) == 0) {
+        float rand = BLI_hash_int_01(BLI_hash_int_2d(iz, gpd->runtime.sbuffer_used)) * 2.0f - 1.0f;
+        factor_value[2] = rand * brush_settings->random_value;
+      }
+      else {
+        factor_value[2] = random_color[2];
+      }
+
+      /* Apply random curve. */
+      if (brush_settings->flag2 & GP_BRUSH_USE_VAL_RAND_PRESS) {
+        factor_value[2] *= BKE_curvemapping_evaluateF(
+            brush_settings->curve_rand_value, 0, pen_pressure);
+      }
+    }
+
+    rgb_to_hsv_v(tpt->vert_color, hsv);
+    add_v3_v3(hsv, factor_value);
+    /* For Hue need to cover all range, but for Saturation and Value
+     * is not logic because the effect is too hard, so the value is just clamped. */
+    if (hsv[0] < 0.0f) {
+      hsv[0] += 1.0f;
+    }
+    else if (hsv[0] > 1.0f) {
+      hsv[0] -= 1.0f;
+    }
+
+    CLAMP3(hsv, 0.0f, 1.0f);
+    hsv_to_rgb_v(hsv, tpt->vert_color);
+  }
+}
+
+void ED_gpencil_sbuffer_vertex_color_set(Depsgraph *depsgraph,
+                                         Object *ob,
+                                         ToolSettings *ts,
+                                         Brush *brush,
+                                         Material *material,
+                                         float random_color[3],
+                                         float pen_pressure)
 {
   bGPdata *gpd = (bGPdata *)ob->data;
   Object *ob_eval = (Object *)DEG_get_evaluated_id(depsgraph, &ob->id);
   bGPdata *gpd_eval = (bGPdata *)ob_eval->data;
   MaterialGPencilStyle *gp_style = material->gp_style;
 
+  int idx = gpd->runtime.sbuffer_used;
+  tGPspoint *tpt = (tGPspoint *)gpd->runtime.sbuffer + idx;
+
   float vertex_color[4];
   copy_v3_v3(vertex_color, brush->rgb);
   vertex_color[3] = brush->gpencil_settings->vertex_factor;
@@ -2593,15 +2741,18 @@ void ED_gpencil_sbuffer_vertex_color_set(
   }
   /* Copy stroke vertex color. */
   if (GPENCIL_USE_VERTEX_COLOR_STROKE(ts, brush)) {
-    copy_v4_v4(gpd->runtime.vert_color, vertex_color);
+    copy_v4_v4(tpt->vert_color, vertex_color);
   }
   else {
-    copy_v4_v4(gpd->runtime.vert_color, gp_style->stroke_rgba);
+    copy_v4_v4(tpt->vert_color, gp_style->stroke_rgba);
   }
 
-  /* Copy to eval data because paint operators don't tag refresh until end for speedup painting. */
+  /* Random Color. */
+  gpencil_sbuffer_vertex_color_random(gpd, brush, tpt, random_color, pen_pressure);
+
+  /* Copy to eval data because paint operators don't tag refresh until end for speedup
+     painting. */
   if (gpd_eval != NULL) {
-    copy_v4_v4(gpd_eval->runtime.vert_color, gpd->runtime.vert_color);
     copy_v4_v4(gpd_eval->runtime.vert_color_fill, gpd->runtime.vert_color_fill);
     gpd_eval->runtime.matid = gpd->runtime.matid;
   }