Fix T73973: GPencil Fill fails when zoom the image

The problem was related of how the initial pixel to create outline was detected. Now, a limit is set for any image to keep a fillable image in all situations, not only when some strokes contain the fill.

1 files changed, 50 insertions, 55 deletions

diff --git a/source/blender/editors/gpencil/gpencil_fill.c b/source/blender/editors/gpencil/gpencil_fill.c
index 0f57862efb2..82373850dc8 100644
--- a/source/blender/editors/gpencil/gpencil_fill.c
+++ b/source/blender/editors/gpencil/gpencil_fill.c
@@ -621,40 +621,38 @@ static void gpencil_boundaryfill_area(tGPDfill *tgpf)
 
     get_pixel(ibuf, v, rgba);
 
-    if (true) { /* Was: 'rgba' */
-      /* check if no border(red) or already filled color(green) */
-      if ((rgba[0] != 1.0f) && (rgba[1] != 1.0f)) {
-        /* fill current pixel with green */
-        set_pixel(ibuf, v, fill_col);
-
-        /* add contact pixels */
-        /* pixel left */
-        if (v - 1 >= 0) {
-          index = v - 1;
-          if (!is_leak_narrow(ibuf, maxpixel, tgpf->fill_leak, v, LEAK_HORZ)) {
-            BLI_stack_push(stack, &index);
-          }
+    /* check if no border(red) or already filled color(green) */
+    if ((rgba[0] != 1.0f) && (rgba[1] != 1.0f)) {
+      /* fill current pixel with green */
+      set_pixel(ibuf, v, fill_col);
+
+      /* add contact pixels */
+      /* pixel left */
+      if (v - 1 >= 0) {
+        index = v - 1;
+        if (!is_leak_narrow(ibuf, maxpixel, tgpf->fill_leak, v, LEAK_HORZ)) {
+          BLI_stack_push(stack, &index);
         }
-        /* pixel right */
-        if (v + 1 <= maxpixel) {
-          index = v + 1;
-          if (!is_leak_narrow(ibuf, maxpixel, tgpf->fill_leak, v, LEAK_HORZ)) {
-            BLI_stack_push(stack, &index);
-          }
+      }
+      /* pixel right */
+      if (v + 1 <= maxpixel) {
+        index = v + 1;
+        if (!is_leak_narrow(ibuf, maxpixel, tgpf->fill_leak, v, LEAK_HORZ)) {
+          BLI_stack_push(stack, &index);
         }
-        /* pixel top */
-        if (v + ibuf->x <= maxpixel) {
-          index = v + ibuf->x;
-          if (!is_leak_narrow(ibuf, maxpixel, tgpf->fill_leak, v, LEAK_VERT)) {
-            BLI_stack_push(stack, &index);
-          }
+      }
+      /* pixel top */
+      if (v + ibuf->x <= maxpixel) {
+        index = v + ibuf->x;
+        if (!is_leak_narrow(ibuf, maxpixel, tgpf->fill_leak, v, LEAK_VERT)) {
+          BLI_stack_push(stack, &index);
         }
-        /* pixel bottom */
-        if (v - ibuf->x >= 0) {
-          index = v - ibuf->x;
-          if (!is_leak_narrow(ibuf, maxpixel, tgpf->fill_leak, v, LEAK_VERT)) {
-            BLI_stack_push(stack, &index);
-          }
+      }
+      /* pixel bottom */
+      if (v - ibuf->x >= 0) {
+        index = v - ibuf->x;
+        if (!is_leak_narrow(ibuf, maxpixel, tgpf->fill_leak, v, LEAK_VERT)) {
+          BLI_stack_push(stack, &index);
         }
       }
     }
@@ -726,31 +724,32 @@ static bool gpencil_check_borders(tGPDfill *tgpf)
   return found;
 }
 
-/* clean external border of image to avoid infinite loops */
-static void gpencil_clean_borders(tGPDfill *tgpf)
+/* Set a border to create image limits. */
+static void gpencil_set_borders(tGPDfill *tgpf, const bool transparent)
 {
   ImBuf *ibuf;
   void *lock;
-  const float fill_col[4] = {0.0f, 0.0f, 0.0f, 0.0f};
+  const float fill_col[2][4] = {{1.0f, 0.0f, 0.0f, 1.0f}, {0.0f, 0.0f, 0.0f, 0.0f}};
   ibuf = BKE_image_acquire_ibuf(tgpf->ima, NULL, &lock);
   int idx;
   int pixel = 0;
+  const int coloridx = transparent ? 0 : 1;
 
   /* horizontal lines */
   for (idx = 0; idx < ibuf->x; idx++) {
     /* bottom line */
-    set_pixel(ibuf, idx, fill_col);
+    set_pixel(ibuf, idx, fill_col[coloridx]);
     /* top line */
     pixel = idx + (ibuf->x * (ibuf->y - 1));
-    set_pixel(ibuf, pixel, fill_col);
+    set_pixel(ibuf, pixel, fill_col[coloridx]);
   }
   /* vertical lines */
   for (idx = 0; idx < ibuf->y; idx++) {
     /* left line */
-    set_pixel(ibuf, ibuf->x * idx, fill_col);
+    set_pixel(ibuf, ibuf->x * idx, fill_col[coloridx]);
     /* right line */
     pixel = ibuf->x * idx + (ibuf->x - 1);
-    set_pixel(ibuf, pixel, fill_col);
+    set_pixel(ibuf, pixel, fill_col[coloridx]);
   }
 
   /* release ibuf */
@@ -1503,30 +1502,26 @@ static int gpencil_fill_modal(bContext *C, wmOperator *op, const wmEvent *event)
             /* render screen to temp image */
             if (gp_render_offscreen(tgpf)) {
 
+              /* Set red borders to create a external limit. */
+              gpencil_set_borders(tgpf, true);
+
               /* apply boundary fill */
               gpencil_boundaryfill_area(tgpf);
 
-              /* Check if detected some border to fill. */
-              if (gpencil_check_borders(tgpf)) {
-
-                /* clean borders to avoid infinite loops */
-                gpencil_clean_borders(tgpf);
+              /* Clean borders to avoid infinite loops. */
+              gpencil_set_borders(tgpf, false);
 
-                /* analyze outline */
-                gpencil_get_outline_points(tgpf);
+              /* analyze outline */
+              gpencil_get_outline_points(tgpf);
 
-                /* create array of points from stack */
-                gpencil_points_from_stack(tgpf);
+              /* create array of points from stack */
+              gpencil_points_from_stack(tgpf);
 
-                /* create z-depth array for reproject */
-                gpencil_get_depth_array(tgpf);
+              /* create z-depth array for reproject */
+              gpencil_get_depth_array(tgpf);
 
-                /* create stroke and reproject */
-                gpencil_stroke_from_buffer(tgpf);
-              }
-              else {
-                BKE_report(op->reports, RPT_ERROR, "Fill canceled. No edges detected");
-              }
+              /* create stroke and reproject */
+              gpencil_stroke_from_buffer(tgpf);
             }
 
             /* free temp stack data */