fix for lasso failing/glitches on overlapping lines, replace scanfill with 2d pixel filling for drawing and selection.

1 files changed, 53 insertions, 0 deletions

diff --git a/source/blender/blenlib/intern/math_geom.c b/source/blender/blenlib/intern/math_geom.c
index e45714f33da..ce36d1f9fc3 100644
--- a/source/blender/blenlib/intern/math_geom.c
+++ b/source/blender/blenlib/intern/math_geom.c
@@ -1997,6 +1997,59 @@ void plot_line_v2v2i(const int p1[2], const int p2[2], bool (*callback)(int, int
 	}
 }
 
+void fill_poly_v2i_n(
+        const int xmin, const int ymin, const int xmax, const int ymax,
+        const int verts[][2], const int nr,
+        void (*callback)(int, int, void *), void *userData)
+{
+	/* originally by Darel Rex Finley, 2007 */
+
+	int  nodes, pixel_y, i, j, swap;
+	int *node_x = MEM_mallocN(sizeof(*node_x) * (nr + 1), __func__);
+
+	/* Loop through the rows of the image. */
+	for (pixel_y = ymin; pixel_y < ymax; pixel_y++) {
+
+		/* Build a list of nodes. */
+		nodes = 0; j = nr - 1;
+		for (i=0; i<nr; i++) {
+			if ((verts[i][1] < pixel_y && verts[j][1] >= pixel_y) ||
+			    (verts[j][1] < pixel_y && verts[i][1] >= pixel_y))
+			{
+				node_x[nodes++] = (int)(verts[i][0] +
+				                        ((double)(pixel_y - verts[i][1]) / (verts[j][1] - verts[i][1])) *
+				                        (verts[j][0] - verts[i][0]));
+			}
+			j = i;
+		}
+
+		/* Sort the nodes, via a simple "Bubble" sort. */
+		i = 0;
+		while (i < nodes - 1) {
+			if (node_x[i] > node_x[i + 1]) {
+				SWAP_TVAL(swap, node_x[i], node_x[i + 1]);
+				if (i) i--;
+			}
+			else {
+				i++;
+			}
+		}
+
+		/* Fill the pixels between node pairs. */
+		for (i = 0; i < nodes; i += 2) {
+			if (node_x[i] >= xmax) break;
+			if (node_x[i + 1] >  xmin) {
+				if (node_x[i    ] < xmin) node_x[i    ] = xmin;
+				if (node_x[i + 1] > xmax) node_x[i + 1] = xmax;
+				for (j = node_x[i]; j < node_x[i + 1]; j++) {
+					callback(j - xmin, pixel_y - ymin, userData);
+				}
+			}
+		}
+	}
+	MEM_freeN(node_x);
+}
+
 /****************************** Axis Utils ********************************/
 
 /**