bugfix - [#18063] Projection paint branch: draw tool "drops out" when model extends beyond view borders

reported by michael williamson.

Was caused by point inside triangle test using an error limit that didnt adjust for different size triangles.

1 files changed, 7 insertions, 7 deletions

diff --git a/source/blender/src/imagepaint.c b/source/blender/src/imagepaint.c
index 46a91f772e0..2c8a5f7a401 100644
--- a/source/blender/src/imagepaint.c
+++ b/source/blender/src/imagepaint.c
@@ -1960,16 +1960,15 @@ static float angle_2d_clockwise(const float p1[2], const float p2[2], const floa
 #define ISECT_ALL3 ((1<<3)-1)
 #define ISECT_ALL4 ((1<<4)-1)
 
+/* limit must be a fraction over 1.0f */
 static int IsectPT2Df_limit(float pt[2], float v1[2], float v2[2], float v3[2], float limit)
 {
-	return (AreaF2Dfl(v1,v2,v3) + limit) > (AreaF2Dfl(pt,v1,v2) + AreaF2Dfl(pt,v2,v3) + AreaF2Dfl(pt,v3,v1));
+	return ((AreaF2Dfl(pt,v1,v2) + AreaF2Dfl(pt,v2,v3) + AreaF2Dfl(pt,v3,v1)) / (AreaF2Dfl(v1,v2,v3))) < limit;
 }
 
 /* Clip the face by a bucket and set the uv-space bucket_bounds_uv
  * so we have the clipped UV's to do pixel intersection tests with 
  * */
-
-
 static int float_z_sort_flip(const void *p1, const void *p2) {
 	return (((float *)p1)[2] < ((float *)p2)[2] ? 1:-1);
 }
@@ -2019,18 +2018,19 @@ static void project_bucket_clip_face(
 	/* use IsectPT2Df_limit here so we catch points are are touching the tri edge (or a small fraction over) */
 	bucket_bounds_ss[0][0] = bucket_bounds->xmax;
 	bucket_bounds_ss[0][1] = bucket_bounds->ymin;
-	inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[0], v1coSS, v2coSS, v3coSS, 0.01f) ? ISECT_1 : 0);
+	inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[0], v1coSS, v2coSS, v3coSS, 1+PROJ_GEOM_TOLERANCE) ? ISECT_1 : 0);
+	
 	bucket_bounds_ss[1][0] = bucket_bounds->xmax;
 	bucket_bounds_ss[1][1] = bucket_bounds->ymax;
-	inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[1], v1coSS, v2coSS, v3coSS, 0.01f) ? ISECT_2 : 0);
+	inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[1], v1coSS, v2coSS, v3coSS, 1+PROJ_GEOM_TOLERANCE) ? ISECT_2 : 0);
 
 	bucket_bounds_ss[2][0] = bucket_bounds->xmin;
 	bucket_bounds_ss[2][1] = bucket_bounds->ymax;
-	inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[2], v1coSS, v2coSS, v3coSS, 0.01f) ? ISECT_3 : 0);
+	inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[2], v1coSS, v2coSS, v3coSS, 1+PROJ_GEOM_TOLERANCE) ? ISECT_3 : 0);
 
 	bucket_bounds_ss[3][0] = bucket_bounds->xmin;
 	bucket_bounds_ss[3][1] = bucket_bounds->ymin;
-	inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[3], v1coSS, v2coSS, v3coSS, 0.01f) ? ISECT_4 : 0);
+	inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[3], v1coSS, v2coSS, v3coSS, 1+PROJ_GEOM_TOLERANCE) ? ISECT_4 : 0);
 	
 	if (inside_face_flag == ISECT_ALL4) {
 		/* bucket is totally inside the screenspace face, we can safely use weights */