6 files changed, 23 insertions, 19 deletions

diff --git a/source/blender/blenlib/BLI_math_geom.h b/source/blender/blenlib/BLI_math_geom.h
index 7cb91a45118..448396811d3 100644
--- a/source/blender/blenlib/BLI_math_geom.h
+++ b/source/blender/blenlib/BLI_math_geom.h
@@ -53,6 +53,7 @@ float area_tri_signed_v2(const float v1[2], const float v2[2], const float v3[2]
 float area_tri_v3(const float a[3], const float b[3], const float c[3]);
 float area_quad_v3(const float a[3], const float b[3], const float c[3], const float d[3]);
 float area_poly_v3(int nr, float verts[][3], const float normal[3]);
+float area_poly_v2(int nr, float verts[][2]);
 
 int is_quad_convex_v3(const float v1[3], const float v2[3], const float v3[3], const float v4[3]);
 int is_quad_convex_v2(const float v1[2], const float v2[2], const float v3[2], const float v4[2]);
diff --git a/source/blender/blenlib/intern/math_geom.c b/source/blender/blenlib/intern/math_geom.c
index 5f1047d054e..fc1d0e99a30 100644
--- a/source/blender/blenlib/intern/math_geom.c
+++ b/source/blender/blenlib/intern/math_geom.c
@@ -149,6 +149,25 @@ float area_poly_v3(int nr, float verts[][3], const float normal[3])
 	return fabsf(0.5f * area / max);
 }
 
+float area_poly_v2(int nr, float verts[][2])
+{
+	int a;
+	float area;
+	float *co_curr, *co_prev;
+
+	/* The Trapezium Area Rule */
+	co_prev = verts[nr - 1];
+	co_curr = verts[0];
+	area = 0.0f;
+	for (a = 0; a < nr; a++) {
+		area += (co_curr[0] - co_prev[0]) * (co_curr[1] + co_prev[1]);
+		co_prev = verts[a];
+		co_curr = verts[a + 1];
+	}
+
+	return fabsf(0.5f * area);
+}
+
 /********************************* Distance **********************************/
 
 /* distance p to line v1-v2
diff --git a/source/blender/bmesh/intern/bmesh_polygon.c b/source/blender/bmesh/intern/bmesh_polygon.c
index 953e7f4d20c..4545c9bb564 100644
--- a/source/blender/bmesh/intern/bmesh_polygon.c
+++ b/source/blender/bmesh/intern/bmesh_polygon.c
@@ -158,7 +158,6 @@ float BM_face_calc_area(BMFace *f)
 	BMLoop *l;
 	BMIter iter;
 	float (*verts)[3] = BLI_array_alloca(verts, f->len);
-	float normal[3];
 	float area;
 	int i;
 
@@ -173,6 +172,7 @@ float BM_face_calc_area(BMFace *f)
 		area = area_quad_v3(verts[0], verts[1], verts[2], verts[3]);
 	}
 	else {
+		float normal[3];
 		calc_poly_normal(normal, verts, f->len);
 		area = area_poly_v3(f->len, verts, normal);
 	}
diff --git a/source/blender/editors/uvedit/uvedit_draw.c b/source/blender/editors/uvedit/uvedit_draw.c
index 607640090aa..023f281aea9 100644
--- a/source/blender/editors/uvedit/uvedit_draw.c
+++ b/source/blender/editors/uvedit/uvedit_draw.c
@@ -194,8 +194,7 @@ static void draw_uvs_stretch(SpaceImage *sima, Scene *scene, BMEditMesh *em, MTe
 				uv_poly_copy_aspect(tf_uvorig, tf_uv, aspx, aspy, efa->len);
 
 				totarea += BM_face_calc_area(efa);
-				//totuvarea += tf_area(tf, efa->v4!=0);
-				totuvarea += uv_poly_area(tf_uv, efa->len);
+				totuvarea += area_poly_v2(efa->len, tf_uv);
 				
 				if (uvedit_face_visible_test(scene, ima, efa, tf)) {
 					BM_elem_flag_enable(efa, BM_ELEM_TAG);
@@ -238,8 +237,7 @@ static void draw_uvs_stretch(SpaceImage *sima, Scene *scene, BMEditMesh *em, MTe
 
 						uv_poly_copy_aspect(tf_uvorig, tf_uv, aspx, aspy, efa->len);
 
-						//uvarea = tf_area(tf, efa->v4!=0) / totuvarea;
-						uvarea = uv_poly_area(tf_uv, efa->len) / totuvarea;
+						uvarea = area_poly_v2(efa->len, tf_uv) / totuvarea;
 						
 						if (area < FLT_EPSILON || uvarea < FLT_EPSILON)
 							areadiff = 1.0f;
diff --git a/source/blender/editors/uvedit/uvedit_intern.h b/source/blender/editors/uvedit/uvedit_intern.h
index 4d52282d540..b6d82451d2f 100644
--- a/source/blender/editors/uvedit/uvedit_intern.h
+++ b/source/blender/editors/uvedit/uvedit_intern.h
@@ -50,7 +50,6 @@ struct BMVert;
 int uvedit_face_visible_nolocal(struct Scene *scene, struct BMFace *efa);
 
 /* geometric utilities */
-float uv_poly_area(float uv[][2], int len);
 void  uv_poly_copy_aspect(float uv_orig[][2], float uv[][2], float aspx, float aspy, int len);
 void  uv_poly_center(struct BMEditMesh *em, struct BMFace *f, float r_cent[2]);
 
diff --git a/source/blender/editors/uvedit/uvedit_ops.c b/source/blender/editors/uvedit/uvedit_ops.c
index 4336eb02752..2194ce28353 100644
--- a/source/blender/editors/uvedit/uvedit_ops.c
+++ b/source/blender/editors/uvedit/uvedit_ops.c
@@ -575,19 +575,6 @@ void uv_poly_center(BMEditMesh *em, BMFace *f, float r_cent[2])
 	mul_v2_fl(r_cent, 1.0f / (float)f->len);
 }
 
-float uv_poly_area(float uv[][2], int len)
-{
-	//BMESH_TODO: make this not suck
-	//maybe use scanfill? I dunno.
-
-	if (len >= 4)
-		return area_tri_v2(uv[0], uv[1], uv[2]) + area_tri_v2(uv[0], uv[2], uv[3]); 
-	else
-		return area_tri_v2(uv[0], uv[1], uv[2]); 
-
-	return 1.0;
-}
-
 void uv_poly_copy_aspect(float uv_orig[][2], float uv[][2], float aspx, float aspy, int len)
 {
 	int i;