1 files changed, 26 insertions, 1 deletions

diff --git a/src/common/geom.c b/src/common/geom.c
index 219270f..eb35727 100644
--- a/src/common/geom.c
+++ b/src/common/geom.c
@@ -1,6 +1,12 @@
 #include "common/geom.h"
+#include <math.h>
+#include <common/geom.h>
 #include "morpher/matrix.h"
 
+static inline IntVector int_round(RealVector x) {
+  return (IntVector) round(x);
+}
+
 CartesianMapping m(int x, int y) {
   return (CartesianMapping) {{x, y},
                              {x, y}};
@@ -10,6 +16,10 @@ CartesianVector v(int x, int y) {
   return (CartesianVector) {x, y};
 }
 
+BarycentricVector b(double a, double b) {
+  return (BarycentricVector) {a, b};
+}
+
 bool mappings_equals(CartesianMapping m1, CartesianMapping m2) {
   return vector_equals(m1.origin, m2.origin) && vector_equals(m1.target, m2.target);
 }
@@ -18,7 +28,22 @@ bool vector_equals(CartesianVector v1, CartesianVector v2) {
   return v1.x == v2.x && v1.y == v2.y;
 }
 
-IntVector triangle_area(CartesianVector v1, CartesianVector v2, CartesianVector v3) {
+bool barycentric_vector_equals(BarycentricVector b1, BarycentricVector b2) {
+  return b1.a == b2.a && b1.b == b2.b;
+}
+
+IntVector square_area(CartesianVector v1, CartesianVector v2, CartesianVector v3) {
   return matrix_int_det2(v1.x - v3.x, v2.x - v3.x,
                          v1.y - v3.y, v2.y - v3.y);
 }
+
+BarycentricVector cartesian_to_barycentric(Triangle t, CartesianVector p) {
+  RealVector total_area = square_area(t.v[0], t.v[1], t.v[2]);
+  return (BarycentricVector) {square_area(t.v[1], t.v[2], p) / total_area,
+                              square_area(t.v[2], t.v[0], p) / total_area};
+}
+
+CartesianVector barycentric_to_cartesian(Triangle t, BarycentricVector p) {
+  return (CartesianVector) {int_round(p.a * (t.v[0].x - t.v[2].x) + p.b * (t.v[1].x - t.v[2].x) + t.v[2].x),
+                            int_round(p.a * (t.v[0].y - t.v[2].y) + p.b * (t.v[1].y - t.v[2].y) + t.v[2].y)};
+}