From a767c658cb603de9ec9f0577627b9b32cbf82b2b Mon Sep 17 00:00:00 2001
From: pacien
Date: Fri, 22 Dec 2017 01:53:55 +0100
Subject: Simplify and add geom. and matrix utility functions

Signed-off-by: pacien <pacien.trangirard@pacien.net>
---
 src/common/geom.c    | 19 ++++++++++++++++
 src/common/matrix.c  | 63 ----------------------------------------------------
 src/morpher/matrix.c | 16 +++++++++++++
 3 files changed, 35 insertions(+), 63 deletions(-)
 delete mode 100644 src/common/matrix.c
 create mode 100644 src/morpher/matrix.c

(limited to 'src')

diff --git a/src/common/geom.c b/src/common/geom.c
index 7abb422..219270f 100644
--- a/src/common/geom.c
+++ b/src/common/geom.c
@@ -1,5 +1,24 @@
 #include "common/geom.h"
+#include "morpher/matrix.h"
+
+CartesianMapping m(int x, int y) {
+  return (CartesianMapping) {{x, y},
+                             {x, y}};
+}
+
+CartesianVector v(int x, int y) {
+  return (CartesianVector) {x, y};
+}
+
+bool mappings_equals(CartesianMapping m1, CartesianMapping m2) {
+  return vector_equals(m1.origin, m2.origin) && vector_equals(m1.target, m2.target);
+}
 
 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) {
+  return matrix_int_det2(v1.x - v3.x, v2.x - v3.x,
+                         v1.y - v3.y, v2.y - v3.y);
+}
diff --git a/src/common/matrix.c b/src/common/matrix.c
deleted file mode 100644
index 60f9afb..0000000
--- a/src/common/matrix.c
+++ /dev/null
@@ -1,63 +0,0 @@
-#include "common/matrix.h"
-#include <assert.h>
-#include <memory.h>
-#include <stdlib.h>
-#include "common/mem.h"
-
-static inline IntSquareMatrix *matrix_without_row(IntSquareMatrix *target, IntSquareMatrix *origin,
-                                                  IntVector omitted_row) {
-  int origin_row, target_row;
-
-  for (origin_row = 0, target_row = 0; origin_row < origin->dim; ++origin_row)
-    if (origin_row != omitted_row)
-      target->elements[target_row++] = origin->elements[origin_row];
-
-  return target;
-}
-
-static inline IntVector det_dev_sign(IntVector row, IntVector col) {
-  assert(row > 0 && col > 0);
-  return ((row + col) % 2 == 0) ? 1 : -1;
-}
-
-static inline IntVector det_reduce(IntSquareMatrix *matrix) {
-  IntSquareMatrix sub_matrix;
-  int row;
-  IntVector det = 0;
-
-  assert(matrix->dim > 2);
-
-  sub_matrix.dim = matrix->dim - 1;
-  sub_matrix.elements = malloc_or_die(sub_matrix.dim * sizeof(IntVector *));
-
-  for (row = 0; row < matrix->dim; ++row)
-    det += matrix->elements[row][matrix->dim - 1]
-           * det_dev_sign(row + 1, matrix->dim)
-           * matrix_int_det(matrix_without_row(&sub_matrix, matrix, row));
-
-
-  free(sub_matrix.elements);
-  return det;
-}
-
-IntVector matrix_int_det(IntSquareMatrix *matrix) {
-  assert(matrix->dim > 0);
-  switch (matrix->dim) {
-    case 1:
-      return matrix->elements[0][0];
-
-    case 2:
-      return matrix->elements[0][0] * matrix->elements[1][1] - matrix->elements[0][1] * matrix->elements[1][0];
-
-    default:
-      return det_reduce(matrix);
-  }
-}
-
-void matrix_reshape(IntVector **bi_dim, IntVector *flat, int width, int height) {
-  int row;
-  assert(width > 0 && height > 0);
-
-  for (row = 0; row < height; ++row)
-    bi_dim[row] = flat + row * width;
-}
diff --git a/src/morpher/matrix.c b/src/morpher/matrix.c
new file mode 100644
index 0000000..2fe1193
--- /dev/null
+++ b/src/morpher/matrix.c
@@ -0,0 +1,16 @@
+#include "morpher/matrix.h"
+
+IntVector matrix_int_det2(IntVector u11, IntVector u12,
+                          IntVector u21, IntVector u22) {
+
+  return u11 * u22 - u12 * u21;
+}
+
+IntVector matrix_int_det3(IntVector u11, IntVector u12, IntVector u13,
+                          IntVector u21, IntVector u22, IntVector u23,
+                          IntVector u31, IntVector u32, IntVector u33) {
+
+  return u11 * matrix_int_det2(u22, u23, u32, u33)
+         - u21 * matrix_int_det2(u12, u13, u32, u33)
+         + u31 * matrix_int_det2(u12, u13, u22, u23);
+}
-- 
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