1 files changed, 111 insertions, 0 deletions

diff --git a/test/mat4_test.c b/test/mat4_test.c
new file mode 100644
index 0000000..d4f61bc
--- /dev/null
+++ b/test/mat4_test.c
@@ -0,0 +1,111 @@
+#include <math/mat4.h>
+
+#include <math/float.h>
+
+#include "test.h"
+
+#include <stdio.h>
+
+static const float eps = 1e-9;
+
+static inline void print_mat4(mat4 m) {
+  printf("\n");
+  for (int i = 0; i < 4; ++i) {
+    for (int j = 0; j < 4; ++j) {
+      printf("%6.3f  ", mat4_at(m, i, j));
+    }
+    printf("\n");
+  }
+}
+
+TEST_CASE(lookat_right) {
+  const mat4 m = mat4_lookat(/*position=*/vec3_make(0, 0, 0),
+                             /*target=*/vec3_make(1, 0, 0),
+                             /*up=*/vec3_make(0, 1, 0));
+
+  const mat4 expected = mat4_from_array((const float*)(float[4][4]){
+      {0, 0, 1, 0},
+      {0, 1, 0, 0},
+      {1, 0, 0, 0},
+      {0, 0, 0, 1},
+  });
+
+  TEST_TRUE(mat4_eq(m, expected, eps));
+}
+
+TEST_CASE(lookat_left) {
+  const mat4 m = mat4_lookat(/*position=*/vec3_make(0, 0, 0),
+                             /*target=*/vec3_make(-1, 0, 0),
+                             /*up=*/vec3_make(0, 1, 0));
+
+  const mat4 expected = mat4_from_array((const float*)(float[4][4]){
+      {0, 0, -1, 0},
+      {0, 1, 0, 0},
+      {-1, 0, 0, 0},
+      {0, 0, 0, 1},
+  });
+
+  TEST_TRUE(mat4_eq(m, expected, eps));
+}
+
+TEST_CASE(lookat_up) {
+  const mat4 m = mat4_lookat(/*position=*/vec3_make(0, 0, 0),
+                             /*target=*/vec3_make(0, 1, 0),
+                             /*up=*/vec3_make(0, 0, 1));
+
+  const mat4 expected = mat4_from_array((const float*)(float[4][4]){
+      {1, 0, 0, 0},
+      {0, 0, 1, 0},
+      {0, 1, 0, 0},
+      {0, 0, 0, 1},
+  });
+
+  TEST_TRUE(mat4_eq(m, expected, eps));
+}
+
+TEST_CASE(lookat_down) {
+  const mat4 m = mat4_lookat(/*position=*/vec3_make(0, 0, 0),
+                             /*target=*/vec3_make(0, -1, 0),
+                             /*up=*/vec3_make(0, 0, -1));
+
+  const mat4 expected = mat4_from_array((const float*)(float[4][4]){
+      {1, 0, 0, 0},
+      {0, 0, -1, 0},
+      {0, -1, 0, 0},
+      {0, 0, 0, 1},
+  });
+
+  TEST_TRUE(mat4_eq(m, expected, eps));
+}
+
+TEST_CASE(lookat_forward) {
+  const mat4 m = mat4_lookat(/*position=*/vec3_make(0, 0, 0),
+                             /*target=*/vec3_make(0, 0, -1),
+                             /*up=*/vec3_make(0, 1, 0));
+
+  const mat4 expected = mat4_from_array((const float*)(float[4][4]){
+      {1, 0, 0, 0},
+      {0, 1, 0, 0},
+      {0, 0, -1, 0},
+      {0, 0, 0, 1},
+  });
+
+  TEST_TRUE(mat4_eq(m, expected, eps));
+}
+
+TEST_CASE(lookat_back) {
+  const mat4 m = mat4_lookat(/*position=*/vec3_make(0, 0, 0),
+                             /*target=*/vec3_make(0, 0, 1),
+                             /*up=*/vec3_make(0, 1, 0));
+
+  const mat4 expected = mat4_from_array((const float*)(float[4][4]){
+      {-1, 0, 0, 0},
+      {0, 1, 0, 0},
+      {0, 0, 1, 0},
+      {0, 0, 0, 1},
+  });
+
+  TEST_TRUE(mat4_eq(m, expected, eps));
+}
+
+int main() { return 0; }