1 files changed, 61 insertions, 0 deletions
diff --git a/src/libultra_code_O2/guLookAt.c b/src/libultra_code_O2/guLookAt.c
new file mode 100644
index 000000000..ca5560214
--- /dev/null
+++ b/src/libultra_code_O2/guLookAt.c
@@ -0,0 +1,61 @@
+#include "global.h"
+
+void guLookAtF(f32 mf[4][4], f32 xEye, f32 yEye, f32 zEye, f32 xAt, f32 yAt, f32 zAt, f32 xUp, f32 yUp, f32 zUp) {
+    f32 length;
+    f32 xLook, yLook, zLook;
+    f32 xRight, yRight, zRight;
+
+    guMtxIdentF(mf);
+
+    xLook = xAt - xEye;
+    yLook = yAt - yEye;
+    zLook = zAt - zEye;
+    length = -1.0 / sqrtf(SQ(xLook) + SQ(yLook) + SQ(zLook));
+    xLook *= length;
+    yLook *= length;
+    zLook *= length;
+
+    xRight = yUp * zLook - zUp * yLook;
+    yRight = zUp * xLook - xUp * zLook;
+    zRight = xUp * yLook - yUp * xLook;
+    length = 1.0 / sqrtf(SQ(xRight) + SQ(yRight) + SQ(zRight));
+    xRight *= length;
+    yRight *= length;
+    zRight *= length;
+
+    xUp = yLook * zRight - zLook * yRight;
+    yUp = zLook * xRight - xLook * zRight;
+    zUp = xLook * yRight - yLook * xRight;
+    length = 1.0 / sqrtf(SQ(xUp) + SQ(yUp) + SQ(zUp));
+    xUp *= length;
+    yUp *= length;
+    zUp *= length;
+
+    mf[0][0] = xRight;
+    mf[1][0] = yRight;
+    mf[2][0] = zRight;
+    mf[3][0] = -(xEye * xRight + yEye * yRight + zEye * zRight);
+
+    mf[0][1] = xUp;
+    mf[1][1] = yUp;
+    mf[2][1] = zUp;
+    mf[3][1] = -(xEye * xUp + yEye * yUp + zEye * zUp);
+
+    mf[0][2] = xLook;
+    mf[1][2] = yLook;
+    mf[2][2] = zLook;
+    mf[3][2] = -(xEye * xLook + yEye * yLook + zEye * zLook);
+
+    mf[0][3] = 0;
+    mf[1][3] = 0;
+    mf[2][3] = 0;
+    mf[3][3] = 1;
+}
+
+void guLookAt(Mtx* m, f32 xEye, f32 yEye, f32 zEye, f32 xAt, f32 yAt, f32 zAt, f32 xUp, f32 yUp, f32 zUp) {
+    f32 mf[4][4];
+
+    guLookAtF(mf, xEye, yEye, zEye, xAt, yAt, zAt, xUp, yUp, zUp);
+
+    guMtxF2L(mf, m);
+}