X-Git-Url: http://de.git.xonotic.org/?a=blobdiff_plain;f=matrixlib.c;h=5433aaccbb032661c0c3cb7eddc0c5bf5a760c82;hb=8b57bcb1deffad227731484e52d631277fe3d521;hp=a036d822053a494c8ae1d23058e7bfa54814e73e;hpb=9966a66abf1877c448f36aa012fd1d5e38063568;p=xonotic%2Fdarkplaces.git

diff --git a/matrixlib.c b/matrixlib.c
index a036d822..5433aacc 100644
--- a/matrixlib.c
+++ b/matrixlib.c
@@ -2,6 +2,16 @@
 #include <math.h>
 #include "matrixlib.h"
 
+const matrix4x4_t identitymatrix =
+{
+	{
+		{1, 0, 0, 0},
+		{0, 1, 0, 0},
+		{0, 0, 1, 0},
+		{0, 0, 0, 1}
+	}
+};
+
 void Matrix4x4_Copy (matrix4x4_t *out, const matrix4x4_t *in)
 {
 	*out = *in;
@@ -148,6 +158,29 @@ void Matrix4x4_Invert_Simple (matrix4x4_t *out, const matrix4x4_t *in1)
 	out->m[3][3] = 1;
 }
 
+void Matrix4x4_Normalize (matrix4x4_t *out, matrix4x4_t *in1)
+{
+	// scale rotation matrix vectors to a length of 1
+	// note: this is only designed to undo uniform scaling
+	double scale = 1.0 / sqrt(in1->m[0][0] * in1->m[0][0] + in1->m[0][1] * in1->m[0][1] + in1->m[0][2] * in1->m[0][2]);
+	out->m[0][0] = (float)(in1->m[0][0] * scale);
+	out->m[0][1] = (float)(in1->m[1][0] * scale);
+	out->m[0][2] = (float)(in1->m[2][0] * scale);
+	out->m[0][3] = (float)(in1->m[0][3]);
+	out->m[1][0] = (float)(in1->m[0][1] * scale);
+	out->m[1][1] = (float)(in1->m[1][1] * scale);
+	out->m[1][2] = (float)(in1->m[2][1] * scale);
+	out->m[1][3] = (float)(in1->m[1][3]);
+	out->m[2][0] = (float)(in1->m[0][2] * scale);
+	out->m[2][1] = (float)(in1->m[1][2] * scale);
+	out->m[2][2] = (float)(in1->m[2][2] * scale);
+	out->m[2][3] = (float)(in1->m[2][3]);
+	out->m[3][0] = 0;
+	out->m[3][1] = 0;
+	out->m[3][2] = 0;
+	out->m[3][3] = 1;
+}
+
 void Matrix4x4_CreateIdentity (matrix4x4_t *out)
 {
 	out->m[0][0]=1.0f;