From: havoc <havoc@d7cf8633-e32d-0410-b094-e92efae38249>
Date: Sun, 13 Nov 2005 12:05:24 +0000 (+0000)
Subject: added Matrix4x4_Normalize
X-Git-Tag: xonotic-v0.1.0preview~4477
X-Git-Url: https://git.rm.cloudns.org/?a=commitdiff_plain;h=2ca3c4f06325e060856e75634d584a0f19f1df12;p=xonotic%2Fdarkplaces.git

added Matrix4x4_Normalize
now normalizes dlight matrix so that attached dlight entities won't be smaller/bigger than normal


git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@5807 d7cf8633-e32d-0410-b094-e92efae38249
---

diff --git a/cl_main.c b/cl_main.c
index fa535661..13c04f1e 100644
--- a/cl_main.c
+++ b/cl_main.c
@@ -519,7 +519,7 @@ void CL_AllocDlight(entity_render_t *ent, matrix4x4_t *matrix, float radius, flo
 dlightsetup:
 	//Con_Printf("dlight %i : %f %f %f : %f %f %f\n", i, org[0], org[1], org[2], red * radius, green * radius, blue * radius);
 	memset (dl, 0, sizeof(*dl));
-	dl->matrix = *matrix;
+	Matrix4x4_Normalize(&dl->matrix, matrix);
 	dl->ent = ent;
 	dl->origin[0] = dl->matrix.m[0][3];
 	dl->origin[1] = dl->matrix.m[1][3];
diff --git a/matrixlib.c b/matrixlib.c
index 550a5118..5433aacc 100644
--- a/matrixlib.c
+++ b/matrixlib.c
@@ -158,6 +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;
diff --git a/matrixlib.h b/matrixlib.h
index 06890e29..d3d29ed1 100644
--- a/matrixlib.h
+++ b/matrixlib.h
@@ -34,6 +34,9 @@ void Matrix4x4_Transpose3x3 (matrix4x4_t *out, const matrix4x4_t *in1);
 // creates a matrix that does the opposite of the matrix provided
 // only supports translate, rotate, scale (not scale3) matrices
 void Matrix4x4_Invert_Simple (matrix4x4_t *out, const matrix4x4_t *in1);
+// creates a matrix that does the same rotation and translation as the matrix
+// provided, but no uniform scaling, does not support scale3 matrices
+void Matrix4x4_Normalize (matrix4x4_t *out, matrix4x4_t *in1);
 
 // creates an identity matrix
 // (a matrix which does nothing)