1 files changed, 58 insertions, 0 deletions
diff --git a/lib/ultralib/src/gu/perspective.c b/lib/ultralib/src/gu/perspective.c
new file mode 100644
index 0000000..be571d4
--- /dev/null
+++ b/lib/ultralib/src/gu/perspective.c
@@ -0,0 +1,58 @@
+
+/**************************************************************************
+ *									  *
+ *		 Copyright (C) 1994, Silicon Graphics, Inc.		  *
+ *									  *
+ *  These coded instructions, statements, and computer programs  contain  *
+ *  unpublished  proprietary  information of Silicon Graphics, Inc., and  *
+ *  are protected by Federal copyright law.  They  may  not be disclosed  *
+ *  to  third  parties  or copied or duplicated in any form, in whole or  *
+ *  in part, without the prior written consent of Silicon Graphics, Inc.  *
+ *									  *
+ **************************************************************************/
+
+#include "guint.h"
+#include <ultratypes.h>
+
+void guPerspectiveF(float mf[4][4], u16 *perspNorm, float fovy, float aspect, float near, float far, float scale)
+{
+	float	cot;
+	int	i, j;
+
+	guMtxIdentF(mf);
+
+	fovy *= 3.1415926 / 180.0;
+	cot = cosf (fovy/2) / sinf (fovy/2);
+
+	mf[0][0] = cot / aspect;
+	mf[1][1] = cot;
+	mf[2][2] = (near + far) / (near - far);
+	mf[2][3] = -1;
+	mf[3][2] = (2 * near * far) / (near - far);
+	mf[3][3] = 0;
+
+	for (i=0; i<4; i++)
+	    for (j=0; j<4; j++)
+		mf[i][j] *= scale;
+
+	if (perspNorm != (u16 *) NULL) {
+	    if (near+far<=2.0) {
+		*perspNorm = (u16) 0xFFFF;
+	    } else  {
+		*perspNorm = (u16) ((2.0*65536.0)/(near+far));
+		if (*perspNorm<=0) 
+		    *perspNorm = (u16) 0x0001;
+	    }
+	}
+}
+
+void guPerspective(Mtx *m, u16 *perspNorm, float fovy, float aspect, float near, float far, float scale)
+{
+	Matrix	mf;
+
+	guPerspectiveF(mf, perspNorm, fovy, aspect, near, far, scale);
+
+	guMtxF2L(mf, m);
+}
+
+