visetxscale.c
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/*====================================================================
* visetxscale.c
*
* Copyright 1995, Silicon Graphics, Inc.
* All Rights Reserved.
*
* This is UNPUBLISHED PROPRIETARY SOURCE CODE of Silicon Graphics,
* Inc.; the contents of this file may not be disclosed to third
* parties, copied or duplicated in any form, in whole or in part,
* without the prior written permission of Silicon Graphics, Inc.
*
* RESTRICTED RIGHTS LEGEND:
* Use, duplication or disclosure by the Government is subject to
* restrictions as set forth in subdivision (c)(1)(ii) of the Rights
* in Technical Data and Computer Software clause at DFARS
* 252.227-7013, and/or in similar or successor clauses in the FAR,
* DOD or NASA FAR Supplement. Unpublished - rights reserved under the
* Copyright Laws of the United States.
*====================================================================*/
/**************************************************************************
*
* $Revision: 1.1.1.2 $
* $Date: 2002/10/29 08:06:43 $
* $Source: /root/leakn64/depot/rf/sw/n64os20l/libultra/monegi/vi/visetxscale.c,v $
*
**************************************************************************/
#include "osint.h"
#include "rcp.h"
#include "viint.h"
#include "assert.h"
/*
* Name: osViSetXScale
*
* Description:
* Calculate the X-offset based on the X-scaling factor.
* X-scaling can be applied to any of the 28 modes. The input parameter
* "value" can only be within 0.25 <= value <= 1.0.
*
* Globals Referenced:
* __osViNext
*/
void
osViSetXScale(f32 value)
{
register u32 nomValue;
register u32 saveMask;
#ifdef _DEBUG
/* Check that VI manager is running */
if (!__osViDevMgr.active) {
__osError(ERR_OSVISETXSCALE_VIMGR, 0);
return;
}
/* Check for valid value range */
if ((value < 0.25F) || (value > 1.0F)) {
__osError(ERR_OSVISETXSCALE_VALUE, 1, OS_LOG_FLOAT(value));
if (value < 0.25F)
{
value = 0.25F;
}
else
{
value = 1.0F;
}
}
#endif
/*
* x_scale = value * (nomimal x_scale in mode);
* x_offset= (7 * 0x400) / x_scale;
*/
saveMask = __osDisableInt();
__osViNext->x.factor = value;
__osViNext->state |= VI_STATE_X_SCALE;
/* Get nominal X_SCALE value (mask bit [11:0] from VI_X_SCALE reg) */
nomValue = __osViNext->modep->comRegs.xScale & 0x0FFF;
/* Calculate new x-scale value based on factor value */
__osViNext->x.scale = ((u32)(__osViNext->x.factor*(float)nomValue))& 0x0FFF;
/* Calculate new offset based on new x-scale value */
/*
* Don't do this; it just affects subpixel position, and is apparently
* wrong.
__osViNext->x.offset = (u16)((7 * VI_NOMINAL_X_SCALE) /__osViNext->x.scale);
*/
__osRestoreInt(saveMask);
} /* osViSetXScale */