|
|
/****************************************************************************
* apps/graphics/traveler/include/trv_trigtbl.h
* This file defines the fixed precision math environment and look-up tables
* for trigonometric functions.
*
* Copyright (C) 2014 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
#ifndef __APPS_GRAPHICS_TRAVELER_INCLUDE_TRV_TRIGTBL_H
#define __APPS_GRAPHICS_TRAVELER_INCLUDE_TRV_TRIGTBL_H
/****************************************************************************
* Included Files
****************************************************************************/
#include "trv_types.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Angles *******************************************************************/
/* These are definitions of commonly used angles. */
#define TWOPI 1920
#define PI 960
#define HALFPI 480
#define QTRPI 240
/* Here are definitions for those who prefer degrees */
/* NOTE: ANGLE_60 and ANGLE_30 are special values. They were */
/* chosen to match the horizontal screen resolution of 320 pixels. */
/* These, in fact, drive the entire angular measurement system */
#define ANGLE_0 0
#define ANGLE_6 32
#define ANGLE_9 48
#define ANGLE_30 160
#define ANGLE_45 240
#define ANGLE_60 320
#define ANGLE_90 480
#define ANGLE_180 960
#define ANGLE_270 1440
#define ANGLE_360 1920
/* This is the angular change made with each column of the ray caster */
/* This is (2048/360 units/degree) * 59.94 (degrees) / (320 columns) */
#define VIDEO_COLUMN_ANGLE 1
#define VIDEO_ROW_ANGLE 1
/* Fixed precision definitions **********************************************/
/* SMALL precision (6 bits past binary point) */
/* This occurs frequently because each CELL is 64x64 */
#define sUNITY 64
#define sHALF 32
#define sQUARTER 16
#define sSHIFT 6
#define sMASK 63
#define sTRUNC(a) ((a) >> sSHIFT)
#define sROUND(a) (((a) + sHALF) >> sSHIFT)
#define sFIX(a) ((a) << sSHIFT)
#define sSNAP(a) ((a) & (~sMASK))
#define sFRAC(a) ((a) & sMASK)
#define sMUL(a,b) (((int32_t)(a) * (int32_t)(b)) >> sSHIFT )
#define sDIV(a,b) (((int32_t)(a) << sSHIFT) / (b))
#define sFLOAT(a) ((float)(a) / (float)sUNITY)
/* DOUBLE precision (12 bits past binary point) */
/* This precision results when two SMALL precision numbers are multiplied */
#define dUNITY 4096
#define dHALF 2048
#define dSHIFT 12
#define dMASK 4095
#define dTRUNC(a) ((a) >> dSHIFT)
#define dROUND(a) (((a) + dHALF) >> dSHIFT)
#define dFIX(a) ((a) << dSHIFT)
#define dSNAP(a) ((a) & (~dMASK))
#define dFRAC(a) ((a) & dMASK)
/* TRIPLE precision (18 bits past binary point) */
/* This precision results when a SMALL and a DOUBLE precision number
* are multiplied
*/
#define tSHIFT 18
/* QUAD precision (24 bits past binary point) */
/* This precision results when two DOUBLE precision numbers are multiplied */
#define qSHIFT 24
/* BIG precision (16 bits past binary point) */
/* This is convenient precision because it is easy to extract the integer
* portion without shifting or masking
*/
#define bUNITY 65536
#define bHALF 32768
#define bSHIFT 16
#define bMASK 65535
/* Conversions between SMALL, DOUBLE, TRIPLE and BIG precision */
#define sTOd(a) ((a) << (dSHIFT-sSHIFT))
#define sTOb(a) ((a) << (bSHIFT-sSHIFT))
#define dTOs(a) ((a) >> (dSHIFT-sSHIFT))
#define dTOb(a) ((a) << (bSHIFT-dSHIFT))
#define tTOs(a) ((a) >> (tSHIFT-sSHIFT))
#define tTOd(a) ((a) >> (tSHIFT-dSHIFT))
#define tTOb(a) ((a) >> (tSHIFT-bSHIFT))
#define qTOd(a) ((a) >> (qSHIFT-dSHIFT))
#define qTOb(a) ((a) >> (qSHIFT-bSHIFT))
#define bTOs(a) ((a) >> (bSHIFT-sSHIFT))
/* These are general math macros that have nothing to do with fixed precision */
#define ABS(a) ((a) < 0 ? -(a) : (a))
#define MIN(a,b) ((a) < (b) ? (a) : (b))
#define MAX(a,b) ((a) > (b) ? (a) : (b))
/* Trigonometry *************************************************************/
/* Because COS(x) = SIN(x + HALFPI) and COT(x) = TAN(90-x), the following
* provide fast conversions to get cosines from the g_sin_table's and
* cotangents form the g_tan_table.
*/
#define g_cot_table(x) g_tan_table[PI+HALFPI-(x)]
#define g_cos_table ((int16_t*)&g_sin_table[HALFPI])
#define g_sec_table ((int32_t*)&g_csc_table[HALFPI])
/* Here are some MACROs to make life easier */
/* The following extend the range of the table to all positive angles */
#define TAN(x) ((x)>=(PI+HALFPI) ? g_tan_table[(x)-PI] : g_tan_table[x])
/****************************************************************************
* Public Types
****************************************************************************/
/* This structure is useful for manipulating BIG precision types from
* C code (NOTE: The following union assumes LITTLE ENDIAN!).
*/
struct trv_bigfp_s
{
uint16_t f;
int16_t i;
};
/****************************************************************************
* Public Data
****************************************************************************/
/* Here are declarations for the trig tables */
extern const int32_t g_tan_table[PI+HALFPI+1];
extern const int16_t g_sin_table[TWOPI+HALFPI+1];
extern const int32_t g_csc_table[TWOPI+HALFPI+1];
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
#endif /* __APPS_GRAPHICS_TRAVELER_INCLUDE_TRV_TRIGTBL_H */
|
