201 lines
7.1 KiB
C
201 lines
7.1 KiB
C
/****************************************************************************
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* apps/graphics/traveler/include/trv_trigtbl.h
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* This file defines the fixed precision math environment and look-up tables
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* for trigonometric functions.
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*
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* Copyright (C) 2014 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <gnutt@nuttx.org>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name NuttX nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************/
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#ifndef __APPS_GRAPHICS_TRAVELER_INCLUDE_TRV_TRIGTBL_H
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#define __APPS_GRAPHICS_TRAVELER_INCLUDE_TRV_TRIGTBL_H
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include "trv_types.h"
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/****************************************************************************
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* Pre-processor Definitions
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****************************************************************************/
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/* Angles *******************************************************************/
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/* These are definitions of commonly used angles. */
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#define TWOPI 1920
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#define PI 960
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#define HALFPI 480
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#define QTRPI 240
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/* Here are definitions for those who prefer degrees */
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/* NOTE: ANGLE_60 and ANGLE_30 are special values. They were */
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/* chosen to match the horizontal screen resolution of 320 pixels. */
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/* These, in fact, drive the entire angular measurement system */
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#define ANGLE_0 0
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#define ANGLE_6 32
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#define ANGLE_9 48
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#define ANGLE_12 64
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#define ANGLE_30 160
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#define ANGLE_45 240
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#define ANGLE_60 320
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#define ANGLE_90 480
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#define ANGLE_180 960
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#define ANGLE_270 1440
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#define ANGLE_360 1920
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/* This is the angular change made with each column of the ray caster */
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/* This is (2048/360 units/degree) * 59.94 (degrees) / (320 columns) */
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#define VIDEO_COLUMN_ANGLE 1
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#define VIDEO_ROW_ANGLE 1
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/* Fixed precision definitions **********************************************/
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/* SMALL precision (6 bits past binary point) */
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/* This occurs frequently because each CELL is 64x64 */
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#define sUNITY 64
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#define sHALF 32
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#define sQUARTER 16
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#define sSHIFT 6
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#define sMASK 63
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#define sTRUNC(a) ((a) >> sSHIFT)
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#define sROUND(a) (((a) + sHALF) >> sSHIFT)
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#define sFIX(a) ((a) << sSHIFT)
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#define sSNAP(a) ((a) & (~sMASK))
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#define sFRAC(a) ((a) & sMASK)
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#define sMUL(a,b) (((int32_t)(a) * (int32_t)(b)) >> sSHIFT )
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#define sDIV(a,b) (((int32_t)(a) << sSHIFT) / (b))
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#define sFLOAT(a) ((float)(a) / (float)sUNITY)
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/* DOUBLE precision (12 bits past binary point) */
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/* This precision results when two SMALL precision numbers are multiplied */
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#define dUNITY 4096
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#define dHALF 2048
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#define dSHIFT 12
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#define dMASK 4095
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#define dTRUNC(a) ((a) >> dSHIFT)
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#define dROUND(a) (((a) + dHALF) >> dSHIFT)
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#define dFIX(a) ((a) << dSHIFT)
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#define dSNAP(a) ((a) & (~dMASK))
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#define dFRAC(a) ((a) & dMASK)
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/* TRIPLE precision (18 bits past binary point) */
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/* This precision results when a SMALL and a DOUBLE precision number
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* are multiplied
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*/
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#define tSHIFT 18
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/* QUAD precision (24 bits past binary point) */
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/* This precision results when two DOUBLE precision numbers are multiplied */
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#define qSHIFT 24
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/* BIG precision (16 bits past binary point) */
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/* This is convenient precision because it is easy to extract the integer
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* portion without shifting or masking
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*/
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#define bUNITY 65536
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#define bHALF 32768
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#define bSHIFT 16
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#define bMASK 65535
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/* Conversions between SMALL, DOUBLE, TRIPLE and BIG precision */
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#define sTOd(a) ((a) << (dSHIFT-sSHIFT))
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#define sTOb(a) ((a) << (bSHIFT-sSHIFT))
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#define dTOs(a) ((a) >> (dSHIFT-sSHIFT))
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#define dTOb(a) ((a) << (bSHIFT-dSHIFT))
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#define tTOs(a) ((a) >> (tSHIFT-sSHIFT))
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#define tTOd(a) ((a) >> (tSHIFT-dSHIFT))
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#define tTOb(a) ((a) >> (tSHIFT-bSHIFT))
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#define qTOd(a) ((a) >> (qSHIFT-dSHIFT))
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#define qTOb(a) ((a) >> (qSHIFT-bSHIFT))
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#define bTOs(a) ((a) >> (bSHIFT-sSHIFT))
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/* These are general math macros that have nothing to do with fixed precision */
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#define ABS(a) ((a) < 0 ? -(a) : (a))
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#define MIN(a,b) ((a) < (b) ? (a) : (b))
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#define MAX(a,b) ((a) > (b) ? (a) : (b))
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/* Trigonometry *************************************************************/
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/* Because COS(x) = SIN(x + HALFPI) and COT(x) = TAN(90-x), the following
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* provide fast conversions to get cosines from the g_sin_table's and
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* cotangents form the g_tan_table.
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*/
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#define g_cot_table(x) g_tan_table[PI+HALFPI-(x)]
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#define g_cos_table ((int16_t*)&g_sin_table[HALFPI])
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#define g_sec_table ((int32_t*)&g_csc_table[HALFPI])
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/* Here are some MACROs to make life easier */
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/* The following extend the range of the table to all positive angles */
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#define TAN(x) ((x)>=(PI+HALFPI) ? g_tan_table[(x)-PI] : g_tan_table[x])
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/****************************************************************************
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* Public Types
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****************************************************************************/
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/* This structure is useful for manipulating BIG precision types from
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* C code (NOTE: The following union assumes LITTLE ENDIAN!).
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*/
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struct trv_bigfp_s
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{
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uint16_t f;
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int16_t i;
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};
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/****************************************************************************
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* Public Data
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****************************************************************************/
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/* Here are declarations for the trig tables */
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extern const int32_t g_tan_table[PI+HALFPI+1];
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extern const int16_t g_sin_table[TWOPI+HALFPI+1];
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extern const int32_t g_csc_table[TWOPI+HALFPI+1];
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/****************************************************************************
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* Public Function Prototypes
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****************************************************************************/
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#endif /* __APPS_GRAPHICS_TRAVELER_INCLUDE_TRV_TRIGTBL_H */
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