nuttx-apps/graphics/traveler/include/trv_paltable.h
2014-12-05 08:44:55 -06:00

83 lines
3.6 KiB
C

/****************************************************************************
* apps/graphics/traveler/include/trv_paltable.h
*
* 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_PALTABLE_H
#define __APPS_GRAPHICS_TRAVELER_INCLUDE_TRV_PALTABLE_H
/****************************************************************************
* Included Files
****************************************************************************/
#include "trv_types.h"
/****************************************************************************
* Pre-processor
****************************************************************************/
/* Here some palette-related definitions. */
#define PALETTE_SIZE 256 /* This is the number of colors in the palette */
#define NUM_ZONES 16 /* This is the number of distance zones in the palette table */
/* Here are some macros used to access the palette table. */
#define PAL_SCALE_BITS 2
#define GET_DISTANCE(x,y) ( (x) >= (y) ? ((x) + ((y) >>1)) : ((y) + ((x) >>1)))
#define GET_ZONE(x,y) (GET_DISTANCE(x,y) >> (sSHIFT+PAL_SCALE_BITS))
#define GET_PALINDEX(d) ((d) >= NUM_ZONES ? (NUM_ZONES-1) : (d))
#define GET_PALPTR(d) g_paltable[GET_PALINDEX(d)]
/* This is a special version which is used by the texture logic. The
* texture engine used 8 bits of fraction in many of its calculation
*/
#define GET_FZONE(x,y,n) (GET_DISTANCE(x,y) >> (sSHIFT+PAL_SCALE_BITS-(n)))
/****************************************************************************
* Public Data
****************************************************************************/
/* This is the palette table which is used to adjust the texture values
* with distance
*/
extern trv_pixel_t *g_paltable[NUM_ZONES];
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
#endif /* __APPS_GRAPHICS_TRAVELER_INCLUDE_TRV_PALTABLE_H */